import { NextRequest, NextResponse } from "next/server";
import { z } from "zod";
import { executeInquireOrderableCash } from "@/lib/kis/trade";
import type { DashboardStockOrderableCashResponse } from "@/features/trade/types/trade.types";
import { hasKisApiSession } from "@/app/api/kis/_session";
import { hasKisConfig, normalizeTradingEnv } from "@/lib/kis/config";
import {
  createKisApiErrorResponse,
  KIS_API_ERROR_CODE,
  toKisApiErrorMessage,
} from "@/app/api/kis/_response";
import {
  readKisAccountParts,
  readKisCredentialsFromHeaders,
} from "@/app/api/kis/domestic/_shared";

/**
 * @file app/api/kis/domestic/orderable-cash/route.ts
 * @description 국내주식 매수가능금액(주문가능현금) 조회 API
 */

const orderableCashBodySchema = z.object({
  symbol: z
    .string()
    .trim()
    .regex(/^\d{6}$/, "종목코드는 6자리 숫자여야 합니다."),
  price: z.coerce.number().positive("기준 가격은 0보다 커야 합니다."),
  orderType: z.enum(["limit", "market"]).default("market"),
});

export async function POST(request: NextRequest) {
  const credentials = readKisCredentialsFromHeaders(request.headers);
  const tradingEnv = normalizeTradingEnv(credentials.tradingEnv);

  const hasSession = await hasKisApiSession();
  if (!hasSession) {
    return createKisApiErrorResponse({
      status: 401,
      code: KIS_API_ERROR_CODE.AUTH_REQUIRED,
      message: "로그인이 필요합니다.",
      tradingEnv,
    });
  }

  if (!hasKisConfig(credentials)) {
    return createKisApiErrorResponse({
      status: 400,
      code: KIS_API_ERROR_CODE.CREDENTIAL_REQUIRED,
      message: "KIS API 키 설정이 필요합니다.",
      tradingEnv,
    });
  }

  const account = readKisAccountParts(request.headers);
  if (!account) {
    return createKisApiErrorResponse({
      status: 400,
      code: KIS_API_ERROR_CODE.ACCOUNT_REQUIRED,
      message:
        "계좌번호가 필요합니다. 설정에서 계좌번호(예: 12345678-01)를 입력해 주세요.",
      tradingEnv,
    });
  }

  try {
    let rawBody: unknown = {};
    try {
      rawBody = (await request.json()) as unknown;
    } catch {
      return createKisApiErrorResponse({
        status: 400,
        code: KIS_API_ERROR_CODE.INVALID_REQUEST,
        message: "요청 본문(JSON)을 읽을 수 없습니다.",
        tradingEnv,
      });
    }

    const parsed = orderableCashBodySchema.safeParse(rawBody);
    if (!parsed.success) {
      return createKisApiErrorResponse({
        status: 400,
        code: KIS_API_ERROR_CODE.INVALID_REQUEST,
        message: parsed.error.issues[0]?.message ?? "요청값이 올바르지 않습니다.",
        tradingEnv,
      });
    }

    const result = await executeInquireOrderableCash(
      {
        symbol: parsed.data.symbol,
        price: parsed.data.price,
        orderType: parsed.data.orderType,
        accountNo: account.accountNo,
        accountProductCode: account.accountProductCode,
      },
      credentials,
    );

    const response: DashboardStockOrderableCashResponse = {
      ok: true,
      tradingEnv,
      orderableCash: result.orderableCash,
      noReceivableBuyAmount: result.noReceivableBuyAmount,
      maxBuyAmount: result.maxBuyAmount,
      maxBuyQuantity: result.maxBuyQuantity,
      noReceivableBuyQuantity: result.noReceivableBuyQuantity,
      fetchedAt: new Date().toISOString(),
    };

    return NextResponse.json(response, {
      headers: {
        "cache-control": "no-store",
      },
    });
  } catch (error) {
    return createKisApiErrorResponse({
      status: 500,
      code: KIS_API_ERROR_CODE.UPSTREAM_FAILURE,
      message: toKisApiErrorMessage(error, "매수가능금액 조회 중 오류가 발생했습니다."),
      tradingEnv,
    });
  }
}