import "server-only";

import type { ConversationActionKind } from "@/lib/ai/conversation-action-resolver";
import type {
  ContextPayload,
  ResolvedChatMediaInput,
  ResolvedImageRef,
  ResolvedTargetAssets,
} from "@/lib/ai/context-memory/types";
import type { IntentArbiterMode } from "@/lib/ai/runtime/intent-arbiter";
import type { TaskBoundaryDecision } from "@/lib/ai/runtime/task-boundary-classifier";

export interface CanvasAgentClarificationGateDecision {
  shouldClarify: boolean;
  clarificationMessage?: string;
  reason?: string;
}

const BATCH_EDIT_REGEX =
  /(全部|都|一起|批量|这几张|这些图|所有|统一处理|都改|全部改|一起改|一起处理)/i;
const EXPLICIT_TARGET_HINT_REGEX =
  /(第\s*[一二三四五六七八九十两\d]+\s*(?:张|个|幅|图)|左边|左侧|左上|左下|右边|右侧|右上|右下|上面|上方|下面|下方|中间|居中|中央|选中的|当前这张|原图|上传图|上一张|上一版|结果图|刚生成|最新生成)/i;
const EXPLICIT_CONTINUATION_TARGET_REGEX =
  /(继续|上一张|上一版|结果图|刚生成|最新生成|原图|上传图|选中的|当前这张)/i;
const ACTIONABLE_EDIT_REGEX =
  /(改|调整|优化|换|替换|去掉|抠|重绘|增强|修|处理|按|保留|统一|背景|清晰|风格|亮一点|暗一点|白底|透明底|去背|扩图|放大|缩小|裁剪|调色)/i;
const ACTIONABLE_GENERATION_REGEX =
  /(生图|生成|画一张|出图|来一张|再来一张|做一张|做图|做视频|视频生成|生成视频|动起来)/i;
const ANALYSIS_ONLY_REGEX = /(分析|看图|看看|识别|描述|总结|解释|判断|评价)/i;
const VAGUE_EXECUTION_REGEX =
  /^(按刚才那个做|按刚才的做|按这个做|按这个来|照这个来|照刚才那个|就这个|这个|来吧|开始吧|搞一下|弄一下|继续吧|就这样|按上一个来|按上一版来|按刚才那个来)$/i;

function normalizeCompactText(text: string) {
  return String(text || "").replace(/\s+/g, "").trim();
}

function sortRefsForCanvasOrdering(refs: ResolvedImageRef[]) {
  return [...refs].sort((left, right) => {
    const leftY = Number(left.y ?? 0);
    const rightY = Number(right.y ?? 0);
    if (Math.abs(leftY - rightY) > 12) {
      return leftY - rightY;
    }
    return Number(left.x ?? 0) - Number(right.x ?? 0);
  });
}

function getPositionLabel(ref: ResolvedImageRef, refs: ResolvedImageRef[]): string {
  if (refs.length <= 1) return "中间";
  const xs = refs.map((item) => Number(item.x ?? 0));
  const ys = refs.map((item) => Number(item.y ?? 0));
  const minX = Math.min(...xs);
  const maxX = Math.max(...xs);
  const minY = Math.min(...ys);
  const maxY = Math.max(...ys);
  const spanX = Math.max(1, maxX - minX);
  const spanY = Math.max(1, maxY - minY);
  const relX = (Number(ref.x ?? 0) - minX) / spanX;
  const relY = (Number(ref.y ?? 0) - minY) / spanY;

  const horizontal = relX <= 0.33 ? "左" : relX >= 0.66 ? "右" : "中";
  const vertical = relY <= 0.33 ? "上" : relY >= 0.66 ? "下" : "中";

  if (horizontal === "中" && vertical === "中") return "中间";
  return `${vertical}${horizontal}`;
}

function buildRefPreviewList(refs: ResolvedImageRef[]) {
  const orderedRefs = sortRefsForCanvasOrdering(refs).slice(0, 4);
  return orderedRefs.map((ref, index) => {
    const position = getPositionLabel(ref, orderedRefs);
    const title = String(ref.title || "").trim();
    return `- 第${index + 1}张（${position}）${title ? `：${title}` : ""}`;
  });
}

function buildMultiSelectionClarificationMessage(selectedRefs: ResolvedImageRef[]) {
  const previewLines = buildRefPreviewList(selectedRefs);
  return [
    `你当前选中了 ${selectedRefs.length} 张图，我还不能确定这一步是只处理其中一张，还是批量处理全部。`,
    previewLines.length > 0 ? "当前选中候选：" : "",
    ...previewLines,
    "请直接回复：",
    "- 处理全部",
    "- 只处理第2张 / 左边那张",
    "",
    "也可以先在画布里只保留一张选中，再让我继续。",
  ]
    .filter(Boolean)
    .join("\n");
}

function buildMissingTargetClarificationMessage(params: {
  selectedRefs: ResolvedImageRef[];
  candidateRefs: ResolvedImageRef[];
}) {
  if (params.selectedRefs.length > 1) {
    return buildMultiSelectionClarificationMessage(params.selectedRefs);
  }

  if (params.candidateRefs.length > 1) {
    const previewLines = buildRefPreviewList(params.candidateRefs);
    return [
      "我这次还没锁定要处理哪张图。",
      `当前画布里有 ${params.candidateRefs.length} 张候选图：`,
      ...previewLines,
      "",
      "请直接回复“处理第2张 / 左边那张 / 选中的这张 / 上一版结果图 / 原图”，或者先在画布里选中一张再继续。",
    ].join("\n");
  }

  return [
    "我还没拿到可处理的目标图。",
    "你可以先上传图片，或者先在画布里选中一张图，再告诉我要怎么处理。",
  ].join("\n");
}

function buildLowConfidenceTargetClarificationMessage(params: {
  candidateRefs: ResolvedImageRef[];
  targetResolution: ResolvedTargetAssets;
}) {
  const previewLines = buildRefPreviewList(params.candidateRefs);
  return [
    "这一步我能继续执行，但当前目标图只是在低置信度下被系统猜中的，我不想替你处理错图。",
    previewLines.length > 0 ? `当前画布里可参考的候选图有 ${params.candidateRefs.length} 张：` : "",
    ...previewLines,
    "",
    `系统当前偏向的是「${params.targetResolution.reason}」这一路径，但我建议你先明确回复“第2张 / 左边那张 / 上一版结果图 / 原图”。`,
  ]
    .filter(Boolean)
    .join("\n");
}

function buildActionClarificationMessage(mode: IntentArbiterMode) {
  if (mode === "generate_image") {
    return [
      "我已经锁定目标图了，但还不清楚你这一步想让我怎么做。",
      "你可以直接回复类似：",
      "- 基于这张再生成 3 张",
      "- 按这个主体重新生成一版海报",
      "- 保留主体，换成白底产品图",
      "- 先分析这张图",
    ].join("\n");
  }

  if (mode === "generate_video") {
    return [
      "我已经锁定参考图了，但这一步的视频目标还不够明确。",
      "你可以直接回复类似：",
      "- 让产品缓慢旋转 5 秒",
      "- 做成首尾帧视频",
      "- 先按这张图规划分镜，不直接生成",
    ].join("\n");
  }

  return [
    "我已经锁定目标图了，但还不清楚你这一步想让我做什么。",
    "你可以直接回复类似：",
    "- 把背景改成白色",
    "- 去掉桌上的杯子",
    "- 提高清晰度并保留原构图",
    "- 先分析这张图",
  ].join("\n");
}

function isCanvasSource(contextPayload?: ContextPayload | null) {
  return (
    contextPayload?.source === "canvas" || contextPayload?.source === "realtime-canvas"
  );
}

function isExecutionMode(mode?: IntentArbiterMode) {
  return mode === "edit_image" || mode === "generate_image" || mode === "generate_video";
}

export function resolveCanvasAgentClarificationGate(params: {
  text: string;
  composerMode?: "agent" | "image" | "video" | "detail";
  contextPayload?: ContextPayload | null;
  mediaInput?: ResolvedChatMediaInput | null;
  targetResolution?: ResolvedTargetAssets | null;
  taskBoundaryDecision: TaskBoundaryDecision;
  executionMode?: IntentArbiterMode;
  actionKind?: ConversationActionKind;
}) {
  if (params.composerMode !== "agent") {
    return { shouldClarify: false } satisfies CanvasAgentClarificationGateDecision;
  }

  if (!isCanvasSource(params.contextPayload)) {
    return { shouldClarify: false } satisfies CanvasAgentClarificationGateDecision;
  }

  if (!isExecutionMode(params.executionMode)) {
    return { shouldClarify: false } satisfies CanvasAgentClarificationGateDecision;
  }

  if (!params.taskBoundaryDecision.shouldAllowExecution) {
    return { shouldClarify: false } satisfies CanvasAgentClarificationGateDecision;
  }

  const text = String(params.text || "").trim();
  const compactText = normalizeCompactText(text);
  const mediaInput = params.mediaInput;
  const targetResolution = params.targetResolution;
  const selectedRefs = mediaInput?.selectedImageRefs || [];
  const candidateRefs = targetResolution?.candidateRefs || mediaInput?.imageRefs || [];

  if (
    params.executionMode === "edit_image" &&
    selectedRefs.length > 1 &&
    !BATCH_EDIT_REGEX.test(compactText) &&
    !EXPLICIT_TARGET_HINT_REGEX.test(compactText)
  ) {
    return {
      shouldClarify: true,
      clarificationMessage: buildMultiSelectionClarificationMessage(selectedRefs),
      reason: "multiple_selected_canvas_targets_without_scope",
    } satisfies CanvasAgentClarificationGateDecision;
  }

  if (targetResolution?.needsClarification) {
    return {
      shouldClarify: true,
      clarificationMessage: buildMissingTargetClarificationMessage({
        selectedRefs,
        candidateRefs,
      }),
      reason: "target_resolution_requires_clarification",
    } satisfies CanvasAgentClarificationGateDecision;
  }

  const shouldClarifyLowConfidenceCanvasTarget =
    params.executionMode === "edit_image" &&
    selectedRefs.length === 0 &&
    (targetResolution?.resolutionMode === "working_memory" ||
      targetResolution?.resolutionMode === "latest_result") &&
    Number(targetResolution?.confidence || 0) < 85 &&
    candidateRefs.length > 1 &&
    !EXPLICIT_TARGET_HINT_REGEX.test(compactText) &&
    !EXPLICIT_CONTINUATION_TARGET_REGEX.test(compactText);

  if (shouldClarifyLowConfidenceCanvasTarget && targetResolution) {
    return {
      shouldClarify: true,
      clarificationMessage: buildLowConfidenceTargetClarificationMessage({
        candidateRefs,
        targetResolution,
      }),
      reason: "low_confidence_canvas_target_guess",
    } satisfies CanvasAgentClarificationGateDecision;
  }

  const lacksExplicitAction =
    !ACTIONABLE_EDIT_REGEX.test(compactText) &&
    !ACTIONABLE_GENERATION_REGEX.test(compactText) &&
    !ANALYSIS_ONLY_REGEX.test(compactText);
  const looksLikeVagueExecution =
    VAGUE_EXECUTION_REGEX.test(compactText) ||
    (compactText.length <= 8 &&
      /^(这个|就这个|按这个|来吧|开始吧|继续吧|就这样)$/.test(compactText));

  if (
    targetResolution &&
    targetResolution.targetRefs.length > 0 &&
    params.actionKind === "default" &&
    lacksExplicitAction &&
    looksLikeVagueExecution
  ) {
    return {
      shouldClarify: true,
      clarificationMessage: buildActionClarificationMessage(params.executionMode),
      reason: "target_locked_but_action_is_too_vague",
    } satisfies CanvasAgentClarificationGateDecision;
  }

  return {
    shouldClarify: false,
  } satisfies CanvasAgentClarificationGateDecision;
}