import { NextRequest, NextResponse } from "next/server";
import { getDefaultStorageConfig, getSystemSetting, upsertSystemSetting } from "@/lib/db/queries";
import {
  PRODUCT_PLANNING_TEMPLATES_KEY,
  parseProductPlanningTemplates,
} from "@/lib/product-planning/templates";
import {
  isProductPlanningEnabled,
  PRODUCT_PLANNING_DISABLED_MESSAGE,
} from "@/lib/product-planning/server-feature";
import { getProductPlanningToken } from "@/lib/product-planning/server-auth";
import type { ProductPlanningTemplateMutationResponse } from "@/lib/product-planning/types";

export const runtime = "nodejs";

function isAdminToken(token: Awaited<ReturnType<typeof getProductPlanningToken>>) {
  const type = String(token?.type || "").trim();
  return type === "admin" || type === "agent_admin";
}

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

function encodeAttachmentFileName(fileName: string) {
  const fallback = fileName.replace(/[^\x20-\x7E]+/g, "_") || "template.xlsx";
  return `attachment; filename="${fallback}"; filename*=UTF-8''${encodeURIComponent(fileName)}`;
}

async function readTemplates() {
  const setting = await getSystemSetting({ key: PRODUCT_PLANNING_TEMPLATES_KEY });
  return parseProductPlanningTemplates(setting?.value);
}

async function tryDeleteTemplateFile(filePath?: string) {
  if (!filePath) return;

  try {
    const storageConfig = await getDefaultStorageConfig().catch(() => undefined);
    if (!storageConfig || storageConfig.type !== "s3") return;

    const { deleteS3ObjectByPath, toDbS3UploadConfig } = await import("@/lib/storage/service");
    const uploadConfig = toDbS3UploadConfig(storageConfig);
    if (!uploadConfig) return;

    await deleteS3ObjectByPath(filePath, uploadConfig);
  } catch (error) {
    console.warn("[ProductPlanning][Templates] delete file failed:", error);
  }
}

export async function GET(
  request: NextRequest,
  context: { params: Promise<{ id: string }> }
) {
  const token = await getProductPlanningToken(request);
  if (!token?.sub) {
    return jsonError(401, "未登录");
  }
  if (!(await isProductPlanningEnabled())) {
    return jsonError(403, PRODUCT_PLANNING_DISABLED_MESSAGE);
  }

  try {
    const { id } = await context.params;
    const templates = await readTemplates();
    const template = templates.find((entry) => entry.id === id);
    if (!template) {
      return jsonError(404, "未找到模板");
    }

    const response = await fetch(template.fileUrl, {
      headers: {
        Accept: template.contentType || "*/*",
      },
      cache: "no-store",
      signal: AbortSignal.timeout(20000),
    });

    if (!response.ok) {
      return jsonError(502, "模板文件下载失败");
    }

    const buffer = await response.arrayBuffer();
    return new NextResponse(buffer, {
      status: 200,
      headers: {
        "Content-Type": template.contentType || response.headers.get("content-type") || "application/octet-stream",
        "Content-Length": String(buffer.byteLength),
        "Content-Disposition": encodeAttachmentFileName(template.fileName),
        "Cache-Control": "no-store",
      },
    });
  } catch (error) {
    console.error("[ProductPlanning][Templates] download failed:", error);
    return jsonError(502, "模板文件下载失败");
  }
}

export async function DELETE(
  request: NextRequest,
  context: { params: Promise<{ id: string }> }
) {
  const token = await getProductPlanningToken(request);
  if (!token?.sub) {
    return jsonError(401, "未登录");
  }
  if (!(await isProductPlanningEnabled())) {
    return jsonError(403, PRODUCT_PLANNING_DISABLED_MESSAGE);
  }

  if (!isAdminToken(token)) {
    return jsonError(403, "需要管理员权限");
  }

  try {
    const { id } = await context.params;
    const templates = await readTemplates();
    const template = templates.find((entry) => entry.id === id);
    if (!template) {
      return jsonError(404, "未找到模板");
    }

    await upsertSystemSetting({
      key: PRODUCT_PLANNING_TEMPLATES_KEY,
      value: templates.filter((entry) => entry.id !== id),
      updatedBy: String(token.sub),
    });

    await tryDeleteTemplateFile(template.filePath);

    return NextResponse.json({
      success: true,
    } satisfies ProductPlanningTemplateMutationResponse);
  } catch (error) {
    console.error("[ProductPlanning][Templates] delete failed:", error);
    return jsonError(502, "模板删除失败");
  }
}