import { describe, it, expect, beforeAll, afterEach } from 'vitest';
import { SessionManager, BaseSession } from '../../src/utils/session-manager';
import { createTestUser, getTestDB } from '../setup';

// Use onboarding_sessions table for testing
const manager = new SessionManager<BaseSession>({
  tableName: 'onboarding_sessions',
  ttlMs: 30 * 60 * 1000, // 30 minutes
  maxMessages: 5,
});

describe('SessionManager', () => {
  describe('create()', () => {
    it('returns session with correct fields', () => {
      const session = manager.create('user123', 'greeting');

      expect(session.user_id).toBe('user123');
      expect(session.status).toBe('greeting');
      expect(session.collected_info).toEqual({});
      expect(session.messages).toEqual([]);
      expect(session.created_at).toBeTypeOf('number');
      expect(session.updated_at).toBeTypeOf('number');
      expect(session.expires_at).toBeGreaterThan(session.created_at);
    });
  });

  describe('save() and get() round-trip', () => {
    it('saves and retrieves session from DB', async () => {
      const db = getTestDB();
      const session = manager.create('user456', 'gathering');
      session.collected_info = { purpose: 'hosting' };
      session.messages = [{ role: 'user', content: 'hello' }];

      await manager.save(db, session);

      const retrieved = await manager.get(db, 'user456');
      expect(retrieved).not.toBeNull();
      expect(retrieved!.user_id).toBe('user456');
      expect(retrieved!.status).toBe('gathering');
      expect(retrieved!.collected_info).toEqual({ purpose: 'hosting' });
      expect(retrieved!.messages).toEqual([{ role: 'user', content: 'hello' }]);
    });
  });

  describe('delete()', () => {
    it('removes session from DB', async () => {
      const db = getTestDB();
      const session = manager.create('user789', 'greeting');
      await manager.save(db, session);

      // Verify it exists
      const exists = await manager.has(db, 'user789');
      expect(exists).toBe(true);

      // Delete
      await manager.delete(db, 'user789');

      // Verify it's gone
      const afterDelete = await manager.get(db, 'user789');
      expect(afterDelete).toBeNull();
    });
  });

  describe('has()', () => {
    it('returns true for existing session', async () => {
      const db = getTestDB();
      const session = manager.create('user_has_test', 'greeting');
      await manager.save(db, session);

      expect(await manager.has(db, 'user_has_test')).toBe(true);
    });

    it('returns false for missing session', async () => {
      const db = getTestDB();
      expect(await manager.has(db, 'nonexistent_user')).toBe(false);
    });
  });

  describe('addMessage()', () => {
    it('adds message to session', () => {
      const session = manager.create('user_msg', 'greeting');
      manager.addMessage(session, 'user', 'hello');

      expect(session.messages).toHaveLength(1);
      expect(session.messages[0]).toEqual({ role: 'user', content: 'hello' });
    });

    it('trims old messages when over limit', () => {
      const session = manager.create('user_trim', 'greeting');

      // maxMessages is 5, add 7 messages
      for (let i = 0; i < 7; i++) {
        manager.addMessage(session, 'user', `message ${i}`);
      }

      expect(session.messages).toHaveLength(5);
      // Should keep the last 5 messages (2..6)
      expect(session.messages[0].content).toBe('message 2');
      expect(session.messages[4].content).toBe('message 6');
    });
  });

  describe('expired sessions', () => {
    it('get() returns null for expired session', async () => {
      const db = getTestDB();

      // Create a session that's already expired
      const now = Date.now();
      const expiredSession: BaseSession = {
        user_id: 'expired_user',
        status: 'greeting',
        collected_info: {},
        messages: [],
        created_at: now - 60000,
        updated_at: now - 60000,
        expires_at: now - 1000, // expired 1 second ago
      };

      // Insert directly with past expires_at
      await db.prepare(
        `INSERT INTO onboarding_sessions (user_id, status, collected_info, messages, created_at, updated_at, expires_at)
         VALUES (?, ?, ?, ?, ?, ?, ?)`
      ).bind(
        expiredSession.user_id,
        expiredSession.status,
        JSON.stringify(expiredSession.collected_info),
        JSON.stringify(expiredSession.messages),
        expiredSession.created_at,
        expiredSession.updated_at,
        expiredSession.expires_at
      ).run();

      const result = await manager.get(db, 'expired_user');
      expect(result).toBeNull();
    });
  });
});