feat: Conversation merge feature with undo support

app/lib/backend/http/api/merge.dart

@@ -0,0 +1,285 @@
+import 'dart:convert';
+
+import 'package:flutter/material.dart';
+import 'package:omi/backend/http/shared.dart';
+import 'package:omi/backend/schema/schema.dart';
+import 'package:omi/env/env.dart';
+
+/// Conversation merge API client functions
+///
+/// Provides 4 merge-related API calls:
+/// 1. previewMerge - Preview merge without committing
+/// 2. mergeConversations - Execute merge with rollback
+/// 3. rollbackMerge - Undo merge within 24h
+/// 4. getMergeHistory - Get recent merge operations
+
+// ==================== Response Models ====================
+
+class MergeMetadata {
+  final int totalSegments;
+  final double totalDurationSeconds;
+  final int actionItemsCombined;
+  final int actionItemsDeduplicated;
+  final int eventsCombined;
+  final int photosCombined;
+  final int audioFilesCombined;
+  final int estimatedProcessingTimeSeconds;
+
+  MergeMetadata({
+    required this.totalSegments,
+    required this.totalDurationSeconds,
+    required this.actionItemsCombined,
+    required this.actionItemsDeduplicated,
+    required this.eventsCombined,
+    this.photosCombined = 0,
+    this.audioFilesCombined = 0,
+    this.estimatedProcessingTimeSeconds = 5,
+  });
+
+  factory MergeMetadata.fromJson(Map<String, dynamic> json) {
+    return MergeMetadata(
+      totalSegments: json['total_segments'] ?? 0,
+      totalDurationSeconds: (json['total_duration_seconds'] ?? 0).toDouble(),
+      actionItemsCombined: json['action_items_combined'] ?? 0,
+      actionItemsDeduplicated: json['action_items_deduplicated'] ?? 0,
+      eventsCombined: json['events_combined'] ?? 0,
+      photosCombined: json['photos_combined'] ?? 0,
+      audioFilesCombined: json['audio_files_combined'] ?? 0,
+      estimatedProcessingTimeSeconds: json['estimated_processing_time_seconds'] ?? 5,
+    );
+  }
+}
+
+class MergePreviewResponse {
+  final Map<String, dynamic> previewConversation;
+  final List<ServerConversation> sourceConversations;
+  final MergeMetadata mergeMetadata;
+  final List<String> warnings;
+
+  MergePreviewResponse({
+    required this.previewConversation,
+    required this.sourceConversations,
+    required this.mergeMetadata,
+    this.warnings = const [],
+  });
+
+  factory MergePreviewResponse.fromJson(Map<String, dynamic> json) {
+    return MergePreviewResponse(
+      previewConversation: json['preview_conversation'] ?? {},
+      sourceConversations:
+          (json['source_conversations'] as List<dynamic>?)?.map((conv) => ServerConversation.fromJson(conv)).toList() ??
+              [],
+      mergeMetadata: MergeMetadata.fromJson(json['merge_metadata'] ?? {}),
+      warnings: (json['warnings'] as List<dynamic>?)?.map((w) => w.toString()).toList() ?? [],
+    );
+  }
+}
+
+class MergeConversationsResponse {
+  final ServerConversation mergedConversation;
+  final String mergeId;
+  final DateTime rollbackAvailableUntil;
+  final MergeMetadata mergeMetadata;
+
+  MergeConversationsResponse({
+    required this.mergedConversation,
+    required this.mergeId,
+    required this.rollbackAvailableUntil,
+    required this.mergeMetadata,
+  });
+
+  String get mergedConversationId => mergedConversation.id;
+
+  factory MergeConversationsResponse.fromJson(Map<String, dynamic> json) {
+    final rollbackUntil = DateTime.tryParse(json['rollback_available_until'] ?? '');
+    if (json['merged_conversation'] == null || rollbackUntil == null) {
+      throw FormatException('Invalid API response for MergeConversationsResponse. Received: $json');
+    }
+    return MergeConversationsResponse(
+      mergedConversation: ServerConversation.fromJson(json['merged_conversation']),
+      mergeId: json['merge_id'] ?? '',
+      rollbackAvailableUntil: rollbackUntil.toLocal(),
+      mergeMetadata: MergeMetadata.fromJson(json['merge_metadata'] ?? {}),
+    );
+  }
+}
+
+class RollbackMergeResponse {
+  final List<ServerConversation> restoredConversations;
+  final String mergeId;
+  final DateTime rollbackTime;
+
+  RollbackMergeResponse({
+    required this.restoredConversations,
+    required this.mergeId,
+    required this.rollbackTime,
+  });
+
+  factory RollbackMergeResponse.fromJson(Map<String, dynamic> json) {
+    final rollbackTime = DateTime.tryParse(json['rollback_time'] ?? '');
+    if (rollbackTime == null) {
+      throw FormatException('Invalid API response for RollbackMergeResponse: missing rollback_time. Received: $json');
+    }
+    return RollbackMergeResponse(
+      restoredConversations: (json['restored_conversations'] as List<dynamic>?)
+              ?.map((conv) => ServerConversation.fromJson(conv))
+              .toList() ??
+          [],
+      mergeId: json['merge_id'] ?? '',
+      rollbackTime: rollbackTime.toLocal(),
+    );
+  }
+}
+
+// ==================== API Functions ====================
+
+/// Preview conversation merge without committing changes
+///
+/// Returns a preview of what the merged conversation will look like,
+/// including AI-generated title, overview, and metadata about the merge.
+///
+/// This is a read-only operation - no database changes are made.
+Future<MergePreviewResponse?> previewMerge(List<String> conversationIds) async {
+  if (conversationIds.length < 2) {
+    debugPrint('previewMerge: Need at least 2 conversations');
+    return null;
+  }
+
+  var response = await makeApiCall(
+    url: '${Env.apiBaseUrl}v1/conversations/merge/preview',
+    headers: {},
+    method: 'POST',
+    body: jsonEncode({
+      'conversation_ids': conversationIds,
+    }),
+  );
+
+  if (response == null) return null;
+  debugPrint('previewMerge: ${response.statusCode}');
+
+  if (response.statusCode == 200) {
+    return MergePreviewResponse.fromJson(jsonDecode(response.body));
+  } else if (response.statusCode == 400) {
+    debugPrint('previewMerge validation failed: ${response.body}');
+    return null;
+  } else {
+    debugPrint('previewMerge error ${response.statusCode}: ${response.body}');
+    return null;
+  }
+}
+
+/// Execute conversation merge with rollback capability
+///
+/// Combines multiple conversations into one merged conversation.
+/// Source conversations are marked as merged (soft deleted).
+/// Creates a rollback snapshot valid for 24 hours.
+///
+/// [conversationIds]: List of conversation IDs to merge (min 2, must be adjacent)
+/// [customTitle]: Optional custom title (overrides AI-generated title)
+///
+/// Returns MergeConversationsResponse with merged conversation and merge_id for rollback
+Future<MergeConversationsResponse?> mergeConversations(
+  List<String> conversationIds, {
+  String? customTitle,
+}) async {
+  if (conversationIds.length < 2) {
+    debugPrint('mergeConversations: Need at least 2 conversations');
+    return null;
+  }
+
+  Map<String, dynamic> body = {
+    'conversation_ids': conversationIds,
+  };
+  if (customTitle != null && customTitle.isNotEmpty) {
+    body['custom_title'] = customTitle;
+  }
+
+  var response = await makeApiCall(
+    url: '${Env.apiBaseUrl}v1/conversations/merge',
+    headers: {},
+    method: 'POST',
+    body: jsonEncode(body),
+  );
+
+  if (response == null) return null;
+  debugPrint('mergeConversations: ${response.statusCode}');
+
+  if (response.statusCode == 200) {
+    return MergeConversationsResponse.fromJson(jsonDecode(response.body));
+  } else if (response.statusCode == 400) {
+    debugPrint('mergeConversations validation failed: ${response.body}');
+    return null;
+  } else if (response.statusCode == 500) {
+    debugPrint('mergeConversations server error: ${response.body}');
+    return null;
+  } else {
+    debugPrint('mergeConversations error ${response.statusCode}: ${response.body}');
+    return null;
+  }
+}
+
+/// Rollback a conversation merge within 24-hour window
+///
+/// Restores source conversations and deletes the merged conversation.
+/// Only works if rollback window hasn't expired and merge wasn't already rolled back.
+///
+/// [mergeId]: Merge operation ID (from mergeConversations response)
+///
+/// Returns RollbackMergeResponse with restored conversations
+Future<RollbackMergeResponse?> rollbackMerge(String mergeId) async {
+  var response = await makeApiCall(
+    url: '${Env.apiBaseUrl}v1/conversations/merge/$mergeId/rollback',
+    headers: {},
+    method: 'POST',
+    body: '',
+  );
+
+  if (response == null) return null;
+  debugPrint('rollbackMerge: ${response.statusCode}');
+
+  if (response.statusCode == 200) {
+    return RollbackMergeResponse.fromJson(jsonDecode(response.body));
+  } else if (response.statusCode == 400) {
+    debugPrint('rollbackMerge not available: ${response.body}');
+    return null;
+  } else if (response.statusCode == 404) {
+    debugPrint('rollbackMerge: Merge history not found');
+    return null;
+  } else {
+    debugPrint('rollbackMerge error ${response.statusCode}: ${response.body}');
+    return null;
+  }
+}
+
+/// Unmerge a merged conversation by its conversation ID
+///
+/// Convenience wrapper that looks up the merge by conversation ID
+/// and calls the rollback endpoint.
+///
+/// [conversationId]: The merged conversation ID
+///
+/// Returns RollbackMergeResponse with restored conversations
+Future<RollbackMergeResponse?> unmergeConversation(String conversationId) async {
+  var response = await makeApiCall(
+    url: '${Env.apiBaseUrl}v1/conversations/$conversationId/unmerge',
+    headers: {},
+    method: 'POST',
+    body: '',
+  );
+
+  if (response == null) return null;
+  debugPrint('unmergeConversation: ${response.statusCode}');
+
+  if (response.statusCode == 200) {
+    return RollbackMergeResponse.fromJson(jsonDecode(response.body));
+  } else if (response.statusCode == 400) {
+    debugPrint('unmergeConversation not available: ${response.body}');
+    return null;
+  } else if (response.statusCode == 404) {
+    debugPrint('unmergeConversation: Conversation not found or not merged');
+    return null;
+  } else {
+    debugPrint('unmergeConversation error ${response.statusCode}: ${response.body}');
+    return null;
+  }
+}

app/lib/backend/schema/conversation.dart

@@ -148,6 +148,13 @@ class ServerConversation {
   final bool deleted;
   final bool isLocked;
 
+  // Conversation merge tracking
+  final String? mergedIntoId; // ID of merged conversation this was combined into
+  final DateTime? mergeTime; // When this conversation was merged
+  final bool isMerged; // True if this conversation was created by merging
+  final List<String> sourceConversationIds; // IDs of source conversations
+  final String? mergeId; // Reference to MergeHistory for rollback
+
   // local label
   bool isNew = false;
 
@@ -169,6 +176,11 @@ class ServerConversation {
     this.externalIntegration,
     this.status = ConversationStatus.completed,
     this.isLocked = false,
+    this.mergedIntoId,
+    this.mergeTime,
+    this.isMerged = false,
+    this.sourceConversationIds = const [],
+    this.mergeId,
   });
 
   factory ServerConversation.fromJson(Map<String, dynamic> json) {
@@ -199,6 +211,13 @@ class ServerConversation {
           ? ConversationStatus.values.asNameMap()[json['status']] ?? ConversationStatus.completed
           : ConversationStatus.completed,
       isLocked: json['is_locked'] ?? false,
+      mergedIntoId: json['merged_into_id'],
+      mergeTime: json['merge_time'] != null ? DateTime.parse(json['merge_time']).toLocal() : null,
+      isMerged: json['is_merged'] ?? false,
+      sourceConversationIds: json['source_conversation_ids'] != null
+          ? (json['source_conversation_ids'] as List<dynamic>).map((id) => id.toString()).toList()
+          : [],
+      mergeId: json['merge_id'],
     );
   }
 
@@ -221,6 +240,11 @@ class ServerConversation {
       'external_data': externalIntegration?.toJson(),
       'status': status.toString().split('.').last,
       'is_locked': isLocked,
+      'merged_into_id': mergedIntoId,
+      'merge_time': mergeTime?.toUtc().toIso8601String(),
+      'is_merged': isMerged,
+      'source_conversation_ids': sourceConversationIds,
+      'merge_id': mergeId,
     };
   }