Support for Kind 1 Edits

app/src/main/java/com/vitorpamplona/amethyst/model/Account.kt

@@ -89,6 +89,7 @@ import com.vitorpamplona.quartz.events.Response
 import com.vitorpamplona.quartz.events.SealedGossipEvent
 import com.vitorpamplona.quartz.events.StatusEvent
 import com.vitorpamplona.quartz.events.TextNoteEvent
+import com.vitorpamplona.quartz.events.TextNoteModificationEvent
 import com.vitorpamplona.quartz.events.WrappedEvent
 import com.vitorpamplona.quartz.events.ZapSplitSetup
 import com.vitorpamplona.quartz.signers.NostrSigner
@@ -1405,6 +1406,25 @@ class Account(
         }
     }
 
+    fun sendEdit(
+        message: String,
+        originalNote: Note,
+        relayList: List<Relay>? = null,
+    ) {
+        if (!isWriteable()) return
+
+        val idHex = originalNote.event?.id() ?: return
+
+        TextNoteModificationEvent.create(
+            content = message,
+            eventId = idHex,
+            signer = signer,
+        ) {
+            Client.send(it, relayList = relayList)
+            LocalCache.justConsume(it, null)
+        }
+    }
+
     fun sendPoll(
         message: String,
         replyTo: List<Note>?,

app/src/main/java/com/vitorpamplona/amethyst/model/LocalCache.kt

@@ -98,6 +98,7 @@ import com.vitorpamplona.quartz.events.RepostEvent
 import com.vitorpamplona.quartz.events.SealedGossipEvent
 import com.vitorpamplona.quartz.events.StatusEvent
 import com.vitorpamplona.quartz.events.TextNoteEvent
+import com.vitorpamplona.quartz.events.TextNoteModificationEvent
 import com.vitorpamplona.quartz.events.VideoHorizontalEvent
 import com.vitorpamplona.quartz.events.VideoVerticalEvent
 import com.vitorpamplona.quartz.events.WikiNoteEvent
@@ -1384,6 +1385,26 @@ object LocalCache {
         refreshObservers(note)
     }
 
+    fun consume(
+        event: TextNoteModificationEvent,
+        relay: Relay?,
+    ) {
+        val note = getOrCreateNote(event.id)
+        val author = getOrCreateUser(event.pubKey)
+
+        if (relay != null) {
+            author.addRelayBeingUsed(relay, event.createdAt)
+            note.addRelay(relay)
+        }
+
+        // Already processed this event.
+        if (note.event != null) return
+
+        note.loadEvent(event, author, emptyList())
+
+        refreshObservers(note)
+    }
+
     fun consume(
         event: HighlightEvent,
         relay: Relay?,
@@ -1695,6 +1716,17 @@ object LocalCache {
         return minTime
     }
 
+    suspend fun findLatestModificationForNote(note: Note): List<Note> {
+        checkNotInMainThread()
+        val time = TimeUtils.now()
+
+        return noteListCache.filter { item ->
+            val noteEvent = item.event
+
+            noteEvent is TextNoteModificationEvent && noteEvent.isTaggedEvent(note.idHex) && !noteEvent.isExpirationBefore(time)
+        }
+    }
+
     fun cleanObservers() {
         noteListCache.forEach { it.clearLive() }
 
@@ -2048,6 +2080,7 @@ object LocalCache {
                 }
                 is StatusEvent -> consume(event, relay)
                 is TextNoteEvent -> consume(event, relay)
+                is TextNoteModificationEvent -> consume(event, relay)
                 is VideoHorizontalEvent -> consume(event, relay)
                 is VideoVerticalEvent -> consume(event, relay)
                 is WikiNoteEvent -> consume(event, relay)

app/src/main/java/com/vitorpamplona/amethyst/model/Note.kt

@@ -948,6 +948,7 @@ class NoteLiveSet(u: Note) {
     val innerRelays = NoteBundledRefresherLiveData(u)
     val innerZaps = NoteBundledRefresherLiveData(u)
     val innerOts = NoteBundledRefresherLiveData(u)
+    val innerModifications = NoteBundledRefresherLiveData(u)
 
     val metadata = innerMetadata.map { it }
     val reactions = innerReactions.map { it }
@@ -1001,8 +1002,9 @@ class NoteLiveSet(u: Note) {
             hasReactions.hasObservers() ||
             replyCount.hasObservers() ||
             reactionCount.hasObservers() ||
-            boostCount.hasObservers()
+            boostCount.hasObservers() ||
             innerOts.hasObservers() ||
+            innerModifications.hasObservers()
     }
 
     fun destroy() {
@@ -1014,6 +1016,7 @@ class NoteLiveSet(u: Note) {
         innerRelays.destroy()
         innerZaps.destroy()
         innerOts.destroy()
+        innerModifications.destroy()
     }
 }
 

app/src/main/java/com/vitorpamplona/amethyst/service/NostrSingleEventDataSource.kt

@@ -37,6 +37,7 @@ import com.vitorpamplona.quartz.events.ReactionEvent
 import com.vitorpamplona.quartz.events.ReportEvent
 import com.vitorpamplona.quartz.events.RepostEvent
 import com.vitorpamplona.quartz.events.TextNoteEvent
+import com.vitorpamplona.quartz.events.TextNoteModificationEvent
 
 object NostrSingleEventDataSource : NostrDataSource("SingleEventFeed") {
     private var eventsToWatch = setOf<Note>()
@@ -136,6 +137,7 @@ object NostrSingleEventDataSource : NostrDataSource("SingleEventFeed") {
                                     LnZapEvent.KIND,
                                     PollNoteEvent.KIND,
                                     OtsEvent.KIND,
+                                    TextNoteModificationEvent.KIND,
                                 ),
                             tags = mapOf("e" to it.map { it.idHex }),
                             since = findMinimumEOSEs(it),

app/src/main/java/com/vitorpamplona/amethyst/ui/actions/EditPostView.kt

@@ -0,0 +1,499 @@
+/**
+ * Copyright (c) 2024 Vitor Pamplona
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy of
+ * this software and associated documentation files (the "Software"), to deal in
+ * the Software without restriction, including without limitation the rights to use,
+ * copy, modify, merge, publish, distribute, sublicense, and/or sell copies of the
+ * Software, and to permit persons to whom the Software is furnished to do so,
+ * subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in all
+ * copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS
+ * FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR
+ * COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN
+ * AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
+ * WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
+ */
+package com.vitorpamplona.amethyst.ui.actions
+
+import android.widget.Toast
+import androidx.compose.foundation.border
+import androidx.compose.foundation.horizontalScroll
+import androidx.compose.foundation.layout.Arrangement
+import androidx.compose.foundation.layout.Box
+import androidx.compose.foundation.layout.Column
+import androidx.compose.foundation.layout.PaddingValues
+import androidx.compose.foundation.layout.Row
+import androidx.compose.foundation.layout.Spacer
+import androidx.compose.foundation.layout.fillMaxHeight
+import androidx.compose.foundation.layout.fillMaxSize
+import androidx.compose.foundation.layout.fillMaxWidth
+import androidx.compose.foundation.layout.height
+import androidx.compose.foundation.layout.heightIn
+import androidx.compose.foundation.layout.imePadding
+import androidx.compose.foundation.layout.padding
+import androidx.compose.foundation.layout.size
+import androidx.compose.foundation.layout.width
+import androidx.compose.foundation.lazy.LazyColumn
+import androidx.compose.foundation.lazy.itemsIndexed
+import androidx.compose.foundation.rememberScrollState
+import androidx.compose.foundation.shape.RoundedCornerShape
+import androidx.compose.foundation.text.KeyboardOptions
+import androidx.compose.foundation.verticalScroll
+import androidx.compose.material.icons.Icons
+import androidx.compose.material.icons.filled.CurrencyBitcoin
+import androidx.compose.material3.ExperimentalMaterial3Api
+import androidx.compose.material3.Icon
+import androidx.compose.material3.IconButton
+import androidx.compose.material3.LocalTextStyle
+import androidx.compose.material3.MaterialTheme
+import androidx.compose.material3.OutlinedTextField
+import androidx.compose.material3.OutlinedTextFieldDefaults
+import androidx.compose.material3.Scaffold
+import androidx.compose.material3.Surface
+import androidx.compose.material3.Text
+import androidx.compose.material3.TopAppBar
+import androidx.compose.material3.TopAppBarDefaults
+import androidx.compose.runtime.Composable
+import androidx.compose.runtime.DisposableEffect
+import androidx.compose.runtime.LaunchedEffect
+import androidx.compose.runtime.getValue
+import androidx.compose.runtime.mutableStateOf
+import androidx.compose.runtime.remember
+import androidx.compose.runtime.rememberCoroutineScope
+import androidx.compose.runtime.setValue
+import androidx.compose.ui.Alignment
+import androidx.compose.ui.Alignment.Companion.CenterVertically
+import androidx.compose.ui.Modifier
+import androidx.compose.ui.draw.clip
+import androidx.compose.ui.focus.FocusRequester
+import androidx.compose.ui.focus.focusRequester
+import androidx.compose.ui.focus.onFocusChanged
+import androidx.compose.ui.graphics.Color
+import androidx.compose.ui.layout.ContentScale
+import androidx.compose.ui.platform.LocalContext
+import androidx.compose.ui.platform.LocalSoftwareKeyboardController
+import androidx.compose.ui.res.painterResource
+import androidx.compose.ui.res.stringResource
+import androidx.compose.ui.text.input.KeyboardCapitalization
+import androidx.compose.ui.text.input.TextFieldValue
+import androidx.compose.ui.text.style.TextDirection
+import androidx.compose.ui.unit.dp
+import androidx.compose.ui.window.Dialog
+import androidx.compose.ui.window.DialogProperties
+import androidx.lifecycle.viewmodel.compose.viewModel
+import coil.compose.AsyncImage
+import com.vitorpamplona.amethyst.R
+import com.vitorpamplona.amethyst.commons.RichTextParser
+import com.vitorpamplona.amethyst.model.Note
+import com.vitorpamplona.amethyst.service.NostrSearchEventOrUserDataSource
+import com.vitorpamplona.amethyst.ui.components.BechLink
+import com.vitorpamplona.amethyst.ui.components.InvoiceRequest
+import com.vitorpamplona.amethyst.ui.components.LoadUrlPreview
+import com.vitorpamplona.amethyst.ui.components.VideoView
+import com.vitorpamplona.amethyst.ui.screen.loggedIn.AccountViewModel
+import com.vitorpamplona.amethyst.ui.screen.loggedIn.UserLine
+import com.vitorpamplona.amethyst.ui.theme.BitcoinOrange
+import com.vitorpamplona.amethyst.ui.theme.QuoteBorder
+import com.vitorpamplona.amethyst.ui.theme.Size10dp
+import com.vitorpamplona.amethyst.ui.theme.Size5dp
+import com.vitorpamplona.amethyst.ui.theme.StdHorzSpacer
+import com.vitorpamplona.amethyst.ui.theme.placeholderText
+import com.vitorpamplona.amethyst.ui.theme.subtleBorder
+import kotlinx.collections.immutable.toImmutableList
+import kotlinx.coroutines.Dispatchers
+import kotlinx.coroutines.delay
+import kotlinx.coroutines.launch
+import kotlinx.coroutines.withContext
+
+@OptIn(ExperimentalMaterial3Api::class)
+@Composable
+fun EditPostView(
+    onClose: () -> Unit,
+    edit: Note,
+    accountViewModel: AccountViewModel,
+    nav: (String) -> Unit,
+) {
+    val postViewModel: EditPostViewModel = viewModel()
+
+    val context = LocalContext.current
+
+    val scrollState = rememberScrollState()
+    val scope = rememberCoroutineScope()
+    var showRelaysDialog by remember { mutableStateOf(false) }
+    var relayList = remember { accountViewModel.account.activeWriteRelays().toImmutableList() }
+
+    LaunchedEffect(Unit) {
+        postViewModel.load(edit, accountViewModel)
+
+        launch(Dispatchers.IO) {
+            postViewModel.imageUploadingError.collect { error ->
+                withContext(Dispatchers.Main) { Toast.makeText(context, error, Toast.LENGTH_SHORT).show() }
+            }
+        }
+    }
+
+    DisposableEffect(Unit) {
+        NostrSearchEventOrUserDataSource.start()
+
+        onDispose {
+            NostrSearchEventOrUserDataSource.clear()
+            NostrSearchEventOrUserDataSource.stop()
+        }
+    }
+
+    Dialog(
+        onDismissRequest = { onClose() },
+        properties =
+            DialogProperties(
+                usePlatformDefaultWidth = false,
+                dismissOnClickOutside = false,
+                decorFitsSystemWindows = false,
+            ),
+    ) {
+        if (showRelaysDialog) {
+            RelaySelectionDialog(
+                preSelectedList = relayList,
+                onClose = { showRelaysDialog = false },
+                onPost = { relayList = it },
+                accountViewModel = accountViewModel,
+                nav = nav,
+            )
+        }
+
+        Scaffold(
+            topBar = {
+                TopAppBar(
+                    title = {
+                        Row(
+                            modifier = Modifier.fillMaxWidth(),
+                            horizontalArrangement = Arrangement.SpaceBetween,
+                            verticalAlignment = Alignment.CenterVertically,
+                        ) {
+                            Spacer(modifier = StdHorzSpacer)
+
+                            Box {
+                                IconButton(
+                                    modifier = Modifier.align(Alignment.Center),
+                                    onClick = { showRelaysDialog = true },
+                                ) {
+                                    Icon(
+                                        painter = painterResource(R.drawable.relays),
+                                        contentDescription = stringResource(id = R.string.relay_list_selector),
+                                        modifier = Modifier.height(25.dp),
+                                        tint = MaterialTheme.colorScheme.onBackground,
+                                    )
+                                }
+                            }
+                            PostButton(
+                                onPost = {
+                                    postViewModel.sendPost(relayList = relayList)
+                                    scope.launch {
+                                        delay(100)
+                                        onClose()
+                                    }
+                                },
+                                isActive = postViewModel.canPost(),
+                            )
+                        }
+                    },
+                    navigationIcon = {
+                        Row {
+                            Spacer(modifier = StdHorzSpacer)
+                            CloseButton(
+                                onPress = {
+                                    postViewModel.cancel()
+                                    scope.launch {
+                                        delay(100)
+                                        onClose()
+                                    }
+                                },
+                            )
+                        }
+                    },
+                    colors =
+                        TopAppBarDefaults.topAppBarColors(
+                            containerColor = MaterialTheme.colorScheme.surface,
+                        ),
+                )
+            },
+        ) { pad ->
+            Surface(
+                modifier =
+                    Modifier
+                        .padding(
+                            start = Size10dp,
+                            top = pad.calculateTopPadding(),
+                            end = Size10dp,
+                            bottom = pad.calculateBottomPadding(),
+                        )
+                        .fillMaxSize(),
+            ) {
+                Column(
+                    modifier =
+                        Modifier
+                            .fillMaxWidth()
+                            .fillMaxHeight(),
+                ) {
+                    Column(
+                        modifier =
+                            Modifier
+                                .imePadding()
+                                .weight(1f),
+                    ) {
+                        Row(
+                            modifier =
+                                Modifier
+                                    .fillMaxWidth()
+                                    .weight(1f),
+                        ) {
+                            Column(
+                                modifier =
+                                    Modifier
+                                        .fillMaxWidth()
+                                        .verticalScroll(scrollState),
+                            ) {
+                                MessageField(postViewModel)
+
+                                val myUrlPreview = postViewModel.urlPreview
+                                if (myUrlPreview != null) {
+                                    Row(modifier = Modifier.padding(vertical = Size5dp, horizontal = Size10dp)) {
+                                        if (RichTextParser.isValidURL(myUrlPreview)) {
+                                            if (RichTextParser.isImageUrl(myUrlPreview)) {
+                                                AsyncImage(
+                                                    model = myUrlPreview,
+                                                    contentDescription = myUrlPreview,
+                                                    contentScale = ContentScale.FillWidth,
+                                                    modifier =
+                                                        Modifier
+                                                            .padding(top = 4.dp)
+                                                            .fillMaxWidth()
+                                                            .clip(shape = QuoteBorder)
+                                                            .border(
+                                                                1.dp,
+                                                                MaterialTheme.colorScheme.subtleBorder,
+                                                                QuoteBorder,
+                                                            ),
+                                                )
+                                            } else if (RichTextParser.isVideoUrl(myUrlPreview)) {
+                                                VideoView(
+                                                    myUrlPreview,
+                                                    roundedCorner = true,
+                                                    accountViewModel = accountViewModel,
+                                                )
+                                            } else {
+                                                LoadUrlPreview(myUrlPreview, myUrlPreview, accountViewModel)
+                                            }
+                                        } else if (RichTextParser.startsWithNIP19Scheme(myUrlPreview)) {
+                                            val bgColor = MaterialTheme.colorScheme.background
+                                            val backgroundColor = remember { mutableStateOf(bgColor) }
+
+                                            BechLink(
+                                                myUrlPreview,
+                                                true,
+                                                backgroundColor,
+                                                accountViewModel,
+                                                nav,
+                                            )
+                                        } else if (RichTextParser.isUrlWithoutScheme(myUrlPreview)) {
+                                            LoadUrlPreview("https://$myUrlPreview", myUrlPreview, accountViewModel)
+                                        }
+                                    }
+                                }
+
+                                val url = postViewModel.contentToAddUrl
+                                if (url != null) {
+                                    Row(
+                                        verticalAlignment = Alignment.CenterVertically,
+                                        modifier = Modifier.padding(vertical = Size5dp, horizontal = Size10dp),
+                                    ) {
+                                        ImageVideoDescription(
+                                            url,
+                                            accountViewModel.account.defaultFileServer,
+                                            onAdd = { alt, server, sensitiveContent ->
+                                                postViewModel.upload(url, alt, sensitiveContent, false, server, context)
+                                                if (!server.isNip95) {
+                                                    accountViewModel.account.changeDefaultFileServer(server.server)
+                                                }
+                                            },
+                                            onCancel = { postViewModel.contentToAddUrl = null },
+                                            onError = { scope.launch { postViewModel.imageUploadingError.emit(it) } },
+                                            accountViewModel = accountViewModel,
+                                        )
+                                    }
+                                }
+
+                                val user = postViewModel.account?.userProfile()
+                                val lud16 = user?.info?.lnAddress()
+
+                                if (lud16 != null && postViewModel.wantsInvoice) {
+                                    Row(
+                                        verticalAlignment = Alignment.CenterVertically,
+                                        modifier = Modifier.padding(vertical = Size5dp, horizontal = Size10dp),
+                                    ) {
+                                        Column(Modifier.fillMaxWidth()) {
+                                            InvoiceRequest(
+                                                lud16,
+                                                user.pubkeyHex,
+                                                accountViewModel.account,
+                                                stringResource(id = R.string.lightning_invoice),
+                                                stringResource(id = R.string.lightning_create_and_add_invoice),
+                                                onSuccess = {
+                                                    postViewModel.message =
+                                                        TextFieldValue(postViewModel.message.text + "\n\n" + it)
+                                                    postViewModel.wantsInvoice = false
+                                                },
+                                                onClose = { postViewModel.wantsInvoice = false },
+                                                onError = { title, message -> accountViewModel.toast(title, message) },
+                                            )
+                                        }
+                                    }
+                                }
+                            }
+                        }
+
+                        ShowUserSuggestionListForEdit(
+                            postViewModel,
+                            accountViewModel,
+                            modifier = Modifier.heightIn(0.dp, 300.dp),
+                        )
+
+                        BottomRowActions(postViewModel)
+                    }
+                }
+            }
+        }
+    }
+}
+
+@Composable
+fun ShowUserSuggestionListForEdit(
+    editPostViewModel: EditPostViewModel,
+    accountViewModel: AccountViewModel,
+    modifier: Modifier = Modifier.heightIn(0.dp, 200.dp),
+) {
+    val userSuggestions = editPostViewModel.userSuggestions
+    if (userSuggestions.isNotEmpty()) {
+        LazyColumn(
+            contentPadding =
+                PaddingValues(
+                    top = 10.dp,
+                ),
+            modifier = modifier,
+        ) {
+            itemsIndexed(
+                userSuggestions,
+                key = { _, item -> item.pubkeyHex },
+            ) { _, item ->
+                UserLine(item, accountViewModel) { editPostViewModel.autocompleteWithUser(item) }
+            }
+        }
+    }
+}
+
+@Composable
+private fun BottomRowActions(postViewModel: EditPostViewModel) {
+    val scrollState = rememberScrollState()
+
+    Row(
+        modifier =
+            Modifier
+                .horizontalScroll(scrollState)
+                .fillMaxWidth()
+                .height(50.dp),
+        verticalAlignment = CenterVertically,
+    ) {
+        UploadFromGallery(
+            isUploading = postViewModel.isUploadingImage,
+            tint = MaterialTheme.colorScheme.onBackground,
+            modifier = Modifier,
+        ) {
+            postViewModel.selectImage(it)
+        }
+
+        if (postViewModel.canAddInvoice) {
+            AddLnInvoiceButton(postViewModel.wantsInvoice) {
+                postViewModel.wantsInvoice = !postViewModel.wantsInvoice
+            }
+        }
+    }
+}
+
+@Composable
+private fun MessageField(postViewModel: EditPostViewModel) {
+    val focusRequester = remember { FocusRequester() }
+    val keyboardController = LocalSoftwareKeyboardController.current
+
+    LaunchedEffect(Unit) {
+        launch {
+            delay(200)
+            focusRequester.requestFocus()
+        }
+    }
+
+    OutlinedTextField(
+        value = postViewModel.message,
+        onValueChange = { postViewModel.updateMessage(it) },
+        keyboardOptions =
+            KeyboardOptions.Default.copy(
+                capitalization = KeyboardCapitalization.Sentences,
+            ),
+        modifier =
+            Modifier
+                .fillMaxWidth()
+                .border(
+                    width = 1.dp,
+                    color = MaterialTheme.colorScheme.surface,
+                    shape = RoundedCornerShape(8.dp),
+                )
+                .focusRequester(focusRequester)
+                .onFocusChanged {
+                    if (it.isFocused) {
+                        keyboardController?.show()
+                    }
+                },
+        placeholder = {
+            Text(
+                text = stringResource(R.string.what_s_on_your_mind),
+                color = MaterialTheme.colorScheme.placeholderText,
+            )
+        },
+        colors =
+            OutlinedTextFieldDefaults.colors(
+                focusedBorderColor = Color.Transparent,
+                unfocusedBorderColor = Color.Transparent,
+            ),
+        visualTransformation = UrlUserTagTransformation(MaterialTheme.colorScheme.primary),
+        textStyle = LocalTextStyle.current.copy(textDirection = TextDirection.Content),
+    )
+}
+
+@Composable
+private fun AddLnInvoiceButton(
+    isLnInvoiceActive: Boolean,
+    onClick: () -> Unit,
+) {
+    IconButton(
+        onClick = { onClick() },
+    ) {
+        if (!isLnInvoiceActive) {
+            Icon(
+                imageVector = Icons.Default.CurrencyBitcoin,
+                contentDescription = stringResource(id = R.string.add_bitcoin_invoice),
+                modifier = Modifier.size(20.dp),
+                tint = MaterialTheme.colorScheme.onBackground,
+            )
+        } else {
+            Icon(
+                imageVector = Icons.Default.CurrencyBitcoin,
+                contentDescription = stringResource(id = R.string.cancel_bitcoin_invoice),
+                modifier = Modifier.size(20.dp),
+                tint = BitcoinOrange,
+            )
+        }
+    }
+}

app/src/main/java/com/vitorpamplona/amethyst/ui/actions/EditPostViewModel.kt

@@ -0,0 +1,362 @@
+/**
+ * Copyright (c) 2024 Vitor Pamplona
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy of
+ * this software and associated documentation files (the "Software"), to deal in
+ * the Software without restriction, including without limitation the rights to use,
+ * copy, modify, merge, publish, distribute, sublicense, and/or sell copies of the
+ * Software, and to permit persons to whom the Software is furnished to do so,
+ * subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in all
+ * copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS
+ * FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR
+ * COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN
+ * AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
+ * WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
+ */
+package com.vitorpamplona.amethyst.ui.actions
+
+import android.content.Context
+import android.net.Uri
+import android.util.Log
+import androidx.compose.runtime.Stable
+import androidx.compose.runtime.getValue
+import androidx.compose.runtime.mutableStateOf
+import androidx.compose.runtime.setValue
+import androidx.compose.ui.text.TextRange
+import androidx.compose.ui.text.input.TextFieldValue
+import androidx.lifecycle.ViewModel
+import androidx.lifecycle.viewModelScope
+import com.vitorpamplona.amethyst.commons.RichTextParser
+import com.vitorpamplona.amethyst.commons.insertUrlAtCursor
+import com.vitorpamplona.amethyst.model.Account
+import com.vitorpamplona.amethyst.model.LocalCache
+import com.vitorpamplona.amethyst.model.Note
+import com.vitorpamplona.amethyst.model.User
+import com.vitorpamplona.amethyst.service.FileHeader
+import com.vitorpamplona.amethyst.service.Nip96Uploader
+import com.vitorpamplona.amethyst.service.NostrSearchEventOrUserDataSource
+import com.vitorpamplona.amethyst.service.relays.Relay
+import com.vitorpamplona.amethyst.ui.components.MediaCompressor
+import com.vitorpamplona.amethyst.ui.screen.loggedIn.AccountViewModel
+import com.vitorpamplona.quartz.events.FileHeaderEvent
+import com.vitorpamplona.quartz.events.FileStorageEvent
+import com.vitorpamplona.quartz.events.FileStorageHeaderEvent
+import kotlinx.coroutines.CancellationException
+import kotlinx.coroutines.Dispatchers
+import kotlinx.coroutines.channels.BufferOverflow
+import kotlinx.coroutines.flow.MutableSharedFlow
+import kotlinx.coroutines.launch
+
+@Stable
+open class EditPostViewModel() : ViewModel() {
+    var accountViewModel: AccountViewModel? = null
+    var account: Account? = null
+
+    var editedFromNote: Note? = null
+
+    var nip94attachments by mutableStateOf<List<FileHeaderEvent>>(emptyList())
+    var nip95attachments by
+        mutableStateOf<List<Pair<FileStorageEvent, FileStorageHeaderEvent>>>(emptyList())
+
+    var message by mutableStateOf(TextFieldValue(""))
+    var urlPreview by mutableStateOf<String?>(null)
+    var isUploadingImage by mutableStateOf(false)
+    val imageUploadingError =
+        MutableSharedFlow<String?>(0, 3, onBufferOverflow = BufferOverflow.DROP_OLDEST)
+
+    var userSuggestions by mutableStateOf<List<User>>(emptyList())
+    var userSuggestionAnchor: TextRange? = null
+    var userSuggestionsMainMessage: UserSuggestionAnchor? = null
+
+    // Images and Videos
+    var contentToAddUrl by mutableStateOf<Uri?>(null)
+
+    // Invoices
+    var canAddInvoice by mutableStateOf(false)
+    var wantsInvoice by mutableStateOf(false)
+
+    open fun load(
+        edit: Note,
+        accountViewModel: AccountViewModel,
+    ) {
+        this.accountViewModel = accountViewModel
+        this.account = accountViewModel.account
+
+        canAddInvoice = accountViewModel.userProfile().info?.lnAddress() != null
+        contentToAddUrl = null
+
+        message = TextFieldValue(edit.event?.content() ?: "")
+        urlPreview = findUrlInMessage()
+
+        editedFromNote = edit
+    }
+
+    fun sendPost(relayList: List<Relay>? = null) {
+        viewModelScope.launch(Dispatchers.IO) { innerSendPost(relayList) }
+    }
+
+    suspend fun innerSendPost(relayList: List<Relay>? = null) {
+        if (accountViewModel == null) {
+            cancel()
+            return
+        }
+
+        nip95attachments.forEach {
+            account?.sendNip95(it.first, it.second, relayList)
+        }
+
+        account?.sendEdit(
+            message = message.text,
+            originalNote = editedFromNote!!,
+            relayList = relayList,
+        )
+
+        cancel()
+    }
+
+    fun upload(
+        galleryUri: Uri,
+        alt: String?,
+        sensitiveContent: Boolean,
+        isPrivate: Boolean = false,
+        server: ServerOption,
+        context: Context,
+    ) {
+        isUploadingImage = true
+        contentToAddUrl = null
+
+        val contentResolver = context.contentResolver
+        val contentType = contentResolver.getType(galleryUri)
+
+        viewModelScope.launch(Dispatchers.IO) {
+            MediaCompressor()
+                .compress(
+                    galleryUri,
+                    contentType,
+                    context.applicationContext,
+                    onReady = { fileUri, contentType, size ->
+                        if (server.isNip95) {
+                            contentResolver.openInputStream(fileUri)?.use {
+                                createNIP95Record(it.readBytes(), contentType, alt, sensitiveContent)
+                            }
+                        } else {
+                            viewModelScope.launch(Dispatchers.IO) {
+                                try {
+                                    val result =
+                                        Nip96Uploader(account)
+                                            .uploadImage(
+                                                uri = fileUri,
+                                                contentType = contentType,
+                                                size = size,
+                                                alt = alt,
+                                                sensitiveContent = if (sensitiveContent) "" else null,
+                                                server = server.server,
+                                                contentResolver = contentResolver,
+                                                onProgress = {},
+                                            )
+
+                                    createNIP94Record(
+                                        uploadingResult = result,
+                                        localContentType = contentType,
+                                        alt = alt,
+                                        sensitiveContent = sensitiveContent,
+                                    )
+                                } catch (e: Exception) {
+                                    if (e is CancellationException) throw e
+                                    Log.e(
+                                        "ImageUploader",
+                                        "Failed to upload ${e.message}",
+                                        e,
+                                    )
+                                    isUploadingImage = false
+                                    viewModelScope.launch {
+                                        imageUploadingError.emit("Failed to upload: ${e.message}")
+                                    }
+                                }
+                            }
+                        }
+                    },
+                    onError = {
+                        isUploadingImage = false
+                        viewModelScope.launch { imageUploadingError.emit(it) }
+                    },
+                )
+        }
+    }
+
+    open fun cancel() {
+        message = TextFieldValue("")
+
+        editedFromNote = null
+
+        contentToAddUrl = null
+        urlPreview = null
+        isUploadingImage = false
+
+        wantsInvoice = false
+
+        userSuggestions = emptyList()
+        userSuggestionAnchor = null
+        userSuggestionsMainMessage = null
+
+        NostrSearchEventOrUserDataSource.clear()
+    }
+
+    open fun findUrlInMessage(): String? {
+        return message.text.split('\n').firstNotNullOfOrNull { paragraph ->
+            paragraph.split(' ').firstOrNull { word: String ->
+                RichTextParser.isValidURL(word) || RichTextParser.isUrlWithoutScheme(word)
+            }
+        }
+    }
+
+    open fun updateMessage(it: TextFieldValue) {
+        message = it
+        urlPreview = findUrlInMessage()
+
+        if (it.selection.collapsed) {
+            val lastWord =
+                it.text.substring(0, it.selection.end).substringAfterLast("\n").substringAfterLast(" ")
+            userSuggestionAnchor = it.selection
+            userSuggestionsMainMessage = UserSuggestionAnchor.MAIN_MESSAGE
+            if (lastWord.startsWith("@") && lastWord.length > 2) {
+                NostrSearchEventOrUserDataSource.search(lastWord.removePrefix("@"))
+                viewModelScope.launch(Dispatchers.IO) {
+                    userSuggestions =
+                        LocalCache.findUsersStartingWith(lastWord.removePrefix("@"))
+                            .sortedWith(compareBy({ account?.isFollowing(it) }, { it.toBestDisplayName() }))
+                            .reversed()
+                }
+            } else {
+                NostrSearchEventOrUserDataSource.clear()
+                userSuggestions = emptyList()
+            }
+        }
+    }
+
+    open fun autocompleteWithUser(item: User) {
+        userSuggestionAnchor?.let {
+            if (userSuggestionsMainMessage == UserSuggestionAnchor.MAIN_MESSAGE) {
+                val lastWord =
+                    message.text.substring(0, it.end).substringAfterLast("\n").substringAfterLast(" ")
+                val lastWordStart = it.end - lastWord.length
+                val wordToInsert = "@${item.pubkeyNpub()}"
+
+                message =
+                    TextFieldValue(
+                        message.text.replaceRange(lastWordStart, it.end, wordToInsert),
+                        TextRange(lastWordStart + wordToInsert.length, lastWordStart + wordToInsert.length),
+                    )
+            }
+
+            userSuggestionAnchor = null
+            userSuggestionsMainMessage = null
+            userSuggestions = emptyList()
+        }
+    }
+
+    fun canPost(): Boolean {
+        return message.text.isNotBlank() &&
+            !isUploadingImage &&
+            !wantsInvoice &&
+            contentToAddUrl == null
+    }
+
+    suspend fun createNIP94Record(
+        uploadingResult: Nip96Uploader.PartialEvent,
+        localContentType: String?,
+        alt: String?,
+        sensitiveContent: Boolean,
+    ) {
+        // Images don't seem to be ready immediately after upload
+        val imageUrl = uploadingResult.tags?.firstOrNull { it.size > 1 && it[0] == "url" }?.get(1)
+        val remoteMimeType =
+            uploadingResult.tags?.firstOrNull { it.size > 1 && it[0] == "m" }?.get(1)?.ifBlank { null }
+        val originalHash =
+            uploadingResult.tags?.firstOrNull { it.size > 1 && it[0] == "ox" }?.get(1)?.ifBlank { null }
+        val dim =
+            uploadingResult.tags?.firstOrNull { it.size > 1 && it[0] == "dim" }?.get(1)?.ifBlank { null }
+        val magnet =
+            uploadingResult.tags
+                ?.firstOrNull { it.size > 1 && it[0] == "magnet" }
+                ?.get(1)
+                ?.ifBlank { null }
+
+        if (imageUrl.isNullOrBlank()) {
+            Log.e("ImageDownload", "Couldn't download image from server")
+            cancel()
+            isUploadingImage = false
+            viewModelScope.launch { imageUploadingError.emit("Failed to upload the image / video") }
+            return
+        }
+
+        FileHeader.prepare(
+            fileUrl = imageUrl,
+            mimeType = remoteMimeType ?: localContentType,
+            dimPrecomputed = dim,
+            onReady = { header: FileHeader ->
+                account?.createHeader(imageUrl, magnet, header, alt, sensitiveContent, originalHash) { event ->
+                    isUploadingImage = false
+                    nip94attachments = nip94attachments + event
+
+                    message = message.insertUrlAtCursor(imageUrl)
+                    urlPreview = findUrlInMessage()
+                }
+            },
+            onError = {
+                isUploadingImage = false
+                viewModelScope.launch { imageUploadingError.emit("Failed to upload the image / video") }
+            },
+        )
+    }
+
+    fun createNIP95Record(
+        bytes: ByteArray,
+        mimeType: String?,
+        alt: String?,
+        sensitiveContent: Boolean,
+    ) {
+        if (bytes.size > 80000) {
+            viewModelScope.launch {
+                imageUploadingError.emit("Media is too big for NIP-95")
+                isUploadingImage = false
+            }
+            return
+        }
+
+        viewModelScope.launch(Dispatchers.IO) {
+            FileHeader.prepare(
+                bytes,
+                mimeType,
+                null,
+                onReady = {
+                    account?.createNip95(bytes, headerInfo = it, alt, sensitiveContent) { nip95 ->
+                        nip95attachments = nip95attachments + nip95
+                        val note = nip95.let { it1 -> account?.consumeNip95(it1.first, it1.second) }
+
+                        isUploadingImage = false
+
+                        note?.let {
+                            message = message.insertUrlAtCursor("nostr:" + it.toNEvent())
+                        }
+
+                        urlPreview = findUrlInMessage()
+                    }
+                },
+                onError = {
+                    isUploadingImage = false
+                    viewModelScope.launch { imageUploadingError.emit("Failed to upload the image / video") }
+                },
+            )
+        }
+    }
+
+    fun selectImage(uri: Uri) {
+        contentToAddUrl = uri
+    }
+}

app/src/main/java/com/vitorpamplona/amethyst/ui/note/BadgeCompose.kt

@@ -167,7 +167,7 @@ fun BadgeCompose(
                                 tint = MaterialTheme.colorScheme.placeholderText,
                             )
 
-                            NoteDropDownMenu(note, popupExpanded, accountViewModel)
+                            NoteDropDownMenu(note, popupExpanded, accountViewModel, nav)
                         }
                     }
 

app/src/main/java/com/vitorpamplona/amethyst/ui/note/MessageSetCompose.kt

@@ -129,7 +129,7 @@ fun MessageSetCompose(
                     nav = nav,
                 )
 
-                NoteDropDownMenu(baseNote, popupExpanded, accountViewModel)
+                NoteDropDownMenu(baseNote, popupExpanded, accountViewModel, nav)
             }
         }
 

app/src/main/java/com/vitorpamplona/amethyst/ui/note/MultiSetCompose.kt

@@ -166,7 +166,7 @@ fun MultiSetCompose(
                 nav = nav,
             )
 
-            NoteDropDownMenu(baseNote, popupExpanded, accountViewModel)
+            NoteDropDownMenu(baseNote, popupExpanded, accountViewModel, nav)
         }
 
         Divider(

app/src/main/java/com/vitorpamplona/amethyst/ui/note/NoteCompose.kt

@@ -60,16 +60,16 @@ import androidx.compose.material3.lightColorScheme
 import androidx.compose.runtime.Composable
 import androidx.compose.runtime.LaunchedEffect
 import androidx.compose.runtime.MutableState
-import androidx.compose.runtime.State
+import androidx.compose.runtime.Stable
 import androidx.compose.runtime.derivedStateOf
 import androidx.compose.runtime.getValue
 import androidx.compose.runtime.livedata.observeAsState
 import androidx.compose.runtime.mutableStateOf
+import androidx.compose.runtime.produceState
 import androidx.compose.runtime.remember
 import androidx.compose.runtime.rememberCoroutineScope
 import androidx.compose.runtime.setValue
 import androidx.compose.ui.Alignment
-import androidx.compose.ui.Alignment.Companion.Center
 import androidx.compose.ui.Alignment.Companion.CenterVertically
 import androidx.compose.ui.Modifier
 import androidx.compose.ui.draw.clip
@@ -85,7 +85,6 @@ import androidx.compose.ui.res.painterResource
 import androidx.compose.ui.res.stringResource
 import androidx.compose.ui.text.AnnotatedString
 import androidx.compose.ui.text.buildAnnotatedString
-import androidx.compose.ui.text.capitalize
 import androidx.compose.ui.text.font.FontWeight
 import androidx.compose.ui.text.style.TextAlign
 import androidx.compose.ui.text.style.TextOverflow
@@ -785,7 +784,7 @@ fun LongCommunityHeader(
         )
         Spacer(DoubleHorzSpacer)
         NormalTimeAgo(baseNote = baseNote, Modifier.weight(1f))
-        MoreOptionsButton(baseNote, accountViewModel)
+        MoreOptionsButton(baseNote, accountViewModel, nav)
     }
 }
 
@@ -1091,6 +1090,12 @@ fun InnerNoteWithReactions(
     }
 }
 
+@Stable
+class EditState(
+    val showOriginal: MutableState<Boolean> = mutableStateOf(false),
+    val modificationsInOrder: MutableState<List<Note>> = mutableStateOf(emptyList()),
+)
+
 @Composable
 private fun NoteBody(
     baseNote: Note,
@@ -1103,9 +1108,19 @@ private fun NoteBody(
     accountViewModel: AccountViewModel,
     nav: (String) -> Unit,
 ) {
+    val editState by
+        produceState(initialValue = EditState(), key1 = baseNote) {
+            accountViewModel.findModificationEventsForNote(baseNote) { newModifications ->
+                if (value.modificationsInOrder.value != newModifications) {
+                    value.modificationsInOrder.value = newModifications
+                }
+            }
+        }
+
     FirstUserInfoRow(
         baseNote = baseNote,
         showAuthorPicture = showAuthorPicture,
+        editState = editState,
         accountViewModel = accountViewModel,
         nav = nav,
     )
@@ -1133,12 +1148,13 @@ private fun NoteBody(
     }
 
     RenderNoteRow(
-        baseNote,
+        baseNote = baseNote,
-        backgroundColor,
+        backgroundColor = backgroundColor,
-        makeItShort,
+        makeItShort = makeItShort,
-        canPreview,
+        canPreview = canPreview,
-        accountViewModel,
+        editState = editState,
-        nav,
+        accountViewModel = accountViewModel,
+        nav = nav,
     )
 
     val noteEvent = baseNote.event
@@ -1155,6 +1171,7 @@ private fun RenderNoteRow(
     backgroundColor: MutableState<Color>,
     makeItShort: Boolean,
     canPreview: Boolean,
+    editState: EditState,
     accountViewModel: AccountViewModel,
     nav: (String) -> Unit,
 ) {
@@ -1287,6 +1304,7 @@ private fun RenderNoteRow(
                 makeItShort,
                 canPreview,
                 backgroundColor,
+                editState,
                 accountViewModel,
                 nav,
             )
@@ -1343,19 +1361,29 @@ fun RenderTextEvent(
     makeItShort: Boolean,
     canPreview: Boolean,
     backgroundColor: MutableState<Color>,
+    editState: EditState,
     accountViewModel: AccountViewModel,
     nav: (String) -> Unit,
 ) {
-    LoadDecryptedContent(note, accountViewModel) { body ->
+    LoadDecryptedContent(
+        note,
+        accountViewModel,
+    ) { body ->
         val eventContent by
             remember(note.event) {
                 derivedStateOf {
                     val subject = (note.event as? TextNoteEvent)?.subject()?.ifEmpty { null }
+                    val newBody =
+                        if (editState.showOriginal.value || editState.modificationsInOrder.value.isEmpty()) {
+                            body
+                        } else {
+                            editState.modificationsInOrder.value.firstOrNull()?.event?.content() ?: body
+                        }
 
-                    if (!subject.isNullOrBlank() && !body.split("\n")[0].contains(subject)) {
+                    if (!subject.isNullOrBlank() && !newBody.split("\n")[0].contains(subject)) {
-                        "### $subject\n$body"
+                        "### $subject\n$newBody"
                     } else {
-                        body
+                        newBody
                     }
                 }
             }
@@ -2789,6 +2817,7 @@ fun DisplayLocation(
 fun FirstUserInfoRow(
     baseNote: Note,
     showAuthorPicture: Boolean,
+    editState: EditState,
     accountViewModel: AccountViewModel,
     nav: (String) -> Unit,
 ) {
@@ -2823,12 +2852,37 @@ fun FirstUserInfoRow(
             DisplayFollowingHashtagsInPost(baseNote, accountViewModel, nav)
         }
 
+        if (!editState.modificationsInOrder.value.isEmpty()) {
+            DisplayEditStatus(editState.showOriginal)
+        }
+
         TimeAgo(baseNote)
 
-        MoreOptionsButton(baseNote, accountViewModel)
+        MoreOptionsButton(baseNote, accountViewModel, nav)
     }
 }
 
+@Composable
+fun DisplayEditStatus(showOriginal: MutableState<Boolean>) {
+    ClickableText(
+        text =
+            if (showOriginal.value) {
+                buildAnnotatedString { append(stringResource(id = R.string.original)) }
+            } else {
+                buildAnnotatedString { append(stringResource(id = R.string.edited)) }
+            },
+        onClick = { showOriginal.value = !showOriginal.value },
+        style =
+            LocalTextStyle.current.copy(
+                color = MaterialTheme.colorScheme.placeholderText,
+                fontSize = Font14SP,
+                fontWeight = FontWeight.Bold,
+            ),
+        maxLines = 1,
+        modifier = HalfStartPadding,
+    )
+}
+
 @Composable
 private fun BoostedMark() {
     Text(
@@ -2844,6 +2898,7 @@ private fun BoostedMark() {
 fun MoreOptionsButton(
     baseNote: Note,
     accountViewModel: AccountViewModel,
+    nav: (String) -> Unit,
 ) {
     val popupExpanded = remember { mutableStateOf(false) }
     val enablePopup = remember { { popupExpanded.value = true } }
@@ -2858,6 +2913,7 @@ fun MoreOptionsButton(
             baseNote,
             popupExpanded,
             accountViewModel,
+            nav,
         )
     }
 }

app/src/main/java/com/vitorpamplona/amethyst/ui/note/UserProfilePicture.kt

@@ -66,6 +66,7 @@ import androidx.lifecycle.map
 import com.vitorpamplona.amethyst.R
 import com.vitorpamplona.amethyst.model.Note
 import com.vitorpamplona.amethyst.model.User
+import com.vitorpamplona.amethyst.ui.actions.EditPostView
 import com.vitorpamplona.amethyst.ui.components.RobohashAsyncImage
 import com.vitorpamplona.amethyst.ui.components.RobohashFallbackAsyncImage
 import com.vitorpamplona.amethyst.ui.screen.loggedIn.AccountViewModel
@@ -455,6 +456,7 @@ fun NoteDropDownMenu(
     note: Note,
     popupExpanded: MutableState<Boolean>,
     accountViewModel: AccountViewModel,
+    nav: (String) -> Unit,
 ) {
     var reportDialogShowing by remember { mutableStateOf(false) }
 
@@ -473,6 +475,20 @@ fun NoteDropDownMenu(
 
     val onDismiss = remember(popupExpanded) { { popupExpanded.value = false } }
 
+    val wantsToEditPost =
+        remember {
+            mutableStateOf(false)
+        }
+
+    if (wantsToEditPost.value) {
+        EditPostView(
+            onClose = { wantsToEditPost.value = false },
+            edit = note,
+            accountViewModel = accountViewModel,
+            nav = nav,
+        )
+    }
+
     DropdownMenu(
         expanded = popupExpanded.value,
         onDismissRequest = onDismiss,
@@ -551,6 +567,14 @@ fun NoteDropDownMenu(
             },
         )
         Divider()
+        if (state.isLoggedUser) {
+            DropdownMenuItem(
+                text = { Text(stringResource(R.string.edit_post)) },
+                onClick = {
+                    wantsToEditPost.value = true
+                },
+            )
+        }
         DropdownMenuItem(
             text = { Text(stringResource(R.string.broadcast)) },
             onClick = {

app/src/main/java/com/vitorpamplona/amethyst/ui/screen/ThreadFeedView.kt

@@ -58,6 +58,7 @@ import androidx.compose.runtime.derivedStateOf
 import androidx.compose.runtime.getValue
 import androidx.compose.runtime.livedata.observeAsState
 import androidx.compose.runtime.mutableStateOf
+import androidx.compose.runtime.produceState
 import androidx.compose.runtime.remember
 import androidx.compose.runtime.rememberCoroutineScope
 import androidx.compose.runtime.setValue
@@ -102,11 +103,13 @@ import com.vitorpamplona.amethyst.ui.note.AudioTrackHeader
 import com.vitorpamplona.amethyst.ui.note.BadgeDisplay
 import com.vitorpamplona.amethyst.ui.note.BlankNote
 import com.vitorpamplona.amethyst.ui.note.CreateImageHeader
+import com.vitorpamplona.amethyst.ui.note.DisplayEditStatus
 import com.vitorpamplona.amethyst.ui.note.DisplayHighlight
 import com.vitorpamplona.amethyst.ui.note.DisplayLocation
 import com.vitorpamplona.amethyst.ui.note.DisplayOts
 import com.vitorpamplona.amethyst.ui.note.DisplayPeopleList
 import com.vitorpamplona.amethyst.ui.note.DisplayRelaySet
+import com.vitorpamplona.amethyst.ui.note.EditState
 import com.vitorpamplona.amethyst.ui.note.FileHeaderDisplay
 import com.vitorpamplona.amethyst.ui.note.FileStorageHeaderDisplay
 import com.vitorpamplona.amethyst.ui.note.HiddenNote
@@ -120,6 +123,7 @@ import com.vitorpamplona.amethyst.ui.note.NoteUsernameDisplay
 import com.vitorpamplona.amethyst.ui.note.ReactionsRow
 import com.vitorpamplona.amethyst.ui.note.RenderAppDefinition
 import com.vitorpamplona.amethyst.ui.note.RenderEmojiPack
+import com.vitorpamplona.amethyst.ui.note.RenderFhirResource
 import com.vitorpamplona.amethyst.ui.note.RenderGitPatchEvent
 import com.vitorpamplona.amethyst.ui.note.RenderGitRepositoryEvent
 import com.vitorpamplona.amethyst.ui.note.RenderPinListEvent
@@ -156,6 +160,7 @@ import com.vitorpamplona.quartz.events.CommunityDefinitionEvent
 import com.vitorpamplona.quartz.events.CommunityPostApprovalEvent
 import com.vitorpamplona.quartz.events.EmojiPackEvent
 import com.vitorpamplona.quartz.events.Event
+import com.vitorpamplona.quartz.events.FhirResourceEvent
 import com.vitorpamplona.quartz.events.FileHeaderEvent
 import com.vitorpamplona.quartz.events.FileStorageHeaderEvent
 import com.vitorpamplona.quartz.events.GenericRepostEvent
@@ -372,6 +377,15 @@ fun NoteMaster(
             onClick = { showHiddenNote = true },
         )
     } else {
+        val editState by
+            produceState(initialValue = EditState(), key1 = baseNote) {
+                accountViewModel.findModificationEventsForNote(baseNote) { newModifications ->
+                    if (value.modificationsInOrder.value != newModifications) {
+                        value.modificationsInOrder.value = newModifications
+                    }
+                }
+            }
+
         Column(
             modifier
                 .fillMaxWidth()
@@ -407,6 +421,10 @@ fun NoteMaster(
                             DisplayFollowingHashtagsInPost(baseNote, accountViewModel, nav)
                         }
 
+                        if (!editState.modificationsInOrder.value.isEmpty()) {
+                            DisplayEditStatus(editState.showOriginal)
+                        }
+
                         Text(
                             timeAgo(note.createdAt(), context = context),
                             color = MaterialTheme.colorScheme.placeholderText,
@@ -424,7 +442,7 @@ fun NoteMaster(
                                 tint = MaterialTheme.colorScheme.placeholderText,
                             )
 
-                            NoteDropDownMenu(baseNote, moreActionsExpanded, accountViewModel)
+                            NoteDropDownMenu(baseNote, moreActionsExpanded, accountViewModel, nav)
                         }
                     }
 
@@ -532,6 +550,8 @@ fun NoteMaster(
                             accountViewModel,
                             nav,
                         )
+                    } else if (noteEvent is FhirResourceEvent) {
+                        RenderFhirResource(baseNote, accountViewModel, nav)
                     } else if (noteEvent is GitRepositoryEvent) {
                         RenderGitRepositoryEvent(baseNote, accountViewModel, nav)
                     } else if (noteEvent is GitPatchEvent) {
@@ -577,6 +597,7 @@ fun NoteMaster(
                             false,
                             canPreview,
                             backgroundColor,
+                            editState,
                             accountViewModel,
                             nav,
                         )
@@ -829,6 +850,11 @@ private fun RenderWikiHeaderForThreadPreview() {
     val accountViewModel = mockAccountViewModel()
     val nav: (String) -> Unit = {}
 
+    val editState by
+        remember {
+            mutableStateOf(EditState())
+        }
+
     runBlocking {
         withContext(Dispatchers.IO) {
             LocalCache.justConsume(event, null)
@@ -851,6 +877,7 @@ private fun RenderWikiHeaderForThreadPreview() {
                         false,
                         true,
                         backgroundColor,
+                        editState,
                         accountViewModel,
                         nav,
                     )
@@ -870,6 +897,7 @@ private fun RenderWikiHeaderForThreadPreview() {
                         false,
                         true,
                         backgroundColor,
+                        editState,
                         accountViewModel,
                         nav,
                     )

app/src/main/java/com/vitorpamplona/amethyst/ui/screen/loggedIn/AccountViewModel.kt

@@ -932,6 +932,15 @@ class AccountViewModel(val account: Account, val settings: SettingsState) : View
         }
     }
 
+    suspend fun findModificationEventsForNote(
+        note: Note,
+        onResult: (List<Note>) -> Unit,
+    ) {
+        withContext(Dispatchers.IO) {
+            onResult(LocalCache.findLatestModificationForNote(note))
+        }
+    }
+
     private suspend fun checkGetOrCreateChannel(key: HexKey): Channel? {
         return LocalCache.checkGetOrCreateChannel(key)
     }

app/src/main/java/com/vitorpamplona/amethyst/ui/screen/loggedIn/ChannelScreen.kt

@@ -865,7 +865,7 @@ fun LongChannelHeader(
                 )
                 Spacer(DoubleHorzSpacer)
                 NormalTimeAgo(note, remember { Modifier.weight(1f) })
-                MoreOptionsButton(note, accountViewModel)
+                MoreOptionsButton(note, accountViewModel, nav)
             }
         }
     }

app/src/main/java/com/vitorpamplona/amethyst/ui/screen/loggedIn/VideoScreen.kt

@@ -363,12 +363,12 @@ private fun RenderAuthorInformation(
         ) {
             Row(verticalAlignment = Alignment.CenterVertically) {
                 NoteUsernameDisplay(note, remember { Modifier.weight(1f) })
-                VideoUserOptionAction(note, accountViewModel)
+                VideoUserOptionAction(note, accountViewModel, nav)
             }
             Row(verticalAlignment = Alignment.CenterVertically) {
                 ObserveDisplayNip05Status(
-                    remember { note.author!! },
+                    note.author!!,
-                    remember { Modifier.weight(1f) },
+                    Modifier.weight(1f),
                     accountViewModel,
                     nav = nav,
                 )
@@ -387,6 +387,7 @@ private fun RenderAuthorInformation(
 private fun VideoUserOptionAction(
     note: Note,
     accountViewModel: AccountViewModel,
+    nav: (String) -> Unit,
 ) {
     val popupExpanded = remember { mutableStateOf(false) }
     val enablePopup = remember { { popupExpanded.value = true } }
@@ -406,6 +407,7 @@ private fun VideoUserOptionAction(
             note,
             popupExpanded,
             accountViewModel,
+            nav,
         )
     }
 }

app/src/main/res/values/strings.xml

@@ -50,6 +50,8 @@
     <string name="view_count">View count</string>
     <string name="boost">Boost</string>
     <string name="boosted">boosted</string>
+    <string name="edited">edited</string>
+    <string name="original">original</string>
     <string name="quote">Quote</string>
     <string name="fork">Fork</string>
     <string name="new_amount_in_sats">New Amount in Sats</string>
@@ -790,4 +792,6 @@
 
     <string name="ots_info_title">Timestamp Proof</string>
     <string name="ots_info_description">There\'s proof this post was signed sometime before %1$s. The proof was stamped in the Bitcoin blockchain at that date and time.</string>
+
+    <string name="edit_post">Edit Post</string>
 </resources>

quartz/src/main/java/com/vitorpamplona/quartz/events/EventFactory.kt

@@ -126,6 +126,7 @@ class EventFactory {
             SealedGossipEvent.KIND -> SealedGossipEvent(id, pubKey, createdAt, tags, content, sig)
             StatusEvent.KIND -> StatusEvent(id, pubKey, createdAt, tags, content, sig)
             TextNoteEvent.KIND -> TextNoteEvent(id, pubKey, createdAt, tags, content, sig)
+            TextNoteModificationEvent.KIND -> TextNoteModificationEvent(id, pubKey, createdAt, tags, content, sig)
             VideoHorizontalEvent.KIND -> VideoHorizontalEvent(id, pubKey, createdAt, tags, content, sig)
             VideoVerticalEvent.KIND -> VideoVerticalEvent(id, pubKey, createdAt, tags, content, sig)
             VideoViewEvent.KIND -> VideoViewEvent(id, pubKey, createdAt, tags, content, sig)

quartz/src/main/java/com/vitorpamplona/quartz/events/TextNoteModificationEvent.kt

@@ -0,0 +1,52 @@
+/**
+ * Copyright (c) 2024 Vitor Pamplona
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy of
+ * this software and associated documentation files (the "Software"), to deal in
+ * the Software without restriction, including without limitation the rights to use,
+ * copy, modify, merge, publish, distribute, sublicense, and/or sell copies of the
+ * Software, and to permit persons to whom the Software is furnished to do so,
+ * subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in all
+ * copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS
+ * FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR
+ * COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN
+ * AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
+ * WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
+ */
+package com.vitorpamplona.quartz.events
+
+import androidx.compose.runtime.Immutable
+import com.vitorpamplona.quartz.encoders.HexKey
+import com.vitorpamplona.quartz.signers.NostrSigner
+import com.vitorpamplona.quartz.utils.TimeUtils
+
+@Immutable
+class TextNoteModificationEvent(
+    id: HexKey,
+    pubKey: HexKey,
+    createdAt: Long,
+    tags: Array<Array<String>>,
+    content: String,
+    sig: HexKey,
+) : Event(id, pubKey, createdAt, KIND, tags, content, sig) {
+    companion object {
+        const val KIND = 1010
+        const val ALT = "Content Change Event"
+
+        fun create(
+            content: String,
+            eventId: HexKey,
+            signer: NostrSigner,
+            createdAt: Long = TimeUtils.now(),
+            onReady: (TextNoteModificationEvent) -> Unit,
+        ) {
+            val tags = arrayOf(arrayOf("e", eventId), arrayOf("alt", CalendarDateSlotEvent.ALT))
+            signer.sign(createdAt, KIND, tags, content, onReady)
+        }
+    }
+}