import { SEEDANCE_25_MODEL } from "@/lib/video-settings";

export type VideoInputEngine = "seedance" | "minimax" | "bailian";
export type VideoInputMode = "reference" | "frames";
export type VideoMaterialKind = "image" | "video" | "audio";

export const BAILIAN_27_VIDEO_MODEL = "wan2.7-i2v-2026-04-25";
export const BAILIAN_30_VIDEO_MODEL = "wan3.0-video";
export const BAILIAN_VIDEO_MODELS = [
  { id: BAILIAN_27_VIDEO_MODEL, label: "Wan 2.7 · 首尾帧" },
  { id: BAILIAN_30_VIDEO_MODEL, label: "Wan 3.0 · 多图参考" }
] as const;

export type VideoInputSelection = {
  engine: VideoInputEngine;
  model: string;
  inputMode: VideoInputMode;
};

export function videoInputHint(selection: VideoInputSelection): string {
  if (selection.engine === "seedance") {
    return selection.model === SEEDANCE_25_MODEL
      ? "多素材参考：最多 30 张图片、10 段视频、10 段音频，总计 50 个。可在提示词中用 @图片1 等编号指定用途。"
      : "多素材参考：最多 9 张图片、3 段视频、3 段音频；音频需要搭配图片或视频。可用 @图片1 等编号指定用途。";
  }
  if (selection.engine === "minimax") {
    return selection.inputMode === "frames"
      ? "首帧模式：可不上传图片，或上传 1 张图片固定视频开头；有首帧时比例跟随图片。若想用多张图共同指导内容，请切换到「多图参考」。"
      : "多图参考：最多 9 张图片。图片用于指导人物、服装或场景，不会被固定为视频首帧；可在提示词中引用 @图片1 等编号。";
  }
  if (selection.model === BAILIAN_27_VIDEO_MODEL) {
    return "Wan 2.7 首尾帧：上传 1 张图片作为首帧，或按顺序上传 2 张作为首帧和尾帧。多图参考请切换到 Wan 3.0。";
  }
  return selection.inputMode === "frames"
    ? "首尾帧：上传 1 张首帧图，或按顺序上传 2 张首尾帧图。若想让更多图片共同指导内容，请切换到「多图参考」。"
    : "多图参考：可只输入文字，或上传最多 10 张图片指导人物、服装和场景；参考图不会固定为首尾帧，可在提示词中引用 @图片1 等编号。";
}

export function videoMaterialError(selection: VideoInputSelection, materials: readonly { type: VideoMaterialKind }[]): string | null {
  const imageCount = materials.filter((item) => item.type === "image").length;
  const videoCount = materials.filter((item) => item.type === "video").length;
  const audioCount = materials.filter((item) => item.type === "audio").length;
  if (selection.engine === "seedance") {
    const is25 = selection.model === SEEDANCE_25_MODEL;
    const maxImages = is25 ? 30 : 9;
    const maxVideo = is25 ? 10 : 3;
    const maxAudio = is25 ? 10 : 3;
    if (imageCount > maxImages || videoCount > maxVideo || audioCount > maxAudio || is25 && materials.length > 50) {
      return `${is25 ? "Seedance 2.5" : "Seedance 2.0"} 最多支持 ${maxImages} 张图片、${maxVideo} 段视频、${maxAudio} 段音频${is25 ? "，总计 50 个素材" : ""}；请移除超出的素材。`;
    }
    if (!is25 && audioCount > 0 && imageCount + videoCount === 0) {
      return "Seedance 2.0 的音频不能单独生成视频；请添加至少 1 张图片或 1 段视频，或切换到 Seedance 2.5。";
    }
    return null;
  }
  if (selection.engine === "minimax") {
    if (videoCount || audioCount) return "MiniMax H3 当前只接受图片素材；请移除视频和音频，或切换到 Seedance。";
    if (selection.inputMode === "frames" && imageCount > 1) {
      return "MiniMax H3 首帧模式最多只能上传 1 张图；请切换到「多图参考」或移除多余图片。";
    }
    if (selection.inputMode === "reference" && imageCount > 9) {
      return "MiniMax H3 多图参考最多支持 9 张图片；请移除多余图片。";
    }
    return null;
  }
  if (videoCount || audioCount) return "百炼当前只接受图片素材；请移除视频和音频，或切换到 Seedance。";
  if (selection.model === BAILIAN_27_VIDEO_MODEL || selection.inputMode === "frames") {
    if (!imageCount) return "首尾帧模式需要至少 1 张图片作为首帧；请上传图片，或切换到 Wan 3.0 多图参考。";
    if (imageCount > 2) return "首尾帧模式最多支持 2 张图片；请切换到 Wan 3.0 多图参考，或移除多余图片。";
    return null;
  }
  if (imageCount > 10) return "Wan 3.0 多图参考最多支持 10 张图片；请移除多余图片。";
  return null;
}

export function videoImageFileError(selection: VideoInputSelection, file: Pick<File, "name" | "size" | "type">): string | null {
  if (selection.engine === "seedance" || selection.engine === "bailian" && selection.model === BAILIAN_27_VIDEO_MODEL) return null;
  const format = file.name.split(".").pop()?.toLowerCase() || file.type.split("/").pop()?.toLowerCase() || "";
  const isMinimax = selection.engine === "minimax";
  const formats = isMinimax ? ["jpg", "jpeg", "png", "webp", "heic", "heif"] : ["jpg", "jpeg", "png", "bmp", "webp"];
  const maxBytes = (isMinimax ? 30 : 20) * 1024 * 1024;
  const modelLabel = isMinimax ? "MiniMax H3" : "Wan 3.0";
  if (!formats.includes(format)) {
    return `${modelLabel} 不支持「${file.name}」的格式；请转换为 ${isMinimax ? "JPG、PNG、WEBP、HEIC 或 HEIF" : "JPG、PNG、BMP 或 WEBP"} 后上传。`;
  }
  if (file.size > maxBytes) return `${modelLabel} 的单张图片不能超过 ${isMinimax ? 30 : 20} MB；请压缩「${file.name}」后重试。`;
  return null;
}