export type VideoCanvasMotionMention = {
  custom: boolean;
  id: string;
  index: number;
  label: string;
  motionId: string;
  offset: number;
  previewUrl: string;
  prompt: string;
};

function normalizeMotionMentionId(value: unknown) {
  return String(value || "")
    .trim()
    .replace(/[^A-Za-z0-9_-]+/g, "-")
    .slice(0, 120);
}

export function normalizeVideoCanvasMotionMentions(
  value: unknown,
): VideoCanvasMotionMention[] {
  if (!Array.isArray(value)) return [];

  return value.slice(0, 100).flatMap((item, position) => {
    if (!item || typeof item !== "object") return [];
    const record = item as Record<string, unknown>;
    const label = String(record.label || "").trim().slice(0, 100);
    if (!label) return [];
    const motionId =
      normalizeMotionMentionId(record.motionId) || `motion-${position + 1}`;

    return [{
      custom: record.custom === true,
      id:
        normalizeMotionMentionId(record.id) ||
        `motion-mention-${motionId}-${position + 1}`,
      index: Math.max(
        1,
        Math.min(100, Math.round(Number(record.index) || position + 1)),
      ),
      label,
      motionId,
      offset: Math.max(0, Math.round(Number(record.offset) || 0)),
      previewUrl: String(record.previewUrl || "").trim().slice(0, 4096),
      prompt: String(record.prompt || label).trim().slice(0, 2000) || label,
    }];
  });
}

export function composeVideoCanvasMotionPrompt(
  prompt: string,
  motionMentions: VideoCanvasMotionMention[],
) {
  return [
    String(prompt || "").trim(),
    ...motionMentions.map((mention) => {
      const instruction = mention.prompt.trim() || mention.label;
      return `运镜要求「${mention.label}」：${instruction}`;
    }),
  ]
    .filter(Boolean)
    .join(" ");
}