'use strict';

var compileSchema = require('./compile')
  , resolve = require('./compile/resolve')
  , Cache = require('./cache')
  , SchemaObject = require('./compile/schema_obj')
  , stableStringify = require('fast-json-stable-stringify')
  , formats = require('./compile/formats')
  , rules = require('./compile/rules')
  , $dataMetaSchema = require('./data')
  , util = require('./compile/util');

module.exports = Ajv;

Ajv.prototype.validate = validate;
Ajv.prototype.compile = compile;
Ajv.prototype.addSchema = addSchema;
Ajv.prototype.addMetaSchema = addMetaSchema;
Ajv.prototype.validateSchema = validateSchema;
Ajv.prototype.getSchema = getSchema;
Ajv.prototype.removeSchema = removeSchema;
Ajv.prototype.addFormat = addFormat;
Ajv.prototype.errorsText = errorsText;

Ajv.prototype._addSchema = _addSchema;
Ajv.prototype._compile = _compile;

Ajv.prototype.compileAsync = require('./compile/async');
var customKeyword = require('./keyword');
Ajv.prototype.addKeyword = customKeyword.add;
Ajv.prototype.getKeyword = customKeyword.get;
Ajv.prototype.removeKeyword = customKeyword.remove;
Ajv.prototype.validateKeyword = customKeyword.validate;

var errorClasses = require('./compile/error_classes');
Ajv.ValidationError = errorClasses.Validation;
Ajv.MissingRefError = errorClasses.MissingRef;
Ajv.$dataMetaSchema = $dataMetaSchema;

var META_SCHEMA_ID = 'http://json-schema.org/draft-07/schema';

var META_IGNORE_OPTIONS = [ 'removeAdditional', 'useDefaults', 'coerceTypes' ];
var META_SUPPORT_DATA = ['/properties'];

/**
 * Creates validator instance.
 * Usage: `Ajv(opts)`
 * @param {Object} opts optional options
 * @return {Object} ajv instance
 */
function Ajv(opts) {
  if (!(this instanceof Ajv)) return new Ajv(opts);
  opts = this._opts = util.copy(opts) || {};
  setLogger(this);
  this._schemas = {};
  this._refs = {};
  this._fragments = {};
  this._formats = formats(opts.format);

  this._cache = opts.cache || new Cache;
  this._loadingSchemas = {};
  this._compilations = [];
  this.RULES = rules();
  this._getId = chooseGetId(opts);

  opts.loopRequired = opts.loopRequired || Infinity;
  if (opts.errorDataPath == 'property') opts._errorDataPathProperty = true;
  if (opts.serialize === undefined) opts.serialize = stableStringify;
  this._metaOpts = getMetaSchemaOptions(this);

  if (opts.formats) addInitialFormats(this);
  addDefaultMetaSchema(this);
  if (typeof opts.meta == 'object') this.addMetaSchema(opts.meta);
  if (opts.nullable) this.addKeyword('nullable', {metaSchema: {type: 'boolean'}});
  addInitialSchemas(this);
}



/**
 * Validate data using schema
 * Schema will be compiled and cached (using serialized JSON as key. [fast-json-stable-stringify](https://github.com/epoberezkin/fast-json-stable-stringify) is used to serialize.
 * @this   Ajv
 * @param  {String|Object} schemaKeyRef key, ref or schema object
 * @param  {Any} data to be validated
 * @return {Boolean} validation result. Errors from the last validation will be available in `ajv.errors` (and also in compiled schema: `schema.errors`).
 */
function validate(schemaKeyRef, data) {
  var v;
  if (typeof schemaKeyRef == 'string') {
    v = this.getSchema(schemaKeyRef);
    if (!v) throw new Error('no schema with key or ref "' + schemaKeyRef + '"');
  } else {
    var schemaObj = this._addSchema(schemaKeyRef);
    v = schemaObj.validate || this._compile(schemaObj);
  }

  var valid = v(data);
  if (v.$async !== true) this.errors = v.errors;
  return valid;
}


/**
 * Create validating function for passed schema.
 * @this   Ajv
 * @param  {Object} schema schema object
 * @param  {Boolean} _meta true if schema is a meta-schema. Used internally to compile meta schemas of custom keywords.
 * @return {Function} validating function
 */
function compile(schema, _meta) {
  var schemaObj = this._addSchema(schema, undefined, _meta);
  return schemaObj.validate || this._compile(schemaObj);
}


/**
 * Adds schema to the instance.
 * @this   Ajv
 * @param {Object|Array} schema schema or array of schemas. If array is passed, `key` and other parameters will be ignored.
 * @param {String} key Optional schema key. Can be passed to `validate` method instead of schema object or id/ref. One schema per instance can have empty `id` and `key`.
 * @param {Boolean} _skipValidation true to skip schema validation. Used internally, option validateSchema should be used instead.
 * @param {Boolean} _meta true if schema is a meta-schema. Used internally, addMetaSchema should be used instead.
 * @return {Ajv} this for method chaining
 */
function addSchema(schema, key, _skipValidation, _meta) {
  if (Array.isArray(schema)){
    for (var i=0; i<schema.length; i++) this.addSchema(schema[i], undefined, _skipValidation, _meta);
    return this;
  }
  var id = this._getId(schema);
  if (id !== undefined && typeof id != 'string')
    throw new Error('schema id must be string');
  key = resolve.normalizeId(key || id);
  checkUnique(this, key);
  this._schemas[key] = this._addSchema(schema, _skipValidation, _meta, true);
  return this;
}


/**
 * Add schema that will be used to validate other schemas
 * options in META_IGNORE_OPTIONS are alway set to false
 * @this   Ajv
 * @param {Object} schema schema object
 * @param {String} key optional schema key
 * @param {Boolean} skipValidation true to skip schema validation, can be used to override validateSchema option for meta-schema
 * @return {Ajv} this for method chaining
 */
function addMetaSchema(schema, key, skipValidation) {
  this.addSchema(schema, key, skipValidation, true);
  return this;
}


/**
 * Validate schema
 * @this   Ajv
 * @param {Object} schema schema to validate
 * @param {Boolean} throwOrLogError pass true to throw (or log) an error if invalid
 * @return {Boolean} true if schema is valid
 */
function validateSchema(schema, throwOrLogError) {
  var $schema = schema.$schema;
  if ($schema !== undefined && typeof $schema != 'string')
    throw new Error('$schema must be a string');
  $schema = $schema || this._opts.defaultMeta || defaultMeta(this);
  if (!$schema) {
    this.logger.warn('meta-schema not available');
    this.errors = null;
    return true;
  }
  var valid = this.validate($schema, schema);
  if (!valid && throwOrLogError) {
    var message = 'schema is invalid: ' + this.errorsText();
    if (this._opts.validateSchema == 'log') this.logger.error(message);
    else throw new Error(message);
  }
  return valid;
}


function defaultMeta(self) {
  var meta = self._opts.meta;
  self._opts.defaultMeta = typeof meta == 'object'
                            ? self._getId(meta) || meta
                            : self.getSchema(META_SCHEMA_ID)
                              ? META_SCHEMA_ID
                              : undefined;
  return self._opts.defaultMeta;
}


/**
 * Get compiled schema from the instance by `key` or `ref`.
 * @this   Ajv
 * @param  {String} keyRef `key` that was passed to `addSchema` or full schema reference (`schema.id` or resolved id).
 * @return {Function} schema validating function (with property `schema`).
 */
function getSchema(keyRef) {
  var schemaObj = _getSchemaObj(this, keyRef);
  switch (typeof schemaObj) {
    case 'object': return schemaObj.validate || this._compile(schemaObj);
    case 'string': return this.getSchema(schemaObj);
    case 'undefined': return _getSchemaFragment(this, keyRef);
  }
}


function _getSchemaFragment(self, ref) {
  var res = resolve.schema.call(self, { schema: {} }, ref);
  if (res) {
    var schema = res.schema
      , root = res.root
      , baseId = res.baseId;
    var v = compileSchema.call(self, schema, root, undefined, baseId);
    self._fragments[ref] = new SchemaObject({
      ref: ref,
      fragment: true,
      schema: schema,
      root: root,
      baseId: baseId,
      validate: v
    });
    return v;
  }
}


function _getSchemaObj(self, keyRef) {
  keyRef = resolve.normalizeId(keyRef);
  return self._schemas[keyRef] || self._refs[keyRef] || self._fragments[keyRef];
}


/**
 * Remove cached schema(s).
 * If no parameter is passed all schemas but meta-schemas are removed.
 * If RegExp is passed all schemas with key/id matching pattern but meta-schemas are removed.
 * Even if schema is referenced by other schemas it still can be removed as other schemas have local references.
 * @this   Ajv
 * @param  {String|Object|RegExp} schemaKeyRef key, ref, pattern to match key/ref or schema object
 * @return {Ajv} this for method chaining
 */
function removeSchema(schemaKeyRef) {
  if (schemaKeyRef instanceof RegExp) {
    _removeAllSchemas(this, this._schemas, schemaKeyRef);
    _removeAllSchemas(this, this._refs, schemaKeyRef);
    return this;
  }
  switch (typeof schemaKeyRef) {
    case 'undefined':
      _removeAllSchemas(this, this._schemas);
      _removeAllSchemas(this, this._refs);
      this._cache.clear();
      return this;
    case 'string':
      var schemaObj = _getSchemaObj(this, schemaKeyRef);
      if (schemaObj) this._cache.del(schemaObj.cacheKey);
      delete this._schemas[schemaKeyRef];
      delete this._refs[schemaKeyRef];
      return this;
    case 'object':
      var serialize = this._opts.serialize;
      var cacheKey = serialize ? serialize(schemaKeyRef) : schemaKeyRef;
      this._cache.del(cacheKey);
      var id = this._getId(schemaKeyRef);
      if (id) {
        id = resolve.normalizeId(id);
        delete this._schemas[id];
        delete this._refs[id];
      }
  }
  return this;
}


function _removeAllSchemas(self, schemas, regex) {
  for (var keyRef in schemas) {
    var schemaObj = schemas[keyRef];
    if (!schemaObj.meta && (!regex || regex.test(keyRef))) {
      self._cache.del(schemaObj.cacheKey);
      delete schemas[keyRef];
    }
  }
}


/* @this   Ajv */
function _addSchema(schema, skipValidation, meta, shouldAddSchema) {
  if (typeof schema != 'object' && typeof schema != 'boolean')
    throw new Error('schema should be object or boolean');
  var serialize = this._opts.serialize;
  var cacheKey = serialize ? serialize(schema) : schema;
  var cached = this._cache.get(cacheKey);
  if (cached) return cached;

  shouldAddSchema = shouldAddSchema || this._opts.addUsedSchema !== false;

  var id = resolve.normalizeId(this._getId(schema));
  if (id && shouldAddSchema) checkUnique(this, id);

  var willValidate = this._opts.validateSchema !== false && !skipValidation;
  var recursiveMeta;
  if (willValidate && !(recursiveMeta = id && id == resolve.normalizeId(schema.$schema)))
    this.validateSchema(schema, true);

  var localRefs = resolve.ids.call(this, schema);

  var schemaObj = new SchemaObject({
    id: id,
    schema: schema,
    localRefs: localRefs,
    cacheKey: cacheKey,
    meta: meta
  });

  if (id[0] != '#' && shouldAddSchema) this._refs[id] = schemaObj;
  this._cache.put(cacheKey, schemaObj);

  if (willValidate && recursiveMeta) this.validateSchema(schema, true);

  return schemaObj;
}


/* @this   Ajv */
function _compile(schemaObj, root) {
  if (schemaObj.compiling) {
    schemaObj.validate = callValidate;
    callValidate.schema = schemaObj.schema;
    callValidate.errors = null;
    callValidate.root = root ? root : callValidate;
    if (schemaObj.schema.$async === true)
      callValidate.$async = true;
    return callValidate;
  }
  schemaObj.compiling = true;

  var currentOpts;
  if (schemaObj.meta) {
    currentOpts = this._opts;
    this._opts = this._metaOpts;
  }

  var v;
  try { v = compileSchema.call(this, schemaObj.schema, root, schemaObj.localRefs); }
  catch(e) {
    delete schemaObj.validate;
    throw e;
  }
  finally {
    schemaObj.compiling = false;
    if (schemaObj.meta) this._opts = currentOpts;
  }

  schemaObj.validate = v;
  schemaObj.refs = v.refs;
  schemaObj.refVal = v.refVal;
  schemaObj.root = v.root;
  return v;


  /* @this   {*} - custom context, see passContext option */
  function callValidate() {
    /* jshint validthis: true */
    var _validate = schemaObj.validate;
    var result = _validate.apply(this, arguments);
    callValidate.errors = _validate.errors;
    return result;
  }
}


function chooseGetId(opts) {
  switch (opts.schemaId) {
    case 'auto': return _get$IdOrId;
    case 'id': return _getId;
    default: return _get$Id;
  }
}

/* @this   Ajv */
function _getId(schema) {
  if (schema.$id) this.logger.warn('schema $id ignored', schema.$id);
  return schema.id;
}

/* @this   Ajv */
function _get$Id(schema) {
  if (schema.id) this.logger.warn('schema id ignored', schema.id);
  return schema.$id;
}


function _get$IdOrId(schema) {
  if (schema.$id && schema.id && schema.$id != schema.id)
    throw new Error('schema $id is different from id');
  return schema.$id || schema.id;
}


/**
 * Convert array of error message objects to string
 * @this   Ajv
 * @param  {Array<Object>} errors optional array of validation errors, if not passed errors from the instance are used.
 * @param  {Object} options optional options with properties `separator` and `dataVar`.
 * @return {String} human readable string with all errors descriptions
 */
function errorsText(errors, options) {
  errors = errors || this.errors;
  if (!errors) return 'No errors';
  options = options || {};
  var separator = options.separator === undefined ? ', ' : options.separator;
  var dataVar = options.dataVar === undefined ? 'data' : options.dataVar;

  var text = '';
  for (var i=0; i<errors.length; i++) {
    var e = errors[i];
    if (e) text += dataVar + e.dataPath + ' ' + e.message + separator;
  }
  return text.slice(0, -separator.length);
}


/**
 * Add custom format
 * @this   Ajv
 * @param {String} name format name
 * @param {String|RegExp|Function} format string is converted to RegExp; function should return boolean (true when valid)
 * @return {Ajv} this for method chaining
 */
function addFormat(name, format) {
  if (typeof format == 'string') format = new RegExp(format);
  this._formats[name] = format;
  return this;
}


function addDefaultMetaSchema(self) {
  var $dataSchema;
  if (self._opts.$data) {
    $dataSchema = require('./refs/data.json');
    self.addMetaSchema($dataSchema, $dataSchema.$id, true);
  }
  if (self._opts.meta === false) return;
  var metaSchema = require('./refs/json-schema-draft-07.json');
  if (self._opts.$data) metaSchema = $dataMetaSchema(metaSchema, META_SUPPORT_DATA);
  self.addMetaSchema(metaSchema, META_SCHEMA_ID, true);
  self._refs['http://json-schema.org/schema'] = META_SCHEMA_ID;
}


function addInitialSchemas(self) {
  var optsSchemas = self._opts.schemas;
  if (!optsSchemas) return;
  if (Array.isArray(optsSchemas)) self.addSchema(optsSchemas);
  else for (var key in optsSchemas) self.addSchema(optsSchemas[key], key);
}


function addInitialFormats(self) {
  for (var name in self._opts.formats) {
    var format = self._opts.formats[name];
    self.addFormat(name, format);
  }
}


function checkUnique(self, id) {
  if (self._schemas[id] || self._refs[id])
    throw new Error('schema with key or id "' + id + '" already exists');
}


function getMetaSchemaOptions(self) {
  var metaOpts = util.copy(self._opts);
  for (var i=0; i<META_IGNORE_OPTIONS.length; i++)
    delete metaOpts[META_IGNORE_OPTIONS[i]];
  return metaOpts;
}


function setLogger(self) {
  var logger = self._opts.logger;
  if (logger === false) {
    self.logger = {log: noop, warn: noop, error: noop};
  } else {
    if (logger === undefined) logger = console;
    if (!(typeof logger == 'object' && logger.log && logger.warn && logger.error))
      throw new Error('logger must implement log, warn and error methods');
    self.logger = logger;
  }
}


function noop() {}
