import type { FastifyInstance } from 'fastify';
import { LlmService } from '../services/llm/llm.service.js';
import { QuestionService } from '../services/questions/question.service.js';
import { TestsService } from '../services/tests/tests.service.js';
import { notFound } from '../utils/errors.js';
import type { CreateTestInput } from '../services/tests/tests.service.js';
import type { TestSnapshot } from '../services/tests/tests.service.js';

const STACKS = ['html', 'css', 'js', 'ts', 'react', 'vue', 'nodejs', 'git', 'web_basics'] as const;
const LEVELS = ['basic', 'beginner', 'intermediate', 'advanced', 'expert'] as const;

const createTestSchema = {
  body: {
    type: 'object',
    required: ['stack', 'level', 'questionCount'],
    properties: {
      stack: { type: 'string', enum: STACKS },
      level: { type: 'string', enum: LEVELS },
      questionCount: { type: 'integer', minimum: 1, maximum: 50 },
      mode: { type: 'string', enum: ['fixed', 'infinite', 'marathon'] },
    },
    additionalProperties: false,
  },
};

const testIdParamsSchema = {
  params: {
    type: 'object',
    required: ['testId'],
    properties: {
      testId: { type: 'string', format: 'uuid' },
    },
  },
};

const answerSchema = {
  params: {
    type: 'object',
    required: ['testId'],
    properties: {
      testId: { type: 'string', format: 'uuid' },
    },
  },
  body: {
    type: 'object',
    required: ['questionId', 'answer'],
    properties: {
      questionId: { type: 'string', format: 'uuid' },
      answer: {
        oneOf: [
          { type: 'string' },
          { type: 'array', items: { type: 'string' } },
        ],
      },
    },
    additionalProperties: false,
  },
};

const historyQuerySchema = {
  querystring: {
    type: 'object',
    properties: {
      limit: { type: 'integer', minimum: 1, maximum: 100 },
      offset: { type: 'integer', minimum: 0 },
    },
    additionalProperties: false,
  },
};

function stripAnswersForClient(
  q: TestSnapshot
): Omit<TestSnapshot, 'correctAnswer' | 'explanation'> {
  const { correctAnswer: _, explanation: __, ...rest } = q;
  return rest;
}

export async function testsRoutes(app: FastifyInstance) {
  const llmService = new LlmService();
  const questionService = new QuestionService(app.db, llmService);
  const testsService = new TestsService(app.db, questionService);
  const { rateLimitOptions } = app;

  app.get(
    '/',
    {
      schema: historyQuerySchema,
      config: { rateLimit: rateLimitOptions.apiAuthed },
      preHandler: [app.authenticate],
    },
    async (req, reply) => {
      const userId = req.user!.id;
      const { limit, offset } = (req.query as { limit?: number; offset?: number }) ?? {};
      const { tests: testList, total } = await testsService.getHistory(
        userId,
        { limit, offset }
      );
      return reply.send({ tests: testList, total });
    }
  );

  app.post(
    '/',
    {
      schema: createTestSchema,
      config: { rateLimit: rateLimitOptions.apiAuthed },
      preHandler: [app.authenticate, app.withSubscription],
    },
    async (req, reply) => {
      const userId = req.user!.id;
      const body = req.body as CreateTestInput;
      const test = await testsService.createTest(userId, body);
      const hideAnswers = test.status === 'in_progress';
      const response = {
        ...test,
        questions: hideAnswers
          ? test.questions.map(stripAnswersForClient)
          : test.questions,
      };
      return reply.status(201).send(response);
    }
  );

  app.post(
    '/:testId/answer',
    {
      schema: answerSchema,
      config: { rateLimit: rateLimitOptions.apiAuthed },
      preHandler: [app.authenticate],
    },
    async (req, reply) => {
      const userId = req.user!.id;
      const { testId } = req.params as { testId: string };
      const { questionId, answer } = req.body as { questionId: string; answer: string | string[] };
      const snapshot = await testsService.answerQuestion(
        userId,
        testId,
        questionId,
        answer
      );
      return reply.send(snapshot);
    }
  );

  app.post(
    '/:testId/finish',
    {
      schema: testIdParamsSchema,
      config: { rateLimit: rateLimitOptions.apiAuthed },
      preHandler: [app.authenticate],
    },
    async (req, reply) => {
      const userId = req.user!.id;
      const { testId } = req.params as { testId: string };
      const test = await testsService.finishTest(userId, testId);
      return reply.send(test);
    }
  );

  app.get(
    '/:testId',
    {
      schema: testIdParamsSchema,
      config: { rateLimit: rateLimitOptions.apiAuthed },
      preHandler: [app.authenticate],
    },
    async (req, reply) => {
      const userId = req.user!.id;
      const { testId } = req.params as { testId: string };
      const test = await testsService.getById(userId, testId);
      if (!test) {
        throw notFound('Test not found');
      }
      const hideAnswers = test.status === 'in_progress';
      const response = {
        ...test,
        questions: hideAnswers
          ? test.questions.map(stripAnswersForClient)
          : test.questions,
      };
      return reply.send(response);
    }
  );

}