import 'package:flutter/foundation.dart';
import 'package:flutter_riverpod/flutter_riverpod.dart';
import 'package:supabase_flutter/supabase_flutter.dart';
import 'package:uuid/uuid.dart';

import '../models/programmer_task_comment.model.dart';
import 'supabase_provider.dart';

/// Bucket reused for programmer-task comment attachments (public read;
/// authenticated write; owner/privileged delete — already hardened by
/// 20260926120000_task_attachment_write_hardening.sql).
const _attachmentBucket = 'task_attachments';

/// A file selected for upload with a comment.
typedef CommentUpload = ({String name, Uint8List bytes});

/// Comments for a task (newest first), streamed live.
final programmerTaskCommentsProvider =
    StreamProvider.family<List<ProgrammerTaskComment>, String>((ref, taskId) {
  final client = ref.watch(supabaseClientProvider);
  return client
      .from('programmer_task_comments')
      .stream(primaryKey: ['id'])
      .eq('task_id', taskId)
      .order('created_at', ascending: false)
      .map((rows) => rows.map(ProgrammerTaskComment.fromMap).toList());
});

final programmerTaskCommentsControllerProvider =
    Provider<ProgrammerTaskCommentsController>((ref) {
  return ProgrammerTaskCommentsController(ref.watch(supabaseClientProvider));
});

class ProgrammerTaskCommentsController {
  ProgrammerTaskCommentsController(this._client);
  final dynamic _client;

  /// Public URL for a stored attachment path.
  String attachmentUrl(String path) =>
      _client.storage.from(_attachmentBucket).getPublicUrl(path);

  /// Adds a comment, uploading any [files] to the attachment bucket first.
  /// Requires either a non-empty [body] or at least one file.
  Future<void> addComment({
    required String taskId,
    required String body,
    List<CommentUpload> files = const [],
  }) async {
    final userId = _client.auth.currentUser?.id;
    if (userId == null) throw Exception('Not authenticated');

    final attachments = <Map<String, dynamic>>[];
    for (final file in files) {
      final path =
          'programmer_tasks/$taskId/comments/${const Uuid().v4()}_${file.name}';
      await _client.storage.from(_attachmentBucket).uploadBinary(
            path,
            file.bytes,
            fileOptions: const FileOptions(upsert: true),
          );
      attachments.add({'path': path, 'name': file.name});
    }

    await _client.from('programmer_task_comments').insert({
      'task_id': taskId,
      'author_id': userId,
      'body': body,
      'attachments': attachments,
    });
  }
}