<?php

abstract class HeraldField extends Phobject {

  private $adapter;

  const STANDARD_BOOL = 'standard.bool';
  const STANDARD_TEXT = 'standard.text';
  const STANDARD_TEXT_LIST = 'standard.text.list';
  const STANDARD_TEXT_MAP = 'standard.text.map';
  const STANDARD_PHID = 'standard.phid';
  const STANDARD_PHID_LIST = 'standard.phid.list';
  const STANDARD_PHID_BOOL = 'standard.phid.bool';
  const STANDARD_PHID_NULLABLE = 'standard.phid.nullable';

  abstract public function getHeraldFieldName();
  abstract public function getHeraldFieldValue($object);

  protected function getHeraldFieldStandardType() {
    throw new PhutilMethodNotImplementedException();
  }

  protected function getDatasource() {
    throw new PhutilMethodNotImplementedException();
  }

  protected function getDatasourceValueMap() {
    return null;
  }

  public function getHeraldFieldConditions() {
    $standard_type = $this->getHeraldFieldStandardType();
    switch ($standard_type) {
      case self::STANDARD_BOOL:
        return array(
          HeraldAdapter::CONDITION_IS_TRUE,
          HeraldAdapter::CONDITION_IS_FALSE,
        );
      case self::STANDARD_TEXT:
        return array(
          HeraldAdapter::CONDITION_CONTAINS,
          HeraldAdapter::CONDITION_NOT_CONTAINS,
          HeraldAdapter::CONDITION_IS,
          HeraldAdapter::CONDITION_IS_NOT,
          HeraldAdapter::CONDITION_REGEXP,
        );
      case self::STANDARD_PHID:
        return array(
          HeraldAdapter::CONDITION_IS_ANY,
          HeraldAdapter::CONDITION_IS_NOT_ANY,
        );
      case self::STANDARD_PHID_LIST:
        return array(
          HeraldAdapter::CONDITION_INCLUDE_ALL,
          HeraldAdapter::CONDITION_INCLUDE_ANY,
          HeraldAdapter::CONDITION_INCLUDE_NONE,
          HeraldAdapter::CONDITION_EXISTS,
          HeraldAdapter::CONDITION_NOT_EXISTS,
        );
      case self::STANDARD_PHID_BOOL:
        return array(
          HeraldAdapter::CONDITION_EXISTS,
          HeraldAdapter::CONDITION_NOT_EXISTS,
        );
      case self::STANDARD_PHID_NULLABLE:
        return array(
          HeraldAdapter::CONDITION_IS_ANY,
          HeraldAdapter::CONDITION_IS_NOT_ANY,
          HeraldAdapter::CONDITION_EXISTS,
          HeraldAdapter::CONDITION_NOT_EXISTS,
        );
      case self::STANDARD_TEXT_LIST:
        return array(
          HeraldAdapter::CONDITION_CONTAINS,
          HeraldAdapter::CONDITION_REGEXP,
        );
      case self::STANDARD_TEXT_MAP:
        return array(
          HeraldAdapter::CONDITION_CONTAINS,
          HeraldAdapter::CONDITION_REGEXP,
          HeraldAdapter::CONDITION_REGEXP_PAIR,
        );
    }

    throw new Exception(
      pht(
        'Herald field "%s" has unknown standard type "%s".',
        get_class($this),
        $standard_type));
  }

  public function getHeraldFieldValueType($condition) {
    $standard_type = $this->getHeraldFieldStandardType();
    switch ($standard_type) {
      case self::STANDARD_BOOL:
      case self::STANDARD_PHID_BOOL:
        return new HeraldEmptyFieldValue();
      case self::STANDARD_TEXT:
      case self::STANDARD_TEXT_LIST:
      case self::STANDARD_TEXT_MAP:
        return new HeraldTextFieldValue();
      case self::STANDARD_PHID:
      case self::STANDARD_PHID_NULLABLE:
      case self::STANDARD_PHID_LIST:
        switch ($condition) {
          case HeraldAdapter::CONDITION_EXISTS:
          case HeraldAdapter::CONDITION_NOT_EXISTS:
            return new HeraldEmptyFieldValue();
          default:
            $tokenizer = id(new HeraldTokenizerFieldValue())
              ->setKey($this->getHeraldFieldName())
              ->setDatasource($this->getDatasource());

            $value_map = $this->getDatasourceValueMap();
            if ($value_map !== null) {
              $tokenizer->setValueMap($value_map);
            }

            return $tokenizer;
        }
        break;

    }

    throw new Exception(
      pht(
        'Herald field "%s" has unknown standard type "%s".',
        get_class($this),
        $standard_type));
  }

  abstract public function supportsObject($object);

  public function getFieldsForObject($object) {
    return array($this->getFieldConstant() => $this);
  }

  public function renderConditionValue(
    PhabricatorUser $viewer,
    $condition,
    $value) {

    $value_type = $this->getHeraldFieldValueType($condition);
    $value_type->setViewer($viewer);
    return $value_type->renderFieldValue($value);
  }

  public function getEditorValue(
    PhabricatorUser $viewer,
    $condition,
    $value) {

    $value_type = $this->getHeraldFieldValueType($condition);
    $value_type->setViewer($viewer);
    return $value_type->renderEditorValue($value);
  }

  final public function setAdapter(HeraldAdapter $adapter) {
    $this->adapter = $adapter;
    return $this;
  }

  final public function getAdapter() {
    return $this->adapter;
  }

  final public function getFieldConstant() {
    $class = new ReflectionClass($this);

    $const = $class->getConstant('FIELDCONST');
    if ($const === false) {
      throw new Exception(
        pht(
          '"%s" class "%s" must define a "%s" property.',
          __CLASS__,
          get_class($this),
          'FIELDCONST'));
    }

    $limit = self::getFieldConstantByteLimit();
    if (!is_string($const) || (strlen($const) > $limit)) {
      throw new Exception(
        pht(
          '"%s" class "%s" has an invalid "%s" property. Field constants '.
          'must be strings and no more than %s bytes in length.',
          __CLASS__,
          get_class($this),
          'FIELDCONST',
          new PhutilNumber($limit)));
    }

    return $const;
  }

  final public static function getFieldConstantByteLimit() {
    return 64;
  }

  final public static function getAllFields() {
    return id(new PhutilClassMapQuery())
      ->setAncestorClass(__CLASS__)
      ->setUniqueMethod('getFieldConstant')
      ->execute();
  }

}