const fs = require('node:fs');
const path = require('node:path');
const crypto = require('node:crypto');
const { getConfigFilePath } = require('../utils/paths.cjs');

const defaultConfig = {
  api_key: '',
  base_url: '',
  model_name: 'gpt-3.5-turbo',
  image_model: {
    provider: 'volcengine',
    base_url: 'https://ark.cn-beijing.volces.com/api/v3',
    api_key: '',
    model_name: '',
    status: 'untested',
    tested_at: '',
    last_error: '',
  },
  file_parser: {
    provider: 'local',
    mineru_token: '',
  },
  developer_mode: false,
  real_time_render: true,
  analytics_client_id: '',
  analytics_created_at: '',
};

function createAnalyticsClientId() {
  return crypto.randomUUID();
}

function createAnalyticsCreatedAt() {
  return new Date().toISOString().slice(0, 10);
}

function normalizeConfig(config) {
  const fileParser = config && config.file_parser ? config.file_parser : {};
  return {
    ...defaultConfig,
    ...config,
    image_model: {
      ...defaultConfig.image_model,
      ...(config && config.image_model ? config.image_model : {}),
    },
    file_parser: {
      provider: fileParser.provider || defaultConfig.file_parser.provider,
      mineru_token: fileParser.mineru_token || defaultConfig.file_parser.mineru_token,
    },
  };
}

function createConfigStore(app) {
  const configFile = getConfigFilePath(app);

  function persist(config) {
    fs.mkdirSync(path.dirname(configFile), { recursive: true });
    fs.writeFileSync(configFile, JSON.stringify(config, null, 2), 'utf-8');
  }

  function withAnalyticsIdentity(config) {
    if (config.analytics_client_id && config.analytics_created_at) {
      return config;
    }

    return {
      ...config,
      analytics_client_id: config.analytics_client_id || createAnalyticsClientId(),
      analytics_created_at: config.analytics_created_at || createAnalyticsCreatedAt(),
    };
  }

  return {
    getConfigFilePath() {
      return configFile;
    },

    load() {
      if (!fs.existsSync(configFile)) {
        const config = withAnalyticsIdentity(normalizeConfig());
        persist(config);
        return config;
      }

      try {
        const raw = fs.readFileSync(configFile, 'utf-8');
        const config = normalizeConfig(JSON.parse(raw));
        const nextConfig = withAnalyticsIdentity(config);
        if (nextConfig !== config) {
          persist(nextConfig);
        }
        return nextConfig;
      } catch (error) {
        throw new Error(`配置文件读取失败：${error.message}`);
      }
    },

    save(config) {
      try {
        const currentConfig = fs.existsSync(configFile)
          ? normalizeConfig(JSON.parse(fs.readFileSync(configFile, 'utf-8')))
          : normalizeConfig();
        const nextConfig = withAnalyticsIdentity(normalizeConfig({
          ...config,
          analytics_client_id: config?.analytics_client_id || currentConfig.analytics_client_id,
          analytics_created_at: config?.analytics_created_at || currentConfig.analytics_created_at,
        }));
        persist(nextConfig);
        return { success: true, message: '配置已保存', config_path: configFile };
      } catch (error) {
        throw new Error(`配置文件保存失败：${error.message}`);
      }
    },
  };
}

module.exports = {
  createConfigStore,
};