using General_Ledger_Service.DTOs.Budget;
using General_Ledger_Service.DTOs.Common;
using General_Ledger_Service.Enums;
using General_Ledger_Service.Exceptions;
using General_Ledger_Service.Infra.UoW;
using General_Ledger_Service.Interfaces.Repositories;
using General_Ledger_Service.Interfaces.Services;
using General_Ledger_Service.Models;

namespace General_Ledger_Service.Services
{
    public class BudgetService(
        IBudgetRepository budgetRepository,
        IFiscalCalendarRepository fiscalCalendarRepository,
        IAccountRepository accountRepository,
        ICostCenterRepository costCenterRepository,
        IAuditLogRepository auditLogRepository,
        IUnitOfWork unitOfWork) : IBudgetService
    {
        private readonly IBudgetRepository _budgetRepository = budgetRepository;
        private readonly IFiscalCalendarRepository _fiscalCalendarRepository = fiscalCalendarRepository;
        private readonly IAccountRepository _accountRepository = accountRepository;
        private readonly ICostCenterRepository _costCenterRepository = costCenterRepository;
        private readonly IAuditLogRepository _auditLogRepository = auditLogRepository;
        private readonly IUnitOfWork _unitOfWork = unitOfWork;

        public async Task<ApiResponse> CreateAsync(CreateBudgetRequest request)
        {
            _ = await _fiscalCalendarRepository.GetFiscalYearByIdAsync(request.FiscalYearId)
                ?? throw new NotFoundException("Fiscal year not found");

            var budget = new Budget
            {
                FiscalYearId = request.FiscalYearId,
                Name = request.Name
            };

            await _unitOfWork.BeginAsync();
            try
            {
                await _budgetRepository.AddAsync(budget);
                await _unitOfWork.SaveChangesAsync();

                await _auditLogRepository.AddAsync(new AuditLog
                {
                    Category = AuditCategory.Administrative,
                    EntityName = "Budget",
                    EntityId = budget.BudgetId.ToString(),
                    Action = AuditAction.Create,
                    Description = $"Budget {budget.Name} created",
                    PerformedBy = null
                });
                await _unitOfWork.SaveChangesAsync();

                await _unitOfWork.CommitAsync();
            }
            catch
            {
                await _unitOfWork.RollbackAsync();
                throw;
            }

            return ResponseHelpers.Created("Budget created successfully", budget);
        }

        public async Task<ApiResponse> AddLinesAsync(long budgetId, List<BudgetLineRequest> request)
        {
            var budget = await _budgetRepository.GetByIdAsync(budgetId)
                ?? throw new NotFoundException("Budget not found");

            var lines = new List<BudgetLine>();
            foreach (var lineRequest in request)
            {
                var account = await _accountRepository.GetByCodeAsync(lineRequest.AccountCode)
                    ?? throw new NotFoundException($"Account {lineRequest.AccountCode} not found");

                _ = await _fiscalCalendarRepository.GetPeriodByIdAsync(lineRequest.PeriodId)
                    ?? throw new NotFoundException($"Period {lineRequest.PeriodId} not found");

                long? costCenterId = null;
                if (!string.IsNullOrWhiteSpace(lineRequest.CostCenterCode))
                {
                    var costCenter = await _costCenterRepository.GetByCodeAsync(lineRequest.CostCenterCode)
                        ?? throw new NotFoundException($"Cost center {lineRequest.CostCenterCode} not found");
                    costCenterId = costCenter.CostCenterId;
                }

                lines.Add(new BudgetLine
                {
                    BudgetId = budgetId,
                    AccountId = account.AccountId,
                    PeriodId = lineRequest.PeriodId,
                    CostCenterId = costCenterId,
                    BudgetedAmount = lineRequest.BudgetedAmount
                });
            }

            await _unitOfWork.BeginAsync();
            try
            {
                await _budgetRepository.AddLinesAsync(lines);
                await _unitOfWork.SaveChangesAsync();

                await _auditLogRepository.AddAsync(new AuditLog
                {
                    Category = AuditCategory.Administrative,
                    EntityName = "Budget",
                    EntityId = budget.BudgetId.ToString(),
                    Action = AuditAction.Update,
                    Description = $"{lines.Count} budget line(s) added to {budget.Name}",
                    PerformedBy = null
                });
                await _unitOfWork.SaveChangesAsync();

                await _unitOfWork.CommitAsync();
            }
            catch
            {
                await _unitOfWork.RollbackAsync();
                throw;
            }

            return ResponseHelpers.Created("Budget lines added successfully", lines);
        }

        public async Task<ApiResponse> ListAsync()
        {
            var budgets = await _budgetRepository.GetAllAsync();
            return ResponseHelpers.Ok("Budgets retrieved successfully", budgets);
        }
    }
}