using System;
using System.Collections.Generic;
using System.Net;
using System.Net.Http;
using System.Text.Json;
using System.Threading.Tasks;

using Amazon.Lambda.APIGatewayEvents;
using Amazon.Lambda.Core;
using OpenTelemetry.Contrib.Instrumentation.AWSLambda.Implementation;
using Shared;
using Shared.DataAccess;

[assembly: LambdaSerializer(typeof(Amazon.Lambda.Serialization.SystemTextJson.DefaultLambdaJsonSerializer))]

namespace GetProducts
{
    public class Function
    {
        private readonly ProductsDAO dataAccess;
        public Function()
        {
            Tracing.Init();
            this.dataAccess = new DynamoDbProducts();
        }
        
        public Task<APIGatewayProxyResponse> TracingFunctionHandler(APIGatewayProxyRequest request, ILambdaContext context)
        {
            return AWSLambdaWrapper.Trace(Tracing.TraceProvider, FunctionHandler, request, context);
        }

        public async Task<APIGatewayProxyResponse> FunctionHandler(APIGatewayProxyRequest apigProxyEvent,
            ILambdaContext context)
        {
            if (!apigProxyEvent.HttpMethod.Equals(HttpMethod.Get.Method))
            {
                return new APIGatewayProxyResponse
                {
                    Body = "Only GET allowed",
                    StatusCode = (int)HttpStatusCode.MethodNotAllowed,
                };
            }
    
            context.Logger.LogLine($"Received {apigProxyEvent}");

            var products = await dataAccess.GetAllProducts();
    
            context.Logger.LogLine($"Found {products.Products.Count} product(s)");
    
            return new APIGatewayProxyResponse
            {
                Body = JsonSerializer.Serialize(products),
                StatusCode = 200,
                Headers = new Dictionary<string, string> {{"Content-Type", "application/json"}}
            };
        }
    }
}