using GB5Shared.DTO.Framework.AutoNumber;
using GB5Shared.DTO.Framework.Criteria;
using GB5Shared.DTO.Framework.Login;
using GB5Shared.GenerateAutoNumber;
using GB5Shared.Resource.Response;
using GB5Shared.Validation;
using MaintenanceDAL.CustomCode.Activity;
using MaintenanceDAL.DTO.Activity;
using MaintenanceDAL.DTO.ActivityType;

namespace MaintenanceBLL.Activity
{
    public class ActivityBLL : IActivityBLL
    {
        private readonly IActivityDAL _activityDAL;
        private readonly AutoNumber _autoNumber;
        private readonly IValidation _validation;

        public ActivityBLL(IActivityDAL activityDAL, AutoNumber autoNumber, IValidation validation)
        {
            _activityDAL = activityDAL;
            _autoNumber = autoNumber;
            _validation = validation;
        }

        // Activity-only success messages. Edit the wording HERE to change the Activity response text
        // without touching the shared GB5Shared SuccessResponse resource (which every module uses).
        private const string ActivitySaveSuccessMessage = "Details have been saved successfully with Code =";
        private const string ActivityUpdateSuccessMessage = "Details have been updated successfully with Code =";
        private const string ActivityDeleteSuccessMessage = "Activity deleted successfully.";
        private const string ActivityDeleteNotFoundMessage = "Activity not found or already deleted.";

        public async Task<string> GetActivity(int activityId, LoginDTO loginDTO)
        {
            try
            {
                return await _activityDAL.GetActivity(activityId, loginDTO);
            }
            catch (Exception)
            {
                throw;
            }
        }
        public async Task<string> GetSelectListActivity(CriteriaDTO criteriaDTO, LoginDTO loginDTO)
        {
            try
            {
                return await _activityDAL.GetSelectListActivity(criteriaDTO, loginDTO);
            }
            catch (Exception)
            {
                throw;
            }
        }
        public async Task<string> SaveActivity(ActivityDTO activityDTO, LoginDTO loginDTO)
        {
            if(activityDTO == null)
            {
                throw new ArgumentNullException(nameof(activityDTO));
            }

            // Field-level validation — surfaces "<field> cannot be empty or whitespace." in the response.
            await _validation.NotEmpty(activityDTO.ActivityCode, nameof(activityDTO.ActivityCode));
            await _validation.NotEmpty(activityDTO.ActivityName, nameof(activityDTO.ActivityName));

            AutoNumberDTO? autoNumberDTO = null;
            activityDTO.ActivityModifiedById = loginDTO.UserId;
            activityDTO.ActivityModifiedOn = DateTime.UtcNow;
            bool IsNewData = activityDTO.ActivityId == 0;
            var count = 1;
            if(IsNewData)
            {
                try
                {
                    autoNumberDTO = await _autoNumber.GetAutoNumber(count, "ACTIVITY", loginDTO);
                    activityDTO.ActivityId = autoNumberDTO.StartNumber;
                    activityDTO.ActivityCreatedById = loginDTO.UserId;
                    activityDTO.ActivityCreatedOn = DateTime.UtcNow;
                    await _activityDAL.SaveActivity(activityDTO, loginDTO);
                    return $"{ActivitySaveSuccessMessage} {activityDTO.ActivityCode}";
                }
                catch
                {
                    // Roll back the allocated ACTIVITY number so a failed insert doesn't burn a code.
                    // (IDs are negative here, so guard only on whether a number was actually allocated.)
                    if (autoNumberDTO != null)
                        await _autoNumber.RollbackAutoNumber("ACTIVITY", autoNumberDTO.StartNumber, loginDTO);
                    throw;
                }
            }
            else
            {
                await _activityDAL.UpdateActivity(activityDTO, loginDTO);
                return $"{ActivityUpdateSuccessMessage} {activityDTO.ActivityCode}";
            }
        }

        public async Task<string> DeleteActivity(int activityId, LoginDTO loginDTO)
        {
            // 0 is the "new record" sentinel; GB5 AutoNumber issues negative PKs, which are valid.
            if (activityId == 0)
            {
                throw new ArgumentException("Invalid Activity Id.");
            }

            int rows = await _activityDAL.DeleteActivity(activityId, loginDTO);
            return rows > 0 ? ActivityDeleteSuccessMessage : ActivityDeleteNotFoundMessage;
        }

    }
}