using System;
using System.Collections.Generic;
using System.Text.Json;
using System.Threading;
using System.Threading.Tasks;
using FrameworkBLL.ReportViewer;
using FrameworkDAL.CustomCode.Promotion;
using FrameworkDAL.DTO.ReportViewer;
using GB5Shared.DTO.Framework.Login;
using GB5Shared.DTO.Promotion;
using GB5Shared.Promotion;
using Newtonsoft.Json;

namespace FrameworkBLL.Promotion.Adapters
{
    // ============================================================
    // ReportViewPromotionAdapter — IPromotableEntity for MREPORTVIEW
    // ("REPORTVIEW"). Parent row only in this first pass — MREPORTVIEWFIELDS
    // (the per-column display settings) are deliberately NOT bundled yet: each
    // field row carries its own REPORTVSFIELDSID/DIMENSIONFIELDID FK
    // references, which have exactly the same cross-environment
    // ID-portability problem as ReportView's own FKs below, just one level
    // deeper. Solving that properly is a follow-up, not attempted here —
    // promoting the view's own settings without its field-level formatting is
    // still a useful, honest first slice, not a silent partial promise.
    //
    // ReportView has several raw ID references that do NOT survive a move
    // between two separate databases (AutoNumber-assigned IDs mean nothing
    // outside the database that assigned them):
    //   - ReportId (mandatory) — resolved via MREPORT.ReportCode, the natural
    //     key, both at export (Id -> Code) and import (Code -> local Id).
    //     Import fails clearly if the destination has no matching Report —
    //     referential completeness, not a silent broken FK.
    //   - ReportHeaderId (optional) — resolved via MREPORTHEADER.ReportHeaderCode,
    //     same natural-key pattern as ReportId, now that ReportHeaderPromotionAdapter
    //     exists (REPORTHEADER is itself a promotable entity type). Null/absent if
    //     the view has no header attached (ReportHeaderId at its -1/0 sentinel).
    //   - TemplateId / SecondTemplateId / PageId / ApplicableMenuIds — still
    //     optional, still conservatively BLOCKED if set to a real
    //     (non-sentinel) value — no adapter exists yet for Template/Page/Menu
    //     to resolve them via natural key the way ReportHeader now can.
    //     Remapping these is a real, scoped follow-up, not attempted here.
    //   - ClientIds — almost always tenant-specific data; treated as a
    //     hardcoded-tenant-literal validation block, not merely an
    //     ID-portability problem.
    //
    // IMPORTANT: these risky fields are still carried in the bundle payload
    // (under RawFlags) even though ImportPromotedAsync never maps them onto
    // the destination row. ValidateForPromotionAsync only sees the bundle
    // (never the live DTO) and runs at BOTH export time (fail fast) and
    // ingest time (never trust only the origin's copy) — if these fields
    // were trimmed away before validation ran, "block if ClientIds is set"
    // would never actually fire, since the dangerous value wouldn't be there
    // to inspect. Import simply ignores RawFlags — it exists for validation
    // to see, not for import to use.
    //
    // Note: TemplateId/PageId's DTO default (bare 0) doesn't match their own
    // DB column default (-1) -- a separate, pre-existing inconsistency this
    // adapter works around defensively by treating EITHER 0 or -1 as "unset",
    // rather than fixing that mismatch here (out of scope for Promotion).
    // ============================================================
    public class ReportViewPromotionAdapter : IPromotableEntity
    {
        public string EntityTypeCode => "REPORTVIEW";

        private readonly IReportViewBLL _ReportViewBLL;
        private readonly IReportCodeLookupDAL _ReportCodeLookup;
        private readonly IReportHeaderCodeLookupDAL _ReportHeaderCodeLookup;

        public ReportViewPromotionAdapter(
            IReportViewBLL reportViewBLL, IReportCodeLookupDAL reportCodeLookup,
            IReportHeaderCodeLookupDAL reportHeaderCodeLookup)
        {
            _ReportViewBLL          = reportViewBLL;
            _ReportCodeLookup       = reportCodeLookup;
            _ReportHeaderCodeLookup = reportHeaderCodeLookup;
        }

        private class RawFlags
        {
            public string? ClientIds { get; set; }
            public int TemplateId { get; set; }
            public int SecondTemplateId { get; set; }
            public int PageId { get; set; }
            public string? ApplicableMenuIds { get; set; }
        }

        private class PortablePayload
        {
            public string ReportCode { get; set; } = string.Empty;
            /// <summary>Null if the view has no header attached.</summary>
            public string? ReportHeaderCode { get; set; }
            public string ReportViewName { get; set; } = string.Empty;
            public byte ReportViewType { get; set; }
            public byte ReportViewIsSystemView { get; set; }
            public byte ReportViewIsDefaultView { get; set; }
            public byte ReportViewPageFormat { get; set; }
            public byte ReportViewPageOrientation { get; set; }
            public byte ReportViewColumnFreeze { get; set; }
            public string ReportViewPivotFormat { get; set; } = string.Empty;
            public byte ReportViewIsDataPivot { get; set; }
            public string OrderByFields { get; set; } = string.Empty;
            public string DynamicFooter { get; set; } = string.Empty;
            public string ReportTitle { get; set; } = string.Empty;
            public byte ReportViewIsHeaderRequired { get; set; }
            public byte IsVisible { get; set; }
            public string? ReportViewRemarks { get; set; }
            public string? Remarks { get; set; }
            public short SortOrder { get; set; }

            /// <summary>Seen only by ValidateForPromotionAsync — never mapped onto the
            /// destination row by ImportPromotedAsync. See the class header comment.</summary>
            public RawFlags Flags { get; set; } = new();
        }

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

            var reportCode = await _ReportCodeLookup.GetReportCodeById(dto.ReportId, login, ct).ConfigureAwait(false)
                ?? throw new InvalidOperationException(
                    $"ReportView {originEntityId} references ReportId {dto.ReportId}, which has no ReportCode — cannot promote.");

            string? reportHeaderCode = null;
            if (dto.ReportHeaderId != 0 && dto.ReportHeaderId != -1)
            {
                reportHeaderCode = await _ReportHeaderCodeLookup.GetReportHeaderCodeById(dto.ReportHeaderId, login, ct)
                    .ConfigureAwait(false)
                    ?? throw new InvalidOperationException(
                        $"ReportView {originEntityId} references ReportHeaderId {dto.ReportHeaderId}, " +
                        "which has no ReportHeaderCode — cannot promote.");
            }

            var payload = new PortablePayload
            {
                ReportCode                 = reportCode,
                ReportHeaderCode           = reportHeaderCode,
                ReportViewName              = dto.ReportViewName,
                ReportViewType              = dto.ReportViewType,
                ReportViewIsSystemView      = dto.ReportViewIsSystemView,
                ReportViewIsDefaultView     = dto.ReportViewIsDefaultView,
                ReportViewPageFormat        = dto.ReportViewPageFormat,
                ReportViewPageOrientation   = dto.ReportViewPageOrientation,
                ReportViewColumnFreeze      = dto.ReportViewColumnFreeze,
                ReportViewPivotFormat       = dto.ReportViewPivotFormat,
                ReportViewIsDataPivot       = dto.ReportViewIsDataPivot,
                OrderByFields               = dto.OrderByFields,
                DynamicFooter               = dto.DynamicFooter,
                ReportTitle                 = dto.ReportTitle,
                ReportViewIsHeaderRequired  = dto.ReportViewIsHeaderRequired,
                IsVisible                   = dto.IsVisible,
                ReportViewRemarks           = dto.ReportViewRemarks,
                Remarks                     = dto.Remarks,
                SortOrder                   = dto.SortOrder,
                Flags = new RawFlags
                {
                    ClientIds          = dto.ClientIds,
                    TemplateId         = dto.TemplateId,
                    SecondTemplateId   = dto.SecondTemplateId,
                    PageId             = dto.PageId,
                    ApplicableMenuIds  = dto.ApplicableMenuIds
                }
            };

            return new PromotionBundleDTO
            {
                EntityTypeCode = EntityTypeCode,
                OriginEntityId = originEntityId,
                PayloadJson    = System.Text.Json.JsonSerializer.Serialize(payload),
                ChildPayloadsJson = new Dictionary<string, string>() // Fields deliberately not bundled yet
            };
        }

        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("ReportView payload could not be parsed."));

            var reasons = new List<string>();
            var flags = payload.Flags;

            var clientIds = flags.ClientIds?.Trim();
            if (!string.IsNullOrEmpty(clientIds) && clientIds != ",-1")
                reasons.Add("ReportView.ClientIds references specific client(s) — not promotable.");

            if (flags.TemplateId != 0 && flags.TemplateId != -1)
                reasons.Add("ReportView.TemplateId is set — template remapping is not yet supported.");
            if (flags.SecondTemplateId != 0 && flags.SecondTemplateId != -1)
                reasons.Add("ReportView.SecondTemplateId is set — template remapping is not yet supported.");
            if (flags.PageId != 0 && flags.PageId != -1)
                reasons.Add("ReportView.PageId is set — page remapping is not yet supported.");
            if (!string.IsNullOrWhiteSpace(flags.ApplicableMenuIds))
                reasons.Add("ReportView.ApplicableMenuIds is set — menu remapping is not yet supported.");

            var result = reasons.Count == 0
                ? PromotionValidationResultDTO.Ok()
                : new PromotionValidationResultDTO { IsPromotable = false, BlockingReasons = reasons };
            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("ReportView promotion payload could not be parsed.");

            var reportId = await _ReportCodeLookup.GetReportIdByCode(payload.ReportCode, login, ct).ConfigureAwait(false)
                ?? throw new InvalidOperationException(
                    $"No Report with ReportCode '{payload.ReportCode}' exists at this destination — " +
                    "promote the Report itself first.");

            var reportHeaderId = -1; // sentinel: no header attached
            if (!string.IsNullOrWhiteSpace(payload.ReportHeaderCode))
            {
                reportHeaderId = await _ReportHeaderCodeLookup.GetReportHeaderIdByCode(payload.ReportHeaderCode, login, ct)
                    .ConfigureAwait(false)
                    ?? throw new InvalidOperationException(
                        $"No ReportHeader with ReportHeaderCode '{payload.ReportHeaderCode}' exists at this " +
                        "destination — promote the ReportHeader itself first.");
            }

            // payload.Flags is deliberately NOT read here — see the class header comment.
            // TemplateId/PageId are explicitly stamped to their real "unset" sentinel (-1, which
            // has a genuine dummy MFILE row) rather than left at ReportViewDTO's own bare-0
            // default — MREPORTVIEW.TEMPLATEID/PAGEID are NOT NULL with FKs to MFILE, which has
            // no FILEID=0 row, so leaving them at 0 throws a real FK violation on every import.
            // Found live 2026-08-21 verifying the first-ever real Promotion Import execution.
            var dto = new ReportViewDTO
            {
                ReportViewId               = existingDestinationId ?? 0,
                ReportId                    = reportId,
                ReportHeaderId              = reportHeaderId,
                TemplateId                  = -1,
                PageId                      = -1,
                ReportViewName              = payload.ReportViewName,
                ReportViewType              = payload.ReportViewType,
                ReportViewIsSystemView      = payload.ReportViewIsSystemView,
                ReportViewIsDefaultView     = payload.ReportViewIsDefaultView,
                ReportViewPageFormat        = payload.ReportViewPageFormat,
                ReportViewPageOrientation   = payload.ReportViewPageOrientation,
                ReportViewColumnFreeze      = payload.ReportViewColumnFreeze,
                ReportViewPivotFormat       = payload.ReportViewPivotFormat,
                ReportViewIsDataPivot       = payload.ReportViewIsDataPivot,
                OrderByFields               = payload.OrderByFields,
                DynamicFooter               = payload.DynamicFooter,
                ReportTitle                 = payload.ReportTitle,
                ReportViewIsHeaderRequired  = payload.ReportViewIsHeaderRequired,
                IsVisible                   = payload.IsVisible,
                ReportViewRemarks           = payload.ReportViewRemarks,
                Remarks                     = payload.Remarks,
                SortOrder                   = payload.SortOrder,
                ReportViewSourceType        = destinationSourceType
            };

            await _ReportViewBLL.SaveReportView(dto, login, ct).ConfigureAwait(false);
            return dto.ReportViewId; // mutated in place by SaveReportView when isNew
        }
    }
}