import { isCanvasImageReadyForAi } from "@/lib/canvas/local-upload-state";
import type { CanvasNode } from "@/types/canvas";

export type LayoutReplaceSource = {
  id: string;
  imageUrl: string;
  kind: "canvas" | "upload";
  nodeId?: string;
  title: string;
};

function resolveCanvasImageUrl(node: CanvasNode) {
  const data = (node.data || {}) as Record<string, any>;
  return String(
    data.src ||
      data.previewImage ||
      data.imageUrl ||
      data.renderArtifacts?.screenshotUrl ||
      ""
  ).trim();
}

export function getLayoutReplaceSourceIdentity(source: LayoutReplaceSource) {
  if (source.kind === "canvas" && source.nodeId) {
    return `canvas:${source.nodeId}`;
  }
  return `${source.kind}:${source.imageUrl}`;
}

export function getReadyCanvasLayoutReplaceSource(
  node: CanvasNode
): LayoutReplaceSource | null {
  if (!isCanvasImageReadyForAi(node)) return null;
  const data = (node.data || {}) as Record<string, any>;
  const imageUrl = resolveCanvasImageUrl(node);
  return {
    id: `canvas:${node.id}`,
    imageUrl,
    kind: "canvas",
    nodeId: node.id,
    title: String(data.title || "画布图片").trim() || "画布图片",
  };
}

export function mergeUniqueLayoutReplaceSources(
  current: LayoutReplaceSource[],
  incoming: LayoutReplaceSource[],
  maxCount: number
) {
  const next = [...current];
  const identities = new Set(next.map(getLayoutReplaceSourceIdentity));
  for (const source of incoming) {
    const identity = getLayoutReplaceSourceIdentity(source);
    if (next.length >= maxCount) break;
    if (identities.has(identity)) continue;
    identities.add(identity);
    next.push(source);
  }
  return next;
}

export function getAvailableCanvasLayoutReplaceSources(
  canvasSources: LayoutReplaceSource[],
  currentSources: LayoutReplaceSource[]
) {
  const existingIdentities = new Set(
    currentSources.map(getLayoutReplaceSourceIdentity)
  );
  return canvasSources.filter(
    (source) =>
      Boolean(source.nodeId) &&
      !existingIdentities.has(getLayoutReplaceSourceIdentity(source))
  );
}