import {module} from './module';
import {loopbackValidations} from 'vendor';

directive.$inject = ['$interpolate', '$compile', '$window']
export function directive(interpolate, compile, $window) {
    return {
        restrict: 'A',
        require: ['ngModel', '^^form'],
        link: function (scope, element, attrs, ctrl) {
            let vnValidations = $window.validations;

            if(!attrs['vnValidation'])
                return;

            let split = attrs['vnValidation'].split('.');

            if(split.length != 2)
                throw new Error(`vnValidation: Attribute must have this syntax: [entity].[field]`);

            let entityName = firstUpper(split[0]);
            let fieldName = split[1];

            let entity = vnValidations[entityName];

            if(!entity)
                throw new Error(`vnValidation: Entity '${entityName}' doesn't exist`);

            let validations = entity.validations[fieldName];

            if(!validations)
                return;

            let input = ctrl[0],
                form = ctrl[1],
                messages = [],
                customValidator = {},
                parentMessage;

            let i = 0;
            for(let conf of validations){
                let key = `v${i++}`;

                let messageNode = createMessage(form.$name, input.$name, key);
                customValidator[key] = messageNode;
                messages.push(messageNode);

                input.$validators[key] = function(value) {
                    return isValid(value, conf, messageNode);
                }
            }

            if(messages.length > 0) {
                parentMessage = angular.element(createMessages(form.$name, input.$name));
                messages.forEach(function (item) {
                    parentMessage.append(item);
                });
                messages = null;
                element.after(compile(parentMessage)(scope));
            }

            scope.$on('destroy', function() {
                customValidator = null;
            });
        }
    }

    function firstUpper(str) {
        return str.charAt(0).toUpperCase() + str.substr(1);
    }
    function createMessage(form, input, key) {
        var template = '<span class="mdl-textfield__error" ng-show="{{form}}.$dirty && {{form}}.{{input}}.$error.{{key}}"></span>';
        var span = interpolate(template)({ form: form, input: input, key: key });
        var element = angular.element(span);
        return element;
    }
    function createMessages(form, input) {
        var template = '<div ng-show="{{form}}.$dirty && {{form}}.{{input}}.$invalid"></div>';
        return interpolate(template)({ form: form, input: input });
    }

    // Loopback code with modifications

    function isValid(value, conf, messageNode) {
        let valid = true;
        let inst = {value: value};
        let validator = validators[conf.validation];

        if(!validator)
            return true;

        validator.call(inst, 'value', conf, err);

        function err(kind) {
            var message, code = conf.code || conf.validation;
            if (conf.message) {
                message = conf.message;
            }
            if (!message && defaultMessages[conf.validation]) {
                message = defaultMessages[conf.validation];
            }
            if (!message) {
                message = 'is invalid';
            }
            if (kind) {
                code += '.' + kind;
                if (message[kind]) {
                    message = message[kind];
                } else if (defaultMessages.common[kind]) {
                    message = defaultMessages.common[kind];
                } else {
                    message = 'is invalid';
                }
            }
            messageNode.text(message); // code
            valid = false;
        }

        return valid;
    }
}
module.directive('vnValidation', directive);

// Code portion of 'lib/validations.js' from 'loopback-datasource-juggler' package

/*!
 * Presence validator
 */
function validatePresence(attr, conf, err, options) {
  if (blank(this[attr])) {
    err();
  }
}

/*!
 * Absence validator
 */
function validateAbsence(attr, conf, err, options) {
  if (!blank(this[attr])) {
    err();
  }
}

/*!
 * Length validator
 */
function validateLength(attr, conf, err, options) {
  if (nullCheck.call(this, attr, conf, err)) return;

  var len = this[attr].length;
  if (conf.min && len < conf.min) {
    err('min');
  }
  if (conf.max && len > conf.max) {
    err('max');
  }
  if (conf.is && len !== conf.is) {
    err('is');
  }
}

/*!
 * Numericality validator
 */
function validateNumericality(attr, conf, err, options) {
  if (nullCheck.call(this, attr, conf, err)) return;

  if (typeof this[attr] !== 'number' || isNaN(this[attr])) {
    return err('number');
  }
  if (conf.int && this[attr] !== Math.round(this[attr])) {
    return err('int');
  }
}

/*!
 * Inclusion validator
 */
function validateInclusion(attr, conf, err, options) {
  if (nullCheck.call(this, attr, conf, err)) return;

  if (!~conf.in.indexOf(this[attr])) {
    err();
  }
}

/*!
 * Exclusion validator
 */
function validateExclusion(attr, conf, err, options) {
  if (nullCheck.call(this, attr, conf, err)) return;

  if (~conf.in.indexOf(this[attr])) {
    err();
  }
}

/*!
 * Format validator
 */
function validateFormat(attr, conf, err, options) {
  if (nullCheck.call(this, attr, conf, err)) return;

  if (typeof this[attr] === 'string') {
    if (!this[attr].match(conf['with'])) {
      err();
    }
  } else {
    err();
  }
}

/*!
 * Custom validator
 */
function validateCustom(attr, conf, err, options, done) {
  if (typeof options === 'function') {
    done = options;
    options = {};
  }
  conf.customValidator.call(this, err, done);
}

/*!
 * Uniqueness validator
 */
function validateUniqueness(attr, conf, err, options, done) {
  if (typeof options === 'function') {
    done = options;
    options = {};
  }
  if (blank(this[attr])) {
    return process.nextTick(done);
  }
  var cond = {where: {}};
  cond.where[attr] = this[attr];

  if (conf && conf.scopedTo) {
    conf.scopedTo.forEach(function(k) {
      var val = this[k];
      if (val !== undefined)
        cond.where[k] = this[k];
    }, this);
  }

  var idName = this.constructor.definition.idName();
  var isNewRecord = this.isNewRecord();
  this.constructor.find(cond, options, function(error, found) {
    if (error) {
      err(error);
    } else if (found.length > 1) {
      err();
    } else if (found.length === 1 && idName === attr && isNewRecord) {
      err();
    } else if (found.length === 1 && (
      !this.id || !found[0].id || found[0].id.toString() != this.id.toString()
    )) {
      err();
    }
    done();
  }.bind(this));
}

var validators = {
  presence: validatePresence,
  absence: validateAbsence,
  length: validateLength,
  numericality: validateNumericality,
  inclusion: validateInclusion,
  exclusion: validateExclusion,
  format: validateFormat,
  custom: validateCustom,
  uniqueness: validateUniqueness,
};

var defaultMessages = {
  presence: 'can\'t be blank',
  absence: 'can\'t be set',
  'unknown-property': 'is not defined in the model',
  length: {
    min: 'too short',
    max: 'too long',
    is: 'length is wrong',
  },
  common: {
    blank: 'is blank',
    'null': 'is null',
  },
  numericality: {
    'int': 'is not an integer',
    'number': 'is not a number',
  },
  inclusion: 'is not included in the list',
  exclusion: 'is reserved',
  uniqueness: 'is not unique',
};

/**
 * Checks if attribute is undefined or null. Calls err function with 'blank' or 'null'.
 * See defaultMessages. You can affect this behaviour with conf.allowBlank and conf.allowNull.
 * @param {String} attr Property name of attribute
 * @param {Object} conf conf object for validator
 * @param {Function} err
 * @return {Boolean} returns true if attribute is null or blank
 */
function nullCheck(attr, conf, err) {
  // First determine if attribute is defined
  if (typeof this[attr] === 'undefined') {
    if (!conf.allowBlank) {
      err('blank');
    }
    return true;
  } else {
    // Now check if attribute is null
    if (this[attr] === null) {
      if (!conf.allowNull) {
        err('null');
      }
      return true;
    }
  }
  return false;
}

/*!
 * Return true when v is undefined, blank array, null or empty string
 * otherwise returns false
 *
 * @param {Mix} v
 * Returns true if `v` is blank.
 */
function blank(v) {
  if (typeof v === 'undefined') return true;
  if (v instanceof Array && v.length === 0) return true;
  if (v === null) return true;
  if (typeof v === 'number' && isNaN(v)) return true;
  if (typeof v == 'string' && v === '') return true;
  return false;
}