const express = require('express');
const bodyParser = require('body-parser');
const Mock = require('mockjs');
const fs = require('fs-extra');
const dayjs = require('dayjs');
const swaggerUi = require('swagger-ui-express');
const swaggerJSDoc = require('swagger-jsdoc');


const app = express();
const PORT = 3000;
const CONFIG_PATH = './mock-config.json';

app.use(bodyParser.json());

function formatResponse(data, code = 200, message = 'success') {
  return {
    code,
    type: code === 200 ? 'success' : 'error',
    message,
    result: data,
    extras: null,
    time: dayjs().format('YYYY-MM-DD HH:mm:ss')
  };
}

function registerMockApi(config) {
  const { method, path, response, query, swagger } = config;
  const methodName = method.toLowerCase();

 app[methodName](path, async (req, res, next) => {
  try {
    console.log(`[MOCK] Incoming: ${req.method} ${req.path}`, req.query);

    // 默认 fallback
    if (path === '/api/mall/recommend' && Object.keys(req.query).length === 0) {
      const defaultConfig = global.mockConfigs.find(c =>
        c.path === path && c.query?.type === 'home'
      );
      if (defaultConfig) {
        console.log(`[MOCK] Fallback to default (home)`);
        return res.json(formatResponse(defaultConfig.response));
      }
    }

    // 精确 query 匹配
    if (query) {
      const isMatch = Object.entries(query).every(([key, val]) => req.query[key] === val);
      if (!isMatch) return next(); // 继续往下找
    }

    return res.json(formatResponse(response));
  } catch (err) {
    res.json(formatResponse(null, 500, err.message));
  }
});
}

async function startServer() {
  

  // 读取配置
  let mockConfigs = fs.existsSync(CONFIG_PATH) ? fs.readJsonSync(CONFIG_PATH) : [];
  global.mockConfigs = mockConfigs;

  // 注册接口
  mockConfigs.forEach(registerMockApi);

  

  // swagger 文档支持
  const swaggerDefinition = {
    openapi: '3.0.0',
    info: {
      title: 'Mock API Docs',
      version: '1.0.0',
      description: 'Dynamically registered mock APIs'
    },
    servers: []
  };

  function buildSwaggerSpecFromMocks(configs) {
    const paths = {};
    configs.forEach(({ method, path, swagger }) => {
      const cleanPath = path.replace(/:([^/]+)/g, '{$1}');
      const methodName = method.toLowerCase();
      const summary = swagger?.summary || `Mocked ${method} ${path}`;
      const description = swagger?.description || '';
      const responses = swagger?.responses || {
        200: {
          description: 'Mock response',
          content: {
            'application/json': {
              schema: { type: 'object' }
            }
          }
        }
      };
      paths[cleanPath] = paths[cleanPath] || {};
      paths[cleanPath][methodName] = {
        summary,
        description,
        parameters: swagger?.parameters || [],
        responses
      };
    });
    return { ...swaggerDefinition, paths };
  }

  app.use('/swagger', (req, res, next) => {
    res.setHeader('Cache-Control', 'no-store');
    next();
  });

  app.use('/swagger', swaggerUi.serve, (req, res, next) => {
    const protocol = req.headers['x-forwarded-proto'] || req.protocol;
    const host = req.get('host');
    const dynamicSwaggerDefinition = {
      ...swaggerDefinition,
      servers: [
        { url: `${protocol}://${host}`, description: 'Current host' }
      ]
    };
    const spec = buildSwaggerSpecFromMocks(global.mockConfigs);
    const dynamicSpec = { ...spec, servers: dynamicSwaggerDefinition.servers };
    swaggerUi.setup(dynamicSpec)(req, res, next);
  });

  app.listen(PORT, () => {
    console.log(`✅ Mock Server is running at http://localhost:${PORT}`);
    console.log(`📚 Swagger UI available at http://localhost:${PORT}/swagger`);
  });
}

startServer();