using AmpDAL.CustomCode.ApiRequestChecklist;
using AmpDAL.DTO.ApiRequestChecklist;
using GB5Shared.DTO.Framework.Login;
using GB5Shared.GenerateAutoNumber;
using GB5Shared.Resource.Response;
using Microsoft.Extensions.Logging;

namespace AMPBLL.ApiRequestChecklist;

public class ApiRequestChecklistBLL(
    IApiRequestChecklistDAL _dal,
    AutoNumber _autoNumber,
    ILogger<ApiRequestChecklistBLL> _logger
) : IApiRequestChecklistBLL
{
    // Stages 0,1,3,10,11,12 are system-managed — no checklist seeding required.
    // Only stages 2,4,5,6,7,8,9 have sign-off items.
    private static readonly IReadOnlyDictionary<byte, IReadOnlyList<string>> StageItems =
        new Dictionary<byte, IReadOnlyList<string>>
        {
            [2] = ["Duplicate review complete", "Business justification approved", "Domain and type confirmed"],
            [4] = ["MAPI draft record created (LINKEDAPIID set)", "API domain confirmed", "Proposed version number agreed"],
            [5] = ["MAPIINTERFACE record created", "HTTP method and path agreed", "Spec type selected (OpenAPI/AsyncAPI)"],
            [6] = ["MAPIINTERFACE parsed successfully", "Error codes standardized", "Pagination strategy confirmed", "Auth method documented"],
            [7] = ["MAPISCHEMA request/response JSON populated", "All MAPIPARAMETER ISREQUIRED set", "Auth tested", "Pagination tested", "Error responses tested"],
            [8] = ["Consumer tested against spec", "SLA response-time benchmarks met", "No undocumented breaking changes"],
            [9] = ["MAPI ABOUTAPI non-empty", "MAPI KEYFEATURES non-empty", "MAPI USECASES non-empty", "MAPIARTIFACT documentation uploaded", "MAPIEXPOSUREPOLICY record exists", "Consumers notified"]
        };

    public async Task<List<ApiRequestChecklistDTO>> GetChecklistAsync(int apiRequestId, byte? stage, LoginDTO login, CancellationToken ct)
    {
        if (apiRequestId == 0)
            throw new ArgumentException("ApiRequestId must be a positive number.");

        try
        {
            return stage.HasValue
                ? await _dal.GetByStageAsync(apiRequestId, stage.Value, login.ClientId, login, ct).ConfigureAwait(false)
                : await _dal.GetByRequestAsync(apiRequestId, login.ClientId, login, ct).ConfigureAwait(false);
        }
        catch (Exception ex)
        {
            _logger.LogError(ex, "GetChecklist failed for ApiRequestId {ApiRequestId}", apiRequestId);
            throw;
        }
    }

    public async Task<string> CompleteItemAsync(int checklistId, int apiRequestId, LoginDTO login, CancellationToken ct)
    {
        if (checklistId  == 0) throw new ArgumentException("ChecklistId must be a positive number.");
        if (apiRequestId == 0) throw new ArgumentException("ApiRequestId must be a positive number.");

        try
        {
            await _dal.CompleteItemAsync(checklistId, apiRequestId, login.UserId, login.ClientId, login, ct).ConfigureAwait(false);
            return SuccessResponse.UpdateSuccess;
        }
        catch (Exception ex)
        {
            _logger.LogError(ex, "CompleteItem failed for ChecklistId {ChecklistId}", checklistId);
            throw;
        }
    }

    public async Task<int> SeedStageItemsAsync(int apiRequestId, byte stage, LoginDTO login, CancellationToken ct)
    {
        if (apiRequestId == 0)
            throw new ArgumentException("ApiRequestId must be a positive number.");

        if (!StageItems.TryGetValue(stage, out var items))
            throw new ArgumentException($"Stage {stage} is system-managed; no checklist required.");

        // Guard: skip if already seeded for this request + stage
        var existing = await _dal.GetByStageAsync(apiRequestId, stage, login.ClientId, login, ct).ConfigureAwait(false);
        if (existing.Count > 0)
        {
            _logger.LogWarning(
                "SeedStageItems skipped — already seeded. ApiRequestId {ApiRequestId} | Stage {Stage}",
                apiRequestId, stage);
            return 0;
        }

        try
        {
            var autoNumberDto = await _autoNumber.GetNumberAsync(items.Count, "MAPIREQUESTCHECKLIST", login).ConfigureAwait(false);

            if (autoNumberDto is null || autoNumberDto.StartNumber <= 0)
                throw new InvalidOperationException($"AutoNumber returned invalid result for Stage {stage}.");

            int nextId = autoNumberDto.StartNumber;

            for (short i = 0; i < items.Count; i++)
            {
                ct.ThrowIfCancellationRequested();

                var dto = new ApiRequestChecklistSaveDTO
                {
                    ChecklistId = nextId++,
                    TenantId = login.ClientId,
                    ApiRequestId = apiRequestId,
                    Stage = stage,
                    ItemText = items[i],
                    IsComplete = 0,
                    SortOrder = (short)(i + 1)
                };

                await _dal.InsertChecklistItemAsync(dto, login, ct).ConfigureAwait(false);
            }

            _logger.LogInformation(
                "SeedStageItems completed. ApiRequestId {ApiRequestId} | Stage {Stage} | Items seeded {Count}",
                apiRequestId, stage, items.Count);

            return items.Count;
        }
        catch (Exception ex) when (ex is not ArgumentException && ex is not InvalidOperationException)
        {
            _logger.LogError(ex,
                "SeedStageItems failed. ApiRequestId {ApiRequestId} | Stage {Stage}",
                apiRequestId, stage);
            throw;
        }
    }
}