import { VIDEO_DURATION_MAX } from "@/lib/video-settings";

const SEEDANCE_FPS = 24;
const SEEDANCE_TOKEN_SCALE = 1_000_000;

export type SeedanceBillingEstimateInput = {
  resolution?: unknown;
  aspectRatio?: unknown;
  outputDurationSeconds: number;
  inputVideoDurationSeconds?: number;
  inputVideo?: boolean;
  markupMultiplier: number;
};

export type SeedanceActualBillingInput = {
  resolution?: unknown;
  inputVideo?: boolean;
  completionTokens: number;
  markupMultiplier: number;
};

/**
 * 火山方舟文档的 Seedance 2.0 视频 token 单价，单位为“分/百万 token”。
 * 480p/720p、1080p 和 4K 的单价不同；含输入视频时使用对应的输入视频档。
 */
export function seedanceTokenPriceFenPerMillion(resolution: unknown, inputVideo = false): number {
  const normalized = normalizeSeedanceResolution(resolution);
  const prices: Record<string, { withoutVideo: number; withVideo: number }> = {
    "480p": { withoutVideo: 4_600, withVideo: 2_800 },
    "720p": { withoutVideo: 4_600, withVideo: 2_800 },
    "1080p": { withoutVideo: 5_100, withVideo: 3_100 },
    "4k": { withoutVideo: 2_600, withVideo: 1_600 }
  };
  const price = prices[normalized] || prices["720p"];
  return inputVideo ? price.withVideo : price.withoutVideo;
}

export function calculateSeedanceActualAmountFen(input: SeedanceActualBillingInput): number {
  if (!Number.isFinite(input.completionTokens) || input.completionTokens <= 0) {
    throw new Error("Seedance 实际 token 用量必须大于 0。");
  }
  if (!Number.isFinite(input.markupMultiplier) || input.markupMultiplier < 1) {
    throw new Error("Seedance 计费倍率不能低于 1.00。");
  }
  const tokenPriceFenPerMillion = seedanceTokenPriceFenPerMillion(input.resolution, input.inputVideo);
  return Math.max(1, Math.ceil(
    input.completionTokens * tokenPriceFenPerMillion * input.markupMultiplier / SEEDANCE_TOKEN_SCALE
  ));
}

export function estimateSeedanceAmountFen(input: SeedanceBillingEstimateInput): number {
  if (!Number.isFinite(input.outputDurationSeconds) || input.outputDurationSeconds <= 0) {
    throw new Error("Seedance 输出时长必须大于 0。");
  }
  const inputVideo = Boolean(input.inputVideo);
  const inputDuration = inputVideo
    ? normalizeInputVideoDuration(input.inputVideoDurationSeconds)
    : 0;
  const completionTokens = estimateSeedanceCompletionTokens({
    resolution: input.resolution,
    aspectRatio: input.aspectRatio,
    outputDurationSeconds: input.outputDurationSeconds,
    inputVideoDurationSeconds: inputDuration
  });
  return Math.max(1, Math.ceil(
    completionTokens * seedanceTokenPriceFenPerMillion(input.resolution, inputVideo) * input.markupMultiplier / SEEDANCE_TOKEN_SCALE
  ));
}

export function estimateSeedanceCompletionTokens(input: {
  resolution?: unknown;
  aspectRatio?: unknown;
  outputDurationSeconds: number;
  inputVideoDurationSeconds?: number;
}): number {
  const dimensions = seedanceOutputDimensions(input.resolution, input.aspectRatio);
  const inputDuration = Math.max(0, Number(input.inputVideoDurationSeconds) || 0);
  const outputDuration = Math.max(0, Number(input.outputDurationSeconds) || 0);
  return Math.ceil(
    (inputDuration + outputDuration) * dimensions.width * dimensions.height * SEEDANCE_FPS / 1024
  );
}

/**
 * 没有媒体元数据时按官方可接收的最大输入视频时长冻结，避免先扣少、成功后补扣造成余额不足。
 */
export function normalizeInputVideoDuration(value: unknown): number {
  const duration = Number(value);
  if (!Number.isFinite(duration) || duration <= 0) return VIDEO_DURATION_MAX;
  return Math.min(VIDEO_DURATION_MAX, duration);
}

export function normalizeSeedanceResolution(value: unknown): string {
  const normalized = String(value || "720p").trim().toLowerCase();
  if (normalized === "4k" || normalized === "4K".toLowerCase()) return "4k";
  if (normalized === "480p" || normalized === "1080p") return normalized;
  return "720p";
}

export function seedanceOutputDimensions(resolution: unknown, aspectRatio: unknown): { width: number; height: number } {
  const base = {
    "480p": { width: 854, height: 480 },
    "720p": { width: 1280, height: 720 },
    "1080p": { width: 1920, height: 1080 },
    "4k": { width: 3840, height: 2160 }
  }[normalizeSeedanceResolution(resolution)] || { width: 1280, height: 720 };
  const ratio = parseAspectRatio(aspectRatio);
  const area = base.width * base.height;
  return {
    width: Math.max(1, Math.round(Math.sqrt(area * ratio))),
    height: Math.max(1, Math.round(Math.sqrt(area / ratio)))
  };
}

export function requestHasInputVideo(requestPayload: Record<string, unknown>): boolean {
  return requestMaterials(requestPayload).some((material) => String(material.type || "").toLowerCase() === "video");
}

export function requestInputVideoDurationSeconds(requestPayload: Record<string, unknown>): number | undefined {
  const videoMaterials = requestMaterials(requestPayload)
    .filter((material) => String(material.type || "").toLowerCase() === "video");
  if (!videoMaterials.length) return undefined;
  const knownDurations = videoMaterials
    .map((material) => firstFiniteNumber(
      material.duration,
      material.durationSeconds,
      recordValue(material.metadata)?.duration,
      recordValue(material.metadata)?.durationSeconds
    ))
    .filter((value): value is number => value !== undefined && value > 0);
  if (!knownDurations.length) return undefined;
  return Math.min(VIDEO_DURATION_MAX, knownDurations.reduce((sum, value) => sum + value, 0));
}

function requestMaterials(requestPayload: Record<string, unknown>): Array<Record<string, unknown>> {
  const assembled = recordValue(requestPayload.assembled);
  const input = recordValue(requestPayload.input);
  const assembledMaterials = recordArray(assembled?.materials);
  const inputMaterials = recordArray(input?.materials);
  const materials = assembledMaterials.length ? assembledMaterials : inputMaterials;
  return materials;
}

function parseAspectRatio(value: unknown): number {
  const normalized = String(value || "16:9").trim().toLowerCase();
  const match = normalized.match(/^(\d+(?:\.\d+)?)\s*[:/]\s*(\d+(?:\.\d+)?)$/);
  if (!match) return 16 / 9;
  const width = Number(match[1]);
  const height = Number(match[2]);
  return Number.isFinite(width) && Number.isFinite(height) && width > 0 && height > 0
    ? width / height
    : 16 / 9;
}

function recordArray(value: unknown): Array<Record<string, unknown>> {
  return Array.isArray(value) ? value.map(recordValue).filter((item): item is Record<string, unknown> => Boolean(item)) : [];
}

function recordValue(value: unknown): Record<string, unknown> | undefined {
  return typeof value === "object" && value !== null && !Array.isArray(value)
    ? value as Record<string, unknown>
    : undefined;
}

function firstFiniteNumber(...values: unknown[]): number | undefined {
  for (const value of values) {
    const parsed = Number(value);
    if (Number.isFinite(parsed)) return parsed;
  }
  return undefined;
}