using FastEndpoints;
using GB5Shared.DTO.Framework.Login;
using GB5Shared.DTO.Framework.ResponseStandard;
using GB5Shared.FastEndPoint;
using PayRollBLL.SAPPaySlip;
using System.Threading;
using System.Threading.Tasks;
using static GB5Shared.GB5Constant.Constant;

namespace PayRollSL.EndPoints.SAPPaySlip
{
    /// <summary>
    /// GET /PaySlip/GetSAPPaySlip
    ///
    /// Retrieves the logged-in employee's payslip PDF from the SAP ZPY_PAYSLIP_SRV OData service.
    ///
    /// The following are resolved automatically from the login session and server configuration:
    ///   • EmployeeID  — LoginDTO.UserCode
    ///   • SapClient   — morganizationunit.organizationunitcode (by LoginDTO.ClientId)
    ///   • Username    — SapPaySlip:Username in appsettings.json
    ///   • Password    — SapPaySlip:Password in appsettings.json
    ///
    /// Query parameters (caller provides):
    ///   FiscalYear — 4-digit year between 2000 and 2100 (e.g. "2025")
    ///   Month      — Month number 1–12, 1- or 2-digit (e.g. "1" or "01")
    ///
    /// On success each item in the response contains:
    ///   EmployeeID  — SAP employee number, zero-padded (e.g. "00001493")
    ///   FiscalYear  — 4-digit year
    ///   Month       — 2-digit month
    ///   PayslipForm — Base64-encoded PDF; decode with atob() (browser) or
    ///                 Convert.FromBase64String() (.NET) to render or download.
    /// </summary>
    public class GetSAPPaySlip
        : BaseEndpoint<GetSAPPaySlip.GetSAPPaySlipParameters, ResponseStandardDTO<object>>
    {
        private readonly ISAPPaySlipBLL _bll;

        public GetSAPPaySlip(ISAPPaySlipBLL bll) => _bll = bll;

        public override void Configure()
        {
            Get("/PaySlip/GetSAPPaySlip");
            AllowAnonymous();
        }

        public record GetSAPPaySlipParameters(
            [property: FromHeader] string Login,

            /// <summary>SAP employee number, e.g. "1493" or "00001493".</summary>
            [property: QueryParam] string EmployeeID,

            /// <summary>4-digit fiscal year (2000–2100), e.g. "2025".</summary>
            [property: QueryParam] string FiscalYear,

            /// <summary>Month number 1–12, e.g. "1" or "01".</summary>
            [property: QueryParam] string Month
        );

        protected override string? GetCacheKey(GetSAPPaySlipParameters req, LoginDTO login) => null;

        protected override async Task<ResponseStandardDTO<object>> ExecuteAsync(
            GetSAPPaySlipParameters req,
            LoginDTO login,
            CancellationToken ct)
        {
            var results = await _bll.GetPaySlipAsync(
                req.EmployeeID,
                req.FiscalYear,
                req.Month,
                login,
                ct);

            return await GB5Shared.ResponseStandard.Response
                .CreateSuccessResponse(results, CacheKeyLevel.NOT_REQUIRED, login);
        }
    }
}