using System;
using System.Threading;
using System.Threading.Tasks;
using GB5Shared.DTO.Framework.Login;
using GB5Shared.DTO.Promotion;
using GB5Shared.Promotion;
using Newtonsoft.Json;
using WiBLL.WiSubProcess;
using WiDAL.CustomCode.Promotion;
using WiDAL.DTOs;

namespace WiBLL.Promotion
{
    // ============================================================
    // WiSubProcessPromotionAdapter — IPromotableEntity for MWISUBPROCESS ("WISUBPROCESS"). No
    // child rows of its own. Natural key WiSubProcessCode
    // (UK_MWISUBPROCESS_WISUBPROCESSCODE_TENANTID, confirmed via schema).
    //
    // WiSubProcessDTO DOES declare a WiProcessCode property, but WiSubProcessBLL.GetById's own
    // query (checked directly, not assumed) never selects it — only WIPROCESSNAME is joined in.
    // Export therefore always resolves WiProcessId -> WiProcessCode via IWiProcessCodeLookupDAL,
    // never trusting the DTO field to be populated (the same "lite vs full" trap class as
    // ReportView's own Lite bug, caught here by checking the real query before assuming).
    // ============================================================
    public class WiSubProcessPromotionAdapter : IPromotableEntity
    {
        public string EntityTypeCode => "WISUBPROCESS";

        private readonly IWiSubProcessBLL _WiSubProcessBLL;
        private readonly IWiProcessCodeLookupDAL _WiProcessCodeLookup;
        private readonly IWiSubProcessCodeLookupDAL _WiSubProcessCodeLookup;

        public WiSubProcessPromotionAdapter(
            IWiSubProcessBLL wiSubProcessBLL, IWiProcessCodeLookupDAL wiProcessCodeLookup,
            IWiSubProcessCodeLookupDAL wiSubProcessCodeLookup)
        {
            _WiSubProcessBLL        = wiSubProcessBLL;
            _WiProcessCodeLookup    = wiProcessCodeLookup;
            _WiSubProcessCodeLookup = wiSubProcessCodeLookup;
        }

        private class PortablePayload
        {
            public string WiSubProcessCode { get; set; } = string.Empty;
            public string WiSubProcessName { get; set; } = string.Empty;
            public string WiProcessCode { get; set; } = string.Empty;
            public short DisplayOrder { get; set; }
            public string? Description { get; set; }
            public int IsActive { get; set; }
            public short SortOrder { get; set; } = 9999;
        }

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

            var wiProcessCode = await _WiProcessCodeLookup.GetWiProcessCodeById(dto.WiProcessId, login, ct)
                    .ConfigureAwait(false)
                ?? throw new InvalidOperationException(
                    $"WiSubProcess {originEntityId} references WiProcessId {dto.WiProcessId}, which has no WiProcessCode — cannot promote.");

            var payload = new PortablePayload
            {
                WiSubProcessCode = dto.WiSubProcessCode,
                WiSubProcessName = dto.WiSubProcessName,
                WiProcessCode = wiProcessCode,
                DisplayOrder = dto.DisplayOrder,
                Description = dto.Description,
                IsActive = dto.IsActive,
                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);
            if (payload is null)
                return Task.FromResult(PromotionValidationResultDTO.Block("WiSubProcess payload could not be parsed."));

            var reasons = new System.Collections.Generic.List<string>();
            if (string.IsNullOrWhiteSpace(payload.WiSubProcessCode))
                reasons.Add("WiSubProcess.WiSubProcessCode is required to promote.");
            if (string.IsNullOrWhiteSpace(payload.WiProcessCode))
                reasons.Add("WiSubProcess.WiProcessId has no resolvable WiProcessCode — cannot promote.");

            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("WiSubProcess promotion payload could not be parsed.");

            var wiProcessId = await _WiProcessCodeLookup.GetWiProcessIdByCode(payload.WiProcessCode, login, ct)
                    .ConfigureAwait(false)
                ?? throw new InvalidOperationException(
                    $"No WiProcess with WiProcessCode '{payload.WiProcessCode}' exists at this destination.");

            var resolvedId = existingDestinationId
                ?? await _WiSubProcessCodeLookup.GetWiSubProcessIdByCode(payload.WiSubProcessCode, login, ct).ConfigureAwait(false)
                ?? 0;

            var dto = new WiSubProcessDTO
            {
                WiSubProcessId = resolvedId,
                WiProcessId = wiProcessId,
                WiSubProcessCode = payload.WiSubProcessCode,
                WiSubProcessName = payload.WiSubProcessName,
                DisplayOrder = payload.DisplayOrder,
                Description = payload.Description,
                IsActive = payload.IsActive,
                SortOrder = payload.SortOrder,
                SourceType = destinationSourceType
            };

            await _WiSubProcessBLL.Save(dto, login, ct).ConfigureAwait(false);
            return dto.WiSubProcessId; // mutated in place by Save when isNew
        }
    }
}