using System;
using System.Collections.Generic;
using System.IO;
using System.IO.Compression;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
using Microsoft.AspNetCore.Authorization;
using Microsoft.AspNetCore.DataProtection;
using Microsoft.AspNetCore.Mvc;
using Microsoft.Extensions.Logging;
using Microsoft.Extensions.Options;
using NuGet.Packaging.Core;
using NuGet.Versioning;
using nuget_host.Data;
using nuget_host.Entities;
using nuget_host.Helpers;

namespace nuget_host.Controllers
{

    [AllowAnonymous]
    public class PackagesController : Controller
    {
        private readonly ILogger<PackagesController> logger;
        private readonly IDataProtector protector;

        private readonly NugetSettings nugetSettings;
        ApplicationDbContext dbContext;

        public PackagesController(
            ILoggerFactory loggerFactory,
            IDataProtectionProvider provider,
            IOptions<NugetSettings> nugetOptions,
            ApplicationDbContext dbContext)
        {
            logger = loggerFactory.CreateLogger<PackagesController>();
            nugetSettings = nugetOptions.Value;
            protector = provider.CreateProtector(nugetSettings.ProtectionTitle);
            this.dbContext = dbContext;
        }

        [HttpPut("packages")]
        public async Task<IActionResult> Put()
        {
            try
            {
                var clientVersionId = Request.Headers["X-NuGet-Client-Version"];
                var apiKey = Request.Headers["X-NuGet-ApiKey"];
                ViewData["versionId"] = typeof(PackagesController).Assembly.FullName;
                var files = new List<string>();
                ViewData["files"] = files;

                var clearkey = protector.Unprotect(apiKey);
                var apikey = dbContext.ApiKeys.SingleOrDefault(k => k.Id == clearkey);
                if (apikey == null)
                {
                    logger.LogError("403 : no api-key");
                    return Unauthorized();
                }

                foreach (var file in Request.Form.Files)
                {
                    string initpath = Path.Combine(Environment.GetEnvironmentVariable("TEMP") ??
                    Environment.GetEnvironmentVariable("TMP") ?? "/tmp",
                     $"nuget_host-{Guid.NewGuid()}.nupkg");

                    using (FileStream fw = new FileStream(initpath, FileMode.Create))
                    {
                        file.CopyTo(fw);
                    }

                    using (FileStream fw = new FileStream(initpath, FileMode.Open))
                    {
                        var archive = new ZipArchive(fw);

                        var nuspec = archive.Entries.FirstOrDefault(e => e.FullName.EndsWith(".nuspec"));
                        if (nuspec==null) return BadRequest("no nuspec from archive");
                        string pkgpath;
                        NuGetVersion version;
                        string pkgid;
                        string fullpath;

                        using (var specstr = nuspec.Open())
                        {
                            NuspecCoreReader reader = new NuspecCoreReader(specstr);

                            string pkgdesc = reader.GetDescription();
                            pkgid = reader.GetId();
                            version = reader.GetVersion();
                            string pkgidpath = Path.Combine(nugetSettings.PackagesRootDir,
                                pkgid);
                            pkgpath = Path.Combine(pkgidpath, version.ToFullString());
                            string name = $"{pkgid}-{version}.nupkg";
                            fullpath = Path.Combine(pkgpath, name);
                            
                            var destpkgiddir = new DirectoryInfo(pkgidpath);
                            Package package = dbContext.Packages.SingleOrDefault(p => p.Id == pkgid);
                            if (package != null) 
                            {
                                if (package.OwnerId != apikey.UserId)
                                {
                                    return new ForbidResult();
                                }
                            }
                            else 
                            {
                                package = new Package
                                {
                                    Id = pkgid,
                                    Description = pkgdesc,
                                    OwnerId = apikey.UserId
                                };
                                dbContext.Packages.Add(package);
                            }
                            if (!destpkgiddir.Exists) destpkgiddir.Create();

                            var source = new FileInfo(initpath);
                            var dest = new FileInfo(fullpath);
                            var destdir = new DirectoryInfo(dest.DirectoryName);
                            if (dest.Exists)
                            {
                                ViewData["msg"] = "existant";
                                ViewData["ecode"] = 1;
                                logger.LogWarning("400 : existant");
                                return BadRequest(ViewData);
                            }
                            else
                            {
                                destdir.Create();

                                source.MoveTo(fullpath);
                                files.Add(name);
                                var newversion = new PackageVersion
                                {
                                    Package = package,
                                    Major = version.Major,
                                    Minor = version.Minor,
                                    Patch = version.Patch,
                                    IsPrerelease = version.IsPrerelease,
                                    FullString = version.ToFullString()
                                };
                                dbContext.PackageVersions.Add(newversion);
                                await dbContext.SaveChangesAsync();
                                logger.LogInformation($"new package : {nuspec.Name}");
                            }
                        }
                        using (var shacrypto = System.Security.Cryptography.SHA512.Create())
                        {
                            using (var stream = System.IO.File.OpenRead(fullpath))
                            {
                                var hash = shacrypto.ComputeHash(stream);
                                var shafullname = fullpath + ".sha512";
                                var hashtext = Convert.ToBase64String(hash);
                                var hashtextbytes = Encoding.ASCII.GetBytes(hashtext);

                                using (var shafile = System.IO.File.OpenWrite(shafullname))
                                {
                                    shafile.Write(hashtextbytes, 0, hashtextbytes.Length);
                                }
                            }
                        }
                        nuspec.ExtractToFile(Path.Combine(pkgpath, pkgid + ".nuspec"));
                    }

                }
                return Ok(ViewData);
            }
            catch (Exception ex)
            {
                logger.LogError(ex.Message);
                logger.LogError("Stack Trace: "+ ex.StackTrace);
                return new ObjectResult(new { ViewData, ex.Message})
                { StatusCode = 500 };
            }
        }
        // dotnet add . package -s http://localhost:5000/packages nuget-cli
        // packages/FindPackagesById()?id='nuget-cli'&semVerLevel=2.0.0
        [HttpGet("packages/FindPackagesById()")]
        public IActionResult Index(string id, string semVerLevel)
        {
            if (string.IsNullOrEmpty(id))
            {
                ViewData["msg"] = "no id";
            }
            else
            {
                ViewData["id"] = id;
                // TODO Assert valid sem ver spec
                var filelst = new DirectoryInfo(nugetSettings.PackagesRootDir);
                var lst = filelst.GetDirectories(id);
                ViewData["lst"] = lst.Select(entry => entry.Name);
            }
            return Ok(ViewData);
        }



        [Authorize]
        [HttpGet("api/get-key/{*apikey}")]
        public IActionResult GetApiKey(string apiKey)
        {
            return Ok(protector.Protect(apiKey));
        }
    }
}