const is = require('@sindresorhus/is');
const clone = require('fast-clone');

const definitions = require('./definitions');

const defaultsParser = require('./defaults');
const fileParser = require('./file');
const cliParser = require('./cli');
const envParser = require('./env');

const { getPlatformApi } = require('../platform');
const { resolveConfigPresets } = require('./presets');
const { get, getLanguageList, getManagerList } = require('../manager');

exports.parseConfigs = parseConfigs;
exports.mergeChildConfig = mergeChildConfig;
exports.filterConfig = filterConfig;
exports.getManagerConfig = getManagerConfig;

function getManagerConfig(config, manager) {
  let managerConfig = config;
  const language = get(manager, 'language');
  if (language) {
    managerConfig = mergeChildConfig(managerConfig, config[language]);
  }
  managerConfig = mergeChildConfig(managerConfig, config[manager]);
  for (const i of getLanguageList().concat(getManagerList())) {
    delete managerConfig[i];
  }
  managerConfig.language = language;
  managerConfig.manager = manager;
  return managerConfig;
}

async function parseConfigs(env, argv) {
  logger.debug('Parsing configs');

  // Get configs
  const defaultConfig = await resolveConfigPresets(defaultsParser.getConfig());
  const fileConfig = await resolveConfigPresets(fileParser.getConfig(env));
  const cliConfig = await resolveConfigPresets(cliParser.getConfig(argv));
  const envConfig = await resolveConfigPresets(envParser.getConfig(env));

  let config = mergeChildConfig(defaultConfig, fileConfig);
  config = mergeChildConfig(config, envConfig);
  config = mergeChildConfig(config, cliConfig);

  // Set log level
  logger.levels('stdout', config.logLevel);

  // Add file logger
  // istanbul ignore if
  if (config.logFile) {
    logger.debug(
      `Enabling ${config.logFileLevel} logging to ${config.logFile}`
    );
    logger.addStream({
      name: 'logfile',
      path: config.logFile,
      level: config.logFileLevel,
    });
  }

  logger.trace({ config: defaultConfig }, 'Default config');
  logger.debug({ config: fileConfig }, 'File config');
  logger.debug({ config: cliConfig }, 'CLI config');
  logger.debug({ config: envConfig }, 'Env config');

  // Get global config
  logger.trace({ config }, 'Raw config');

  // Check platforms and tokens
  if (config.platform === 'github') {
    if (!config.token && !env.GITHUB_TOKEN) {
      throw new Error('You need to supply a GitHub token.');
    }
  } else if (config.platform === 'gitlab') {
    if (!config.token && !env.GITLAB_TOKEN) {
      throw new Error('You need to supply a GitLab token.');
    }
  } else if (config.platform === 'vsts') {
    if (!config.token && !env.VSTS_TOKEN) {
      throw new Error('You need to supply a VSTS token.');
    }
  } else {
    throw new Error(`Unsupported platform: ${config.platform}.`);
  }

  if (config.autodiscover) {
    // Autodiscover list of repositories
    const discovered = await getPlatformApi(config.platform).getRepos(
      config.token,
      config.endpoint
    );
    if (!(discovered && discovered.length)) {
      // Soft fail (no error thrown) if no accessible repositories
      logger.info(
        'The account associated with your token does not have access to any repos'
      );
      return config;
    }
    // istanbul ignore if
    if (config.repositories && config.repositories.length) {
      logger.debug(
        'Checking autodiscovered repositories against configured repositories'
      );
      for (const configuredRepo of config.repositories) {
        const repository = repoName(configuredRepo);
        let found = false;
        for (let i = discovered.length - 1; i > -1; i -= 1) {
          if (repository === repoName(discovered[i])) {
            found = true;
            logger.debug(
              { repository },
              'Using configured repository settings'
            );
            discovered[i] = configuredRepo;
          }
        }
        if (!found) {
          logger.warn(
            { repository },
            'Configured repository is in not in autodiscover list'
          );
        }
      }
    }
    config.repositories = discovered;
  }

  // istanbul ignore next
  function repoName(value) {
    return String(is.string(value) ? value : value.repository).toLowerCase();
  }

  // Print config
  logger.trace({ config }, 'Global config');
  // Remove log file entries
  delete config.logFile;
  delete config.logFileLevel;
  return config;
}

function mergeChildConfig(parent, child) {
  logger.trace({ parent, child }, `mergeChildConfig`);
  if (!child) {
    return parent;
  }
  const parentConfig = clone(parent);
  const childConfig = clone(child);
  const config = { ...parentConfig, ...childConfig };
  for (const option of definitions.getOptions()) {
    if (
      option.mergeable &&
      childConfig[option.name] &&
      parentConfig[option.name]
    ) {
      logger.trace(`mergeable option: ${option.name}`);
      if (option.type === 'list') {
        config[option.name] = (parentConfig[option.name] || []).concat(
          config[option.name] || []
        );
      } else {
        config[option.name] = mergeChildConfig(
          parentConfig[option.name],
          childConfig[option.name]
        );
      }
      logger.trace(
        { result: config[option.name] },
        `Merged config.${option.name}`
      );
    }
  }
  return config;
}

function filterConfig(inputConfig, targetStage) {
  logger.trace({ config: inputConfig }, `filterConfig('${targetStage}')`);
  const outputConfig = { ...inputConfig };
  const stages = ['global', 'repository', 'package', 'branch', 'pr'];
  const targetIndex = stages.indexOf(targetStage);
  for (const option of definitions.getOptions()) {
    const optionIndex = stages.indexOf(option.stage);
    if (optionIndex !== -1 && optionIndex < targetIndex) {
      delete outputConfig[option.name];
    }
  }
  return outputConfig;
}