/**
 * @license
 * Copyright Google Inc. All Rights Reserved.
 *
 * Use of this source code is governed by an MIT-style license that can be
 * found in the LICENSE file at https://angular.io/license
 */

import {isBlank, isPresent, looseIdentical} from '../facade/lang';
import {FormArray, FormControl, FormGroup} from '../model';
import {Validators} from '../validators';

import {AbstractControlDirective} from './abstract_control_directive';
import {AbstractFormGroupDirective} from './abstract_form_group_directive';
import {CheckboxControlValueAccessor} from './checkbox_value_accessor';
import {ControlContainer} from './control_container';
import {ControlValueAccessor} from './control_value_accessor';
import {DefaultValueAccessor} from './default_value_accessor';
import {NgControl} from './ng_control';
import {normalizeAsyncValidator, normalizeValidator} from './normalize_validator';
import {NumberValueAccessor} from './number_value_accessor';
import {RadioControlValueAccessor} from './radio_control_value_accessor';
import {RangeValueAccessor} from './range_value_accessor';
import {FormArrayName} from './reactive_directives/form_group_name';
import {SelectControlValueAccessor} from './select_control_value_accessor';
import {SelectMultipleControlValueAccessor} from './select_multiple_control_value_accessor';
import {AsyncValidatorFn, Validator, ValidatorFn} from './validators';


export function controlPath(name: string, parent: ControlContainer): string[] {
  return [...parent.path, name];
}

export function setUpControl(control: FormControl, dir: NgControl): void {
  if (!control) _throwError(dir, 'Cannot find control with');
  if (!dir.valueAccessor) _throwError(dir, 'No value accessor for form control with');

  control.validator = Validators.compose([control.validator, dir.validator]);
  control.asyncValidator = Validators.composeAsync([control.asyncValidator, dir.asyncValidator]);
  dir.valueAccessor.writeValue(control.value);

  // view -> model
  dir.valueAccessor.registerOnChange((newValue: any) => {
    dir.viewToModelUpdate(newValue);
    control.markAsDirty();
    control.setValue(newValue, {emitModelToViewChange: false});
  });

  // touched
  dir.valueAccessor.registerOnTouched(() => control.markAsTouched());

  control.registerOnChange((newValue: any, emitModelEvent: boolean) => {
    // control -> view
    dir.valueAccessor.writeValue(newValue);

    // control -> ngModel
    if (emitModelEvent) dir.viewToModelUpdate(newValue);
  });

  if (dir.valueAccessor.setDisabledState) {
    control.registerOnDisabledChange(
        (isDisabled: boolean) => { dir.valueAccessor.setDisabledState(isDisabled); });
  }

  // re-run validation when validator binding changes, e.g. minlength=3 -> minlength=4
  dir._rawValidators.forEach((validator: Validator | ValidatorFn) => {
    if ((<Validator>validator).registerOnValidatorChange)
      (<Validator>validator).registerOnValidatorChange(() => control.updateValueAndValidity());
  });

  dir._rawAsyncValidators.forEach((validator: Validator | ValidatorFn) => {
    if ((<Validator>validator).registerOnValidatorChange)
      (<Validator>validator).registerOnValidatorChange(() => control.updateValueAndValidity());
  });
}

export function cleanUpControl(control: FormControl, dir: NgControl) {
  dir.valueAccessor.registerOnChange(() => _noControlError(dir));
  dir.valueAccessor.registerOnTouched(() => _noControlError(dir));
  dir._rawValidators.forEach((validator: Validator) => validator.registerOnValidatorChange(null));
  dir._rawAsyncValidators.forEach(
      (validator: Validator) => validator.registerOnValidatorChange(null));
  if (control) control._clearChangeFns();
}

export function setUpFormContainer(
    control: FormGroup | FormArray, dir: AbstractFormGroupDirective | FormArrayName) {
  if (isBlank(control)) _throwError(dir, 'Cannot find control with');
  control.validator = Validators.compose([control.validator, dir.validator]);
  control.asyncValidator = Validators.composeAsync([control.asyncValidator, dir.asyncValidator]);
}

function _noControlError(dir: NgControl) {
  return _throwError(dir, 'There is no FormControl instance attached to form control element with');
}

function _throwError(dir: AbstractControlDirective, message: string): void {
  let messageEnd: string;
  if (dir.path.length > 1) {
    messageEnd = `path: '${dir.path.join(' -> ')}'`;
  } else if (dir.path[0]) {
    messageEnd = `name: '${dir.path}'`;
  } else {
    messageEnd = 'unspecified name attribute';
  }
  throw new Error(`${message} ${messageEnd}`);
}

export function composeValidators(validators: /* Array<Validator|Function> */ any[]): ValidatorFn {
  return isPresent(validators) ? Validators.compose(validators.map(normalizeValidator)) : null;
}

export function composeAsyncValidators(validators: /* Array<Validator|Function> */ any[]):
    AsyncValidatorFn {
  return isPresent(validators) ? Validators.composeAsync(validators.map(normalizeAsyncValidator)) :
                                 null;
}

export function isPropertyUpdated(changes: {[key: string]: any}, viewModel: any): boolean {
  if (!changes.hasOwnProperty('model')) return false;
  const change = changes['model'];

  if (change.isFirstChange()) return true;
  return !looseIdentical(viewModel, change.currentValue);
}

const BUILTIN_ACCESSORS = [
  CheckboxControlValueAccessor,
  RangeValueAccessor,
  NumberValueAccessor,
  SelectControlValueAccessor,
  SelectMultipleControlValueAccessor,
  RadioControlValueAccessor,
];

export function isBuiltInAccessor(valueAccessor: ControlValueAccessor): boolean {
  return BUILTIN_ACCESSORS.some(a => valueAccessor.constructor === a);
}

// TODO: vsavkin remove it once https://github.com/angular/angular/issues/3011 is implemented
export function selectValueAccessor(
    dir: NgControl, valueAccessors: ControlValueAccessor[]): ControlValueAccessor {
  if (!valueAccessors) return null;

  var defaultAccessor: ControlValueAccessor;
  var builtinAccessor: ControlValueAccessor;
  var customAccessor: ControlValueAccessor;
  valueAccessors.forEach((v: ControlValueAccessor) => {
    if (v.constructor === DefaultValueAccessor) {
      defaultAccessor = v;

    } else if (isBuiltInAccessor(v)) {
      if (builtinAccessor)
        _throwError(dir, 'More than one built-in value accessor matches form control with');
      builtinAccessor = v;

    } else {
      if (customAccessor)
        _throwError(dir, 'More than one custom value accessor matches form control with');
      customAccessor = v;
    }
  });

  if (customAccessor) return customAccessor;
  if (builtinAccessor) return builtinAccessor;
  if (defaultAccessor) return defaultAccessor;

  _throwError(dir, 'No valid value accessor for form control with');
  return null;
}