using System;
using System.Collections.Generic;
using System.Linq;
using System.Threading;
using System.Threading.Tasks;
using FrameworkBLL.ReportHeaderMgmt;
using FrameworkDAL.CustomCode.Promotion;
using FrameworkDAL.DTO.ReportHeader;
using GB5Shared.DTO.Framework.Login;
using GB5Shared.DTO.Promotion;
using GB5Shared.Promotion;
using Newtonsoft.Json;

namespace FrameworkBLL.Promotion.Adapters
{
    // ============================================================
    // ReportHeaderPromotionAdapter — IPromotableEntity for MREPORTHEADER
    // ("REPORTHEADER"). Unlike ReportView/DrillDown, this entity's own detail
    // rows (MREPORTHEADERDETAIL — grid-cell layout: row/column spans, font,
    // color, expression) are all plain values with no cross-environment ID
    // references, so the full parent+children bundle travels together with
    // no blocked fields at all.
    //
    // ReportHeaderCode is the natural key (MREPORTHEADER's own unique
    // constraint is (ReportHeaderCode, ClientId), not ReportHeaderCode alone)
    // — resolved at both export and import, same pattern as ReportView's
    // ReportCode. A header explicitly scoped to a specific ClientId (not the
    // -1 "not tenant-specific" sentinel) is blocked from promotion entirely,
    // same tenant-literal reasoning as ReportView's ClientIds check. At
    // import, ClientId is always forced to -1 regardless of the origin's own
    // value — a promoted header is shared/framework-level by definition, never
    // bound to one specific client at the destination either.
    //
    // Enables ReportViewPromotionAdapter to resolve ReportHeaderId going
    // forward (previously unconditionally blocked) once this entity type is
    // registered and promotable — see ReportViewPromotionAdapter's own updated
    // comment.
    //
    // Note: like ReportViewBLL, ReportHeaderBLL.SaveReportHeader never sets
    // dto.ReportHeaderSourceType server-side either (confirmed by reading it)
    // — this adapter sets it explicitly before calling Save, same as the
    // ReportView adapter does, but the underlying gap in ReportHeaderBLL is
    // real and separate, flagged not fixed (out of scope for Promotion).
    // ============================================================
    public class ReportHeaderPromotionAdapter : IPromotableEntity
    {
        public string EntityTypeCode => "REPORTHEADER";

        private readonly IReportHeaderBLL _ReportHeaderBLL;
        private readonly IReportHeaderCodeLookupDAL _ReportHeaderCodeLookup;

        public ReportHeaderPromotionAdapter(
            IReportHeaderBLL reportHeaderBLL, IReportHeaderCodeLookupDAL reportHeaderCodeLookup)
        {
            _ReportHeaderBLL        = reportHeaderBLL;
            _ReportHeaderCodeLookup = reportHeaderCodeLookup;
        }

        private class DetailPayload
        {
            public short SlNo { get; set; }
            public byte FromRowNumber { get; set; }
            public byte ToRowNumber { get; set; }
            public byte RowHeight { get; set; }
            public byte FromColumnNumber { get; set; }
            public byte ToColumnNumber { get; set; }
            public byte CellWidth { get; set; }
            public string? Expression { get; set; }
            public byte Alignment { get; set; }
            public string? Font { get; set; }
            public byte FontSize { get; set; }
            public string? Color { get; set; }
            public byte Style { get; set; }
            public byte IsEmptySuppress { get; set; }
        }

        private class RawFlags
        {
            public int ClientId { get; set; }
        }

        private class PortablePayload
        {
            public string ReportHeaderCode { get; set; } = string.Empty;
            public string ReportHeaderName { get; set; } = string.Empty;
            public string? Particulars { get; set; }
            public string? Remarks { get; set; }
            public short SortOrder { get; set; }
            public List<DetailPayload> Details { get; set; } = new();

            /// <summary>Seen only by ValidateForPromotionAsync — ImportPromotedAsync always forces
            /// ClientId to -1 at the destination regardless of this value.</summary>
            public RawFlags Flags { get; set; } = new();
        }

        public async Task<PromotionBundleDTO> ExportForPromotionAsync(
            int originEntityId, LoginDTO login, CancellationToken ct)
        {
            var json = await _ReportHeaderBLL.GetReportHeader(originEntityId, login, ct).ConfigureAwait(false);
            var dto = JsonConvert.DeserializeObject<ReportHeaderDTO>(json)
                ?? throw new InvalidOperationException($"ReportHeader {originEntityId} not found.");

            var payload = new PortablePayload
            {
                ReportHeaderCode = dto.ReportHeaderCode,
                ReportHeaderName = dto.ReportHeaderName,
                Particulars      = dto.ReportHeaderParticulars,
                Remarks          = dto.ReportHeaderRemarks,
                SortOrder        = dto.ReportHeaderSortOrder,
                Details = (dto.ReportHeaderDetailArray ?? new List<ReportHeaderDetailDTO>()).Select(d => new DetailPayload
                {
                    SlNo             = d.ReportHeaderDetailSlNo,
                    FromRowNumber    = d.ReportHeaderDetailFromRowNumber,
                    ToRowNumber      = d.ReportHeaderDetailToRowNumber,
                    RowHeight        = d.ReportHeaderDetailRowHeight,
                    FromColumnNumber = d.ReportHeaderDetailFromColumnNumber,
                    ToColumnNumber   = d.ReportHeaderDetailToColumnNumber,
                    CellWidth        = d.ReportHeaderDetailCellWidth,
                    Expression       = d.ReportHeaderDetailExpression,
                    Alignment        = d.ReportHeaderDetailAlignment,
                    Font             = d.ReportHeaderDetailFont,
                    FontSize         = d.ReportHeaderDetailFontSize,
                    Color            = d.ReportHeaderDetailColor,
                    Style            = d.ReportHeaderDetailStyle,
                    IsEmptySuppress  = d.ReportHeaderDetailIsEmptySuppress
                }).ToList(),
                Flags = new RawFlags { ClientId = dto.ReportHeaderBaseClinetId }
            };

            return new PromotionBundleDTO
            {
                EntityTypeCode = EntityTypeCode,
                OriginEntityId = originEntityId,
                PayloadJson    = System.Text.Json.JsonSerializer.Serialize(payload)
            };
        }

        public Task<PromotionValidationResultDTO> ValidateForPromotionAsync(
            PromotionBundleDTO bundle, CancellationToken ct)
        {
            var payload = System.Text.Json.JsonSerializer.Deserialize<PortablePayload>(bundle.PayloadJson);
            if (payload is null)
                return Task.FromResult(PromotionValidationResultDTO.Block("ReportHeader payload could not be parsed."));

            var result = payload.Flags.ClientId != -1
                ? PromotionValidationResultDTO.Block("ReportHeader is scoped to a specific ClientId — not promotable.")
                : PromotionValidationResultDTO.Ok();
            return Task.FromResult(result);
        }

        public async Task<int> ImportPromotedAsync(
            PromotionBundleDTO bundle, byte destinationSourceType, int? existingDestinationId,
            LoginDTO login, CancellationToken ct)
        {
            var payload = System.Text.Json.JsonSerializer.Deserialize<PortablePayload>(bundle.PayloadJson)
                ?? throw new InvalidOperationException("ReportHeader promotion payload could not be parsed.");

            // If this is an update to a previously-promoted header, existingDestinationId already
            // identifies it directly — no code lookup needed. Otherwise, check whether a header with
            // this code already exists at the destination (created independently, not via a prior
            // promotion) so Import updates it rather than violating the (Code, ClientId) unique
            // constraint with a duplicate insert.
            var resolvedId = existingDestinationId
                ?? await _ReportHeaderCodeLookup.GetReportHeaderIdByCode(payload.ReportHeaderCode, login, ct).ConfigureAwait(false)
                ?? 0;

            var dto = new ReportHeaderDTO
            {
                ReportHeaderId          = resolvedId,
                ReportHeaderCode        = payload.ReportHeaderCode,
                ReportHeaderName        = payload.ReportHeaderName,
                ReportHeaderParticulars = payload.Particulars,
                ReportHeaderRemarks     = payload.Remarks,
                ReportHeaderSortOrder   = payload.SortOrder,
                ReportHeaderSourceType  = destinationSourceType,
                ReportHeaderBaseClinetId = -1, // always forced — see class header comment
                ReportHeaderDetailArray = payload.Details.Select(d => new ReportHeaderDetailDTO
                {
                    ReportHeaderDetailSlNo             = d.SlNo,
                    ReportHeaderDetailFromRowNumber    = d.FromRowNumber,
                    ReportHeaderDetailToRowNumber      = d.ToRowNumber,
                    ReportHeaderDetailRowHeight        = d.RowHeight,
                    ReportHeaderDetailFromColumnNumber = d.FromColumnNumber,
                    ReportHeaderDetailToColumnNumber   = d.ToColumnNumber,
                    ReportHeaderDetailCellWidth        = d.CellWidth,
                    ReportHeaderDetailExpression       = d.Expression,
                    ReportHeaderDetailAlignment        = d.Alignment,
                    ReportHeaderDetailFont             = d.Font,
                    ReportHeaderDetailFontSize         = d.FontSize,
                    ReportHeaderDetailColor            = d.Color,
                    ReportHeaderDetailStyle            = d.Style,
                    ReportHeaderDetailIsEmptySuppress  = d.IsEmptySuppress
                }).ToList()
            };

            await _ReportHeaderBLL.SaveReportHeader(dto, login, ct).ConfigureAwait(false);
            return dto.ReportHeaderId; // mutated in place by SaveReportHeader when isNew
        }
    }
}