const args = require('args-parser')(process.argv);
const settings = require('./settings.json');

const { coalesce } = require('./src/utils/helpers');
const { defaultSettings } = require('./src/default-settings');


const fields = [
  // Webapp settings
  {
    local: 'webroot',
    env: 'WEB_ROOT',
    default: '',
    type: 'string'
  },
  {
    local: 'webapp_port',
    env: 'WEB_PORT',
    default: '8088',
    type: 'number'
  },
  {
    local: 'accessUrl',
    env: 'WEB_ACCESSURL',
    default: '',
    type: 'string'
  },
  {
    local: 'autoJoin',
    env: 'AUTOJOIN_ENABLED',
    default: false,
    type: 'boolean'
  },
  {
    local: 'autoJoinServer',
    env: 'AUTOJOIN_SERVERURL',
    default: '',
    type: 'string'
  },
  {
    local: 'autoJoinRoom',
    env: 'AUTOJOIN_ROOM',
    default: '',
    type: 'string'
  },
  {
    local: 'autoJoinPassword',
    env: 'AUTOJOIN_PASSWORD',
    default: '',
    type: 'string'
  },
  {
    local: 'authentication',
    env: 'AUTHENTICATION',
    default: {
      mechanism: 'none'
    },
    type: 'object'
  },
  {
    local: 'customServer',
    env: 'CUSTOM_SERVER',
    default: null,
    type: 'object'
  },
  {
    local: 'servers',
    env: 'SERVERS',
    default: [],
    type: 'array'
  },
  // Server settings
  {
    local: 'serverroot',
    env: 'SERVER_ROOT',
    default: '/slserver',
    type: 'string'
  },
  {
    local: 'server_port',
    env: 'SERVER_PORT',
    default: '8089',
    type: 'number'
  },
  {
    local: 'autoplay',
    env: 'AUTOPLAY',
    default: defaultSettings.autoplay,
    type: 'boolean'
  },
  {
    local: 'clientPollInterval',
    env: 'CLIENTPOLLINTERVAL',
    default: defaultSettings.clientPollInterval,
    type: 'number'
  },
  {
    local: 'syncMode',
    env: 'SYNCMODE',
    default: defaultSettings.syncMode,
    type: 'string'
  },
  {
    local: 'syncFlexibility',
    env: 'SYNCFLEXIBILITY',
    default: defaultSettings.syncFlexibility,
    type: 'number'
  },
  {
    local: 'hideUsername',
    env: 'HIDEUSERNAME',
    default: defaultSettings.hideUsername,
    type: 'boolean'
  }
];


// Returns the parsed setting or default value if wrong type or unable to be parsed
const parseSetting = (value, setting) => {
  if (setting.type === 'array') {
    // If setting is array. (Have to treat arrays differently since typeof array is 'object')
    if (Array.isArray(value)) {
      return value;
    } else if (typeof value === 'string') {
      // If setting is string, we have a chance to parse it and it might become an array
      try {
        const parsed = JSON.parse(value);
        if (Array.isArray(parsed)) {
          // Success, we parsed and got an array
          return parsed;
        }
      } catch (e) {
        console.error(e.message);
      }
    }
  } else {
    // If setting is not array
    if (typeof value === setting.type) {
      return value;
    } else if (typeof value === 'string') {
      // If setting is string, we have a chance to parse it and it might become an array
      try {
        const parsed = JSON.parse(value);
        if (typeof parsed === setting.type) {
          return parsed;
        }
      } catch (e) {
        console.error(e.message);
      }
    }
  }

  console.error(`Error parsing [${setting.type}]: ${e.message} Reverting to default. Value: '${value}'`);
  return setting.default;
}

module.exports = {
  readSettings() {
    // Load and export our settings in preference of Args -> ENV -> Settings file -> Default
    const output = {};
    for (let i = 0; i < fields.length; i++) {
      const setting = fields[i];
      // console.log('Processing setting', setting);
      // console.log(`Args: '${args[setting.env]}'; '${args[setting.local]}'`);
      // console.log(`ENV: '${process.env[setting.env]}'; '${process.env[setting.local]}'`);
      // console.log(`Settings: '${settings[setting.local]}'; '${setting.default}'`);
      const value = coalesce(args[setting.env], args[setting.local], process.env[setting.env], process.env[setting.local], settings[setting.env], settings[setting.local], setting.default);
      output[setting.local] = parseSetting(value, setting);

      // Backwards compatibilty for PORT ENV setting
      if (setting.local == 'webapp_port' && output[setting.local] == 8088) {
        let port = args['PORT'] || process.env['PORT'] || settings['PORT'];
        if (port && port !== 8088) {
          console.log(`Please change 'PORT' to 'WEB_PORT'. Setting WEB_PORT to '${port}'`)
          output[setting.local] = port;
        }
      }

      // Remove trailing slashes, if they exist
      if ((setting.local == 'webroot' || setting.local == 'accessUrl') && output[setting.local].endsWith("/")) {
        console.log(`${setting.local}/${setting.env} should not end in '/'. Removing trailing slash(es) for you.`);
        output[setting.local] = output[setting.local].replace(/\/+$/, "");
        console.log(`- Done.`);
      }
      // Add leading slash, if not provided
      if (setting.local == 'webroot' && output[setting.local].length > 1 && !output[setting.local].startsWith("/")) {
        console.log(`${setting.local}/${setting.env} should always start with '/'. Adding the leading slash for you.`);
        // Make sure it starts with one leading slash
        output[setting.local] = `/${output[setting.local]}`;
        console.log(`- Done.`);
      }
      // Make sure 'webroot' and 'serverroot' aren't set to '/'. Revert to default if they do.
      if ((setting.local == 'webroot' || setting.local == 'serverroot') && output[setting.local] == '/') {
        console.log(`${setting.local}/${setting.env} cannot be set to '/'. Reverting to default: '${setting.default}'`);
        output[setting.local] = setting.default;
        console.log(`- Done.`);
      }
      process.env[setting.env] = typeof output[setting.local] === 'object' ? JSON.stringify(output[setting.local]) : output[setting.local];
    }

    //console.log('Our settings are', output)
    return output;
  }
};