using Newtonsoft.Json;
using ReserveManagementSystemApi.Enums;
using ReserveManagementSystemLib.Models;
using ReserveManagementSystemLib.Repositories;

namespace ReserveManagementSystemApi.Services
{
    public class AuditHistoryService : IAuditHistoryService
    {
        private readonly IAuditHistoryRepository _auditHistoryRepository;
        const string SYSTEM_MODIFIED_BY = "RMS";

        public AuditHistoryService(IAuditHistoryRepository auditHistoryRepository)
        {
            _auditHistoryRepository = auditHistoryRepository;
        }

        public async Task<IEnumerable<AuditHistory>> GetAllAsync()
        {
            try
            {
                return await _auditHistoryRepository.GetAll().OrderByDescending(o => o.ModifiedDate).ToListAsync();
            }
            catch (Exception ex)
            {
                Log.Error(ex, "Failure retrieving audit histories.");
                throw;
            }
        }

        public async Task<AuditHistory> FindByIdAsync(int id)
        {
            AuditHistory history;
            try
            {
                history = await _auditHistoryRepository.FindByIdAsync(id);
            }
            catch (Exception ex)
            {
                Log.Error(ex, $"Failure retrieving history with id {id}.");
                throw;
            }

            if (history == null)
            {
                throw new Exception($"Audit history with id {id} not found.");
            }

            return history;
        }

        public async Task<AuditHistory> AddHistoryAsync(AuditHistory history)
        {
            return await _auditHistoryRepository.AddHistoryAsync(history);
        }

        public async Task<int> AddAuditHistoriesForNonexistingLoansAsync(List<Loan> loans)
        {
            var currentDate = DateTime.Now;
            var histories = loans.Select(loan => new AuditHistory
            {
                LoanId = null,
                MemberNumber = loan.MemberNumber,
                LoanNumber = loan.LoanNumber,
                ModifiedBy = SYSTEM_MODIFIED_BY,
                ModifiedDate = currentDate,
                ActivityType = ActivityType.Error.ToString(),
                AuditDescription = "Loan in closed file not found",
                OldValue = null,
                NewValue = null
            }).ToList();

            return await _auditHistoryRepository.AddHistoriesAsync(histories);
        }

        public AuditHistory GetAuditHistoryForNonexistingClosedLoan(Loan loan)
        {
            var currentDate = DateTime.Now;
            return new AuditHistory
            {
                LoanId = null,
                MemberNumber = loan.MemberNumber,
                LoanNumber = loan.LoanNumber,
                ModifiedBy = SYSTEM_MODIFIED_BY,
                ModifiedDate = currentDate,
                ActivityType = ActivityType.Error.ToString(),
                AuditDescription = "Loan in closed import not found",
                OldValue = null,
                NewValue = null
            };
        }

        public AuditHistory GetExistingLoanUpdateHistoryAsync(Loan loan, Loan originalLoan)
        {
            var currentDate = DateTime.Now;
            return new AuditHistory
            {
                LoanId = loan.LoanId,
                MemberNumber = loan.MemberNumber,
                LoanNumber = loan.LoanNumber,
                ModifiedBy = SYSTEM_MODIFIED_BY,
                ModifiedDate = currentDate,
                ActivityType = ActivityType.NewLoanUpdate.ToString(),
                AuditDescription = "Loan found in table, record updated",
                OldValue = JsonConvert.SerializeObject(originalLoan),
                NewValue = JsonConvert.SerializeObject(loan)
            };
        }

        public AuditHistory GetLoanStatusChangeHistory(Loan loan, string oldStatus, string description)
        {
            return new AuditHistory
            {
                LoanId = loan.LoanId,
                MemberNumber = loan.MemberNumber,
                LoanNumber = loan.LoanNumber,
                ModifiedBy = SYSTEM_MODIFIED_BY,
                ModifiedDate = DateTime.Now,
                ActivityType = ActivityType.LoanStatusChange.ToString(),
                OldValue = oldStatus,
                NewValue = loan.LoanStatus,
                AuditDescription = description
            };
        }

        public async Task<int> AddHistoriesAsync(List<AuditHistory> histories)
        {
            return await _auditHistoryRepository.AddHistoriesAsync(histories);
        }

        public async Task AddErrorHistoryAsync(string memberNumber, string loanNumber, string description)
        {
            var auditHist = new AuditHistory
            {
                MemberNumber = memberNumber,
                LoanNumber = loanNumber,
                ActivityType = ActivityType.Error.ToString(),
                ModifiedDate = DateTime.Now,
                AuditDescription = description,
                ModifiedBy = SYSTEM_MODIFIED_BY
            };

            await _auditHistoryRepository.AddHistoryAsync(auditHist);
        }
    }
}