import { coerceArray } from '../../../util/array.ts';
import { regEx } from '../../../util/regex.ts';
import { GenericVersioningApi } from '../generic.ts';
import type { GenericVersion, VersioningApi } from '../types.ts';

export const id = 'perl';
export const displayName = 'Perl';
export const urls = ['[Perl version module](https://metacpan.org/pod/version)'];
export const supportsRanges = false;

// https://metacpan.org/pod/version#Decimal-Versions
const decimalVersionPattern = regEx(
  /^(?<intPart>\d+)\.(?<decimalPart>\d+(?:_\d+)?)$/,
);
// https://metacpan.org/pod/version#Dotted-Decimal-Versions
const dottedDecimalVersionPattern = regEx(
  /^v?(?<versionValue>\d+(?:\.\d+)*(?:_\d+)?)$/,
);

class PerlVersioningApi extends GenericVersioningApi {
  protected _parse(version: string): GenericVersion | null {
    return (
      this._parseDecimalVersion(version) ??
      this._parseDottedDecimalVersion(version)
    );
  }

  private _parseDecimalVersion(version: string): GenericVersion | null {
    const matches = decimalVersionPattern.exec(version);
    if (!matches) {
      return null;
    }
    const { intPart, decimalPart } = matches.groups!;
    const prerelease = decimalPart.includes('_') ? 'alpha' : '';

    const decimalComponents = coerceArray(
      decimalPart
        .replace(regEx(/_/g), '')
        .match(regEx(/.{1,3}/g))
        ?.map((value) => {
          let component = value;
          while (component.length < 3) {
            component += '0';
          }
          return Number.parseInt(component, 10);
        }),
    );
    const release = [Number.parseInt(intPart, 10), ...decimalComponents];
    return { release, prerelease };
  }

  private _parseDottedDecimalVersion(version: string): GenericVersion | null {
    const matches = dottedDecimalVersionPattern.exec(version);
    if (!matches) {
      return null;
    }
    const { versionValue } = matches.groups!;
    const prerelease = versionValue.includes('_') ? 'alpha' : '';
    const release = versionValue.split(regEx(/[._]/)).map(Number);
    return { release, prerelease };
  }
}

export const api: VersioningApi = new PerlVersioningApi();

export default api;