export type MaterialPlaceholder = {
  token: string;
  type: "image" | "video" | "audio";
  index: number;
};

const materialTokenPattern = /@(参考视频|图片|图|视频|音频)(\d+)/g;

export function extractMaterialPlaceholders(prompt: string): MaterialPlaceholder[] {
  const placeholders: MaterialPlaceholder[] = [];
  const seen = new Set<string>();
  for (const match of prompt.matchAll(materialTokenPattern)) {
    const kind = match[1];
    const index = Number(match[2]);
    if (!Number.isInteger(index) || index < 1) continue;
    const type = typeForKind(kind);
    const token = labelForPlaceholder(type, index);
    if (seen.has(token)) continue;
    seen.add(token);
    placeholders.push({ token, type, index });
  }
  return placeholders;
}

function typeForKind(kind: string): MaterialPlaceholder["type"] {
  if (kind === "视频" || kind === "参考视频") return "video";
  if (kind === "音频") return "audio";
  return "image";
}

function labelForPlaceholder(type: MaterialPlaceholder["type"], index: number) {
  if (type === "video") return `@视频${index}`;
  if (type === "audio") return `@音频${index}`;
  return `@图片${index}`;
}