using Amazon.Lambda.Core;
using System;

// Assembly attribute to enable the Lambda function's JSON input to be converted into a .NET class.
[assembly: LambdaSerializer(typeof(Amazon.Lambda.Serialization.SystemTextJson.CamelCaseLambdaJsonSerializer))]

namespace StockSeller
{
    public class StockEvent
    {
        public int StockPrice;
    }

    public class TransactionResult
    {
        public string Id { get; set; } = string.Empty;
        public string Price { get; set; } = string.Empty;
        public string Type { get; set; } = string.Empty;
        public string Qty { get; set; } = string.Empty;
        public string Timestamp { get; set; } = string.Empty;
    }

    public class Function
    {

        private static readonly Random rand = new Random((Int32)(DateTime.UtcNow.Subtract(new DateTime(1970, 1, 1))).TotalSeconds);

        public TransactionResult FunctionHandler(StockEvent stockEvent, ILambdaContext context)
        {
            // Sample Lambda function which mocks the operation of selling a random number
            // of shares for a stock.

            // For demonstration purposes, this Lambda function does not actually perform any
            // actual transactions. It simply returns a mocked result.

            // Parameters
            // ----------
            // stockEvent: StockEvent, required
            //     Input event to the Lambda function

            // context: ILambdaContext
            //     Lambda Context runtime methods and attributes

            // Returns
            // ------
            //     TransactionResult: Object containing details of the stock selling transaction

            return new TransactionResult
            {
                Id = rand.Next().ToString(),
                Type = "Sell",
                Price = stockEvent.StockPrice.ToString(),
                Qty = (rand.Next() % 10 + 1).ToString(),
                Timestamp = DateTime.Now.ToString("yyyyMMddHHmmssffff")
            };
        }
    }
}