import { materialContentForProvider, type PromptMaterial } from "@/lib/prompt/assembler";
import {
  SEEDANCE_20_MODEL,
  VIDEO_DURATION_DEFAULT,
  VIDEO_RATIO_DEFAULT,
  VIDEO_RESOLUTION_DEFAULT,
  clampVideoDuration,
  isSeedance25Model,
  isSupportedSeedanceModel,
  normalizeSeedanceModel,
  normalizeVideoDuration,
  normalizeVideoRatio,
  normalizeVideoResolution
} from "@/lib/video-settings";

export type SeedanceSettings = {
  ratio?: string;
  duration?: number;
  resolution?: string;
};

export type SeedanceCreateInput = {
  model?: string;
  prompt: string;
  settings: SeedanceSettings;
  materials: PromptMaterial[];
  origin: string;
};

export type SeedanceQueryResult = {
  status: "queued" | "running" | "succeeded" | "failed" | "cancelled" | "expired";
  resultUrl?: string;
  errorMessage?: string;
  usage?: SeedanceUsage;
  raw: Record<string, unknown>;
};

export type SeedanceUsage = {
  completionTokens: number;
};

export function getSeedanceConfig() {
  const model = normalizeSeedanceModel(process.env.SEEDANCE_MODEL, SEEDANCE_20_MODEL);
  return {
    apiKey: process.env.SEEDANCE_API_KEY,
    baseUrl: process.env.SEEDANCE_BASE_URL || "https://ark.cn-beijing.volces.com/api/v3",
    model,
    ratio: normalizeVideoRatio(process.env.SEEDANCE_RATIO, VIDEO_RATIO_DEFAULT),
    duration: clampVideoDuration(process.env.SEEDANCE_DURATION, VIDEO_DURATION_DEFAULT, { model }),
    resolution: normalizeVideoResolution(process.env.SEEDANCE_RESOLUTION, model, VIDEO_RESOLUTION_DEFAULT)
  };
}

export async function createSeedanceTask(input: SeedanceCreateInput) {
  const config = getSeedanceConfig();
  if (!config.apiKey) throw new Error("缺少 SEEDANCE_API_KEY。请在 .env.local 配置火山方舟 API Key。");
  if (input.model !== undefined && !isSupportedSeedanceModel(input.model)) {
    throw new Error("不支持的 Seedance 视频模型。");
  }
  const model = normalizeSeedanceModel(input.model, config.model);
  const materialContent = materialContentForProvider(input.materials, input.origin);
  if (!isSeedance25Model(model) && materialContent.length > 4) {
    throw new Error("Seedance 2.0 最多支持 4 个素材（加上文本后 content 最多 5 项）。");
  }
  if (isSeedance25Model(model)) validateSeedance25Materials(input.materials);
  const payload = {
    model,
    content: [
      { type: "text", text: input.prompt },
      ...materialContent
    ],
    generate_audio: true,
    ...(isSeedance25Model(model) && materialContent.length > 0 ? { omni_reference_task_type: "auto" } : {}),
    ratio: normalizeVideoRatio(input.settings.ratio, config.ratio),
    duration: normalizeVideoDuration(input.settings.duration, model) ?? config.duration,
    resolution: normalizeVideoResolution(input.settings.resolution, model, config.resolution),
    watermark: false
  };
  const response = await fetch(`${config.baseUrl.replace(/\/$/, "")}/contents/generations/tasks`, {
    method: "POST",
    headers: {
      Authorization: `Bearer ${config.apiKey}`,
      "Content-Type": "application/json"
    },
    body: JSON.stringify(payload)
  });
  const json = await response.json().catch(() => ({}));
  if (!response.ok) throw new Error(`Seedance 创建任务失败：${response.status} ${JSON.stringify(json)}`);
  const providerTaskId = json.id || json.task_id || json.data?.id || json.data?.task_id;
  if (!providerTaskId) throw new Error(`Seedance 响应中缺少任务 ID：${JSON.stringify(json)}`);
  return {
    providerTaskId: String(providerTaskId),
    raw: json as Record<string, unknown>,
    payload
  };
}

function validateSeedance25Materials(materials: PromptMaterial[]) {
  const counts = materials.reduce((result, material) => {
    result[material.type] += 1;
    return result;
  }, { image: 0, video: 0, audio: 0 });
  if (counts.image > 30 || counts.video > 10 || counts.audio > 10 || materials.length > 50) {
    throw new Error("Seedance 2.5 最多支持 30 张图片、10 个视频和 10 个音频素材。");
  }
}

export async function querySeedanceTask(providerTaskId: string): Promise<SeedanceQueryResult> {
  const config = getSeedanceConfig();
  if (!config.apiKey) throw new Error("缺少 SEEDANCE_API_KEY，无法查询真实生成任务。");
  const response = await fetch(`${config.baseUrl.replace(/\/$/, "")}/contents/generations/tasks/${providerTaskId}`, {
    headers: {
      Authorization: `Bearer ${config.apiKey}`,
      "Content-Type": "application/json"
    }
  });
  const json = await response.json().catch(() => ({}));
  if (!response.ok) throw new Error(`Seedance 查询任务失败：${response.status}`);
  return {
    status: normalizeSeedanceStatus(json.status || json.data?.status),
    resultUrl:
      json.content?.video_url ||
      json.content?.file_url ||
      json.video_url ||
      json.url ||
      json.output ||
      json.data?.content?.video_url ||
      json.data?.content?.file_url ||
      json.data?.video_url ||
      json.data?.url ||
      json.data?.output,
    errorMessage: json.error?.message || json.data?.error?.message,
    usage: extractSeedanceUsage(json),
    raw: json as Record<string, unknown>
  };
}

export function extractSeedanceUsage(value: unknown): SeedanceUsage | undefined {
  const root = recordValue(value);
  const data = recordValue(root?.data);
  const usage = recordValue(root?.usage) || recordValue(data?.usage);
  if (!usage) return undefined;
  const completionTokens = Number(usage.completion_tokens ?? usage.completionTokens);
  if (!Number.isFinite(completionTokens) || completionTokens <= 0) return undefined;
  return { completionTokens: Math.floor(completionTokens) };
}

function normalizeSeedanceStatus(status: unknown): SeedanceQueryResult["status"] {
  const value = String(status || "").toLowerCase();
  if (["succeeded", "success", "completed"].includes(value)) return "succeeded";
  if (["expired", "timeout"].includes(value)) return "expired";
  if (["failed", "error"].includes(value)) return "failed";
  if (["cancelled", "canceled"].includes(value)) return "cancelled";
  if (["running", "processing", "generating"].includes(value)) return "running";
  return "queued";
}

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