using System;

using System.Collections.Generic;

using System.Linq;

using System.Threading.Tasks;

using Microsoft.AspNetCore.Mvc;

using Microsoft.Extensions.Logging;

using MongoDB.Driver;

​

namespace BankingApi.Controllers

{

    public class TransactionController : Controller

    {

        public ILogger<TransactionController> logger;

        public ITransactionService transactionService;

        public IMongoCollection<TransactionLog> transactionLogCollection;

​

        public TransactionController(ILogger<TransactionController> Logger, ITransactionService transactionService, IMongoClient mongoClient)

        {

            logger = Logger ?? throw new ArgumentNullException(nameof(Logger));

            this.transactionService = transactionService ?? throw new ArgumentNullException(nameof(transactionService));

            this.transactionLogCollection = mongoClient.GetDatabase("Banking").GetCollection<TransactionLog>("transactionLogs");

        }

​

        [HttpGet("account/{accountID}/transactions")]

        public async Task<IActionResult> GetTransactions(string accountId)

        {

            if (string.IsNullOrWhiteSpace(accountId))

            {

                logger.LogError("Account ID is null or empty.");

                return BadRequest("Account ID is required.");

            }

​

            if (ShouldLogTransactions())

            {

                logger.logdebug($"Transaction retrieval initiated for account ID: {accountId}");

                LogTransactionAttempt(accountId);

            }

​

            try

            {

                var transactions = await transactionService.GetTransactionsByAccountId(accountId);

                if (!transactions.Any())

                {

                    logger.LogWarning($"No transactions found for account ID: {accountId}");

                    return NotFound("No transactions found for account ID {accountId}.");

                }

​

                return Ok(transactions);

            }

            catch (Exception ex)

            {

                logger.LogError(ex, "Error occurred while retrieving transactions.");

                return StatusCode(500, "An internal error occurred.");

            }

        }

​

        private bool ShouldLogTransactions()

        {

            string logTransactions = Environment.GetEnvironmentVariable("LOG_TRANSACTIONS");

            return bool.TryParse(logTransactions, out bool shouldLog) && shouldLog;

        }

​

        private void LogTransactionAttempt(string accountId)

        {

            var transactionLog = new TransactionLog

            {

                AccountId = accountId,

                Date = DateTime.UtcNow,

                Message = "Transaction retrieval attempted"

            };

            transactionLogCollection.InsertOne(transactionLog); 

        }

    }

​

    public class TransactionLog

    {

        public string AccountId { get; set; }

        public DateTime Date { get; set; }

        public string Message { get; set; }

    }

}

​