'use strict';

var IDENTIFIER = /^[a-z_$]*$/i; var customRuleCode = require('./dotjs/custom'); var definitionSchema = require('./definition_schema');

module.exports = {

add: addKeyword,
get: getKeyword,
remove: removeKeyword,
validate: validateKeyword

};

/**

* Define custom keyword
* @this  Ajv
* @param {String} keyword custom keyword, should be unique (including different from all standard, custom and macro keywords).
* @param {Object} definition keyword definition object with properties `type` (type(s) which the keyword applies to), `validate` or `compile`.
* @return {Ajv} this for method chaining
*/

function addKeyword(keyword, definition) {

/* jshint validthis: true */
/* eslint no-shadow: 0 */
var RULES = this.RULES;
if (RULES.keywords[keyword])
  throw new Error('Keyword ' + keyword + ' is already defined');

if (!IDENTIFIER.test(keyword))
  throw new Error('Keyword ' + keyword + ' is not a valid identifier');

if (definition) {
  this.validateKeyword(definition, true);

  var dataType = definition.type;
  if (Array.isArray(dataType)) {
    for (var i=0; i<dataType.length; i++)
      _addRule(keyword, dataType[i], definition);
  } else {
    _addRule(keyword, dataType, definition);
  }

  var metaSchema = definition.metaSchema;
  if (metaSchema) {
    if (definition.$data && this._opts.$data) {
      metaSchema = {
        anyOf: [
          metaSchema,
          { '$ref': 'https://raw.githubusercontent.com/epoberezkin/ajv/master/lib/refs/data.json#' }
        ]
      };
    }
    definition.validateSchema = this.compile(metaSchema, true);
  }
}

RULES.keywords[keyword] = RULES.all[keyword] = true;

function _addRule(keyword, dataType, definition) {
  var ruleGroup;
  for (var i=0; i<RULES.length; i++) {
    var rg = RULES[i];
    if (rg.type == dataType) {
      ruleGroup = rg;
      break;
    }
  }

  if (!ruleGroup) {
    ruleGroup = { type: dataType, rules: [] };
    RULES.push(ruleGroup);
  }

  var rule = {
    keyword: keyword,
    definition: definition,
    custom: true,
    code: customRuleCode,
    implements: definition.implements
  };
  ruleGroup.rules.push(rule);
  RULES.custom[keyword] = rule;
}

return this;

}

/**

* Get keyword
* @this  Ajv
* @param {String} keyword pre-defined or custom keyword.
* @return {Object|Boolean} custom keyword definition, `true` if it is a predefined keyword, `false` otherwise.
*/

function getKeyword(keyword) {

/* jshint validthis: true */
var rule = this.RULES.custom[keyword];
return rule ? rule.definition : this.RULES.keywords[keyword] || false;

}

/**

* Remove keyword
* @this  Ajv
* @param {String} keyword pre-defined or custom keyword.
* @return {Ajv} this for method chaining
*/

function removeKeyword(keyword) {

/* jshint validthis: true */
var RULES = this.RULES;
delete RULES.keywords[keyword];
delete RULES.all[keyword];
delete RULES.custom[keyword];
for (var i=0; i<RULES.length; i++) {
  var rules = RULES[i].rules;
  for (var j=0; j<rules.length; j++) {
    if (rules[j].keyword == keyword) {
      rules.splice(j, 1);
      break;
    }
  }
}
return this;

}

/**

* Validate keyword definition
* @this  Ajv
* @param {Object} definition keyword definition object.
* @param {Boolean} throwError true to throw exception if definition is invalid
* @return {boolean} validation result
*/

function validateKeyword(definition, throwError) {

validateKeyword.errors = null;
var v = this._validateKeyword = this._validateKeyword
                                || this.compile(definitionSchema, true);

if (v(definition)) return true;
validateKeyword.errors = v.errors;
if (throwError)
  throw new Error('custom keyword definition is invalid: '  + this.errorsText(v.errors));
else
  return false;

}