import { getVideoCreditCostFromConfig, type VideoImageGenConfigLike } from "@/lib/ai/video-model-config";

export type DiscountableImageGenConfigLike = VideoImageGenConfigLike & {
  creditCostPerImage?: number | null;
  creditDiscountRate?: number | null;
};

function normalizeRoundedCost(value: unknown) {
  const normalized = Number(value);
  if (!Number.isFinite(normalized)) return 0;
  return Math.max(0, Math.round(normalized));
}

export function normalizeImageModelCreditDiscountRate(value: unknown) {
  const normalized = Number(value);
  if (!Number.isFinite(normalized)) return null;
  const rounded = Math.round(normalized * 10) / 10;
  if (rounded <= 0 || rounded >= 10) return null;
  return rounded;
}

export function formatImageModelCreditDiscountLabel(value: unknown) {
  const normalized = normalizeImageModelCreditDiscountRate(value);
  if (normalized === null) return null;
  const displayValue = Number.isInteger(normalized)
    ? String(normalized)
    : normalized.toFixed(1).replace(/\.0$/, "");
  return `${displayValue}折`;
}

export function getImageModelCreditDiscountLabel(
  config: DiscountableImageGenConfigLike | null | undefined
) {
  return formatImageModelCreditDiscountLabel(config?.creditDiscountRate);
}

export function applyImageModelCreditDiscount(
  rawCost: unknown,
  config: DiscountableImageGenConfigLike | null | undefined
) {
  const baseCost = normalizeRoundedCost(rawCost);
  if (baseCost <= 0) return 0;

  const normalizedDiscountRate = normalizeImageModelCreditDiscountRate(
    config?.creditDiscountRate
  );
  if (normalizedDiscountRate === null) return baseCost;

  return Math.max(0, Math.round((baseCost * normalizedDiscountRate) / 10));
}

export function getGenerationCreditCostFromImageGenConfig(
  config: DiscountableImageGenConfigLike | null | undefined,
  target: "image" | "video",
  options?: { duration?: number | null; resolution?: string | null }
) {
  const sourceValue =
    target === "video"
      ? (() => {
          const resolvedVideoCost = getVideoCreditCostFromConfig(
            config,
            options?.duration,
            options?.resolution
          );
          if (resolvedVideoCost > 0) return resolvedVideoCost;
          return config?.creditCostPerVideo ?? config?.creditCostPerImage ?? 0;
        })()
      : config?.creditCostPerImage ?? 0;

  return applyImageModelCreditDiscount(sourceValue, config);
}

export function getImageCreditCostFromConfig(
  config: DiscountableImageGenConfigLike | null | undefined
) {
  return getGenerationCreditCostFromImageGenConfig(config, "image");
}

export function getModelGenerationCreditCost(
  modelConfig: { imageGenConfig?: DiscountableImageGenConfigLike | null } | null | undefined,
  target: "image" | "video",
  options?: { duration?: number | null; resolution?: string | null }
) {
  return getGenerationCreditCostFromImageGenConfig(
    modelConfig?.imageGenConfig,
    target,
    options
  );
}

export function normalizeImageGenPricingConfig<
  T extends DiscountableImageGenConfigLike | null | undefined,
>(config: T): T {
  if (!config) return config;

  const normalizedDiscountRate = normalizeImageModelCreditDiscountRate(
    config.creditDiscountRate
  );

  return {
    ...config,
    creditDiscountRate: normalizedDiscountRate ?? undefined,
  } as T;
}