'use strict';

const version = require('../../package.json').version;
const minimist = require('minimist');
const _ = require('lodash');
const os = require('os');
const chalk = require('chalk');
const getCommandSuggestion = require('../utils/getCommandSuggestion');

class CLI {
  constructor(serverless, inputArray) {
    this.serverless = serverless;
    this.inputArray = inputArray || null;
    this.loadedPlugins = [];
    this.loadedCommands = {};
  }

  setLoadedPlugins(plugins) {
    this.loadedPlugins = plugins;
  }

  setLoadedCommands(commands) {
    this.loadedCommands = commands;
  }

  processInput() {
    let inputArray;

    // check if commands are passed externally (e.g. used by tests)
    // otherwise use process.argv to receive the commands
    if (this.inputArray !== null) {
      inputArray = this.inputArray;
    } else {
      inputArray = process.argv.slice(2);
    }

    const toBase64Helper = (value, index) => {
      if ((index % 2) !== 0) {
        return new Buffer(value.toString()).toString('base64');
      }
      return value;
    };

    const decodedArgsHelper = (arg) => {
      if (_.isString(arg)) {
        return new Buffer(arg, 'base64').toString();
      }
      return arg;
    };

    // get all the commands
    const valuesToIgnore = _.takeWhile(inputArray, (item) => !item.startsWith('-'));
    // get all the options
    const valuesToConvert = _.difference(inputArray, valuesToIgnore);
    // encode all the options values to base64
    const valuesToB64 = _.map(valuesToConvert, toBase64Helper);
    // concat commands with values on base64
    const valuesToParse = _.concat(valuesToIgnore, valuesToB64);

    const argvToParse = minimist(valuesToParse);

    // decode all values to utf8 strings
    const argv = _.mapValues(argvToParse, decodedArgsHelper);

    const commands = [].concat(argv._);
    const options = _.omit(argv, ['_']);

    return { commands, options };
  }

  displayHelp(processedInput) {
    const commands = processedInput.commands;
    const options = processedInput.options;

    // if only "version" or "v" was entered
    if ((commands.length === 0 && (options.version || options.v)) ||
        (commands.length === 1 && (commands.indexOf('version') > -1))) {
      this.getVersionNumber();
      return true;
    }

    // if only "help" or "h" was entered
    if ((commands.length === 0) ||
        (commands.length === 0 && (options.help || options.h)) ||
        (commands.length === 1 && (commands.indexOf('help') > -1))) {
      if (options.verbose || options.v) {
        this.generateVerboseHelp();
      } else {
        this.generateMainHelp();
      }
      return true;
    }

    // if "help" was entered in combination with commands (or one command)
    if (commands.length >= 1 && (options.help || options.h)) {
      this.generateCommandsHelp(commands);
      return true;
    }
    return false;
  }

  displayCommandUsage(commandObject, command, indents) {
    const dotsLength = 30;

    // check if command has lifecycleEvents (can be executed)
    if (commandObject.lifecycleEvents) {
      const usage = commandObject.usage;
      const dots = _.repeat('.', dotsLength - command.length);
      const indent = _.repeat('  ', indents || 0);
      this.consoleLog(`${indent}${chalk.yellow(command)} ${chalk.dim(dots)} ${usage}`);
    }

    _.forEach(commandObject.commands, (subcommandObject, subcommand) => {
      this.displayCommandUsage(subcommandObject, `${command} ${subcommand}`, indents);
    });
  }

  displayCommandOptions(commandObject) {
    const dotsLength = 40;
    _.forEach(commandObject.options, (optionsObject, option) => {
      let optionsDots = _.repeat('.', dotsLength - option.length);
      const optionsUsage = optionsObject.usage;

      if (optionsObject.required) {
        optionsDots = optionsDots.slice(0, optionsDots.length - 18);
      } else {
        optionsDots = optionsDots.slice(0, optionsDots.length - 7);
      }
      if (optionsObject.shortcut) {
        optionsDots = optionsDots.slice(0, optionsDots.length - 5);
      }

      const optionInfo = `    --${option}`;
      let shortcutInfo = '';
      let requiredInfo = '';
      if (optionsObject.shortcut) {
        shortcutInfo = ` / -${optionsObject.shortcut}`;
      }
      if (optionsObject.required) {
        requiredInfo = ' (required)';
      }

      const thingsToLog = `${optionInfo}${shortcutInfo}${requiredInfo} ${
        chalk.dim(optionsDots)} ${optionsUsage}`;
      this.consoleLog(chalk.yellow(thingsToLog));
    });
  }

  generateMainHelp() {
    let platformCommands;
    let frameworkCommands;
    if (this.loadedCommands) {
      const commandKeys = Object.keys(this.loadedCommands);
      const sortedCommandKeys = _.sortBy(commandKeys);
      const partitionedCommandKeys = _.partition(sortedCommandKeys,
        (key) => this.loadedCommands[key].platform);
      platformCommands = _.fromPairs(
        _.map(partitionedCommandKeys[0], key => [key, this.loadedCommands[key]])
      );
      frameworkCommands = _.fromPairs(
        _.map(partitionedCommandKeys[1], key => [key, this.loadedCommands[key]])
      );
    }

    this.consoleLog('');

    this.consoleLog(chalk.yellow.underline('Commands'));
    this.consoleLog(chalk.dim('* You can run commands with "serverless" or the shortcut "sls"'));
    this.consoleLog(chalk.dim('* Pass "--verbose" to this command to get in-depth plugin info'));
    this.consoleLog(chalk.dim('* Pass "--no-color" to disable CLI colors'));
    this.consoleLog(chalk.dim('* Pass "--help" after any <command> for contextual help'));

    this.consoleLog('');

    this.consoleLog(chalk.yellow.underline('Framework'));
    this.consoleLog(chalk.dim('* Documentation: https://serverless.com/framework/docs/'));

    this.consoleLog('');
    if (!_.isEmpty(frameworkCommands)) {
      _.forEach(frameworkCommands, (details, command) => {
        this.displayCommandUsage(details, command);
      });
    } else {
      this.consoleLog('No commands found');
    }

    this.consoleLog('');

    this.consoleLog(chalk.yellow.underline('Platform (Beta)'));
    // eslint-disable-next-line max-len
    this.consoleLog(chalk.dim('* The Serverless Platform is currently in experimental beta. Follow the docs below to get started.'));
    this.consoleLog(chalk.dim('* Documentation: https://serverless.com/platform/docs/'));

    this.consoleLog('');

    if (!_.isEmpty(platformCommands)) {
      _.forEach(platformCommands, (details, command) => {
        this.displayCommandUsage(details, command);
      });
    } else {
      this.consoleLog('No commands found');
    }

    this.consoleLog('');

    // print all the installed plugins
    this.consoleLog(chalk.yellow.underline('Plugins'));

    if (this.loadedPlugins.length) {
      const sortedPlugins = _.sortBy(this.loadedPlugins, (plugin) => plugin.constructor.name);
      this.consoleLog(sortedPlugins.map((plugin) => plugin.constructor.name).join(', '));
    } else {
      this.consoleLog('No plugins added yet');
    }
  }

  generateVerboseHelp() {
    this.consoleLog('');
    this.consoleLog(chalk.yellow.underline('Commands by plugin'));
    this.consoleLog('');

    let pluginCommands = {};

    // add commands to pluginCommands based on command's plugin
    const addToPluginCommands = (cmd) => {
      const pcmd = _.clone(cmd);

      // remove subcommand from clone
      delete pcmd.commands;

      // check if a plugin entry is alreay present in pluginCommands. Use the
      // existing one or create a new plugin entry.
      if (_.has(pluginCommands, pcmd.pluginName)) {
        pluginCommands[pcmd.pluginName] = pluginCommands[pcmd.pluginName].concat(pcmd);
      } else {
        pluginCommands[pcmd.pluginName] = [pcmd];
      }

      // check for subcommands
      if ('commands' in cmd) {
        _.forEach(cmd.commands, (d) => {
          addToPluginCommands(d);
        });
      }
    };

    // fill up pluginCommands with commands in loadedCommands
    _.forEach(this.loadedCommands, (details) => {
      addToPluginCommands(details);
    });

    // sort plugins alphabetically
    pluginCommands = _(pluginCommands).toPairs().sortBy(0).fromPairs()
      .value();

    _.forEach(pluginCommands, (details, plugin) => {
      this.consoleLog(plugin);
      _.forEach(details, (cmd) => {
        // display command usage with single(1) indent
        this.displayCommandUsage(cmd, cmd.key.split(':').join(' '), 1);
      });
      this.consoleLog('');
    });
  }

  generateCommandsHelp(commandsArray) {
    const commandName = commandsArray.join(' ');

    // Get all the commands using getCommands() with filtered entrypoint
    // commands and reduce to the required command.
    const allCommands = this.serverless.pluginManager.getCommands();
    const command = _.reduce(commandsArray, (currentCmd, cmd) => {
      if (currentCmd.commands && cmd in currentCmd.commands) {
        return currentCmd.commands[cmd];
      }
      return null;
    }, { commands: allCommands });

    // Throw error if command not found.
    if (!command) {
      const suggestedCommand = getCommandSuggestion(commandName, allCommands);
      const errorMessage = [
        `Serverless command "${commandName}" not found. Did you mean "${suggestedCommand}"?`,
        ' Run "serverless help" for a list of all available commands.',
      ].join('');
      throw new this.serverless.classes.Error(errorMessage);
    }

    // print the name of the plugin
    this.consoleLog(chalk.yellow.underline(`Plugin: ${command.pluginName}`));

    this.displayCommandUsage(command, commandName);
    this.displayCommandOptions(command);

    this.consoleLog('');
    return null;
  }

  getVersionNumber() {
    this.consoleLog(version);
  }

  asciiGreeting() {
    let art = '';
    art = `${art} _______                             __${os.EOL}`;
    art = `${art}|   _   .-----.----.--.--.-----.----|  .-----.-----.-----.${os.EOL}`;
    art = `${art}|   |___|  -__|   _|  |  |  -__|   _|  |  -__|__ --|__ --|${os.EOL}`;
    art = `${art}|____   |_____|__|  \\___/|_____|__| |__|_____|_____|_____|${os.EOL}`;
    art = `${art}|   |   |             The Serverless Application Framework${os.EOL}`;
    art = `${art}|       |                           serverless.com, v${version}${os.EOL}`;
    art = `${art} -------'`;

    this.consoleLog(chalk.yellow(art));
    this.consoleLog('');
  }

  printDot() {
    process.stdout.write(chalk.yellow('.'));
  }

  log(message) {
    this.consoleLog(`Serverless: ${chalk.yellow(`${message}`)}`);
  }

  consoleLog(message) {
    console.log(message); // eslint-disable-line no-console
  }
}

module.exports = CLI;