const { z } = require("zod");

const { AppError } = require("../utils/AppError");
const { sendData } = require("../utils/reply");
const { FEATURE_FLAG_KEYS, evaluateFeatureFlag } = require("../services/featureFlags");

const QUERY_SCHEMA = z.object({
  q: z.string().trim().min(2).max(100),
  limit: z.coerce.number().int().min(1).max(20).optional(),
});

function buildValidationError(details, statusCode = 400) {
  return new AppError({ code: "VALID_001", message: "参数校验失败", statusCode, details });
}

async function ensureFeatureEnabled(fastify, request) {
  const gate = await evaluateFeatureFlag({
    prisma: fastify.prisma,
    config: fastify.config,
    flagKey: FEATURE_FLAG_KEYS.globalSearch,
    departmentId: request.employee.department_id ?? null,
    strictDepartment: false,
  });
  if (!gate.enabled) {
    throw buildValidationError({ featureFlag: "global_search_v1_disabled", reason: gate.reason }, 409);
  }
}

function matchByValue(query, ...values) {
  const lower = query.toLowerCase();
  const normalized = values.filter(Boolean).map((item) => String(item).toLowerCase());
  if (normalized.some((item) => item === lower)) return "exact";
  if (normalized.some((item) => item.startsWith(lower))) return "prefix";
  return "contains";
}

function compareMatchedBy(left, right) {
  const score = { exact: 0, prefix: 1, contains: 2 };
  return score[left] - score[right];
}

async function searchRoutes(fastify) {
  fastify.get("/search", { preHandler: fastify.authenticate }, async (request, reply) => {
    await ensureFeatureEnabled(fastify, request);
    const parsed = QUERY_SCHEMA.safeParse(request.query ?? {});
    if (!parsed.success) throw buildValidationError(parsed.error.flatten());
    const q = parsed.data.q.trim();
    const limit = parsed.data.limit ?? 10;

    const tasks = [];
    const isAdmin = fastify.hasPermission(request.employee, "*");

    if (fastify.hasPermission(request.employee, "expense.view_own") || fastify.hasPermission(request.employee, "expense.view_all")) {
      tasks.push(
        fastify.prisma.reimbursementForm.findMany({
          where: {
            AND: [
              fastify.hasPermission(request.employee, "expense.view_all") || isAdmin
                ? {}
                : { OR: [{ owner_id: request.employee.id }, { submitter_id: request.employee.id }] },
              {
                OR: [
                  { form_number: { contains: q, mode: "insensitive" } },
                  { description: { contains: q, mode: "insensitive" } },
                ],
              },
            ],
          },
          take: limit,
          orderBy: { updated_at: "desc" },
          select: { id: true, form_number: true, description: true, status: true, updated_at: true },
        }).then((rows) => rows.map((item) => ({
          entityType: "reimbursement",
          entityId: item.id,
          title: item.form_number ?? item.id,
          subtitle: item.description ?? null,
          status: item.status,
          href: `/reimbursements/${item.id}`,
          matchedBy: matchByValue(q, item.form_number, item.description),
          updatedAt: item.updated_at?.toISOString?.() ?? null,
        }))),
      );
    }

    if (fastify.hasPermission(request.employee, "leave.view_own") || fastify.hasPermission(request.employee, "leave.view_all") || fastify.hasPermission(request.employee, "leave.manage")) {
      tasks.push(
        fastify.prisma.leaveRequest.findMany({
          where: {
            AND: [
              fastify.hasPermission(request.employee, "leave.view_all") || fastify.hasPermission(request.employee, "leave.manage") || isAdmin
                ? {}
                : { owner_id: request.employee.id },
              { OR: [{ reason: { contains: q, mode: "insensitive" } }] },
            ],
          },
          take: limit,
          orderBy: { updated_at: "desc" },
          select: { id: true, reason: true, status: true, start_date: true, end_date: true, updated_at: true },
        }).then((rows) => rows.map((item) => ({
          entityType: "leave",
          entityId: item.id,
          title: `请假 ${item.start_date?.toISOString?.()?.slice(0, 10) ?? ""} ~ ${item.end_date?.toISOString?.()?.slice(0, 10) ?? ""}`,
          subtitle: item.reason ?? null,
          status: item.status,
          href: "/leave-requests",
          matchedBy: matchByValue(q, item.reason),
          updatedAt: item.updated_at?.toISOString?.() ?? null,
        }))),
      );
    }

    if (fastify.hasPermission(request.employee, "procurement.view_own") || fastify.hasPermission(request.employee, "procurement.view_all") || fastify.hasPermission(request.employee, "procurement.manage")) {
      tasks.push(
        fastify.prisma.purchaseRequest.findMany({
          where: {
            AND: [
              fastify.hasPermission(request.employee, "procurement.view_all") || fastify.hasPermission(request.employee, "procurement.manage") || isAdmin
                ? {}
                : { applicant_id: request.employee.id },
              {
                OR: [
                  { request_no: { contains: q, mode: "insensitive" } },
                  { title: { contains: q, mode: "insensitive" } },
                ],
              },
            ],
          },
          take: limit,
          orderBy: { updated_at: "desc" },
          select: { id: true, request_no: true, title: true, status: true, updated_at: true },
        }).then((rows) => rows.map((item) => ({
          entityType: "purchase_request",
          entityId: item.id,
          title: item.request_no ?? item.title,
          subtitle: item.title,
          status: item.status,
          href: `/purchase-requests?id=${item.id}`,
          matchedBy: matchByValue(q, item.request_no, item.title),
          updatedAt: item.updated_at?.toISOString?.() ?? null,
        }))),
      );
    }

    if (fastify.hasPermission(request.employee, "travel.view_own") || fastify.hasPermission(request.employee, "travel.view_all") || fastify.hasPermission(request.employee, "travel.manage")) {
      tasks.push(
        fastify.prisma.travelRequest.findMany({
          where: {
            AND: [
              fastify.hasPermission(request.employee, "travel.view_all") || fastify.hasPermission(request.employee, "travel.manage") || isAdmin
                ? {}
                : { OR: [{ applicant_employee_id: request.employee.id }, { submitter_id: request.employee.id }] },
              {
                OR: [
                  { request_no: { contains: q, mode: "insensitive" } },
                  { purpose: { contains: q, mode: "insensitive" } },
                ],
              },
            ],
          },
          take: limit,
          orderBy: { updated_at: "desc" },
          select: { id: true, request_no: true, purpose: true, status: true, updated_at: true },
        }).then((rows) => rows.map((item) => ({
          entityType: "travel_request",
          entityId: item.id,
          title: item.request_no ?? item.purpose,
          subtitle: item.purpose,
          status: item.status,
          href: `/travel-requests?id=${item.id}`,
          matchedBy: matchByValue(q, item.request_no, item.purpose),
          updatedAt: item.updated_at?.toISOString?.() ?? null,
        }))),
      );
    }

    if (
      fastify.hasPermission(request.employee, "asset.view_own") ||
      fastify.hasPermission(request.employee, "asset.view_all") ||
      fastify.hasPermission(request.employee, "asset.manage") ||
      fastify.hasPermission(request.employee, "asset.transfer") ||
      fastify.hasPermission(request.employee, "asset.inventory")
    ) {
      tasks.push(
        fastify.prisma.assetCard.findMany({
          where: {
            AND: [
              fastify.hasPermission(request.employee, "asset.view_all") || fastify.hasPermission(request.employee, "asset.manage") || fastify.hasPermission(request.employee, "asset.transfer") || fastify.hasPermission(request.employee, "asset.inventory") || isAdmin
                ? {}
                : { assignee_employee_id: request.employee.id },
              {
                OR: [
                  { asset_no: { contains: q, mode: "insensitive" } },
                  { serial_no: { contains: q, mode: "insensitive" } },
                  { name: { contains: q, mode: "insensitive" } },
                ],
              },
            ],
          },
          take: limit,
          orderBy: { updated_at: "desc" },
          select: { id: true, asset_no: true, serial_no: true, name: true, status: true, updated_at: true },
        }).then((rows) => rows.map((item) => ({
          entityType: "asset",
          entityId: item.id,
          title: item.asset_no,
          subtitle: item.name ?? item.serial_no ?? null,
          status: item.status,
          href: "/assets",
          matchedBy: matchByValue(q, item.asset_no, item.serial_no, item.name),
          updatedAt: item.updated_at?.toISOString?.() ?? null,
        }))),
      );
    }

    const items = (await Promise.all(tasks)).flat();
    items.sort((left, right) => {
      const matchedDiff = compareMatchedBy(left.matchedBy, right.matchedBy);
      if (matchedDiff !== 0) return matchedDiff;
      return String(right.updatedAt ?? "").localeCompare(String(left.updatedAt ?? ""));
    });

    return sendData(reply, request, { items: items.slice(0, limit) });
  });
}
module.exports = searchRoutes;