using CPRNIMS.Domain.Contracts.Reports;
using CPRNIMS.Infrastructure.Database;
using CPRNIMS.Infrastructure.Dto.Inventory.Reports;
using Dapper;
using Microsoft.Data.SqlClient;
using Microsoft.EntityFrameworkCore;

namespace CPRNIMS.Infrastructure.Reports
{
    public class ReportDataService : IReportDataService
    {
        private readonly NonInventoryDbContext _context;

        public ReportDataService(NonInventoryDbContext context) => _context = context;

        private const string MainSql = """
        SELECT
            R.RISNo,
            PR.PRNo,
            R.QtyIssued,
            R.IssuedTo,
            CASE R.Status
                WHEN 0 THEN 'Draft'
                WHEN 1 THEN 'Approved'
                WHEN 2 THEN 'Cancelled'
                ELSE 'Unknown'
            END                                            AS StatusLabel,
            CreatedBy.CreatedBy,
            ApprovedBy.ApprovedBy,
            R.ApprovedDate,
            R.CreatedDate,
            D.DisciplineName,
            PRD.ItemName,
            PRD.ItemNo,
            IV.QtyIn,
            IV.QtyOut,
            IV.QtyOnHand,
            DEP.Department                                 AS DepartmentName,
            ISNULL(MRS_AGG.TotalReturned, 0)               AS TotalReturned,
            ISNULL(MRS_AGG.MRSCount, 0)                    AS MRSCount,
            R.QtyIssued - ISNULL(MRS_AGG.TotalReturned, 0) AS NetIssued
        FROM dbo.RIS R
        INNER JOIN dbo.Disciplines D ON R.DisciplineId = D.DisciplineId
        INNER JOIN dbo.Inventory IV ON R.InventoryId = IV.InventoryId AND IV.IsActive = 1
        LEFT JOIN dbo.Lot L ON IV.LotId = L.LotId
        OUTER APPLY (SELECT U.FullName ApprovedBy FROM dbo.Users U WHERE R.ApprovedBy = U.UserName) ApprovedBy
        OUTER APPLY (SELECT U2.FullName CreatedBy FROM dbo.Users U2 WHERE R.CreatedBy = U2.UserName) CreatedBy
        INNER JOIN Users U ON IV.UserId = U.Id
        LEFT JOIN dbo.Departments DEP ON U.DepartmentId = DEP.DepartmentId
        LEFT JOIN dbo.PRDetails PRD ON R.PRDetailId = PRD.PRDetailsId AND PRD.IsActive = 1
        LEFT JOIN dbo.PR PR ON PRD.PRId = PR.PRId AND PR.IsActive = 1
        LEFT JOIN (
            SELECT
                RISId,
                COUNT(*)         AS MRSCount,
                SUM(QtyReturned) AS TotalReturned
            FROM dbo.MRS
            WHERE Status != 2
            GROUP BY RISId
        ) MRS_AGG ON R.RISId = MRS_AGG.RISId
        WHERE R.Status != 2
          AND R.CreatedDate >= @DateFrom
          AND R.CreatedDate < DATEADD(DAY, 1, @DateTo)
        ORDER BY R.CreatedDate DESC, R.RISNo ASC;
        """;

        private const string DisciplineSql = """
        SELECT
            D.DisciplineName,
            COUNT(*) AS SlipCount
        FROM dbo.RIS R
        INNER JOIN dbo.Disciplines D ON R.DisciplineId = D.DisciplineId
        WHERE R.Status != 2
          AND R.CreatedDate >= @DateFrom
          AND R.CreatedDate < DATEADD(DAY, 1, @DateTo)
        GROUP BY D.DisciplineName
        ORDER BY SlipCount DESC;
        """;

        private const string RecipientsSql = """
        SELECT TOP 5
            R.IssuedTo      AS Name,
            COUNT(*)        AS SlipCount,
            SUM(IV.QtyOut)  AS QtyOut
        FROM dbo.RIS R
        INNER JOIN dbo.Inventory IV ON R.InventoryId = IV.InventoryId AND IV.IsActive = 1
        WHERE R.Status != 2
          AND R.CreatedDate >= @DateFrom
          AND R.CreatedDate < DATEADD(DAY, 1, @DateTo)
        GROUP BY R.IssuedTo
        ORDER BY COUNT(*) DESC;
        """;

        public List<RISRowDto> GetMain(DateTime dateFrom, DateTime dateTo) =>
            Query<RISRowDto>(MainSql, dateFrom, dateTo);

        public List<DisciplineAggDto> GetDisciplines(DateTime dateFrom, DateTime dateTo) =>
            Query<DisciplineAggDto>(DisciplineSql, dateFrom, dateTo);

        public List<TopRecipientDto> GetRecipients(DateTime dateFrom, DateTime dateTo) =>
            Query<TopRecipientDto>(RecipientsSql, dateFrom, dateTo);

        private List<T> Query<T>(string sql, DateTime from, DateTime to)
        {
            using var conn = new SqlConnection(_context.Database.GetConnectionString());
            return conn.Query<T>(sql, new { DateFrom = from, DateTo = to }).ToList();
        }
    }
}