using System;
using System.Collections.Generic;
using System.IO;
using System.Linq;
using System.Runtime.InteropServices;
using System.Text;
using Microsoft.DotNet.Cli.Build.Framework;
using Microsoft.DotNet.InternalAbstractions;
using Newtonsoft.Json;
using Newtonsoft.Json.Linq;
using static Microsoft.DotNet.Cli.Build.Framework.BuildHelpers;
using static Microsoft.DotNet.Cli.Build.FS;

namespace Microsoft.DotNet.Cli.Build
{
    public class CompileTargets
    {
        public static readonly string CoreCLRVersion = "1.0.2-rc3-24123-01";
        public static readonly bool IsWinx86 = CurrentPlatform.IsWindows && CurrentArchitecture.Isx86;

        public static readonly string[] BinariesForCoreHost = new[]
        {
            "csc"
        };

        public static readonly string[] ProjectsToPublish = new[]
        {
            "dotnet"
        };

        public static readonly string[] FilesToClean = new[]
        {
            "vbc.exe"
        };

        public static string HostPackagePlatformRid => HostPackageSupportedRids[
                             (RuntimeEnvironment.OperatingSystemPlatform == Platform.Windows)
                             ? $"win7-{RuntimeEnvironment.RuntimeArchitecture}"
                             : RuntimeEnvironment.GetRuntimeIdentifier()];

        public static readonly Dictionary<string, string> HostPackageSupportedRids = new Dictionary<string, string>()
        {
            // Key: Current platform RID. Value: The actual publishable (non-dummy) package name produced by the build system for this RID.
            { "win7-x64", "win7-x64" },
            { "win7-x86", "win7-x86" },
            { "osx.10.10-x64", "osx.10.10-x64" },
            { "osx.10.11-x64", "osx.10.10-x64" },
            { "ubuntu.14.04-x64", "ubuntu.14.04-x64" },
            { "centos.7-x64", "rhel.7-x64" },
            { "rhel.7-x64", "rhel.7-x64" },
            { "rhel.7.2-x64", "rhel.7-x64" },
            { "debian.8-x64", "debian.8-x64" }
        };

        public const string SharedFrameworkName = "Microsoft.NETCore.App";

        public static Crossgen CrossgenUtil = new Crossgen(CoreCLRVersion);

        private static string DotnetHostBaseName => $"dotnet{Constants.ExeSuffix}";
        private static string DotnetHostFxrBaseName => $"{Constants.DynamicLibPrefix}hostfxr{Constants.DynamicLibSuffix}";
        private static string HostPolicyBaseName => $"{Constants.DynamicLibPrefix}hostpolicy{Constants.DynamicLibSuffix}";

        // Updates the stage 2 with recent changes.
        [Target(nameof(PrepareTargets.Init), nameof(CompileStage2))]
        public static BuildTargetResult UpdateBuild(BuildTargetContext c)
        {
            return c.Success();
        }

        [Target(nameof(PrepareTargets.Init), nameof(RestoreLockedCoreHost), nameof(CompileStage1), nameof(CompileStage2))]
        public static BuildTargetResult Compile(BuildTargetContext c)
        {
            return c.Success();
        }

        [Target(nameof(PrepareTargets.Init))]
        public static BuildTargetResult RestoreLockedCoreHost(BuildTargetContext c)
        {
            var hostVersion = c.BuildContext.Get<HostVersion>("HostVersion");
            var lockedHostFxrVersion = hostVersion.LockedHostFxrVersion;

            var currentRid = HostPackagePlatformRid;

            string projectJson = $@"{{
  ""dependencies"": {{
      ""Microsoft.NETCore.DotNetHostResolver"" : ""{lockedHostFxrVersion}""
  }},
  ""frameworks"": {{
      ""netcoreapp1.0"": {{}}
  }},
  ""runtimes"": {{
      ""{currentRid}"": {{}}
  }}
}}";
            var tempPjDirectory = Path.Combine(Dirs.Intermediate, "lockedHostTemp");
            FS.Rmdir(tempPjDirectory);
            Directory.CreateDirectory(tempPjDirectory);
            var tempPjFile = Path.Combine(tempPjDirectory, "project.json");
            File.WriteAllText(tempPjFile, projectJson);

            DotNetCli.Stage0.Restore("--verbosity", "verbose",
                    "--fallbacksource", Dirs.CorehostLocalPackages,
                    "--fallbacksource", Dirs.CorehostDummyPackages)
                .WorkingDirectory(tempPjDirectory)
                .Execute()
                .EnsureSuccessful();

            // Clean out before publishing locked binaries
            FS.Rmdir(Dirs.CorehostLocked);

            // Use specific RIDS for non-backward compatible platforms.
            (CurrentPlatform.IsWindows
                ? DotNetCli.Stage0.Publish("--output", Dirs.CorehostLocked, "--no-build")
                : DotNetCli.Stage0.Publish("--output", Dirs.CorehostLocked, "--no-build", "-r", currentRid))
                .WorkingDirectory(tempPjDirectory)
                .Execute()
                .EnsureSuccessful();

            return c.Success();
        }

        [Target(nameof(PrepareTargets.Init))]
        public static BuildTargetResult CompileStage1(BuildTargetContext c)
        {
            CleanBinObj(c, Path.Combine(c.BuildContext.BuildDirectory, "src"));

            if (Directory.Exists(Dirs.Stage1))
            {
                Utils.DeleteDirectory(Dirs.Stage1);
            }
            Directory.CreateDirectory(Dirs.Stage1);

            CopySharedHost(Dirs.Stage1);
            PublishSharedFramework(c, Dirs.Stage1, DotNetCli.Stage0);
            var result = CompileCliSdk(c,
                dotnet: DotNetCli.Stage0,
                outputDir: Dirs.Stage1);

            CleanOutputDir(Path.Combine(Dirs.Stage1, "sdk"));
            FS.CopyRecursive(Dirs.Stage1, Dirs.Stage1Symbols);

            RemovePdbsFromDir(Path.Combine(Dirs.Stage1, "sdk"));

            return result;
        }

        [Target(nameof(PrepareTargets.Init))]
        public static BuildTargetResult CompileStage2(BuildTargetContext c)
        {
            var configuration = c.BuildContext.Get<string>("Configuration");

            CleanBinObj(c, Path.Combine(c.BuildContext.BuildDirectory, "src"));

            if (Directory.Exists(Dirs.Stage2))
            {
                Utils.DeleteDirectory(Dirs.Stage2);
            }
            Directory.CreateDirectory(Dirs.Stage2);

            PublishSharedFramework(c, Dirs.Stage2, DotNetCli.Stage1);
            CopySharedHost(Dirs.Stage2);
            var result = CompileCliSdk(c,
                dotnet: DotNetCli.Stage1,
                outputDir: Dirs.Stage2);

            if (!result.Success)
            {
                return result;
            }

            if (CurrentPlatform.IsWindows)
            {
                // build projects for nuget packages
                var packagingOutputDir = Path.Combine(Dirs.Stage2Compilation, "forPackaging");
                Mkdirp(packagingOutputDir);
                foreach (var project in PackageTargets.ProjectsToPack)
                {
                    // Just build them, we'll pack later
                    var packBuildResult = DotNetCli.Stage1.Build(
                        "--build-base-path",
                        packagingOutputDir,
                        "--configuration",
                        configuration,
                        Path.Combine(c.BuildContext.BuildDirectory, "src", project))
                        .Execute();

                    packBuildResult.EnsureSuccessful();
                }
            }

            CleanOutputDir(Path.Combine(Dirs.Stage2, "sdk"));
            FS.CopyRecursive(Dirs.Stage2, Dirs.Stage2Symbols);

            RemovePdbsFromDir(Path.Combine(Dirs.Stage2, "sdk"));

            return c.Success();
        }

        private static void CleanOutputDir(string directory)
        {
            foreach (var file in FilesToClean)
            {
                FS.RmFilesInDirRecursive(directory, file);
            }
        }

        private static void RemovePdbsFromDir(string directory)
        {
            FS.RmFilesInDirRecursive(directory, "*.pdb");
        }

        private static void CopySharedHost(string outputDir)
        {
            File.Copy(
                Path.Combine(Dirs.CorehostLocked, DotnetHostBaseName),
                Path.Combine(outputDir, DotnetHostBaseName), true);
            File.Copy(
                Path.Combine(Dirs.CorehostLocked, DotnetHostFxrBaseName),
                Path.Combine(outputDir, DotnetHostFxrBaseName), true);
        }

        public static void PublishSharedFramework(BuildTargetContext c, string outputDir, DotNetCli dotnetCli)
        {
            string SharedFrameworkTemplateSourceRoot = Path.Combine(Dirs.RepoRoot, "src", "sharedframework", "framework");
            string SharedFrameworkNugetVersion = c.BuildContext.Get<string>("SharedFrameworkNugetVersion");

            string sharedFrameworkRid;
            if (RuntimeEnvironment.OperatingSystemPlatform == Platform.Windows)
            {
                sharedFrameworkRid = $"win7-{RuntimeEnvironment.RuntimeArchitecture}";
            }
            else
            {
                sharedFrameworkRid = RuntimeEnvironment.GetRuntimeIdentifier();
            }

            string SharedFrameworkSourceRoot = GenerateSharedFrameworkProject(c, SharedFrameworkTemplateSourceRoot, sharedFrameworkRid);

            dotnetCli.Restore(
                "--verbosity", "verbose",
                "--disable-parallel",
                "--infer-runtimes",
                "--fallbacksource", Dirs.CorehostLocalPackages)
                .WorkingDirectory(SharedFrameworkSourceRoot)
                .Execute()
                .EnsureSuccessful();

            // We publish to a sub folder of the PublishRoot so tools like heat and zip can generate folder structures easier.
            string SharedFrameworkNameAndVersionRoot = Path.Combine(outputDir, "shared", SharedFrameworkName, SharedFrameworkNugetVersion);
            c.BuildContext["SharedFrameworkPath"] = SharedFrameworkNameAndVersionRoot;

            if (Directory.Exists(SharedFrameworkNameAndVersionRoot))
            {
                Utils.DeleteDirectory(SharedFrameworkNameAndVersionRoot);
            }

            dotnetCli.Publish(
                "--output", SharedFrameworkNameAndVersionRoot,
                "-r", sharedFrameworkRid,
                SharedFrameworkSourceRoot).Execute().EnsureSuccessful();

            // Clean up artifacts that dotnet-publish generates which we don't need
            DeleteMainPublishOutput(SharedFrameworkNameAndVersionRoot, "framework");
            File.Delete(Path.Combine(SharedFrameworkNameAndVersionRoot, "framework.runtimeconfig.json"));

            // Rename the .deps file
            var destinationDeps = Path.Combine(SharedFrameworkNameAndVersionRoot, $"{SharedFrameworkName}.deps.json");
            File.Move(Path.Combine(SharedFrameworkNameAndVersionRoot, "framework.deps.json"), destinationDeps);
            ChangeEntryPointLibraryName(destinationDeps, null);

            // Generate RID fallback graph
            string runtimeGraphGeneratorRuntime = null;
            switch (RuntimeEnvironment.OperatingSystemPlatform)
            {
                case Platform.Windows:
                    runtimeGraphGeneratorRuntime = "win";
                    break;
                case Platform.Linux:
                    runtimeGraphGeneratorRuntime = "linux";
                    break;
                case Platform.Darwin:
                    runtimeGraphGeneratorRuntime = "osx";
                    break;
            }
            if (!string.IsNullOrEmpty(runtimeGraphGeneratorRuntime))
            {
                var runtimeGraphGeneratorName = "RuntimeGraphGenerator";
                var runtimeGraphGeneratorProject = Path.Combine(Dirs.RepoRoot, "tools", runtimeGraphGeneratorName);
                var runtimeGraphGeneratorOutput = Path.Combine(Dirs.Output, "tools", runtimeGraphGeneratorName);

                dotnetCli.Publish(
                    "--output", runtimeGraphGeneratorOutput,
                    runtimeGraphGeneratorProject).Execute().EnsureSuccessful();
                var runtimeGraphGeneratorExe = Path.Combine(runtimeGraphGeneratorOutput, $"{runtimeGraphGeneratorName}{Constants.ExeSuffix}");

                Cmd(runtimeGraphGeneratorExe, "--project", SharedFrameworkSourceRoot, "--deps", destinationDeps, runtimeGraphGeneratorRuntime)
                    .Execute()
                    .EnsureSuccessful();
            }
            else
            {
                c.Error($"Could not determine rid graph generation runtime for platform {RuntimeEnvironment.OperatingSystemPlatform}");
            }

            // TODO: Issue #2408: Remove corehost and hostfxr from the Shared FX.
            File.Copy(
               Path.Combine(Dirs.CorehostLocked, DotnetHostBaseName),
               Path.Combine(SharedFrameworkNameAndVersionRoot, $"corehost{Constants.ExeSuffix}"), true);
            File.Copy(
                Path.Combine(Dirs.CorehostLocked, DotnetHostFxrBaseName),
                Path.Combine(SharedFrameworkNameAndVersionRoot, DotnetHostFxrBaseName), true);

            // Hostpolicy should be the latest and not the locked version as it is supposed to evolve for
            // the framework and has a tight coupling with coreclr's API in the framework.
            File.Copy(
                Path.Combine(Dirs.CorehostLatest, HostPolicyBaseName),
                Path.Combine(SharedFrameworkNameAndVersionRoot, HostPolicyBaseName), true);

            if (File.Exists(Path.Combine(SharedFrameworkNameAndVersionRoot, "mscorlib.ni.dll")))
            {
                // Publish already places the crossgen'd version of mscorlib into the output, so we can
                // remove the IL version
                File.Delete(Path.Combine(SharedFrameworkNameAndVersionRoot, "mscorlib.dll"));
            }

            CrossgenUtil.CrossgenDirectory(c, SharedFrameworkNameAndVersionRoot);

            // Generate .version file for sharedfx
            var version = SharedFrameworkNugetVersion;
            var content = $@"{c.BuildContext["CommitHash"]}{Environment.NewLine}{version}{Environment.NewLine}";
            File.WriteAllText(Path.Combine(SharedFrameworkNameAndVersionRoot, ".version"), content);
        }

        /// <summary>
        /// Generates the real shared framework project that will get published.
        /// </summary>
        /// <param name="sharedFrameworkTemplatePath">The "sharedFramework" source template folder.</param>
        private static string GenerateSharedFrameworkProject(BuildTargetContext c, string sharedFrameworkTemplatePath, string rid)
        {
            string sharedFrameworkProjectPath = Path.Combine(Dirs.Intermediate, "sharedFramework", "framework");
            Utils.DeleteDirectory(sharedFrameworkProjectPath);
            CopyRecursive(sharedFrameworkTemplatePath, sharedFrameworkProjectPath, true);

            string templateFile = Path.Combine(sharedFrameworkProjectPath, "project.json.template");
            JObject sharedFrameworkProject = JsonUtils.ReadProject(templateFile);
            sharedFrameworkProject["dependencies"]["Microsoft.NETCore.App"] = c.BuildContext.Get<BuildVersion>("BuildVersion").NetCoreAppVersion;
            ((JObject)sharedFrameworkProject["runtimes"]).RemoveAll();
            sharedFrameworkProject["runtimes"][rid] = new JObject();

            string projectJsonPath = Path.Combine(sharedFrameworkProjectPath, "project.json");
            JsonUtils.WriteProject(sharedFrameworkProject, projectJsonPath);

            Rm(templateFile);

            return sharedFrameworkProjectPath;
        }

        private static BuildTargetResult CompileCliSdk(BuildTargetContext c, DotNetCli dotnet, string outputDir)
        {
            var configuration = c.BuildContext.Get<string>("Configuration");
            var buildVersion = c.BuildContext.Get<BuildVersion>("BuildVersion");
            var srcDir = Path.Combine(c.BuildContext.BuildDirectory, "src");
            outputDir = Path.Combine(outputDir, "sdk", buildVersion.NuGetVersion);

            FS.CleanBinObj(c, srcDir);
            Rmdir(outputDir);
            Mkdirp(outputDir);

            foreach (var project in ProjectsToPublish)
            {
                dotnet.Publish(
                    "--native-subdirectory",
                    "--output", outputDir,
                    "--configuration", configuration,
                    "--version-suffix", buildVersion.CommitCountString,
                    Path.Combine(srcDir, project))
                    .Execute()
                    .EnsureSuccessful();
            }

            FixModeFlags(outputDir);

            string compilersProject = Path.Combine(Dirs.RepoRoot, "src", "compilers");
            dotnet.Publish(compilersProject,
                    "--output",
                    outputDir,
                    "--framework",
                    "netstandard1.5")
                    .Execute()
                    .EnsureSuccessful();

            var compilersDeps = Path.Combine(outputDir, "compilers.deps.json");
            var compilersRuntimeConfig = Path.Combine(outputDir, "compilers.runtimeconfig.json");

            File.Copy(Path.Combine(Dirs.CorehostLocked, DotnetHostBaseName), Path.Combine(outputDir, $"corehost{Constants.ExeSuffix}"), overwrite: true);
            File.Copy(Path.Combine(Dirs.CorehostLocked, $"{Constants.DynamicLibPrefix}hostfxr{Constants.DynamicLibSuffix}"), Path.Combine(outputDir, $"{Constants.DynamicLibPrefix}hostfxr{Constants.DynamicLibSuffix}"), overwrite: true);
            File.Copy(Path.Combine(Dirs.CorehostLatest, $"{Constants.DynamicLibPrefix}hostpolicy{Constants.DynamicLibSuffix}"), Path.Combine(outputDir, $"{Constants.DynamicLibPrefix}hostpolicy{Constants.DynamicLibSuffix}"), overwrite: true);

            var binaryToCorehostifyRelDir = Path.Combine("runtimes", "any", "native");
            var binaryToCorehostifyOutDir = Path.Combine(outputDir, binaryToCorehostifyRelDir);
            // Corehostify binaries
            foreach (var binaryToCorehostify in BinariesForCoreHost)
            {
                try
                {
                    // Yes, it is .exe even on Linux. This is the managed exe we're working with
                    File.Copy(Path.Combine(binaryToCorehostifyOutDir, $"{binaryToCorehostify}.exe"), Path.Combine(outputDir, $"{binaryToCorehostify}.dll"));
                    File.Delete(Path.Combine(binaryToCorehostifyOutDir, $"{binaryToCorehostify}.exe"));
                    File.Copy(compilersDeps, Path.Combine(outputDir, binaryToCorehostify + ".deps.json"));
                    File.Copy(compilersRuntimeConfig, Path.Combine(outputDir, binaryToCorehostify + ".runtimeconfig.json"));
                    var binaryToCoreHostifyDeps = Path.Combine(outputDir, binaryToCorehostify + ".deps.json");
                    ChangeEntryPointLibraryName(binaryToCoreHostifyDeps, binaryToCorehostify);
                    foreach (var binaryToRemove in new string[] { "csc", "vbc" })
                    {
                        var assetPath = Path.Combine(binaryToCorehostifyRelDir, $"{binaryToRemove}.exe").Replace(Path.DirectorySeparatorChar, '/');
                        RemoveAssetFromDepsPackages(binaryToCoreHostifyDeps, "runtimeTargets", assetPath);
                    }
                }
                catch (Exception ex)
                {
                    return c.Failed($"Failed to corehostify '{binaryToCorehostify}': {ex.ToString()}");
                }
            }

            // cleanup compilers project output we don't need
            DeleteMainPublishOutput(outputDir, "compilers");
            File.Delete(compilersDeps);
            File.Delete(compilersRuntimeConfig);

            CrossgenUtil.CrossgenDirectory(c, outputDir);

            // Generate .version file
            var version = buildVersion.NuGetVersion;
            var content = $@"{c.BuildContext["CommitHash"]}{Environment.NewLine}{version}{Environment.NewLine}";
            File.WriteAllText(Path.Combine(outputDir, ".version"), content);

            return c.Success();
        }

        private static void RemoveAssetFromDepsPackages(string depsFile, string sectionName, string assetPath)
        {
            JToken deps;
            using (var file = File.OpenText(depsFile))
            using (JsonTextReader reader = new JsonTextReader(file))
            {
                deps = JObject.ReadFrom(reader);
            }

            foreach (JProperty target in deps["targets"])
            {
                foreach (JProperty pv in target.Value.Children<JProperty>())
                {
                    var section = pv.Value[sectionName];
                    if (section != null)
                    {
                        foreach (JProperty relPath in section)
                        {
                            if (assetPath.Equals(relPath.Name))
                            {
                                relPath.Remove();
                                break;
                            }
                        }
                    }
                }
            }
            using (var file = File.CreateText(depsFile))
            using (var writer = new JsonTextWriter(file) { Formatting = Formatting.Indented })
            {
                deps.WriteTo(writer);
            }
        }

        private static void ChangeEntryPointLibraryName(string depsFile, string newName)
        {
            JToken deps;
            using (var file = File.OpenText(depsFile))
            using (JsonTextReader reader = new JsonTextReader(file))
            {
                deps = JObject.ReadFrom(reader);
            }

            string version = null;
            foreach (JProperty target in deps["targets"])
            {
                var targetLibrary = target.Value.Children<JProperty>().FirstOrDefault();
                if (targetLibrary == null)
                {
                    continue;
                }
                version = targetLibrary.Name.Substring(targetLibrary.Name.IndexOf('/') + 1);
                if (newName == null)
                {
                    targetLibrary.Remove();
                }
                else
                {
                    targetLibrary.Replace(new JProperty(newName + '/' + version, targetLibrary.Value));
                }
            }
            if (version != null)
            {
                var library = deps["libraries"].Children<JProperty>().First();
                if (newName == null)
                {
                    library.Remove();
                }
                else
                {
                    library.Replace(new JProperty(newName + '/' + version, library.Value));
                }
                using (var file = File.CreateText(depsFile))
                using (var writer = new JsonTextWriter(file) { Formatting = Formatting.Indented })
                {
                    deps.WriteTo(writer);
                }
            }
        }

        private static void DeleteMainPublishOutput(string path, string name)
        {
            File.Delete(Path.Combine(path, $"{name}{Constants.ExeSuffix}"));
            File.Delete(Path.Combine(path, $"{name}.dll"));
            File.Delete(Path.Combine(path, $"{name}.pdb"));
        }
    }
}