using FabApprovalWorkerService.Models;

using System.Text;

namespace FabApprovalWorkerService.Services;

public interface IECNService {
    Task<IEnumerable<ECN>> GetExpiringTECNs();
    Task<IEnumerable<ECN>> GetExpiredTECNs();
    Task<IEnumerable<string>> GetTECNNotificationUserEmails();
}

public class ECNService : IECNService {
    private readonly ILogger<ECNService> _logger;
    private readonly IDalService _dalService;

    public ECNService(ILogger<ECNService> logger, IDalService dalService) {
        _logger = logger ?? throw new ArgumentNullException("ILogger not injected");
        _dalService = dalService ?? throw new ArgumentNullException("IDalService not injected");
    }

    public async Task<IEnumerable<ECN>> GetExpiredTECNs() {
        try {
            _logger.LogInformation("Attempting to get all TECNs expired in the last day");

            string today = DateTime.Now.ToString("yyyy-MM-dd HH:mm:ss");
            string yesterday = DateTime.Now.AddDays(-1).ToString("yyyy-MM-dd HH:mm:ss");

            StringBuilder queryBuilder = new StringBuilder();
            queryBuilder.Append("select ECNNumber, IsTECN, ExpirationDate, ExtensionDate, OriginatorID, Title ");
            queryBuilder.Append($"from ECN where IsTECN = 1 and ");
            queryBuilder.Append($"ExpirationDate between '{yesterday}' ");
            queryBuilder.Append($"and '{today}'");

            IEnumerable<ECN> expiredTecns = (await _dalService.QueryAsync<ECN>(queryBuilder.ToString()));

            IEnumerable<ECN> expiredTecnsNotExtended = expiredTecns
                                                        .Where(e => e.ExtensionDate < DateTime.Now)
                                                        .ToList();

            return expiredTecnsNotExtended;
        } catch (Exception ex) {
            StringBuilder errMsgBuilder = new();
            errMsgBuilder.Append("An exception occurred when attempting to get all TECNs expired in the last day. ");
            errMsgBuilder.Append($"Exception: {ex.Message}");
            _logger.LogError(errMsgBuilder.ToString());
            throw;
        }
    }

    public async Task<IEnumerable<ECN>> GetExpiringTECNs() {
        try {
            _logger.LogInformation("Attempting to get all TECNs expiring in the next five days");

            string today = DateTime.Now.ToString("yyyy-MM-dd HH:mm:ss");
            string fiveDaysFromToday = DateTime.Now.AddDays(5).ToString("yyyy-MM-dd HH:mm:ss");

            StringBuilder queryBuilder = new StringBuilder();
            queryBuilder.Append("select * from ECN ");
            queryBuilder.Append($"where IsTECN = 1 and ");
            queryBuilder.Append($"ExpirationDate between '{today}' ");
            queryBuilder.Append($"and '{fiveDaysFromToday}';");

            IEnumerable<ECN> expiringTecns = (await _dalService.QueryAsync<ECN>(queryBuilder.ToString()));

            IEnumerable<ECN> expiringTecnsNotExtended = expiringTecns
                                        .Where(e => e.ExtensionDate <= DateTime.Now.AddDays(5))
                                        .ToList();

            return expiringTecnsNotExtended;
        } catch (Exception ex) {
            StringBuilder errMsgBuilder = new();
            errMsgBuilder.Append("An exception occurred when attempting to get all TECNs expiring in the next five days. ");
            errMsgBuilder.Append($"Exception: {ex.Message}");
            _logger.LogError(errMsgBuilder.ToString());
            throw;
        }
    }

    public async Task<IEnumerable<string>> GetTECNNotificationUserEmails() {
        try {
            _logger.LogInformation("Attempting to get TECN notification user emails");

            string sql = "select u.Email from TECNNotificationsUsers t join Users u on t.UserId = u.UserID;";

            IEnumerable<string> tecnNotificationUserEmails = (await _dalService.QueryAsync<string>(sql)).ToList();

            _logger.LogInformation($"Found {tecnNotificationUserEmails.Count()} TECN notification user emails");

            return tecnNotificationUserEmails;
        } catch (Exception ex) {
            StringBuilder errMsgBuilder = new();
            errMsgBuilder.Append("An exception occurred when attempting to get TECN notification user emails. ");
            errMsgBuilder.Append($"Exception: {ex.Message}");
            _logger.LogError(errMsgBuilder.ToString());
            throw;
        }
    }
}