import { PluginValidator, PluginValidatorType } from '@allianz/taly-core';
import { Injectable, inject, Signal } from '@angular/core';
import { AbstractControl, ValidationErrors, ValidatorFn } from '@angular/forms';
import { LocalizeFn } from '@angular/localize/init';
import {
  DEFAULT_OPTIONS,
  EscapedMaxLengthValidatorPluginOptions
} from './escaped-max-length-validator.module';
import { ESCAPED_MAX_LENGTH_PLUGIN_OPTIONS } from './tokens';

declare let $localize: LocalizeFn;

@Injectable({ providedIn: 'root' })
export class EscapedMaxLengthValidator implements PluginValidator<number> {
  private options = inject<Signal<EscapedMaxLengthValidatorPluginOptions>>(
    ESCAPED_MAX_LENGTH_PLUGIN_OPTIONS
  );

  // To be specified when configuring this validator for a form field
  type: PluginValidatorType = 'PLUGIN_MYTEAM_ESCAPED_MAX_LENGTH';

  defaultErrorMessage = '';

  private _setDefaultErrorMessage(max: number) {
    this.defaultErrorMessage = $localize`:@@validation.error.escapedMaxLengthValidator:This field should not contain more than ${max} characters`;
  }

  validate(escapedMaxLength?: number): ValidatorFn {
    const maxLength =
      escapedMaxLength ?? this.options()?.escapedMaxLength ?? DEFAULT_OPTIONS.escapedMaxLength;
    this._setDefaultErrorMessage(maxLength);
    return (control: AbstractControl): ValidationErrors | null => {
      if (!control.value) {
        return null;
      }
      const maxLength =
        escapedMaxLength ?? this.options()?.escapedMaxLength ?? DEFAULT_OPTIONS.escapedMaxLength;
      this._setDefaultErrorMessage(maxLength);
      const actualValue = JSON.stringify(control.value).slice(0, -1).substr(1);

      if (actualValue.length > maxLength) {
        return {
          [this.type]: true
        };
      }

      return null;
    };
  }
}