import { randomUUID } from "node:crypto";
import { NextRequest, NextResponse } from "next/server";
import { upsertSystemSetting } from "@/lib/db/queries";
import { requireAgentWorkflowAdmin } from "@/lib/middleware/admin";
import { uploadFile } from "@/lib/storage/service";
import {
  AGENT_PSD_TEMPLATE_ASSET_VERSION,
  AGENT_PSD_TEMPLATES_KEY,
  normalizeAgentPsdTemplateMode,
  normalizeAgentPsdTemplateStatus,
  upsertAgentPsdTemplate,
  type AgentPsdTemplate,
  type AgentPsdTemplateLayerSlot,
  type AgentPsdTemplateListResponse,
  type AgentPsdTemplateMutationResponse,
} from "@/lib/agents/psd-template-config";
import { normalizeAgentPsdTemplateCategoryTags } from "@/lib/agents/psd-template-category-tag-config";
import { cacheAgentPsdSourceLocally } from "@/lib/agents/psd-local-cache";
import { readAgentPsdTemplates } from "@/lib/agents/psd-template-settings";

export const runtime = "nodejs";

const MAX_TEMPLATE_FILE_SIZE = 80 * 1024 * 1024;
const ALLOWED_TEMPLATE_EXTENSIONS = new Set(["psd", "psb"]);
const PLACEHOLDER_PREVIEW_PNG = Buffer.from(
  "iVBORw0KGgoAAAANSUhEUgAAAAEAAAABCAQAAAC1HAwCAAAAC0lEQVR42mP8/x8AAwMCAO2+p4kAAAAASUVORK5CYII=",
  "base64"
);

function jsonListError(status: number, error: string) {
  const payload: AgentPsdTemplateListResponse = {
    success: false,
    templates: [],
    error,
  };
  return NextResponse.json(payload, { status });
}

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

function getFileExtension(fileName: string) {
  return fileName.toLowerCase().split(".").pop() || "";
}

function getDefaultTemplateName(fileName: string) {
  return fileName.replace(/\.[^.]+$/, "").trim() || "未命名 PSD 模板";
}

function toArrayBuffer(buffer: Buffer) {
  return buffer.buffer.slice(
    buffer.byteOffset,
    buffer.byteOffset + buffer.byteLength
  ) as ArrayBuffer;
}

export async function GET() {
  const session = await requireAgentWorkflowAdmin().catch(() => null);
  if (!session?.user?.id) {
    return jsonListError(401, "未登录");
  }

  try {
    const templates = await readAgentPsdTemplates();
    return NextResponse.json({
      success: true,
      templates,
    } satisfies AgentPsdTemplateListResponse);
  } catch (error) {
    console.error("[PSD Templates][Admin] list failed:", error);
    return jsonListError(503, "PSD 模板读取失败");
  }
}

export async function POST(request: NextRequest) {
  const session = await requireAgentWorkflowAdmin().catch(() => null);
  if (!session?.user?.id) {
    return jsonMutationError(401, "未登录");
  }

  let formData: FormData;
  try {
    formData = await request.formData();
  } catch {
    return jsonMutationError(400, "上传表单解析失败");
  }

  const file = formData.get("file");
  const name =
    String(formData.get("name") || "").trim() ||
    (file instanceof File ? getDefaultTemplateName(file.name) : "");
  const brandName = String(formData.get("brandName") || "").trim();
  const mode = normalizeAgentPsdTemplateMode(formData.get("mode"));
  const secondaryCategory = String(formData.get("secondaryCategory") || "").trim();
  const categoryTags = normalizeAgentPsdTemplateCategoryTags(
    formData.getAll("categoryTags").map((item) => String(item || ""))
  );
  const description = String(formData.get("description") || "").trim();
  const status = normalizeAgentPsdTemplateStatus(formData.get("status"));

  if (!name) {
    return jsonMutationError(400, "缺少模板名称");
  }

  if (!brandName) {
    return jsonMutationError(400, "请选择模板品牌");
  }

  if (name.length > 80) {
    return jsonMutationError(400, "模板名称不能超过 80 个字符");
  }

  if (brandName.length > 64) {
    return jsonMutationError(400, "模板品牌不能超过 64 个字符");
  }

  if (secondaryCategory.length > 64) {
    return jsonMutationError(400, "模板二级分类不能超过 64 个字符");
  }

  if (!(file instanceof File)) {
    return jsonMutationError(400, "缺少 PSD 模板文件");
  }

  const extension = getFileExtension(file.name);
  if (!ALLOWED_TEMPLATE_EXTENSIONS.has(extension)) {
    return jsonMutationError(400, "模板文件仅支持 PSD / PSB");
  }

  if (file.size <= 0) {
    return jsonMutationError(400, "模板文件不能为空");
  }

  if (file.size > MAX_TEMPLATE_FILE_SIZE) {
    return jsonMutationError(400, "模板文件不能超过 80MB");
  }

  try {
    const fileBuffer = await file.arrayBuffer();
    const templateId = randomUUID();
    await cacheAgentPsdSourceLocally({
      templateId,
      fileName: file.name,
      buffer: fileBuffer,
    }).catch((error) => {
      console.warn("[PSD Templates][Admin] failed to cache uploaded PSD locally:", {
        templateId,
        error,
      });
    });
    const [uploadedFile, uploadedPreview] = await Promise.all([
      uploadFile(file.name, fileBuffer),
      uploadFile(
        `agent-psd-preview-placeholder-${Date.now()}.png`,
        toArrayBuffer(PLACEHOLDER_PREVIEW_PNG)
      ),
    ]);

    const now = new Date().toISOString();
    const nextTemplate: AgentPsdTemplate = {
      id: templateId,
      name,
      brandName,
      mode,
      secondaryCategory: secondaryCategory || undefined,
      categoryTags: categoryTags.length > 0 ? categoryTags : undefined,
      description: description || undefined,
      status,
      parseStatus: "pending",
      parseProgress: 0,
      parseStage: "等待手动解析",
      parseError: undefined,
      fileName: file.name,
      fileUrl: uploadedFile.url,
      filePath: uploadedFile.pathname,
      previewUrl: uploadedPreview.url,
      previewPath: uploadedPreview.pathname,
      renderBaseUrl: undefined,
      renderBasePath: undefined,
      width: 1,
      height: 1,
      layerCount: 0,
      layers: [] as AgentPsdTemplateLayerSlot[],
      assetVersion: AGENT_PSD_TEMPLATE_ASSET_VERSION,
      createdAt: now,
      updatedAt: now,
      uploadedById: session.user.id,
    };

    const currentTemplates = await readAgentPsdTemplates();
    const templates = upsertAgentPsdTemplate(currentTemplates, nextTemplate);

    await upsertSystemSetting({
      key: AGENT_PSD_TEMPLATES_KEY,
      value: templates,
      updatedBy: session.user.id,
    });

    return NextResponse.json({
      success: true,
      template: nextTemplate,
    } satisfies AgentPsdTemplateMutationResponse);
  } catch (error) {
    console.error("[PSD Templates][Admin] create failed:", error);
    return jsonMutationError(502, "PSD 模板上传或解析失败");
  }
}