ADFA-2885: Handle merge conflicts

app/src/main/java/com/itsaky/androidide/activities/editor/EditorHandlerActivity.kt

@@ -279,25 +279,28 @@ open class EditorHandlerActivity :
 	 * [onPause] snapshot **and** the in-memory buffer is still clean ([CodeEditorView.isModified] is
 	 * false). A clean buffer may still have undo history after [IDEEditor.markUnmodified] / save; we
 	 * reload anyway so external edits are not ignored. Never replaces buffers with unsaved edits.
+	 *
+	 * @param force If true, reloads even if the buffer is modified or the timestamp hasn't changed.
 	 */
-	private fun checkForExternalFileChanges() {
+	fun checkForExternalFileChanges(force: Boolean = false) {
 		val openFiles = editorViewModel.getOpenedFiles()
-		if (openFiles.isEmpty() || fileTimestamps.isEmpty()) return
+		if (openFiles.isEmpty() || (fileTimestamps.isEmpty() && !force)) return
 
 		lifecycleScope.launch(Dispatchers.IO) {
 			openFiles.forEach { file ->
-				val lastKnownTimestamp = fileTimestamps[file.absolutePath] ?: return@forEach
+				val lastKnownTimestamp = fileTimestamps[file.absolutePath] ?: 0L
 				val currentTimestamp = file.lastModified()
 
-				if (currentTimestamp > lastKnownTimestamp) {
+				if (currentTimestamp > lastKnownTimestamp || force) {
 					val newContent = runCatching { file.readText() }.getOrNull() ?: return@forEach
 					withContext(Dispatchers.Main) {
 						val editorView = getEditorForFile(file) ?: return@withContext
-						if (editorView.isModified) return@withContext
+						if (editorView.isModified && !force) return@withContext
 						val ideEditor = editorView.editor ?: return@withContext
 
 						ideEditor.setText(newContent)
 						editorView.markAsSaved()
+						fileTimestamps[file.absolutePath] = currentTimestamp
 						updateTabs()
 					}
 				}

app/src/main/java/com/itsaky/androidide/fragments/git/GitBottomSheetFragment.kt

@@ -12,24 +12,31 @@ import androidx.core.widget.doAfterTextChanged
 import androidx.fragment.app.Fragment
 import androidx.lifecycle.lifecycleScope
 import androidx.recyclerview.widget.LinearLayoutManager
+import com.google.android.material.bottomsheet.BottomSheetBehavior
 import com.google.android.material.dialog.MaterialAlertDialogBuilder
 import com.itsaky.androidide.R
 import com.itsaky.androidide.activities.PreferencesActivity
+import com.itsaky.androidide.activities.editor.EditorHandlerActivity
 import com.itsaky.androidide.databinding.DialogGitCredentialsBinding
 import com.itsaky.androidide.databinding.FragmentGitBottomSheetBinding
 import com.itsaky.androidide.fragments.git.adapter.GitFileChangeAdapter
 import com.itsaky.androidide.git.core.GitCredentialsManager
+import com.itsaky.androidide.git.core.models.ChangeType
 import com.itsaky.androidide.preferences.internal.GitPreferences
 import com.itsaky.androidide.utils.flashSuccess
+import com.itsaky.androidide.viewmodel.BottomSheetViewModel
 import com.itsaky.androidide.viewmodel.GitBottomSheetViewModel
+import com.itsaky.androidide.viewmodel.GitBottomSheetViewModel.PullUiState
 import kotlinx.coroutines.flow.collectLatest
 import kotlinx.coroutines.flow.combine
 import kotlinx.coroutines.launch
 import org.koin.androidx.viewmodel.ext.android.activityViewModel
+import java.io.File
 
 class GitBottomSheetFragment : Fragment(R.layout.fragment_git_bottom_sheet) {
 
     private val viewModel: GitBottomSheetViewModel by activityViewModel()
+    private val bottomSheetViewModel: BottomSheetViewModel by activityViewModel()
     private lateinit var fileChangeAdapter: GitFileChangeAdapter
     private lateinit var credentialsManager: GitCredentialsManager
 
@@ -43,9 +50,27 @@ class GitBottomSheetFragment : Fragment(R.layout.fragment_git_bottom_sheet) {
 
         fileChangeAdapter = GitFileChangeAdapter(
             onFileClicked = { change ->
-                // Show diff in a dialog when changed file is clicked
-                val dialog = GitDiffViewerDialog.newInstance(change.path)
-                dialog.show(childFragmentManager, "GitDiffViewerDialog")
+                when (change.type) {
+                    ChangeType.CONFLICTED -> {
+                        // Open conflicted file in editor
+                        val activity = requireActivity()
+                        if (activity is EditorHandlerActivity) {
+                            viewLifecycleOwner.lifecycleScope.launch {
+                                val repo = viewModel.currentRepository
+                                repo?.let {
+                                    activity.checkForExternalFileChanges(force = true)
+                                    activity.openFile(File(repo.rootDir, change.path))
+                                    bottomSheetViewModel.setSheetState(BottomSheetBehavior.STATE_COLLAPSED)
+                                }
+                            }
+                        }
+                    }
+                    else -> {
+                        // Show diff in a dialog when changed file is clicked
+                        val dialog = GitDiffViewerDialog.newInstance(change.path)
+                        dialog.show(childFragmentManager, "GitDiffViewerDialog")
+                    }
+                }
             },
             onSelectionChanged = {
                 validateCommitButton()
@@ -81,6 +106,7 @@ class GitBottomSheetFragment : Fragment(R.layout.fragment_git_bottom_sheet) {
                         commitSection.visibility = View.GONE
                         authorWarning.visibility = View.GONE
                         commitHistoryButton.visibility = View.GONE
+                        btnAbortMerge.visibility = View.GONE
                     }
                     allChanges.isEmpty() -> binding.apply {
                         emptyView.visibility = View.VISIBLE
@@ -89,6 +115,7 @@ class GitBottomSheetFragment : Fragment(R.layout.fragment_git_bottom_sheet) {
                         commitSection.visibility = View.GONE
                         authorWarning.visibility = View.GONE
                         commitHistoryButton.visibility = View.VISIBLE
+                        btnAbortMerge.visibility = View.GONE
                     }
                     else -> {
                         binding.apply {
@@ -97,6 +124,7 @@ class GitBottomSheetFragment : Fragment(R.layout.fragment_git_bottom_sheet) {
                             commitSection.visibility = View.VISIBLE
                             authorWarning.visibility = if (hasAuthorInfo()) View.GONE else View.VISIBLE
                             commitHistoryButton.visibility = View.VISIBLE
+                            btnAbortMerge.visibility = if (status.isMerging) View.VISIBLE else View.GONE
                         }
                         fileChangeAdapter.submitList(allChanges)
                     }
@@ -134,6 +162,22 @@ class GitBottomSheetFragment : Fragment(R.layout.fragment_git_bottom_sheet) {
         binding.commitSummary.doAfterTextChanged { validateCommitButton() }
         binding.commitDescription.doAfterTextChanged { validateCommitButton() }
 
+        binding.btnAbortMerge.setOnClickListener {
+            MaterialAlertDialogBuilder(requireContext())
+                .setTitle(R.string.abort_merge)
+                .setMessage(R.string.confirm_abort_merge)
+                .setPositiveButton(R.string.abort_merge) { _, _ ->
+                    viewModel.abortMerge {
+                        val activity = requireActivity()
+                        if (activity is EditorHandlerActivity) {
+                            activity.checkForExternalFileChanges(force = true)
+                        }
+                    }
+                }
+                .setNegativeButton(android.R.string.cancel, null)
+                .show()
+        }
+
         binding.authorAvatar.setOnClickListener {
             showAuthorPopup()
         }
@@ -214,25 +258,38 @@ class GitBottomSheetFragment : Fragment(R.layout.fragment_git_bottom_sheet) {
         viewLifecycleOwner.lifecycleScope.launch {
             viewModel.pullState.collectLatest { state ->
                 when (state) {
-                    is GitBottomSheetViewModel.PullUiState.Idle -> {
+                    is PullUiState.Idle -> {
                         binding.btnPull.isEnabled = true
                         binding.pullProgress.visibility = View.GONE
                     }
-                    is GitBottomSheetViewModel.PullUiState.Pulling -> {
+                    is PullUiState.Pulling -> {
                         binding.btnPull.isEnabled = false
                         binding.pullProgress.visibility = View.VISIBLE
                     }
-                    is GitBottomSheetViewModel.PullUiState.Success -> {
+                    is PullUiState.Success -> {
                         binding.btnPull.isEnabled = true
                         binding.pullProgress.visibility = View.GONE
                         flashSuccess(R.string.pull_successful)
                         viewModel.resetPullState()
                     }
-                    is GitBottomSheetViewModel.PullUiState.Error -> {
+                    is PullUiState.Conflicts -> {
+                        binding.btnPull.isEnabled = true
+                        binding.pullProgress.visibility = View.GONE
+                        val message = state.message ?: getString(R.string.info_merge_conflicts)
+                        MaterialAlertDialogBuilder(requireContext())
+                            .setTitle(getString(R.string.merge_conflicts))
+                            .setMessage(message)
+                            .setPositiveButton(android.R.string.ok, null)
+                            .show()
+                        viewModel.resetPullState()
+                    }
+                    is PullUiState.Error -> {
                         binding.btnPull.isEnabled = true
                         binding.pullProgress.visibility = View.GONE
                         val message =
-                            state.errorResId?.let { getString(it) } ?: state.message
+                            state.message ?: state.errorResId?.let { resId -> 
+                                if (state.errorArgs != null) getString(resId, *state.errorArgs.toTypedArray()) else getString(resId)
+                            }
                         MaterialAlertDialogBuilder(requireContext())
                             .setTitle(R.string.pull_failed)
                             .setMessage(message)

app/src/main/java/com/itsaky/androidide/fragments/git/GitCommitHistoryDialog.kt

@@ -132,8 +132,11 @@ class GitCommitHistoryDialog : DialogFragment() {
                     is GitBottomSheetViewModel.PushUiState.Error -> {
                         binding.btnPush.isEnabled = true
                         binding.pushProgress.visibility = View.GONE
-                        val message =
-                            state.errorResId?.let { getString(it) } ?: state.message
+                        val message = if (state.errorResId != null && state.errorResId != R.string.unknown_error) {
+                            getString(state.errorResId)
+                        } else {
+                            state.message ?: getString(R.string.unknown_error)
+                        }
                         MaterialAlertDialogBuilder(requireContext())
                             .setTitle(R.string.push_failed)
                             .setMessage(message)

app/src/main/java/com/itsaky/androidide/viewmodel/GitBottomSheetViewModel.kt

@@ -22,8 +22,10 @@ import kotlinx.coroutines.flow.MutableStateFlow
 import kotlinx.coroutines.flow.StateFlow
 import kotlinx.coroutines.flow.asStateFlow
 import kotlinx.coroutines.launch
+import org.eclipse.jgit.api.MergeResult.MergeStatus
 import org.eclipse.jgit.api.PullResult
 import org.eclipse.jgit.errors.NoRemoteRepositoryException
+import org.eclipse.jgit.api.errors.CheckoutConflictException
 import org.eclipse.jgit.transport.RemoteRefUpdate
 import org.eclipse.jgit.transport.UsernamePasswordCredentialsProvider
 import org.greenrobot.eventbus.EventBus
@@ -219,8 +221,14 @@ class GitBottomSheetViewModel(private val credentialsManager: GitCredentialsMana
         } else null
 
     private fun handlePushError(update: RemoteRefUpdate) {
+        val resId = if (update.status == RemoteRefUpdate.Status.REJECTED_NONFASTFORWARD) {
+            R.string.push_rejected_nonfastforward
+        } else {
+            R.string.unknown_error
+        }
         _pushState.value = PushUiState.Error(
-            update.message ?: update.status.name
+            message = update.message ?: update.status.name,
+            errorResId = resId
         )
     }
 
@@ -256,6 +264,10 @@ class GitBottomSheetViewModel(private val credentialsManager: GitCredentialsMana
                 }
 
                 handlePullSuccess(username, token)
+            } catch (e: CheckoutConflictException) {
+                log.error("Pull failed with checkout conflict", e)
+                val paths = e.conflictingPaths?.joinToString("\n") ?: ""
+                _pullState.value = PullUiState.Error(errorResId = R.string.checkout_conflict_message, errorArgs = listOf(paths))
             } catch (e: Exception) {
                 log.error("Pull failed", e)
                 if (e.message?.contains("not authorized", ignoreCase = true) == true) {
@@ -274,8 +286,15 @@ class GitBottomSheetViewModel(private val credentialsManager: GitCredentialsMana
     }
 
     private fun handlePullError(result: PullResult) {
-        val status = result.mergeResult?.mergeStatus?.name ?: "Unknown error"
-        _pullState.value = PullUiState.Error("Pull failed: $status")
+        val mergeStatus = result.mergeResult?.mergeStatus
+        val statusName = mergeStatus?.name ?: "Unknown error"
+
+        if (mergeStatus == MergeStatus.CONFLICTING) {
+            _pullState.value = PullUiState.Conflicts()
+            refreshStatus()
+        } else {
+            _pullState.value = PullUiState.Error("Pull failed: $statusName")
+        }
     }
 
     private fun handlePullSuccess(
@@ -302,7 +321,8 @@ class GitBottomSheetViewModel(private val credentialsManager: GitCredentialsMana
         object Idle : PullUiState()
         object Pulling : PullUiState()
         object Success : PullUiState()
-        data class Error(val message: String? = null, val errorResId: Int? = R.string.unknown_error) : PullUiState()
+        data class Conflicts(val message: String? = null) : PullUiState()
+        data class Error(val message: String? = null, val errorResId: Int? = R.string.unknown_error, val errorArgs: List<String>? = null) : PullUiState()
     }
 
     sealed class PushUiState {
@@ -337,4 +357,16 @@ class GitBottomSheetViewModel(private val credentialsManager: GitCredentialsMana
         refreshStatus()
     }
 
+    fun abortMerge(onSuccess: (() -> Unit)? = null) {
+        viewModelScope.launch {
+            try {
+                currentRepository?.abortMerge()
+                refreshStatus()
+                onSuccess?.invoke()
+            } catch (e: Exception) {
+                log.error("Failed to abort merge", e)
+            }
+        }
+    }
+
 }

app/src/main/res/layout/fragment_git_bottom_sheet.xml

@@ -140,7 +140,7 @@
         android:layout_marginBottom="8dp"
         android:enabled="false"
         android:text="@string/commit"
-        app:layout_constraintBottom_toTopOf="@id/commitHistoryButton" />
+        app:layout_constraintBottom_toTopOf="@id/btnAbortMerge" />
 
     <androidx.constraintlayout.widget.Group
         android:id="@+id/commit_section"
@@ -149,6 +149,18 @@
         android:visibility="gone"
         app:constraint_referenced_ids="authorAvatar, commitSummaryLayout, commitDescriptionLayout, commitButton" />
 
+    <com.google.android.material.button.MaterialButton
+        android:id="@+id/btnAbortMerge"
+        style="@style/Widget.MaterialComponents.Button.OutlinedButton"
+        android:layout_width="match_parent"
+        android:layout_height="wrap_content"
+        android:layout_marginBottom="8dp"
+        android:text="@string/abort_merge"
+        android:textColor="?attr/colorError"
+        app:strokeColor="?attr/colorError"
+        android:visibility="gone"
+        app:layout_constraintBottom_toTopOf="@id/commitHistoryButton" />
+
     <com.google.android.material.button.MaterialButton
         android:id="@+id/commitHistoryButton"
         android:layout_width="match_parent"

git-core/src/main/java/com/itsaky/androidide/git/core/GitRepository.kt

@@ -3,6 +3,7 @@ package com.itsaky.androidide.git.core
 import com.itsaky.androidide.git.core.models.GitBranch
 import com.itsaky.androidide.git.core.models.GitCommit
 import com.itsaky.androidide.git.core.models.GitStatus
+import org.eclipse.jgit.api.MergeResult
 import org.eclipse.jgit.api.PullResult
 import org.eclipse.jgit.lib.ProgressMonitor
 import org.eclipse.jgit.transport.CredentialsProvider
@@ -41,4 +42,8 @@ interface GitRepository : Closeable {
         credentialsProvider: CredentialsProvider? = null,
         progressMonitor: ProgressMonitor? = null
     ): PullResult
+
+    // Merge Operations
+    suspend fun merge(branchName: String): MergeResult
+    suspend fun abortMerge()
 }

git-core/src/main/java/com/itsaky/androidide/git/core/JGitRepository.kt

@@ -9,6 +9,7 @@ import kotlinx.coroutines.Dispatchers
 import kotlinx.coroutines.withContext
 import org.eclipse.jgit.api.Git
 import org.eclipse.jgit.api.ListBranchCommand.ListMode
+import org.eclipse.jgit.api.MergeResult
 import org.eclipse.jgit.diff.DiffFormatter
 import org.eclipse.jgit.dircache.DirCacheIterator
 import org.eclipse.jgit.lib.BranchConfig
@@ -22,6 +23,8 @@ import org.eclipse.jgit.storage.file.FileRepositoryBuilder
 import org.eclipse.jgit.transport.CredentialsProvider
 import org.eclipse.jgit.transport.PushResult
 import org.eclipse.jgit.api.PullResult
+import org.eclipse.jgit.api.ResetCommand.ResetType
+import org.eclipse.jgit.lib.RepositoryState
 import org.eclipse.jgit.treewalk.AbstractTreeIterator
 import org.eclipse.jgit.treewalk.CanonicalTreeParser
 import org.eclipse.jgit.treewalk.EmptyTreeIterator
@@ -76,11 +79,12 @@ class JGitRepository(override val rootDir: File) : GitRepository {
 
         jgitStatus.conflicting.forEach { conflicted.add(FileChange(it, ChangeType.CONFLICTED)) }
 
-
+        val isMerging = repository.repositoryState == RepositoryState.MERGING
 
         GitStatus(
             isClean = jgitStatus.isClean,
             hasConflicts = jgitStatus.conflicting.isNotEmpty(),
+            isMerging = isMerging,
             staged = staged,
             unstaged = unstaged,
             untracked = untracked,
@@ -272,6 +276,25 @@ class JGitRepository(override val rootDir: File) : GitRepository {
         pullCommand.call()
     }
 
+    override suspend fun merge(branchName: String): MergeResult = withContext(Dispatchers.IO) {
+        val branchRef = repository.findRef(branchName) ?: throw IllegalArgumentException("Branch $branchName not found")
+        git.merge().include(branchRef).call()
+    }
+
+    override suspend fun abortMerge(): Unit = withContext(Dispatchers.IO) {
+        // Reset working tree and index to HEAD
+        git.reset().setMode(ResetType.HARD).setRef(Constants.ORIG_HEAD).call()
+
+        // Explicitly clear merge-related files to exit the MERGING state
+        repository.apply {
+            writeMergeHeads(null)
+            writeMergeCommitMsg(null)
+            writeCherryPickHead(null)
+            writeRevertHead(null)
+            writeSquashCommitMsg(null)
+        }
+    }
+
     override fun close() {
         repository.close()
         git.close()