/**
 * SQLite Adapter – implements DatabaseInterface with better-sqlite3
 */
import Database from 'better-sqlite3';
import { readFileSync } from 'fs';
import { join, dirname } from 'path';
import { fileURLToPath } from 'url';
import type {
  DatabaseInterface, DBProject, DBDrawing, DBLayer,
  DBElement, DBBlock, DBSetting, DBUser,
} from './DatabaseInterface.js';

const __dirname = dirname(fileURLToPath(import.meta.url));

export class SqliteAdapter implements DatabaseInterface {
  private db: Database.Database;

  constructor(dbPath: string = ':memory:') {
    this.db = new Database(dbPath);
    this.db.pragma('journal_mode = WAL');
    this.db.pragma('foreign_keys = ON');
  }

  async init(): Promise<void> {
    const schemaPath = join(__dirname, 'schema.sql');
    const schema = readFileSync(schemaPath, 'utf-8');
    this.db.exec(schema);
  }

  close(): void {
    this.db.close();
  }

  // ─── Users ──────────────────────────────────────────
  getUser(id: string): DBUser | null {
    return (this.db.prepare('SELECT * FROM users WHERE id = ?').get(id) as DBUser) ?? null;
  }

  getUserByEmail(email: string): DBUser | null {
    return (this.db.prepare('SELECT * FROM users WHERE email = ?').get(email) as DBUser) ?? null;
  }

  createUser(data: Partial<DBUser>): DBUser {
    const id = data.id ?? `user-${Date.now()}`;
    this.db.prepare(
      'INSERT INTO users (id, email, password_hash, name, role) VALUES (?, ?, ?, ?, ?)',
    ).run(id, data.email!, data.password_hash!, data.name!, data.role ?? 'planer');
    return this.getUser(id)!;
  }

  updateUser(id: string, data: Partial<DBUser>): DBUser | null {
    const sets: string[] = [];
    const vals: any[] = [];
    if (data.email !== undefined) { sets.push('email = ?'); vals.push(data.email); }
    if (data.password_hash !== undefined) { sets.push('password_hash = ?'); vals.push(data.password_hash); }
    if (data.name !== undefined) { sets.push('name = ?'); vals.push(data.name); }
    if (data.role !== undefined) { sets.push('role = ?'); vals.push(data.role); }
    sets.push("updated_at = datetime('now')");
    if (sets.length > 1) {
      this.db.prepare(`UPDATE users SET ${sets.join(', ')} WHERE id = ?`).run(...vals, id);
    }
    return this.getUser(id);
  }

  deleteUser(id: string): boolean {
    return this.db.prepare('DELETE FROM users WHERE id = ?').run(id).changes > 0;
  }

  listUsers(): DBUser[] {
    return this.db.prepare('SELECT * FROM users ORDER BY created_at DESC').all() as DBUser[];
  }

  // ─── Projects ──────────────────────────────────────
  listProjects(): DBProject[] {
    return this.db.prepare('SELECT * FROM projects ORDER BY updated_at DESC').all() as DBProject[];
  }

  getProject(id: string): DBProject | null {
    return (this.db.prepare('SELECT * FROM projects WHERE id = ?').get(id) as DBProject) ?? null;
  }

  createProject(data: Partial<DBProject>): DBProject {
    const id = data.id ?? `proj-${Date.now()}`;
    this.db.prepare(
      'INSERT INTO projects (id, name, description, owner_id) VALUES (?, ?, ?, ?)',
    ).run(id, data.name ?? 'Unbenannt', data.description ?? null, data.owner_id ?? 'user-default');
    return this.getProject(id)!;
  }

  updateProject(id: string, data: Partial<DBProject>): DBProject | null {
 const sets: string[] = [];
    const vals: any[] = [];
    if (data.name !== undefined) { sets.push('name = ?'); vals.push(data.name); }
    if (data.description !== undefined) { sets.push('description = ?'); vals.push(data.description); }
    sets.push("updated_at = datetime('now')");
    if (sets.length > 1) {
      this.db.prepare(`UPDATE projects SET ${sets.join(', ')} WHERE id = ?`).run(...vals, id);
    }
    return this.getProject(id);
  }

  deleteProject(id: string): boolean {
    return this.db.prepare('DELETE FROM projects WHERE id = ?').run(id).changes > 0;
  }

  // ─── Drawings ──────────────────────────────────────
  listDrawings(projectId: string): DBDrawing[] {
    return this.db.prepare('SELECT * FROM drawings WHERE project_id = ? ORDER BY updated_at DESC').all(projectId) as DBDrawing[];
  }

  getDrawing(id: string): DBDrawing | null {
    return (this.db.prepare('SELECT * FROM drawings WHERE id = ?').get(id) as DBDrawing) ?? null;
  }

  createDrawing(data: Partial<DBDrawing>): DBDrawing {
    const id = data.id ?? `draw-${Date.now()}`;
    this.db.prepare(
      'INSERT INTO drawings (id, project_id, name, data_json) VALUES (?, ?, ?, ?)',
    ).run(id, data.project_id!, data.name ?? 'Unbenannt', data.data_json ?? '{}');
    return this.getDrawing(id)!;
  }

  updateDrawing(id: string, data: Partial<DBDrawing>): DBDrawing | null {
    const sets: string[] = [];
    const vals: any[] = [];
    if (data.name !== undefined) { sets.push('name = ?'); vals.push(data.name); }
    if (data.data_json !== undefined) { sets.push('data_json = ?'); vals.push(data.data_json); }
    sets.push("updated_at = datetime('now')");
    if (sets.length > 1) {
      this.db.prepare(`UPDATE drawings SET ${sets.join(', ')} WHERE id = ?`).run(...vals, id);
    }
    return this.getDrawing(id);
  }

  deleteDrawing(id: string): boolean {
    return this.db.prepare('DELETE FROM drawings WHERE id = ?').run(id).changes > 0;
  }

  // ─── Layers ────────────────────────────────────────
  listLayers(drawingId: string): DBLayer[] {
    return this.db.prepare('SELECT * FROM layers WHERE drawing_id = ? ORDER BY sort_order').all(drawingId) as DBLayer[];
  }

  createLayer(data: Partial<DBLayer>): DBLayer {
    const id = data.id ?? `layer-${Date.now()}`;
    this.db.prepare(
      'INSERT INTO layers (id, drawing_id, name, visible, locked, color, line_type, transparency, sort_order, parent_id) VALUES (?, ?, ?, ?, ?, ?, ?, ?, ?, ?)',
    ).run(id, data.drawing_id!, data.name ?? 'Layer', data.visible ?? 1, data.locked ?? 0,
      data.color ?? '#ffffff', data.line_type ?? 'solid', data.transparency ?? 0,
      data.sort_order ?? 0, data.parent_id ?? null);
    return this.db.prepare('SELECT * FROM layers WHERE id = ?').get(id) as DBLayer;
  }

  updateLayer(id: string, data: Partial<DBLayer>): DBLayer | null {
    const sets: string[] = [];
    const vals: any[] = [];
    for (const [k, v] of Object.entries(data)) {
      if (['name','visible','locked','color','line_type','transparency','sort_order','parent_id'].includes(k)) {
        sets.push(`${k} = ?`); vals.push(v);
      }
    }
    if (sets.length > 0) {
      this.db.prepare(`UPDATE layers SET ${sets.join(', ')} WHERE id = ?`).run(...vals, id);
    }
    return this.db.prepare('SELECT * FROM layers WHERE id = ?').get(id) as DBLayer ?? null;
  }

  deleteLayer(id: string): boolean {
    return this.db.prepare('DELETE FROM layers WHERE id = ?').run(id).changes > 0;
  }

  // ─── Elements ──────────────────────────────────────
  listElements(drawingId: string): DBElement[] {
    return this.db.prepare('SELECT * FROM elements WHERE drawing_id = ?').all(drawingId) as DBElement[];
  }

  createElement(data: Partial<DBElement>): DBElement {
    const id = data.id ?? `elem-${Date.now()}`;
    this.db.prepare(
      'INSERT INTO elements (id, drawing_id, layer_id, type, x, y, width, height, properties_json) VALUES (?, ?, ?, ?, ?, ?, ?, ?, ?)',
    ).run(id, data.drawing_id!, data.layer_id!, data.type!, data.x ?? 0, data.y ?? 0,
      data.width ?? 0, data.height ?? 0, data.properties_json ?? '{}');
    return this.db.prepare('SELECT * FROM elements WHERE id = ?').get(id) as DBElement;
  }

  updateElement(id: string, data: Partial<DBElement>): DBElement | null {
    const sets: string[] = [];
    const vals: any[] = [];
    for (const [k, v] of Object.entries(data)) {
      if (['layer_id','type','x','y','width','height','properties_json'].includes(k)) {
        sets.push(`${k} = ?`); vals.push(v);
      }
    }
    if (sets.length > 0) {
      this.db.prepare(`UPDATE elements SET ${sets.join(', ')} WHERE id = ?`).run(...vals, id);
    }
    return this.db.prepare('SELECT * FROM elements WHERE id = ?').get(id) as DBElement ?? null;
  }

  deleteElement(id: string): boolean {
    return this.db.prepare('DELETE FROM elements WHERE id = ?').run(id).changes > 0;
  }

  // ─── Blocks ────────────────────────────────────────
  listBlocks(drawingId: string): DBBlock[] {
    return this.db.prepare('SELECT * FROM blocks WHERE drawing_id = ?').all(drawingId) as DBBlock[];
  }

  createBlock(data: Partial<DBBlock>): DBBlock {
    const id = data.id ?? `block-${Date.now()}`;
    this.db.prepare(
      'INSERT INTO blocks (id, drawing_id, name, description, category, elements_json, thumbnail) VALUES (?, ?, ?, ?, ?, ?, ?)',
    ).run(id, data.drawing_id!, data.name ?? 'Block', data.description ?? null,
      data.category ?? 'Allgemein', data.elements_json ?? '[]', data.thumbnail ?? null);
    return this.db.prepare('SELECT * FROM blocks WHERE id = ?').get(id) as DBBlock;
  }

  updateBlock(id: string, data: Partial<DBBlock>): DBBlock | null {
    const sets: string[] = [];
    const vals: any[] = [];
    for (const [k, v] of Object.entries(data)) {
      if (['name','description','category','elements_json','thumbnail'].includes(k)) {
        sets.push(`${k} = ?`); vals.push(v);
      }
    }
    if (sets.length > 0) {
      this.db.prepare(`UPDATE blocks SET ${sets.join(', ')} WHERE id = ?`).run(...vals, id);
    }
    return this.db.prepare('SELECT * FROM blocks WHERE id = ?').get(id) as DBBlock ?? null;
  }

  deleteBlock(id: string): boolean {
    return this.db.prepare('DELETE FROM blocks WHERE id = ?').run(id).changes > 0;
  }

  // ─── Settings ──────────────────────────────────────
  getSetting(key: string): DBSetting | null {
    return (this.db.prepare('SELECT * FROM settings WHERE key = ?').get(key) as DBSetting) ?? null;
  }

  setSetting(key: string, value: string): void {
    this.db.prepare(
      "INSERT INTO settings (key, value, updated_at) VALUES (?, ?, datetime('now')) ON CONFLICT(key) DO UPDATE SET value = excluded.value, updated_at = datetime('now')",
    ).run(key, value);
  }
}