Merge pull request #8989 from wordpress-mobile/issue/5984-post-change…

…-conflict-resolution

Post change conflict resolution dialog

RELEASE-NOTES.txt

@@ -1,3 +1,4 @@
+* Added a dialog for user to resolve a conflicted Post (different local / web version)
 * Refreshed page list layout that includes a timestamp and a featured image thumbnail
 * Fixed a bug causing disappearance of old saved posts
 * Add Importing from Giphy in Editor and Media Library

WordPress/src/main/java/org/wordpress/android/ui/posts/PostAdapterItem.kt

@@ -18,6 +18,7 @@ data class PostAdapterItemData(
     val date: String,
     val postStatus: PostStatus,
     val isLocallyChanged: Boolean,
+    val isConflicted: Boolean,
     val canShowStats: Boolean,
     val canPublishPost: Boolean,
     val canRetryUpload: Boolean,

WordPress/src/main/java/org/wordpress/android/ui/posts/PostUtils.java

@@ -6,6 +6,7 @@
 import android.text.format.DateUtils;
 
 import org.apache.commons.lang3.StringUtils;
+import org.wordpress.android.R;
 import org.wordpress.android.WordPress;
 import org.wordpress.android.analytics.AnalyticsTracker;
 import org.wordpress.android.fluxc.model.MediaModel;
@@ -18,15 +19,18 @@
 import org.wordpress.android.util.AppLog;
 import org.wordpress.android.util.DateTimeUtils;
 import org.wordpress.android.util.HtmlUtils;
+import org.wordpress.android.util.LocaleManager;
 import org.wordpress.android.util.analytics.AnalyticsUtils;
 
 import java.text.BreakIterator;
+import java.text.SimpleDateFormat;
 import java.util.Date;
 import java.util.HashMap;
 import java.util.HashSet;
 import java.util.List;
 import java.util.Map;
 import java.util.Set;
+import java.util.TimeZone;
 import java.util.regex.Matcher;
 import java.util.regex.Pattern;
 
@@ -373,4 +377,36 @@ public static boolean shouldShowGutenbergEditor(boolean isNewPost, PostModel pos
                    || contentContainsGutenbergBlocks(post.getContent())
                    || TextUtils.isEmpty(post.getContent()));
     }
+
+    public static boolean isPostInConflictWithRemote(PostModel post) {
+        // at this point we know there's a potential version conflict (the post has been modified
+        // both locally and on the remote)
+        return !post.getLastModified().equals(post.getRemoteLastModified()) && post.isLocallyChanged();
+    }
+
+    public static String getConflictedPostCustomStringForDialog(PostModel post) {
+        Context context = WordPress.getContext();
+        String firstPart = context.getString(R.string.dialog_confirm_load_remote_post_body);
+        String secondPart =
+                String.format(context.getString(R.string.dialog_confirm_load_remote_post_body_2),
+                        getFormattedDateForLastModified(
+                                context, DateTimeUtils.timestampFromIso8601Millis(post.getLastModified())),
+                        getFormattedDateForLastModified(
+                                context, DateTimeUtils.timestampFromIso8601Millis(post.getRemoteLastModified())));
+        return firstPart + secondPart;
+    }
+
+    /**
+     * E.g. Jul 2, 2013 @ 21:57
+     */
+    public static String getFormattedDateForLastModified(Context context, long timeSinceLastModified) {
+        Date date = new Date(timeSinceLastModified);
+        SimpleDateFormat sdf =
+                new SimpleDateFormat("MMM d, yyyy '@' hh:mm a", LocaleManager.getSafeLocale(context));
+
+        // The timezone on the website is at GMT
+        sdf.setTimeZone(TimeZone.getTimeZone("GMT"));
+
+        return sdf.format(date);
+    }
 }

WordPress/src/main/java/org/wordpress/android/ui/posts/PostViewHolder.kt

@@ -173,6 +173,10 @@ class PostViewHolder(private val view: View, private val config: PostViewHolderC
                 // the Post (or its related media if such a thing exist) *is strictly* queued
                 statusTextResId = R.string.post_queued
                 statusIconResId = R.drawable.ic_gridicons_cloud_upload
+            } else if (postAdapterItem.isConflicted) {
+                statusTextResId = R.string.local_post_is_conflicted
+                statusIconResId = R.drawable.ic_gridicons_notice
+                statusColorResId = R.color.alert_red
             } else if (postAdapterItem.isLocalDraft) {
                 statusTextResId = R.string.local_draft
                 statusIconResId = R.drawable.ic_gridicons_page

WordPress/src/main/java/org/wordpress/android/viewmodel/posts/PostListViewModel.kt

@@ -65,6 +65,7 @@ import org.wordpress.android.ui.uploads.PostEvents
 import org.wordpress.android.ui.uploads.UploadService
 import org.wordpress.android.ui.uploads.VideoOptimizer
 import org.wordpress.android.ui.utils.UiString.UiStringRes
+import org.wordpress.android.ui.utils.UiString.UiStringText
 import org.wordpress.android.util.AppLog
 import org.wordpress.android.util.AppLog.T
 import org.wordpress.android.util.SiteUtils
@@ -79,6 +80,7 @@ import javax.inject.Inject
 
 const val CONFIRM_DELETE_POST_DIALOG_TAG = "CONFIRM_DELETE_POST_DIALOG_TAG"
 const val CONFIRM_PUBLISH_POST_DIALOG_TAG = "CONFIRM_PUBLISH_POST_DIALOG_TAG"
+const val CONFIRM_ON_CONFLICT_LOAD_REMOTE_POST_DIALOG_TAG = "CONFIRM_ON_CONFLICT_LOAD_REMOTE_POST_DIALOG_TAG"
 
 enum class PostListEmptyViewState {
     EMPTY_LIST,
@@ -111,9 +113,12 @@ class PostListViewModel @Inject constructor(
 
     // Keep a reference to the currently being trashed post, so we can hide it during Undo Snackbar
     private var postIdToTrash: Pair<Int, Long>? = null
-    // Since we are using DialogFragments we need to hold onto which post will be published or trashed
+    // Since we are using DialogFragments we need to hold onto which post will be published or trashed / resolved
     private var localPostIdForPublishDialog: Int? = null
     private var localPostIdForTrashDialog: Int? = null
+    private var localPostIdForConflictResolutionDialog: Int? = null
+    private var originalPostCopyForConflictUndo: PostModel? = null
+    private var localPostIdForFetchingRemoteVersionOfConflictedPost: Int? = null
     // Initial target post to scroll to
     private var targetLocalPostId: Int? = null
 
@@ -324,6 +329,18 @@ class PostListViewModel @Inject constructor(
         _dialogAction.postValue(dialogHolder)
     }
 
+    private fun showConflictedPostResolutionDialog(post: PostModel) {
+        val dialogHolder = DialogHolder(
+                tag = CONFIRM_ON_CONFLICT_LOAD_REMOTE_POST_DIALOG_TAG,
+                title = UiStringRes(R.string.dialog_confirm_load_remote_post_title),
+                message = UiStringText(PostUtils.getConflictedPostCustomStringForDialog(post)),
+                positiveButton = UiStringRes(R.string.dialog_confirm_load_remote_post_discard_local),
+                negativeButton = UiStringRes(R.string.dialog_confirm_load_remote_post_discard_web)
+        )
+        localPostIdForConflictResolutionDialog = post.id
+        _dialogAction.postValue(dialogHolder)
+    }
+
     private fun publishPost(localPostId: Int) {
         val post = postStore.getPostByLocalPostId(localPostId)
         if (post != null) {
@@ -337,6 +354,16 @@ class PostListViewModel @Inject constructor(
     }
 
     private fun editPostButtonAction(site: SiteModel, post: PostModel) {
+        // first of all, check whether this post is in Conflicted state.
+        if (doesPostHaveUnhandledConflict(post)) {
+            showConflictedPostResolutionDialog(post)
+            return
+        }
+
+        checkGutenbergOrEdit(site, post)
+    }
+
+    private fun checkGutenbergOrEdit(site: SiteModel, post: PostModel) {
         // Show Gutenberg Warning Dialog if post contains GB blocks and it's not disabled
         if (!isGutenbergEnabled() &&
                 PostUtils.contentContainsGutenbergBlocks(post.content) &&
@@ -406,6 +433,14 @@ class PostListViewModel @Inject constructor(
                             T.POSTS,
                             "Error updating the post with type: ${event.error.type} and message: ${event.error.message}"
                     )
+                } else {
+                    originalPostCopyForConflictUndo?.id?.let {
+                        val updatedPost = postStore.getPostByLocalPostId(it)
+                        // Conflicted post has been successfully updated with its remote version
+                        if (!PostUtils.isPostInConflictWithRemote(updatedPost)) {
+                            conflictedPostUpdatedWithItsRemoteVersion()
+                        }
+                    }
                 }
             }
             is CauseOfOnPostChanged.DeletePost -> {
@@ -525,13 +560,15 @@ class PostListViewModel @Inject constructor(
                 date = PostUtils.getFormattedDate(post),
                 postStatus = postStatus,
                 isLocallyChanged = post.isLocallyChanged,
+                isConflicted = doesPostHaveUnhandledConflict(post),
                 canShowStats = canShowStats,
                 canPublishPost = canPublishPost,
                 canRetryUpload = uploadStatus.uploadError != null && !uploadStatus.hasInProgressMediaUpload,
                 featuredImageId = post.featuredImageId,
                 featuredImageUrl = getFeaturedImageUrl(post.featuredImageId, post.content),
                 uploadStatus = uploadStatus
         )
+
         return PostAdapterItem(
                 data = postData,
                 onSelected = { handlePostButton(PostListButton.BUTTON_EDIT, post) },
@@ -601,6 +638,11 @@ class PostListViewModel @Inject constructor(
                 localPostIdForPublishDialog = null
                 publishPost(it)
             }
+            CONFIRM_ON_CONFLICT_LOAD_REMOTE_POST_DIALOG_TAG -> localPostIdForConflictResolutionDialog?.let {
+                localPostIdForConflictResolutionDialog = null
+                // here load version from remote
+                updateConflictedPostWithItsRemoteVersion(it)
+            }
             else -> throw IllegalArgumentException("Dialog's positive button click is not handled: $instanceTag")
         }
     }
@@ -609,13 +651,19 @@ class PostListViewModel @Inject constructor(
         when (instanceTag) {
             CONFIRM_DELETE_POST_DIALOG_TAG -> localPostIdForTrashDialog = null
             CONFIRM_PUBLISH_POST_DIALOG_TAG -> localPostIdForPublishDialog = null
+            CONFIRM_ON_CONFLICT_LOAD_REMOTE_POST_DIALOG_TAG -> localPostIdForConflictResolutionDialog?.let {
+                updateConflictedPostWithItsLocalVersion(it)
+            }
             else -> throw IllegalArgumentException("Dialog's negative button click is not handled: $instanceTag")
         }
     }
 
     fun onDismissByOutsideTouchForBasicDialog(instanceTag: String) {
-        // Cancel and outside touch dismiss works the same way
-        onNegativeClickedForBasicDialog(instanceTag)
+        // Cancel and outside touch dismiss works the same way for all, except for conflict resolution dialog,
+        // for which tapping outside and actively tapping the "edit local" have different meanings
+        if (instanceTag != CONFIRM_ON_CONFLICT_LOAD_REMOTE_POST_DIALOG_TAG) {
+            onNegativeClickedForBasicDialog(instanceTag)
+        }
     }
 
     // Gutenberg Events
@@ -662,8 +710,81 @@ class PostListViewModel @Inject constructor(
         }
     }
 
+    // Post Conflict Resolution
+
+    private fun updateConflictedPostWithItsRemoteVersion(localPostId: Int) {
+        // We need network connection to load a remote post
+        if (!checkNetworkConnection()) {
+            return
+        }
+
+        val post = postStore.getPostByLocalPostId(localPostId)
+        if (post != null) {
+            originalPostCopyForConflictUndo = post.clone()
+            dispatcher.dispatch(PostActionBuilder.newFetchPostAction(RemotePostPayload(post, site)))
+            _toastMessage.postValue(ToastMessageHolder(R.string.toast_conflict_updating_post, Duration.SHORT))
+        }
+    }
+
+    private fun conflictedPostUpdatedWithItsRemoteVersion() {
+        val undoAction = {
+            // here replace the post with whatever we had before, again
+            if (originalPostCopyForConflictUndo != null) {
+                dispatcher.dispatch(PostActionBuilder.newUpdatePostAction(originalPostCopyForConflictUndo))
+            }
+        }
+        val onDismissAction = {
+            originalPostCopyForConflictUndo = null
+        }
+        val snackbarHolder = SnackbarMessageHolder(R.string.snackbar_conflict_local_version_discarded,
+                R.string.snackbar_conflict_undo, undoAction, onDismissAction)
+        _snackbarAction.postValue(snackbarHolder)
+    }
+
+    private fun updateConflictedPostWithItsLocalVersion(localPostId: Int) {
+        // We need network connection to push local version to remote
+        if (!checkNetworkConnection()) {
+            return
+        }
+
+        // Keep a reference to which post is being updated with the local version so we can avoid showing the conflicted
+        // label during the undo snackbar.
+        localPostIdForFetchingRemoteVersionOfConflictedPost = localPostId
+        pagedListWrapper.invalidateData()
+
+        val post = postStore.getPostByLocalPostId(localPostId) ?: return
+
+        // and now show a snackbar, acting as if the Post was pushed, but effectively push it after the snackbar is gone
+        var isUndoed = false
+        val undoAction = {
+            isUndoed = true
+
+            // Remove the reference for the post being updated and re-show the conflicted label on undo
+            localPostIdForFetchingRemoteVersionOfConflictedPost = null
+            pagedListWrapper.invalidateData()
+        }
+
+        val onDismissAction = {
+            if (!isUndoed) {
+                localPostIdForFetchingRemoteVersionOfConflictedPost = null
+                PostUtils.trackSavePostAnalytics(post, site)
+                dispatcher.dispatch(PostActionBuilder.newPushPostAction(RemotePostPayload(post, site)))
+            }
+        }
+        val snackbarHolder = SnackbarMessageHolder(R.string.snackbar_conflict_web_version_discarded,
+                R.string.snackbar_conflict_undo, undoAction, onDismissAction)
+        _snackbarAction.postValue(snackbarHolder)
+    }
+
     // Utils
 
+    private fun doesPostHaveUnhandledConflict(post: PostModel): Boolean {
+        // If we are fetching the remote version of a conflicted post, it means it's already being handled
+        val isFetchingConflictedPost = localPostIdForFetchingRemoteVersionOfConflictedPost != null &&
+                localPostIdForFetchingRemoteVersionOfConflictedPost == post.id
+        return !isFetchingConflictedPost && PostUtils.isPostInConflictWithRemote(post)
+    }
+
     private fun checkNetworkConnection(): Boolean =
             if (isNetworkAvailable) {
                 true

WordPress/src/main/res/drawable/ic_gridicons_notice.xml

@@ -0,0 +1,9 @@
+<vector xmlns:android="http://schemas.android.com/apk/res/android"
+    android:width="24dp"
+    android:height="24dp"
+    android:viewportWidth="24"
+    android:viewportHeight="24">
+  <path
+      android:fillColor="#FF000000"
+      android:pathData="M12,2C6.477,2 2,6.477 2,12s4.477,10 10,10 10,-4.477 10,-10S17.523,2 12,2zM13,17h-2v-2h2v2zM13,13h-2l-0.5,-6h3l-0.5,6z"/>
+</vector>

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

@@ -310,18 +310,29 @@
     <string name="width">Width</string>
     <string name="featured_in_post">Include image in post content</string>
     <string name="file_not_found">Couldn\'t find the file for upload. Was it deleted or moved?</string>
+    <string name="dialog_confirm_cancel_post_media_uploading">Are you sure? Deleting this post will also cancel the media upload.</string>
     <string name="delete_post">Delete post?</string>
     <string name="delete_page">Delete page?</string>
     <string name="posts_fetching">Fetching posts…</string>
     <string name="pages_fetching">Fetching pages…</string>
-    <string name="dialog_confirm_cancel_post_media_uploading">Are you sure? Deleting this post will also cancel the media upload.</string>
     <string name="dialog_confirm_delete_post">This post will be deleted and sent to Trash</string>
     <string name="dialog_confirm_publish_title">Ready to Publish?</string>
     <string name="dialog_confirm_publish_message_post">This post will be published immediately.</string>
     <string name="dialog_confirm_publish_message_page">This page will be published immediately.</string>
     <string name="dialog_confirm_publish_yes">Publish now</string>
     <string name="dialog_confirm_delete_permanently_post">Are you sure you\'d like to permanently delete this post?</string>
 
+    <!-- post version sync conflict dialog -->
+    <string name="dialog_confirm_load_remote_post_title">Resolve sync conflict</string>
+    <string name="dialog_confirm_load_remote_post_body">This post has two versions that are in conflict. Select the version you would like to discard.\n\n</string>
+    <string name="dialog_confirm_load_remote_post_body_2">Local\nSaved on %s\n\nWeb\nSaved on %s\n</string>
+    <string name="dialog_confirm_load_remote_post_discard_local">Discard Local</string>
+    <string name="dialog_confirm_load_remote_post_discard_web">Discard Web</string>
+    <string name="toast_conflict_updating_post">Updating post</string>
+    <string name="snackbar_conflict_local_version_discarded">Local version discarded</string>
+    <string name="snackbar_conflict_web_version_discarded">Web version discarded</string>
+    <string name="snackbar_conflict_undo">Undo</string>
+
     <!-- gutenberg compatibility dialog -->
     <string name="dialog_gutenberg_compatibility_title">Before you continue</string>
     <string name="dialog_gutenberg_compatibility_message">We are working on the brand new WordPress editor. You can still edit this post, but we recommend previewing it before publishing.</string>
@@ -1381,6 +1392,9 @@
     <string name="local_changes_discarding_error">There was an error in discarding your local changes. Please contact support for more assistance.</string>
     <string name="local_changes_discarding_no_connection">A connection is required to perform this action. Please check your connection and try again.</string>
 
+    <!-- Remote Post has conflicts with local post -->
+    <string name="local_post_is_conflicted">Version conflict</string>
+
     <!-- message on post preview explaining what local changes, local drafts and drafts are -->
     <string name="local_changes_explainer">This post has local changes which haven\'t been published</string>
     <string name="local_draft_explainer">This post is a local draft which hasn\'t been published</string>

libs/utils/WordPressUtils/src/main/java/org/wordpress/android/util/MediaUtils.java

@@ -30,10 +30,7 @@
 import java.net.MalformedURLException;
 import java.net.URL;
 import java.net.URLConnection;
-import java.text.SimpleDateFormat;
-import java.util.Date;
 import java.util.Locale;
-import java.util.TimeZone;
 import java.util.regex.Matcher;
 import java.util.regex.Pattern;
 
@@ -97,19 +94,6 @@ public static boolean isGif(String url) {
         return "gif".equals(MimeTypeMap.getFileExtensionFromUrl(url));
     }
 
-    /**
-     * E.g. Jul 2, 2013 @ 21:57
-     */
-    public static String getDate(long ms) {
-        Date date = new Date(ms);
-        SimpleDateFormat sdf = new SimpleDateFormat("MMM d, yyyy '@' HH:mm", Locale.ENGLISH);
-
-        // The timezone on the website is at GMT
-        sdf.setTimeZone(TimeZone.getTimeZone("GMT"));
-
-        return sdf.format(date);
-    }
-
     public static boolean isLocalFile(String state) {
         if (state == null) {
             return false;