namespace Giants.WebApi.Controllers
{
    using System;
    using System.Collections.Generic;
    using System.IO;
    using System.Linq;
    using System.Threading.Tasks;
    using Giants.Services.Services;
    using Microsoft.AspNetCore.Http;
    using Microsoft.AspNetCore.Mvc;
    using Microsoft.Extensions.Configuration;
    using Microsoft.Extensions.Logging;

    [ApiController]
    [ApiVersion("1.0")]
    [ApiVersion("1.1")]
    [Route("api/[controller]")]
    public class CrashReportsController : ControllerBase
    {
        private readonly ICrashReportService crashReportService;
        private readonly IHttpContextAccessor httpContextAccessor;
        private readonly ILogger<CrashReportsController> logger;
        private readonly IConfiguration configuration;
        private const long MaximumSizeInBytes = 10485760; // 10MB

        public CrashReportsController(
            ICrashReportService crashReportService,
            IHttpContextAccessor httpContextAccessor,
            ILogger<CrashReportsController> logger,
            IConfiguration configuration)
        {
            this.crashReportService = crashReportService;
            this.httpContextAccessor = httpContextAccessor;
            this.logger = logger;
            this.configuration = configuration;
        }

        [HttpPost]
        public async Task Upload()
        {
            this.ValidateFiles(this.Request.Form.Files);

            var file = this.Request.Form.Files.First();
            using (var stream = file.OpenReadStream())
            {
                await this.crashReportService.ProcessReport(file.FileName, this.GetRequestIpAddress(), stream).ConfigureAwait(false);
            }

            bool sentryEnabled = Convert.ToBoolean(this.configuration["SentryEnabled"]);
            if (!sentryEnabled)
            {
                this.logger.LogInformation("Skipping Sentry upload; disabled.");
                return;
            }

            using (var stream = file.OpenReadStream())
            { 
                await this.crashReportService.UploadMinidumpToSentry(file.FileName, stream).ConfigureAwait(false);
            }
        }

        private void ValidateFiles(IEnumerable<IFormFile> formFiles)
        {
            if (formFiles.Count() != 1)
            {
                // We only expect one .zip file
                throw new ArgumentException("Only one file is accepted.", nameof(formFiles));
            }

            var file = this.Request.Form.Files.First();
            if (file.Length > MaximumSizeInBytes)
            {
                throw new ArgumentException("File too large.", nameof(formFiles));
            }

            string fileName = Path.GetFileNameWithoutExtension(file.FileName);
            if (!Guid.TryParse(fileName, out Guid _) || file.Name != "crashrpt")
            {
                throw new ArgumentException("Unexpected file name.", nameof(formFiles));
            }
        }

        private string GetRequestIpAddress()
        {
            return this.httpContextAccessor.HttpContext.Connection.RemoteIpAddress.MapToIPv4().ToString();
        }
    }
}