import type { CanvasCapabilityClientCommand } from "@/lib/canvas/capabilities/client-command";
import { mergeCanvasSnapshots } from "@/lib/video-canvas/merge-snapshot";
import { canvasService } from "@/services/canvas";
import { useCanvasStore } from "@/store/canvas";

/** Runs after the editor has saved and while its save queue is reserved. */
export async function executeCanvasToolbarCapability(
  command: CanvasCapabilityClientCommand,
) {
  const projectId = command.projectId!;
  const before = useCanvasStore.getState();
  if (before.projectId !== projectId) throw new Error("画布已切换，请重新选择图片");
  const base = JSON.stringify({ canvasData: before.getCanvasState() });
  const response = await fetch(`/api/canvas/${projectId}/capabilities`, {
    method: "POST",
    headers: { "Content-Type": "application/json" },
    body: JSON.stringify(command),
  });
  const payload = await response.json().catch(() => ({}));
  if (!response.ok || payload?.success !== true) {
    throw new Error(payload?.error || "图片处理失败");
  }

  const result = await canvasService.getProject(projectId);
  if (!result.success || !result.data?.canvasData) {
    throw new Error(result.error || "结果已生成，但画布同步失败");
  }
  const current = useCanvasStore.getState();
  if (current.projectId !== projectId) return;
  const merged = mergeCanvasSnapshots(
    base,
    JSON.stringify({ canvasData: current.getCanvasState() }),
    JSON.stringify({ canvasData: result.data.canvasData }),
  );
  if (merged.conflicts.length > 0) {
    throw new Error("结果已生成，但画布有冲突；请保留本地改动后刷新查看结果");
  }
  current.loadCanvas(JSON.parse(merged.snapshot).canvasData);
  current.setCanvasRevision(String(result.data.updatedAt), String(result.data.updatedAt));
}