import type {
  CanvasAgentContext,
  CanvasAgentNodeRef,
  CanvasViewOperationPlan,
} from "@/types/canvas/agent-protocol";

function normalizeNodeIds(values: Array<string | null | undefined>, maxItems = 20) {
  return Array.from(
    new Set(values.map((value) => String(value || "").trim()).filter(Boolean))
  ).slice(0, maxItems);
}

function getNodeSourceIds(node?: CanvasAgentNodeRef | null) {
  const metadata = node?.metadata || {};
  const sourceIds = Array.isArray(metadata.sourceNodeIds)
    ? metadata.sourceNodeIds
        .map((value) => String(value || "").trim())
        .filter(Boolean)
    : [];
  return normalizeNodeIds([
    typeof metadata.revisionOf === "string" ? metadata.revisionOf : undefined,
    typeof metadata.sourceNodeId === "string" ? metadata.sourceNodeId : undefined,
    ...sourceIds,
  ]);
}

function isAgentResultNode(node?: CanvasAgentNodeRef | null) {
  const metadata = node?.metadata || {};
  return (
    metadata.generatedByAgent === true ||
    typeof metadata.canvasAgentOperationId === "string" ||
    typeof metadata.canvasAgentMediaItemId === "string" ||
    getNodeSourceIds(node).length > 0
  );
}

export function hasCanvasAgentComparisonViewIntent(userText: string) {
  return /对比|比较|一起看|同时看|原图.*新图|新图.*原图/.test(
    userText.toLowerCase()
  );
}

export function hasCanvasAgentLatestResultViewIntent(userText: string) {
  const text = userText.trim().toLowerCase();
  if (!text) return false;

  const hasLatestResultTarget =
    /刚生成|刚才生成|最新(?:的)?(?:结果|图片|图|生成)|最近(?:的)?(?:结果|图片|图|生成)|上次生成|最后生成|刚出(?:的)?(?:图|结果)|新结果|新图/.test(
      text
    );
  if (!hasLatestResultTarget) return false;

  const hasViewVerb =
    /聚焦|定位|居中|找到|跳到|看(?:看|一下|清楚)?|放大|拉近|focus|locate|zoom/.test(
      text
    );
  if (!hasViewVerb) return false;

  return !/生成(?:一|个|张|幅|段)|出图|做一版|再出|换|改|编辑|抠图|去水印|高清|清晰|扩图|裁剪|删除|替换|背景|视频|模型|洗图|重绘|尺寸|像素|分辨率/.test(
    text
  );
}

export function resolveCanvasAgentComparisonNodeIds(params: {
  context: CanvasAgentContext;
  maxItems?: number;
}) {
  const maxItems = Math.max(2, Math.min(20, params.maxItems || 10));
  const allNodes = [...params.context.selectedNodes, ...params.context.candidateNodes];
  const nodeMap = new Map(allNodes.map((node) => [node.nodeId, node]));
  const selectedNodeIds = normalizeNodeIds(
    [
      ...params.context.selectedNodeIds,
      ...params.context.selectedNodes
        .filter((node) => node.isSelected)
        .map((node) => node.nodeId),
    ],
    maxItems
  ).filter((nodeId) => nodeMap.has(nodeId));

  if (selectedNodeIds.length >= 2) return selectedNodeIds.slice(0, maxItems);

  const selectedNode = selectedNodeIds[0] ? nodeMap.get(selectedNodeIds[0]) : null;
  const selectedSourceIds = getNodeSourceIds(selectedNode).filter((nodeId) =>
    nodeMap.has(nodeId)
  );
  if (selectedNode?.nodeId && selectedSourceIds.length > 0) {
    return normalizeNodeIds([...selectedSourceIds, selectedNode.nodeId], maxItems);
  }

  if (selectedNode?.nodeId) {
    const relatedResult = allNodes.find(
      (node) =>
        node.nodeId !== selectedNode.nodeId &&
        isAgentResultNode(node) &&
        getNodeSourceIds(node).includes(selectedNode.nodeId)
    );
    if (relatedResult) {
      return normalizeNodeIds([selectedNode.nodeId, relatedResult.nodeId], maxItems);
    }
  }

  const latestResultWithSource = allNodes.find((node) => {
    if (!isAgentResultNode(node)) return false;
    return getNodeSourceIds(node).some((nodeId) => nodeMap.has(nodeId));
  });
  if (latestResultWithSource) {
    return normalizeNodeIds(
      [...getNodeSourceIds(latestResultWithSource), latestResultWithSource.nodeId],
      maxItems
    ).filter((nodeId) => nodeMap.has(nodeId));
  }

  return [];
}

export function buildCanvasAgentComparisonViewPlan(params: {
  context: CanvasAgentContext;
  projectId: string;
  operationId: string;
  reason?: string;
}): CanvasViewOperationPlan | null {
  const nodeIds = resolveCanvasAgentComparisonNodeIds({
    context: params.context,
    maxItems: 10,
  });
  if (nodeIds.length < 2) return null;

  return {
    version: 1,
    viewOperationId: `${params.operationId}:view`,
    operation: "focus_nodes",
    projectId: params.projectId,
    nodeIds,
    anchorNodeId: nodeIds[0],
    padding: 140,
    persist: false,
    reason: params.reason || "focus_canvas_comparison_targets",
  };
}

export function buildCanvasAgentLatestResultViewPlan(params: {
  userText: string;
  projectId: string;
  operationId: string;
  reason?: string;
}): CanvasViewOperationPlan | null {
  const projectId = String(params.projectId || "").trim();
  const operationId = String(params.operationId || "").trim();
  if (!projectId || !operationId) return null;
  if (!hasCanvasAgentLatestResultViewIntent(params.userText)) return null;

  return {
    version: 1,
    viewOperationId: `${operationId}:view`,
    operation: "focus_latest_result",
    projectId,
    padding: 120,
    durationMs: 360,
    persist: false,
    reason: params.reason || "focus_latest_canvas_agent_result",
  };
}