export type VideoDurationCostMap = Record<string, number>;

export type VideoImageGenConfigLike = {
  creditCostPerVideo?: number | null;
  videoDurationOptions?: number[] | null;
  creditCostPerVideoByDuration?: Record<string, number> | null;
};

function normalizePositiveInteger(value: unknown) {
  const normalized = Number(value);
  if (!Number.isFinite(normalized)) return null;
  const rounded = Math.round(normalized);
  if (rounded < 1) return null;
  return rounded;
}

export function normalizeVideoDurationOptions(value: unknown): number[] {
  if (!Array.isArray(value)) return [];

  return Array.from(
    new Set(
      value
        .map((item) => normalizePositiveInteger(item))
        .filter((item): item is number => item !== null)
    )
  ).sort((left, right) => left - right);
}

export function normalizeVideoDurationCostMap(
  value: unknown,
  durationOptions?: readonly number[] | null
): VideoDurationCostMap | undefined {
  if (!value || typeof value !== "object") return undefined;

  const allowedDurations = Array.isArray(durationOptions)
    ? new Set(durationOptions.map((item) => String(item)))
    : null;
  const entries = Object.entries(value as Record<string, unknown>)
    .map(([durationKey, costValue]) => {
      const normalizedDuration = normalizePositiveInteger(durationKey);
      const normalizedCost = Number(costValue);
      if (normalizedDuration === null || !Number.isFinite(normalizedCost)) {
        return null;
      }
      const durationText = String(normalizedDuration);
      if (allowedDurations && !allowedDurations.has(durationText)) {
        return null;
      }
      return [durationText, Math.max(0, Math.round(normalizedCost))] as const;
    })
    .filter((entry): entry is readonly [string, number] => Boolean(entry));

  if (entries.length === 0) return undefined;
  return Object.fromEntries(entries);
}

export function getConfiguredVideoDurationOptions(
  config: VideoImageGenConfigLike | null | undefined
): number[] {
  return normalizeVideoDurationOptions(config?.videoDurationOptions);
}

export function buildVideoDurationCostMap(params: {
  durationOptions: readonly number[];
  costMap?: unknown;
  fallbackCost?: number | null | undefined;
}): VideoDurationCostMap | undefined {
  const fallbackCost = Number.isFinite(Number(params.fallbackCost))
    ? Math.max(0, Math.round(Number(params.fallbackCost)))
    : 0;
  const normalizedCostMap =
    normalizeVideoDurationCostMap(params.costMap, params.durationOptions) || {};

  if (params.durationOptions.length === 0 && Object.keys(normalizedCostMap).length === 0) {
    return undefined;
  }

  return Object.fromEntries(
    params.durationOptions.map((duration) => {
      const key = String(duration);
      return [key, normalizedCostMap[key] ?? fallbackCost];
    })
  );
}

export function getVideoCreditCostFromConfig(
  config: VideoImageGenConfigLike | null | undefined,
  duration?: number | null
): number {
  const normalizedDuration = normalizePositiveInteger(duration);
  const durationOptions = getConfiguredVideoDurationOptions(config);
  const durationCostMap = normalizeVideoDurationCostMap(
    config?.creditCostPerVideoByDuration,
    durationOptions
  );

  if (normalizedDuration !== null && durationCostMap) {
    const durationKey = String(normalizedDuration);
    if (Object.prototype.hasOwnProperty.call(durationCostMap, durationKey)) {
      return durationCostMap[durationKey] || 0;
    }
  }

  const fallbackCost = Number(config?.creditCostPerVideo ?? 0);
  return Number.isFinite(fallbackCost) ? Math.max(0, Math.round(fallbackCost)) : 0;
}