import { generateText } from "ai";
import { NextRequest, NextResponse } from "next/server";
import { z } from "zod";
import { inlineVisionImages } from "@/lib/ai/vision-inline";
import { createLogger } from "@/lib/observability/logger";
import {
  PRODUCT_PLANNING_ADVANCED_DISABLED,
  PRODUCT_PLANNING_ADVANCED_DISABLED_MESSAGE,
} from "@/lib/product-planning/advanced-disabled";
import { resolveProductPlanningVisionModel } from "@/lib/product-planning/model-runtime";
import {
  isProductPlanningEnabled,
  PRODUCT_PLANNING_DISABLED_MESSAGE,
} from "@/lib/product-planning/server-feature";
import { getProductPlanningToken } from "@/lib/product-planning/server-auth";
import type { ProductPlanningAnalyzeResponse } from "@/lib/product-planning/types";

export const runtime = "nodejs";
export const maxDuration = 120;

const logger = createLogger("product-planning-analyze-image-api");

const requestSchema = z.object({
  itemId: z.string().trim().min(1),
  imageUrl: z.string().trim().url(),
  title: z.string().trim().optional(),
});

function jsonError(status: number, error: string) {
  const payload: ProductPlanningAnalyzeResponse = {
    success: false,
    error,
  };
  return NextResponse.json(payload, { status });
}

function buildImageAnalyzePrompt(params: { itemId: string; title?: string }) {
  return [
    "你是一名资深电商视觉策划顾问，请分析这张竞品主图，并输出结构化 markdown。",
    `商品ID：${params.itemId}`,
    params.title ? `商品标题：${params.title}` : "",
    "",
    "请至少包含以下部分：",
    "1. 画面场景与拍摄方式",
    "2. 产品外观与结构要点",
    "3. 当前主图正在强调的核心卖点",
    "4. 用户感知风险或信息缺口",
    "5. 给我们做同类商品主图时可复用的优化建议",
    "",
    "要求：",
    "- 用中文输出",
    "- 结论明确，避免空泛形容词",
    "- 结合电商转化场景给出建议",
  ]
    .filter(Boolean)
    .join("\n");
}

export async function POST(request: NextRequest) {
  if (PRODUCT_PLANNING_ADVANCED_DISABLED) {
    return jsonError(503, PRODUCT_PLANNING_ADVANCED_DISABLED_MESSAGE);
  }

  const token = await getProductPlanningToken(request);
  if (!token?.sub) {
    return jsonError(401, "未登录");
  }
  if (!(await isProductPlanningEnabled())) {
    return jsonError(403, PRODUCT_PLANNING_DISABLED_MESSAGE);
  }

  let body: unknown;
  try {
    body = await request.json();
  } catch {
    return jsonError(400, "请求体不是合法 JSON");
  }

  const parsed = requestSchema.safeParse(body);
  if (!parsed.success) {
    return jsonError(400, "请求参数不合法");
  }

  const resolvedModel = await resolveProductPlanningVisionModel();
  if (!resolvedModel.model) {
    return jsonError(500, resolvedModel.error || "当前站点没有可用的图片分析模型");
  }

  try {
    const { inlineDataUrls } = await inlineVisionImages([parsed.data.imageUrl], {
      maxImages: 1,
      maxSide: 900,
      timeoutMs: 12000,
      retries: 1,
      loggerPrefix: "[ProductPlanning][AnalyzeImage]",
    });
    const effectiveImage = inlineDataUrls[0] || parsed.data.imageUrl;

    const { text } = await generateText({
      model: resolvedModel.model,
      messages: [
        {
          role: "user",
          content: [
            {
              type: "text",
              text: buildImageAnalyzePrompt(parsed.data),
            },
            {
              type: "image",
              image: effectiveImage,
            },
          ],
        },
      ],
      temperature: 0.2,
      maxTokens: 1200,
    } as any);

    return NextResponse.json({
      success: true,
      markdown: text,
    } satisfies ProductPlanningAnalyzeResponse);
  } catch (error) {
    logger.error("request_failed", error);
    return jsonError(502, "图片分析失败");
  }
}