import { describe, it, expect, beforeAll, afterAll } from 'vitest';
import type Database from 'better-sqlite3';
import { initDb, closeDb } from '../src/db/index';

let db: InstanceType<typeof Database>;

beforeAll(() => {
  db = initDb(':memory:');
});

afterAll(() => {
  closeDb();
});

describe('Database initialization', () => {
  it('should enable WAL or memory journal mode (WAL for file, memory for :memory:)', () => {
    const result = db.prepare('PRAGMA journal_mode').get() as { journal_mode: string };
    // :memory: databases use 'memory' journal mode, file DBs use 'wal'
    expect(['wal', 'memory']).toContain(result.journal_mode);
  });

  it('should enable foreign keys', () => {
    const result = db.prepare('PRAGMA foreign_keys').get() as { foreign_keys: number };
    expect(result.foreign_keys).toBe(1);
  });
});

describe('Table creation', () => {
  const expectedTables = [
    'users',
    'mqtt_brokers',
    'mqtt_topics',
    'pg_sources',
    'pg_queries',
    'datapoints',
    'layouts',
    'layout_elements',
    'displays',
  ];

  it('should create all 9 tables', () => {
    const tables = db
      .prepare(`SELECT name FROM sqlite_master WHERE type='table' ORDER BY name`)
      .all() as Array<{ name: string }>;
    const tableNames = tables.map((t) => t.name);

    for (const expected of expectedTables) {
      expect(tableNames).toContain(expected);
    }
    expect(tableNames.filter((n) => !n.startsWith('sqlite_')).length).toBe(9);
  });

  it('should create users table with correct columns', () => {
    const cols = db.prepare('PRAGMA table_info(users)').all() as Array<{ name: string }>;
    const colNames = cols.map((c) => c.name);
    expect(colNames).toContain('id');
    expect(colNames).toContain('username');
    expect(colNames).toContain('password_hash');
    expect(colNames).toContain('created_at');
  });

  it('should create mqtt_brokers table with correct columns', () => {
    const cols = db.prepare('PRAGMA table_info(mqtt_brokers)').all() as Array<{ name: string }>;
    const colNames = cols.map((c) => c.name);
    expect(colNames).toContain('id');
    expect(colNames).toContain('name');
    expect(colNames).toContain('host');
    expect(colNames).toContain('port');
    expect(colNames).toContain('use_tls');
    expect(colNames).toContain('enabled');
    expect(colNames).toContain('status');
  });

  it('should create datapoints table with source_type CHECK constraint columns', () => {
    const cols = db.prepare('PRAGMA table_info(datapoints)').all() as Array<{ name: string }>;
    const colNames = cols.map((c) => c.name);
    expect(colNames).toContain('source_type');
    expect(colNames).toContain('source_id');
    expect(colNames).toContain('topic_id');
    expect(colNames).toContain('query_id');
    expect(colNames).toContain('transform');
  });

  it('should create layout_elements with all required columns', () => {
    const cols = db.prepare('PRAGMA table_info(layout_elements)').all() as Array<{ name: string }>;
    const colNames = cols.map((c) => c.name);
    expect(colNames).toContain('layout_id');
    expect(colNames).toContain('datapoint_id');
    expect(colNames).toContain('type');
    expect(colNames).toContain('x');
    expect(colNames).toContain('y');
    expect(colNames).toContain('font_size');
    expect(colNames).toContain('style');
  });
});

describe('Broker insert and retrieve', () => {
  it('should insert and retrieve a broker', () => {
    const result = db.prepare(
      `INSERT INTO mqtt_brokers (name, host, port) VALUES (?, ?, ?)`
    ).run('Test Broker', 'mqtt.example.com', 1883);
    expect(result.lastInsertRowid).toBeGreaterThan(0);

    const broker = db
      .prepare(`SELECT * FROM mqtt_brokers WHERE id = ?`)
      .get(result.lastInsertRowid) as {
      name: string;
      host: string;
      port: number;
      status: string;
    } | undefined;

    expect(broker).toBeDefined();
    expect(broker!.name).toBe('Test Broker');
    expect(broker!.host).toBe('mqtt.example.com');
    expect(broker!.port).toBe(1883);
    expect(broker!.status).toBe('disconnected');
  });

  it('should cascade delete topics when broker is deleted', () => {
    const broker = db.prepare(`INSERT INTO mqtt_brokers (name, host) VALUES (?, ?)`).run(
      'Cascade Broker',
      'cascade.example.com',
    );

    db.prepare(`INSERT INTO mqtt_topics (broker_id, topic) VALUES (?, ?)`).run(
      broker.lastInsertRowid,
      'sensors/temp',
    );

    const topicsBefore = db
      .prepare(`SELECT * FROM mqtt_topics WHERE broker_id = ?`)
      .all(broker.lastInsertRowid);
    expect(topicsBefore.length).toBe(1);

    db.prepare(`DELETE FROM mqtt_brokers WHERE id = ?`).run(broker.lastInsertRowid);

    const topicsAfter = db
      .prepare(`SELECT * FROM mqtt_topics WHERE broker_id = ?`)
      .all(broker.lastInsertRowid);
    expect(topicsAfter.length).toBe(0);
  });

  it('should reject invalid source_type values', () => {
    expect(() => {
      db.prepare(
        `INSERT INTO datapoints (name, label, source_type, source_id) VALUES (?, ?, ?, ?)`
      ).run('dp1', 'Datapoint 1', 'invalid_source', 1);
    }).toThrow();
  });
});