using SPMS.Domain.Common;
using SPMS.Domain.Enums;
using SPMS.Domain.Interfaces;

namespace SPMS.API.Middlewares;

public class ServiceCodeMiddleware
{
    private readonly RequestDelegate _next;

    public ServiceCodeMiddleware(RequestDelegate next) => _next = next;

    public async Task InvokeAsync(HttpContext context, IServiceRepository serviceRepository)
    {
        var path = context.Request.Path;

        // === SKIP: X-Service-Code 불필요 ===
        if (path == "/" ||
            !path.StartsWithSegments("/v1") ||
            path.StartsWithSegments("/v1/out") ||
            path.StartsWithSegments("/v1/in/auth") ||
            path.StartsWithSegments("/v1/in/account") ||
            path.StartsWithSegments("/v1/in/public") ||
            path.StartsWithSegments("/v1/in/service") ||
            (path.StartsWithSegments("/v1/in/device") &&
             !path.StartsWithSegments("/v1/in/device/list")) ||
            path.StartsWithSegments("/swagger") ||
            path.StartsWithSegments("/health"))
        {
            await _next(context);
            return;
        }

        // === OPTIONAL_FOR_ADMIN: 관리자는 X-Service-Code 선택 ===
        if (path.StartsWithSegments("/v1/in/stats") ||
            path.StartsWithSegments("/v1/in/device/list") ||
            path.StartsWithSegments("/v1/in/message/list") ||
            path == "/v1/in/tag/list")
        {
            if (context.Request.Headers.TryGetValue("X-Service-Code", out var optionalCode) &&
                !string.IsNullOrWhiteSpace(optionalCode))
            {
                // 헤더가 있으면 기존 검증 수행
                await ValidateAndSetService(context, serviceRepository, optionalCode!);
                return;
            }

            // 헤더 없음 — 인증된 사용자만 전체 서비스 모드 허용
            if (context.User.Identity?.IsAuthenticated == true)
            {
                // ServiceId 미설정 = 전체 서비스 모드
                await _next(context);
                return;
            }

            // 비인증 요청 → 에러
            context.Response.StatusCode = 400;
            context.Response.ContentType = "application/json";
            await context.Response.WriteAsJsonAsync(
                ApiResponse.Fail(ErrorCodes.ServiceScopeRequired, "X-Service-Code 헤더가 필요합니다."));
            return;
        }

        // === REQUIRED: X-Service-Code 필수 ===
        if (!context.Request.Headers.TryGetValue("X-Service-Code", out var serviceCode) ||
            string.IsNullOrWhiteSpace(serviceCode))
        {
            context.Response.StatusCode = 400;
            context.Response.ContentType = "application/json";
            await context.Response.WriteAsJsonAsync(
                ApiResponse.Fail(ErrorCodes.BadRequest, "X-Service-Code 헤더가 필요합니다."));
            return;
        }

        await ValidateAndSetService(context, serviceRepository, serviceCode!);
    }

    private async Task ValidateAndSetService(HttpContext context, IServiceRepository serviceRepository, string serviceCode)
    {
        var service = await serviceRepository.GetByServiceCodeAsync(serviceCode);
        if (service == null)
        {
            context.Response.StatusCode = 404;
            context.Response.ContentType = "application/json";
            await context.Response.WriteAsJsonAsync(
                ApiResponse.Fail(ErrorCodes.NotFound, "존재하지 않는 서비스입니다."));
            return;
        }

        if (service.Status != ServiceStatus.Active)
        {
            context.Response.StatusCode = 503;
            context.Response.ContentType = "application/json";
            await context.Response.WriteAsJsonAsync(
                ApiResponse.Fail(ErrorCodes.Unauthorized, "비활성 상태의 서비스입니다."));
            return;
        }

        context.Items["Service"] = service;
        context.Items["ServiceId"] = service.Id;
        await _next(context);
    }
}