import type { PzSegmentDefinition, PzSegmentsConfig } from '../types';

export function isLegacyMode(settings: any): boolean {
  return !settings.usePzSegment;
}

const DEFAULT_SEPARATOR = '--';

const DEFAULT_SEGMENTS: PzSegmentDefinition[] = [
  { name: 'locale' },
  { name: 'currency' },
  { name: 'url' }
];

export function getPzSegmentsConfig(settings: any): PzSegmentsConfig {
  if (settings.pzSegments) {
    const customSegments = (settings.pzSegments.segments ?? []).filter(
      (seg: PzSegmentDefinition) =>
        !DEFAULT_SEGMENTS.some((d) => d.name === seg.name)
    );

    return {
      separator: settings.pzSegments.separator ?? DEFAULT_SEPARATOR,
      segments: [...DEFAULT_SEGMENTS, ...customSegments]
    };
  }

  return {
    separator: DEFAULT_SEPARATOR,
    segments: DEFAULT_SEGMENTS
  };
}

export function encodePzValue(
  values: Record<string, string>,
  config: PzSegmentsConfig
): string {
  return config.segments
    .map((seg) => values[seg.name] ?? '')
    .join(config.separator);
}

export function decodePzValue(
  pzValue: string,
  config: PzSegmentsConfig
): Record<string, string> {
  const parts = pzValue.split(config.separator);
  const result: Record<string, string> = {};

  config.segments.forEach((seg, index) => {
    result[seg.name] = parts[index] ?? '';
  });

  return result;
}

export function getBuiltInSegments(
  parsed: Record<string, string>,
  settings: any
): { locale: string; currency: string; url: string } {
  const { defaultLocaleValue, defaultCurrencyCode } = settings.localization;

  return {
    locale: parsed.locale || defaultLocaleValue,
    currency: parsed.currency || defaultCurrencyCode,
    url: parsed.url ? decodeURIComponent(parsed.url) : ''
  };
}

export function parsePzParams(
  params: { pz?: string; locale?: string; currency?: string; url?: string },
  settings: any
): { locale: string; currency: string; url: string; [key: string]: string } {
  if (isLegacyMode(settings)) {
    return {
      locale:
        params.locale ?? settings.localization.defaultLocaleValue,
      currency:
        params.currency ?? settings.localization.defaultCurrencyCode,
      url: params.url ? decodeURIComponent(params.url) : ''
    };
  }

  const config = getPzSegmentsConfig(settings);
  const parsed = decodePzValue(params.pz ?? '', config);
  const builtIn = getBuiltInSegments(parsed, settings);

  return {
    ...parsed,
    ...builtIn
  };
}