<?php

/*
 * Copyright 2012 Facebook, Inc.
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *   http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

/**
 * @group config
 */
final class ArcanistSettings {

  private function getOptions() {
    return array(
      'default' => array(
        'type' => 'string',
        'help' =>
          'The URI of a Phabricator install to connect to by default, if '.
          'arc is run in a project without a Phabricator URI or run outside '.
          'of a project.',
        'example' => '"http://phabricator.example.com/"',
      ),
      'base' => array(
        'type' => 'string',
        'help' =>
          'Base commit ruleset to invoke when determining the start of a '.
          'commit range. See "Arcanist User Guide: Commit Ranges" for '.
          'details.',
        'example' => '"arc:amended, arc:prompt"',
      ),
      'load' => array(
        'type' => 'list',
        'legacy' => 'phutil_libraries',
        'help' =>
          'A list of paths to phutil libraries that should be loaded at '.
          'startup. This can be used to make classes available, like lint or '.
          'unit test engines.',
        'example' => '["/var/arc/customlib/src"]',
      ),
      'lint.engine' => array(
        'type' => 'string',
        'legacy' => 'lint_engine',
        'help' =>
          'The name of a default lint engine to use, if no lint engine is '.
          'specified by the current project.',
        'example' => '"ExampleLintEngine"',
      ),
      'unit.engine' => array(
        'type' => 'string',
        'legacy' => 'unit_engine',
        'help' =>
          'The name of a default unit test engine to use, if no unit test '.
          'engine is specified by the current project.',
        'example' => '"ExampleUnitTestEngine"',
      ),
      'arc.land.onto.default' => array(
        'type' => 'string',
        'help' =>
          'The name of the default branch to land changes onto when '.
          '`arc land` is run.',
        'example' => '"develop"',
      ),
      'history.immutable' => array(
        'type' => 'bool',
        'legacy' => 'immutable_history',
        'help' =>
          'If true, arc will never change repository history (e.g., through '.
          'amending or rebasing). Defaults to true in Mercurial and false in '.
          'Git. This setting has no effect in Subversion.',
        'example' => 'false',
      ),
      'editor' => array(
        'type' => 'string',
        'help' =>
          "Command to use to invoke an interactive editor, like 'nano' or ".
          "'vim'. This setting overrides the EDITOR environmental variable.",
        'example' => '"nano"',
      ),
      'events.listeners' => array(
        'type' => 'list',
        'help' => 'List of event listener classes to install at startup.',
        'example' => '["ExampleEventListener"]',
      ),
    );
  }

  private function getOption($key) {
    return idx($this->getOptions(), $key, array());
  }

  public function getAllKeys() {
    return array_keys($this->getOptions());
  }

  public function getHelp($key) {
    return idx($this->getOption($key), 'help');
  }

  public function getExample($key) {
    return idx($this->getOption($key), 'example');
  }

  public function getType($key) {
    return idx($this->getOption($key), 'type', 'wild');
  }

  public function getLegacyName($key) {
    return idx($this->getOption($key), 'legacy');
  }

  public function willWriteValue($key, $value) {
    $type = $this->getType($key);
    switch ($type) {
      case 'bool':
        if (strtolower($value) === 'false' ||
            strtolower($value) === 'no' ||
            strtolower($value) === 'off' ||
            $value === '' ||
            $value === '0' ||
            $value === 0 ||
            $value === false) {
          $value = false;
        } else if (strtolower($value) === 'true' ||
                   strtolower($value) === 'yes' ||
                   strtolower($value) === 'on' ||
                   $value === '1' ||
                   $value === 1 ||
                   $value === true) {
          $value = true;
        } else {
          throw new ArcanistUsageException(
            "Type of setting '{$key}' must be boolean, like 'true' or ".
            "'false'.");
        }
        break;
      case 'list':
        if (is_array($value)) {
          break;
        }

        if (is_string($value)) {
          $list = json_decode($value, true);
          if (is_array($list)) {
            $value = $list;
            break;
          }
        }

        $list_example = '["apple", "banana", "cherry"]';
        throw new ArcanistUsageException(
          "Type of setting '{$key}' must be list. You can specify a list ".
          "in JSON, like: {$list_example}");

      case 'string':
        if (!is_scalar($value)) {
          throw new ArcanistUsageException(
            "Type of setting '{$key}' must be string.");
        }
        $value = (string)$value;
        break;
      case 'wild':
        break;
    }

    return $value;
  }

  public function willReadValue($key, $value) {
    $type = $this->getType($key);
    switch ($type) {
      case 'string':
        if (!is_string($value)) {
          throw new ArcanistUsageException(
            "Type of setting '{$key}' must be string.");
        }
        break;
      case 'bool':
        if ($value !== true && $value !== false) {
          throw new ArcanistUsageException(
            "Type of setting '{$key}' must be boolean.");
        }
        break;
      case 'list':
        if (!is_array($value)) {
          throw new ArcanistUsageException(
            "Type of setting '{$key}' must be list.");
        }
        break;
      case 'wild':
        break;
    }

    return $value;
  }

  public function formatConfigValueForDisplay($key, $value) {
    if ($value === false) {
      return 'false';
    }

    if ($value === true) {
      return 'true';
    }

    if ($value === null) {
      return 'null';
    }

    if (is_string($value)) {
      return '"'.$value.'"';
    }

    if (is_array($value)) {
      // TODO: Both json_encode() and PhutilJSON do a bad job with one-liners.
      // PhutilJSON splits them across a bunch of lines, while json_encode()
      // escapes all kinds of stuff like "/". It would be nice if PhutilJSON
      // had a mode for pretty one-liners.
      $value = json_encode($value);

      // json_encode() unnecessarily escapes "/" to prevent "</script>" stuff,
      // optimistically unescape it for display to improve readability.
      $value = preg_replace('@(?<!\\\\)\\\\/@', '/', $value);
      return $value;
    }

    return $value;
  }


}