import {
  AndRule,
  type DataRef,
  LiteralRule,
  OrRule,
  type Rule,
  type RuleTestResponse,
} from '@os-team/lexical-rules';
import SRule from '../rules/SRule.js';
import SystemLiteralRule from '../rules/SystemLiteralRule.js';
import PubidLiteralRule from '../rules/PubidLiteralRule.js';
import type { Parser } from './Parser.js';

export interface SystemExternalID {
  type: 'SYSTEM_EXTERNAL_ID';
  systemValue: string;
}

export interface PublicExternalID {
  type: 'PUBLIC_EXTERNAL_ID';
  pubidValue: string;
  systemValue: string;
}

export type ExternalID = SystemExternalID | PublicExternalID;

/**
 * The external entity declaration.
 * See https://www.w3.org/TR/xml/#NT-ExternalID
 */
class ExternalIDParser implements Parser<ExternalID> {
  private readonly rule: Rule<
    [string, undefined, string] | [string, undefined, string, undefined, string]
  >;

  public constructor() {
    const systemRule = new LiteralRule('SYSTEM'); // 'SYSTEM'
    const sRule = new SRule('+'); // S
    const systemLiteralRule = new SystemLiteralRule(); // SystemLiteral
    const systemExtIdRule = new AndRule([systemRule, sRule, systemLiteralRule]); // 'SYSTEM' S SystemLiteral
    const publicRule = new LiteralRule('PUBLIC'); // 'PUBLIC'
    const pubidLieralRule = new PubidLiteralRule(); // PubidLiteral
    const publicExtIdRule = new AndRule([
      publicRule,
      sRule,
      pubidLieralRule,
      sRule,
      systemLiteralRule,
    ]); // 'PUBLIC' S PubidLiteral S SystemLiteral
    this.rule = new OrRule([systemExtIdRule, publicExtIdRule]); // 'SYSTEM' S SystemLiteral | 'PUBLIC' S PubidLiteral S SystemLiteral
  }

  public test(ref: DataRef, pos: number): RuleTestResponse<ExternalID> {
    const [isValid, nextPos, res] = this.rule.test(ref, pos);
    if (!isValid || res === undefined) return [false, nextPos];

    let externalID: ExternalID;
    if (res.length === 5) {
      const [, , pubidValue, , systemValue] = res;
      externalID = { type: 'PUBLIC_EXTERNAL_ID', pubidValue, systemValue };
    } else {
      const [, , systemValue] = res;
      externalID = { type: 'SYSTEM_EXTERNAL_ID', systemValue };
    }

    return [true, nextPos, externalID];
  }

  public build(data: ExternalID) {
    return data.type === 'SYSTEM_EXTERNAL_ID'
      ? `SYSTEM "${data.systemValue.replaceAll('"', "'")}"`
      : `PUBLIC "${data.pubidValue.replaceAll(
          '"',
          "'"
        )}" "${data.systemValue.replaceAll('"', "'")}"`;
  }
}

export default ExternalIDParser;