using System;
using System.Threading;
using System.Threading.Tasks;
using FrameworkBLL.Dashboard;
using FrameworkDAL.CustomCode.Promotion;
using FrameworkDAL.DTO.Dashboard;
using GB5Shared.DTO.Framework.Login;
using GB5Shared.DTO.Promotion;
using GB5Shared.Promotion;
using Newtonsoft.Json;

namespace FrameworkBLL.Promotion.Adapters
{
    // ============================================================
    // DashboardPromotionAdapter — IPromotableEntity for MDASHBOARD ("DASHBOARD").
    // Parent row only in this first pass — the Dashboard's Page placement
    // (MDASHBOARDPAGE: tab order/default-tab/visibility) is a real, portable
    // structural child (its own DashboardPageDTO already carries PageCode,
    // resolvable via PagePromotionAdapter's IPageCodeLookupDAL once that's
    // registered) but is deliberately NOT bundled yet — a follow-up, not a
    // silent gap, same "parent first, children later" pattern already used
    // for ReportView's own Fields.
    //
    // OwnerId/ImageId/DefaultCriteriaConfigId all default to -1 at the DB
    // level with NO foreign key constraint on any of them (confirmed via
    // schema query) — unlike ReportView's TemplateId/PageId, forcing these to
    // -1 at the destination is completely safe, not just a workaround.
    // OwnerId specifically: DashboardBLL.SaveDashboard already reassigns a
    // Personal (DashboardType=0) dashboard's OwnerId to the importing user
    // when left at its default, so no extra handling is needed here for that
    // case; a Shared/Role/System dashboard's own OwnerId is simply never
    // carried across environments either, since a user ID from the origin
    // means nothing at the destination.
    //
    // ModuleId/ModuleCode reuses the existing IModuleCodeLookupDAL — module
    // codes are static/shared across installs, same reasoning as
    // Page/ReportView/DrillDown's own Module references.
    // ============================================================
    public class DashboardPromotionAdapter : IPromotableEntity
    {
        public string EntityTypeCode => "DASHBOARD";

        private readonly IDashboardBLL _DashboardBLL;
        private readonly IModuleCodeLookupDAL _ModuleCodeLookup;
        private readonly IDashboardCodeLookupDAL _DashboardCodeLookup;

        public DashboardPromotionAdapter(
            IDashboardBLL dashboardBLL, IModuleCodeLookupDAL moduleCodeLookup,
            IDashboardCodeLookupDAL dashboardCodeLookup)
        {
            _DashboardBLL        = dashboardBLL;
            _ModuleCodeLookup    = moduleCodeLookup;
            _DashboardCodeLookup = dashboardCodeLookup;
        }

        private class PortablePayload
        {
            public string DashboardCode { get; set; } = string.Empty;
            public string DashboardName { get; set; } = string.Empty;
            public byte DashboardType { get; set; }
            public string? ModuleCode { get; set; }
            public string? ImageLinkURL { get; set; }
            public string? Remarks { get; set; }
            public short SortOrder { get; set; }
        }

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

            string? moduleCode = null;
            if (dto.ModuleId != 0 && dto.ModuleId != -1)
            {
                moduleCode = await _ModuleCodeLookup.GetModuleCodeById(dto.ModuleId, login, ct).ConfigureAwait(false)
                    ?? throw new InvalidOperationException(
                        $"Dashboard {originEntityId} references ModuleId {dto.ModuleId}, which has no ModuleCode — cannot promote.");
            }

            var payload = new PortablePayload
            {
                DashboardCode = dto.DashboardCode,
                DashboardName = dto.DashboardName,
                DashboardType = dto.DashboardType,
                ModuleCode    = moduleCode,
                ImageLinkURL  = dto.ImageLinkURL,
                Remarks       = dto.Remarks,
                SortOrder     = dto.SortOrder
            };

            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);
            var result = payload is null
                ? PromotionValidationResultDTO.Block("Dashboard payload could not be parsed.")
                : payload.DashboardType > 3
                    ? PromotionValidationResultDTO.Block("Dashboard.DashboardType is out of the valid range (0-3).")
                    : 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("Dashboard promotion payload could not be parsed.");

            var moduleId = -1;
            if (!string.IsNullOrWhiteSpace(payload.ModuleCode))
            {
                moduleId = await _ModuleCodeLookup.GetModuleIdByCode(payload.ModuleCode, login, ct).ConfigureAwait(false)
                    ?? throw new InvalidOperationException(
                        $"No Module with ModuleCode '{payload.ModuleCode}' exists at this destination.");
            }

            // If this is an update to a previously-promoted dashboard, existingDestinationId
            // already identifies it directly. Otherwise, check whether a dashboard with this code
            // already exists at the destination (created independently, not via a prior promotion)
            // so Import updates it rather than violating DashboardCode's own unique constraint with
            // a duplicate insert — DASHBOARDCODE has a real UNIQUE constraint (UK_MDASHBOARD_
            // DASHBOARDCODE, confirmed via schema), the same class of collision already hit live
            // with ReportView's own ReportViewName.
            var resolvedId = existingDestinationId
                ?? await _DashboardCodeLookup.GetDashboardIdByCode(payload.DashboardCode, login, ct).ConfigureAwait(false)
                ?? 0;

            var dto = new DashboardDTO
            {
                DashboardId   = resolvedId,
                DashboardCode = payload.DashboardCode,
                DashboardName = payload.DashboardName,
                DashboardType = payload.DashboardType,
                ModuleId      = moduleId,
                OwnerId       = -1, // never mapped — see class header comment
                ImageId       = -1, // never mapped — see class header comment
                ImageLinkURL  = payload.ImageLinkURL,
                Remarks       = payload.Remarks,
                DefaultCriteriaConfigId = -1, // never mapped — see class header comment
                SortOrder     = payload.SortOrder,
                SourceType    = destinationSourceType
            };

            await _DashboardBLL.SaveDashboard(dto, login, ct).ConfigureAwait(false);
            return dto.DashboardId; // mutated in place by SaveDashboard when isNew
        }
    }
}