using TMSDAL.Enums;   // ApprovalType, EnrollmentStatus

namespace TMSDAL.DTO.TrainingEnrollment
{
    // ════════════════════════════════════════════════════════════════════════
    // PRIMARY DTO — full record, used for Insert / Get single
    // ════════════════════════════════════════════════════════════════════════

    /// <summary>
    /// Full enrollment record DTO.
    /// Used for: SaveTrainingEnrollment (INSERT) and GetTrainingEnrollment (SELECT single).
    /// All nullable fields reflect NULL-able DB columns.
    /// </summary>
    public class TrainingEnrollmentDTO
    {
        // ── Identification ────────────────────────────────────────────────
        public int EnrollmentId { get; set; }
        public string? EnrollmentCode { get; set; }
        public string? EnrollmentName { get; set; }

        // ── Instance / Programme (read-only joins on GET) ─────────────────
        public int InstanceId { get; set; }
        public string? InstanceCode { get; set; }
        public string? ProgrammeTitle { get; set; }

        // ── Employee (read-only join on GET) ──────────────────────────────
        public int EmployeeId { get; set; }
        public string? EmployeeName { get; set; }

        // ── Nomination ────────────────────────────────────────────────────
        public byte NominationSource { get; set; }   // NominationSource enum
        public int? NominatedById { get; set; }
        public string? NominatedByName { get; set; }   // FIX: was int? — must be string?
        public DateTime NominatedOn { get; set; }   // FIX: was missing

        // ── Manager Approval ──────────────────────────────────────────────
        public int? ManagerApprovalId { get; set; }
        public DateTime? ManagerApprovedOn { get; set; }
        public string? ManagerRemarks { get; set; } // per-tier audit trail

        // ── HR Approval ───────────────────────────────────────────────────
        public int? HRApprovalId { get; set; }
        public DateTime? HRApprovedOn { get; set; }      // FIX: renamed from HRProcessedOn
        public string? HRRemarks { get; set; }      // per-tier audit trail

        // ── Enrollment State ──────────────────────────────────────────────
        public byte EnrollmentStatus { get; set; }      // EnrollmentStatus enum
        public int WaitlistPosition { get; set; }        // 0 = not on waitlist

        // ── Pre-Assessment ────────────────────────────────────────────────
        public bool PreAssessmentDone { get; set; }  // FIX: was missing (BIT in DB)
        public decimal PreAssessmentScore { get; set; }  // FIX: was missing (NUMERIC 9,4 in DB)

        // ── Notes / Withdrawal ────────────────────────────────────────────
        public string? Remarks { get; set; }  // FIX: was missing
        public string? WithdrawalReason { get; set; }
        public DateTime? WithdrawnOn { get; set; }

        // ── Standard Fields ───────────────────────────────────────────────
        public int TenantId { get; set; }
        public int CreatedById { get; set; }
        public DateTime CreatedOn { get; set; }
        public int ModifiedById { get; set; }
        public DateTime ModifiedOn { get; set; }
    }

    // ════════════════════════════════════════════════════════════════════════
    // LIST DTO — lightweight, used for grids / tables
    // ════════════════════════════════════════════════════════════════════════

    /// <summary>
    /// Lightweight enrollment record for list / grid display.
    /// Returned by: GetEnrollmentsByInstance, GetEnrollmentsByEmployee, GetEnrollmentList.
    /// </summary>
    public class TrainingEnrollmentListDTO
    {
        // ── Identification ────────────────────────────────────────────────
        public int EnrollmentId { get; set; }
        public string EnrollmentCode { get; set; } = string.Empty;
        public string EnrollmentName { get; set; } = string.Empty;

        // ── Instance / Programme ──────────────────────────────────────────
        public int InstanceId { get; set; }
        public string InstanceCode { get; set; } = string.Empty;
        public string ProgrammeTitle { get; set; } = string.Empty;

        // ── Employee ──────────────────────────────────────────────────────
        public int EmployeeId { get; set; }
        public string EmployeeName { get; set; } = string.Empty;

        // ── State ─────────────────────────────────────────────────────────
        public byte NominationSource { get; set; }   // NominationSource enum
        public byte EnrollmentStatus { get; set; }   // EnrollmentStatus enum
        public int? WaitlistPosition { get; set; }   // NULL = not on waitlist

        // ── Approval Timestamps (summary) ─────────────────────────────────
        public DateTime? ManagerApprovedOn { get; set; }
        public DateTime? HRApprovedOn { get; set; }

        // ── Audit ─────────────────────────────────────────────────────────
        public DateTime CreatedOn { get; set; }
    }

    // ════════════════════════════════════════════════════════════════════════
    // PICKLIST DTO — minimal, used for dropdowns / lookups
    // ════════════════════════════════════════════════════════════════════════

    /// <summary>
    /// Minimal enrollment record for dropdown / lookup use.
    /// InstanceCode + ProgrammeTitle give the UI a meaningful display label.
    /// </summary>
    public class TrainingEnrollmentPickListDTO
    {
        public int EnrollmentId { get; set; }
        public string EnrollmentCode { get; set; } = string.Empty;
        public string EnrollmentName { get; set; } = string.Empty;
        public string InstanceCode { get; set; } = string.Empty;
        public string ProgrammeTitle { get; set; } = string.Empty;
    }

    // ════════════════════════════════════════════════════════════════════════
    // APPROVAL DTOs
    // ════════════════════════════════════════════════════════════════════════

    /// <summary>
    /// API input DTO for approving or rejecting an enrollment (Manager or HR).
    /// ApprovalId is resolved by the BLL from the logged-in user.
    /// Status is set by the BLL based on ApprovalType + action taken.
    /// </summary>
    public class ApprovalActionDTO
    {
        public int EnrollmentId { get; set; }
        public ApprovalType ApprovalType { get; set; }   // Manager | HR
        public EnrollmentStatus Status { get; set; }   // strongly typed
        public string? Remarks { get; set; }
    }

    /// <summary>
    /// Internal DAL-only DTO. Built by BLL after resolving ApprovalId.
    /// Never exposed to the controller or API layer.
    /// </summary>
    public class ApprovalUpdateDTO
    {
        public int EnrollmentId { get; set; }
        public ApprovalType ApprovalType { get; set; }
        public EnrollmentStatus Status { get; set; }   // strongly typed
        public int ApprovalId { get; set; }   // resolved by BLL
        public string? Remarks { get; set; }
    }

    // ════════════════════════════════════════════════════════════════════════
    // WITHDRAWAL DTO
    // ════════════════════════════════════════════════════════════════════════

    /// <summary>
    /// API input DTO for withdrawing an enrollment.
    /// EnrollmentStatus is always set to EnrollmentStatus.Withdrawn by the BLL.
    /// </summary>
    public class WithdrawEnrollmentDTO
    {
        public int EnrollmentId { get; set; }
        public string? WithdrawalReason { get; set; }
    }
}