import 'dart:io' show Platform, Directory;
import 'package:flutter/material.dart';
import 'package:path/path.dart' as path;
import 'package:sqflite_common_ffi/sqflite_ffi.dart';

const settingsDir = '.journaler';
const dbFileName = 'journaler.db';

class DB {
  static late Database db;

  static const String _schema = '''
CREATE TABLE IF NOT EXISTS notes (
  id INTEGER PRIMARY KEY AUTOINCREMENT,
  date TEXT DEFAULT CURRENT_TIMESTAMP,
  content TEXT NOT NULL
);
CREATE INDEX IF NOT EXISTS idx_notes_date ON notes (date);
CREATE UNIQUE INDEX IF NOT EXISTS idx_notes_date_unique ON notes (date);
-- Todos are "static", we are only interested in the latest entry
-- ie. they're not really a list but instead a string
-- But we will also keep a history of all todos
-- Because we might as well
CREATE TABLE IF NOT EXISTS scratches (
  id INTEGER PRIMARY KEY AUTOINCREMENT,
  date TEXT DEFAULT CURRENT_TIMESTAMP,
  content TEXT NOT NULL
);
CREATE INDEX IF NOT EXISTS idx_scratches_date ON scratches (date);
CREATE UNIQUE INDEX IF NOT EXISTS idx_scratches_date_unique ON scratches (date);

CREATE TABLE IF NOT EXISTS settings (
  key TEXT PRIMARY KEY NOT NULL,
  value TEXT NOT NULL
);

-- Create virtual FTS5 table for searching notes content
CREATE VIRTUAL TABLE IF NOT EXISTS notes_fts USING fts5(
  content,
  date,
  content='notes',
  content_rowid='id'
);

-- Trigger to keep FTS table in sync with notes table when inserting
CREATE TRIGGER IF NOT EXISTS notes_ai AFTER INSERT ON notes BEGIN
  INSERT INTO notes_fts(rowid, content, date) VALUES (new.id, new.content, new.date);
END;

-- Trigger to keep FTS table in sync when deleting notes
CREATE TRIGGER IF NOT EXISTS notes_ad AFTER DELETE ON notes BEGIN
  DELETE FROM notes_fts WHERE rowid = old.id;
END;

-- Trigger to keep FTS table in sync when updating notes
CREATE TRIGGER IF NOT EXISTS notes_au AFTER UPDATE ON notes BEGIN
  UPDATE notes_fts SET content = new.content, date = new.date WHERE rowid = old.id;
END;
''';

  static Future<String> _getDatabasePath() async {
    debugPrint('Attempting to get database path...');
    if (Platform.isWindows || Platform.isLinux) {
      // Get user's home directory
      final home =
          Platform.environment['HOME'] ?? Platform.environment['USERPROFILE'];
      if (home == null) {
        throw Exception('Could not find home directory');
      }
      debugPrint('Home directory found: $home');

      final dbDir = Directory(path.join(home, settingsDir));
      if (!await dbDir.exists()) {
        await dbDir.create(recursive: true);
        debugPrint('$settingsDir directory created');
      } else {
        debugPrint('$settingsDir directory already exists');
      }

      return path.join(dbDir.path, dbFileName);
    } else {
      // Default path for other platforms
      final databasesPath = await databaseFactoryFfi.getDatabasesPath();
      debugPrint('Using default databases path: $databasesPath');
      return path.join(databasesPath, dbFileName);
    }
  }

  static Future<void> init() async {
    debugPrint('Starting database initialization...');
    sqfliteFfiInit();

    final dbPath = await _getDatabasePath();
    debugPrint('Database path: $dbPath');

    try {
      db = await databaseFactoryFfi.openDatabase(
        dbPath,
        options: OpenDatabaseOptions(
          version: 1,
          onCreate: (db, version) async {
            debugPrint('Creating database schema...');
            await db.execute(_schema);
            debugPrint('Database schema created successfully');
          },
        ),
      );
      debugPrint('Database opened and initialized');
    } catch (e) {
      debugPrint('Failed to initialize database: $e');
      rethrow;
    }
  }

  // Settings Management
  static Future<String?> getSetting(String key) async {
    final List<Map<String, dynamic>> maps = await db.query(
      'settings',
      columns: ['value'],
      where: 'key = ?',
      whereArgs: [key],
    );
    if (maps.isNotEmpty) {
      return maps.first['value'] as String?;
    }
    return null;
  }

  static Future<void> setSetting(String key, String value) async {
    await db.insert('settings', {
      'key': key,
      'value': value,
    }, conflictAlgorithm: ConflictAlgorithm.replace);
    debugPrint("Setting updated: $key = $value");
  }

  // Search notes using FTS
  static Future<List<Map<String, dynamic>>> searchNotes(String query) async {
    try {
      if (query.trim().isEmpty) {
        return [];
      }

      // Process the query for partial word matching
      // Split into individual terms, filter empty ones
      List<String> terms =
          query
              .trim()
              .split(RegExp(r'\s+'))
              .where((term) => term.isNotEmpty)
              .toList();

      if (terms.isEmpty) {
        return [];
      }

      // Add wildcards to each term for prefix matching (e.g., "fuck*" will match "fucked")
      // Join terms with AND for all-term matching (results must contain ALL terms)
      String ftsQuery = terms
          .map((term) {
            // Remove any special characters that might break the query
            String sanitizedTerm = term.replaceAll(RegExp(r'[^\w]'), '');
            if (sanitizedTerm.isEmpty) return '';

            // Add wildcard for stemming/prefix matching
            return '$sanitizedTerm*';
          })
          .where((term) => term.isNotEmpty)
          .join(' AND ');

      if (ftsQuery.isEmpty) {
        debugPrint('Query was sanitized to empty string');
        return [];
      }

      debugPrint('FTS query: "$ftsQuery"');

      // Execute the FTS query with AND logic
      final List<Map<String, dynamic>> results = await db.rawQuery(
        '''
        SELECT n.id, n.date, n.content, snippet(notes_fts, 0, '<b>', '</b>', '...', 20) as snippet
        FROM notes_fts
        JOIN notes n ON notes_fts.rowid = n.id
        WHERE notes_fts MATCH ?
        ORDER BY n.date DESC
        LIMIT 100
      ''',
        [ftsQuery],
      );

      debugPrint('Search query "$ftsQuery" returned ${results.length} results');
      return results;
    } catch (e) {
      debugPrint('Search failed: $e');
      // Return empty results rather than crashing on malformed queries
      return [];
    }
  }
}