using PayRollDAL.DTO.SAP;
using System;
using System.Collections.Generic;
using System.Linq;
using System.Text.Json;

namespace PayRollBLL.SAP.Builders
{
    /// <summary>
    /// SAP Infotype 581 — HRA / Rent Paid.
    /// Service: ZPY_ITDEC_HRA_SRV / ITDecHRA_HeaderSet
    /// Source: TDECLARATIONDETAIL rows where DeclarationDetailType == 2 (Rent).
    /// One SAP item per rent detail record; dates formatted as dd-MMM-yyyy per SAP spec.
    /// </summary>
    public class SAP581Builder : ISapInfotypeBuilder
    {
        private const byte RentType = 2;

        public int    Infotype       => 581;
        public string DisplayName    => "HRA / Rent Paid";
        public string EndpointPath   => "/sap/opu/odata/sap/ZPY_ITDEC_HRA_SRV/ITDecHRA_HeaderSet";
        public string MsgNavProperty => "Nav2IT_Dec_HRA_Msg";

        public string Build(IEnumerable<ITDeclarationSapDTO> rows, string date, string remarks)
        {
            var items = rows
                .Where(r => r.DeclarationDetailId.HasValue
                         && r.DeclarationDetailType == RentType
                         && r.DeclaredAmount != 0)
                .Select(r => new Sap581Item
                {
                    EmployeeID  = r.EmployeeCode,
                    FiscalYear  = r.FiscalYear,
                    Particulars = r.Particulars,
                    From        = r.FromPeriod.HasValue
                                      ? r.FromPeriod.Value.ToString("dd-MMM-yyyy")
                                      : string.Empty,
                    To          = r.ToPeriod.HasValue
                                      ? r.ToPeriod.Value.ToString("dd-MMM-yyyy")
                                      : string.Empty,

                    // IsMetro: 0 = Metro city, 1 = Non-Metro (per ITDeclarationSapDTO)
                    Type = r.IsMetro == 0 ? "Metro" : "Non-Metro",

                    // SAP expects monthly rent; the DB stores the annual declared/approved total.
                    Declared = SapFmt.Amount(Math.Round(r.DeclaredAmount / 12, 2)),
                    Approved = SapFmt.Amount(Math.Round(r.ApprovedAmount / 12, 2)),

                    Remarks              = r.DetailRemarks,
                    LandLordName         = r.ContactName,
                    LandLordPAN          = r.ContactPAN,
                    LandLordTAN          = r.ContactTAN,
                    LandLordAddressLine1 = r.ContactAddress1,
                    LandLordAddressLine2 = r.ContactAddress2,
                    LandLordAddressLine3 = r.ContactAddress3,
                    LandLordAddressLine4 = r.ContactAddress4,
                    LandLordAddressLine5 = r.ContactAddress5,
                })
                .ToList();

            if (items.Count == 0) return string.Empty;

            var payload = new Sap581Payload
            {
                Date                = date,
                Remarks             = remarks,
                Nav2IT_Dec_HRA_Item = items,
            };

            return JsonSerializer.Serialize(payload, SapJsonOptions.Plain);
        }
    }
}