import { describe, it, expect, vi, beforeEach } from 'vitest';
import request from 'supertest';
import { app } from '../index.js';
import pool from '../db.js';

// Mock DB
const mockQuery = vi.fn();
const mockRelease = vi.fn();
const mockCommit = vi.fn();
const mockRollback = vi.fn();
const mockBeginTransaction = vi.fn();

vi.mock('../db.js', () => ({
    default: {
        query: vi.fn(),
        getConnection: vi.fn()
    },
    initDB: vi.fn()
}));

describe('Task Routes', () => {
    beforeEach(() => {
        vi.clearAllMocks();
        mockQuery.mockReset(); // Important to clear implementations
        pool.query = mockQuery;
        pool.getConnection.mockResolvedValue({
            query: mockQuery,
            release: mockRelease,
            beginTransaction: mockBeginTransaction,
            commit: mockCommit,
            rollback: mockRollback
        });
    });

    describe('GET /api/tasks', () => {
        it('returns list of tasks', async () => {
            // Mock fetching task IDs
            mockQuery.mockResolvedValueOnce([[{ id: 't1' }]]);

            // Mock getFullTask queries for 't1'
            // 1. Task details
            mockQuery.mockResolvedValueOnce([[{ id: 't1', title: 'Task 1', status: 'todo' }]]); // Task
            // 2. Subtasks
            mockQuery.mockResolvedValueOnce([[]]); // Subtasks
            // 3. Comments
            mockQuery.mockResolvedValueOnce([[]]); // Comments
            // 4. Activities
            mockQuery.mockResolvedValueOnce([[]]); // Activities
            // 5. Tags
            mockQuery.mockResolvedValueOnce([[]]); // Tags
            // 6. Dependencies
            mockQuery.mockResolvedValueOnce([[]]); // Dependencies

            const res = await request(app).get('/api/tasks');

            expect(res.status).toBe(200);
            expect(res.body).toHaveLength(1);
            expect(res.body[0].title).toBe('Task 1');
        });
    });

    describe('POST /api/tasks', () => {
        it('creates a new task', async () => {
            // Mock INSERTs (1: Task, 2: Activities) -> Return {}
            mockQuery.mockResolvedValueOnce({}); // Insert task
            mockQuery.mockResolvedValueOnce({}); // Insert activity

            // getFullTask queries (3-8)
            mockQuery.mockResolvedValueOnce([[{ id: 'new-id', title: 'New Task', status: 'todo' }]]); // Task
            mockQuery.mockResolvedValueOnce([[]]); // Subtasks
            mockQuery.mockResolvedValueOnce([[]]); // Comments
            mockQuery.mockResolvedValueOnce([[]]); // Activities
            mockQuery.mockResolvedValueOnce([[]]); // Tags
            mockQuery.mockResolvedValueOnce([[]]); // Deps

            const newTask = {
                // For getFullTask called at end
                title: 'New Task',
                description: 'Desc',
                status: 'todo'
            };

            const res = await request(app)
                .post('/api/tasks')
                .send(newTask);

            expect(res.status).toBe(201);
            expect(mockBeginTransaction).toHaveBeenCalled();
            expect(mockCommit).toHaveBeenCalled();
            expect(mockRelease).toHaveBeenCalled();
        });

        it('rolls back on error', async () => {
            mockQuery.mockRejectedValue(new Error('DB Error'));

            const res = await request(app)
                .post('/api/tasks')
                .send({ title: 'Task' });

            expect(res.status).toBe(500);
            expect(mockRollback).toHaveBeenCalled();
            expect(mockRelease).toHaveBeenCalled();
        });
    });

    describe('DELETE /api/tasks/:id', () => {
        it('deletes a task', async () => {
            mockQuery.mockResolvedValue({});

            const res = await request(app).delete('/api/tasks/t1');

            expect(res.status).toBe(200);
            expect(mockQuery).toHaveBeenCalledWith(
                expect.stringContaining('DELETE FROM tasks'),
                ['t1']
            );
        });
    });
});