using System;
using System.IO;
using System.Linq;
using System.Text;
using BizTalkPlatformManagementTool.Models;
using BizTalkPlatformManagementTool.Services;
using BizTalkPlatformManagementTool.Setup;

namespace BizTalkPlatformManagementTool.Tests
{
    internal static class Program
    {
        private static int failures;

        private static int Main()
        {
            Run("JsonRoundTripIsBomTolerantAndAtomic", JsonRoundTripIsBomTolerantAndAtomic);
            Run("DiffUsesApplicationAndNameIdentity", DiffUsesApplicationAndNameIdentity);
            Run("RestoreRejectsDifferentServer", RestoreRejectsDifferentServer);
            Run("RestorePlanUsesSafeOrder", RestorePlanUsesSafeOrder);
            Run("CsvNeutralizesFormulaValues", CsvNeutralizesFormulaValues);
            Run("PackageManifestRejectsTampering", PackageManifestRejectsTampering);
            Run("PackageManifestRejectsUndeclaredAndTraversalFiles", PackageManifestRejectsUndeclaredAndTraversalFiles);
            Run("InstallerActivatesValidatedPayload", InstallerActivatesValidatedPayload);
            Run("InstallerDoesNotMutateOnStagingFailure", InstallerDoesNotMutateOnStagingFailure);
            Run("InstallerRollsBackFailedActivatedSelfTest", InstallerRollsBackFailedActivatedSelfTest);
            Run("InstallerUninstallRemovesProgramDirectory", InstallerUninstallRemovesProgramDirectory);
            Console.WriteLine(failures == 0 ? "ALL TESTS PASSED" : failures + " TEST(S) FAILED");
            return failures == 0 ? 0 : 1;
        }

        private static void Run(string name, Action test)
        {
            try { test(); Console.WriteLine("PASS " + name); }
            catch (Exception ex) { failures++; Console.Error.WriteLine("FAIL " + name + ": " + ex); }
        }

        private static void JsonRoundTripIsBomTolerantAndAtomic()
        {
            InTemp(directory =>
            {
                var path = Path.Combine(directory, "snapshot.json");
                var snapshot = Snapshot("APP", "PORT", ArtifactStates.SendPortStarted);
                JsonFileStore.Save(path, snapshot);
                JsonFileStore.Save(path, snapshot);
                var original = File.ReadAllBytes(path);
                var withBom = new byte[original.Length + 3];
                withBom[0] = 0xef; withBom[1] = 0xbb; withBom[2] = 0xbf;
                Buffer.BlockCopy(original, 0, withBom, 3, original.Length);
                File.WriteAllBytes(path, withBom);
                Assert(JsonFileStore.Load<BizTalkSnapshot>(path).Applications.Count == 1, "BOM JSON did not load");
                Assert(Directory.GetFiles(directory, "*.tmp.*").Length == 0, "temporary files remained");
                Assert(Directory.GetFiles(directory, "*.bak.*").Length == 0, "backup files remained");
            });
        }

        private static void DiffUsesApplicationAndNameIdentity()
        {
            var before = Snapshot("APP-A", "SHARED", ArtifactStates.SendPortStarted);
            before.Applications.Add(Snapshot("APP-B", "SHARED", ArtifactStates.SendPortStarted).Applications[0]);
            var after = Snapshot("APP-A", "SHARED", ArtifactStates.SendPortStopped);
            after.Applications.Add(Snapshot("APP-B", "SHARED", ArtifactStates.SendPortStarted).Applications[0]);
            var diff = SnapshotComparer.Compare(before, after);
            Assert(diff.ArtifactDifferences.Count == 1, "expected one application-scoped difference");
            Assert(diff.ArtifactDifferences[0].Application == "APP-A", "wrong application was compared");
        }

        private static void RestoreRejectsDifferentServer()
        {
            var snapshot = Snapshot("APP", "PORT", ArtifactStates.SendPortStarted);
            snapshot.Server = "BIZTALK-A.example.local";
            SnapshotValidator.EnsureServerMatches(snapshot, "BIZTALK-A");
            Expect<InvalidOperationException>(() => SnapshotValidator.EnsureServerMatches(snapshot, "BIZTALK-B"));
        }

        private static void RestorePlanUsesSafeOrder()
        {
            var snapshot = Snapshot("APP", "PORT", ArtifactStates.SendPortStarted);
            snapshot.HostInstances.Add(new HostInstanceState { InstanceName = "HOST:SERVER", HostName = "HOST", Server = snapshot.Server, RawState = ArtifactStates.HostStarted });
            snapshot.Applications[0].Orchestrations.Add(new OrchestrationState { Application = "APP", Name = "ORCH", OrchestrationStatus = ArtifactStates.OrchestrationBound });
            snapshot.Applications[0].ReceiveLocations.Add(new ReceiveLocationState { Application = "APP", Name = "RL", Enabled = true });
            var plan = new BizTalkOperationService(null).CreateRestorePlan(snapshot, snapshot.Server);
            Assert(plan.Steps.First().Kind == "HostInstance", "host instance must start first");
            Assert(plan.Steps.Last().Kind == "ReceiveLocation", "receive location must be restored last");
            var bound = plan.Steps.Single(x => x.Name == "ORCH");
            Assert(!bound.Execute && bound.Kind == "Note", "bound orchestration must remain unchanged");
        }

        private static void CsvNeutralizesFormulaValues()
        {
            InTemp(directory =>
            {
                var path = Path.Combine(directory, "diff.csv");
                var diff = new SnapshotDiff();
                diff.ArtifactDifferences.Add(new ArtifactDiffEntry { Application = "=cmd|' /C calc'!A0", ArtifactType = "SendPort", Name = "PORT", Before = "Started", After = "Stopped" });
                CsvWriter.WriteDiff(path, diff);
                Assert(File.ReadAllText(path).Contains("'=cmd"), "formula-like CSV field was not neutralized");
            });
        }

        private static void PackageManifestRejectsTampering()
        {
            InTemp(directory =>
            {
                var app = Path.Combine(directory, "application"); Directory.CreateDirectory(app);
                File.WriteAllText(Path.Combine(app, InstallerEngine.ApplicationExeName), "payload");
                File.WriteAllText(Path.Combine(app, InstallerEngine.ApplicationExeName + ".config"), "config");
                var manifest = Path.Combine(directory, "application.manifest");
                PackageManifest.Write(app, manifest);
                PackageManifest.ValidateAndRead(app, manifest);
                File.AppendAllText(Path.Combine(app, InstallerEngine.ApplicationExeName), "tampered");
                Expect<InvalidDataException>(() => PackageManifest.ValidateAndRead(app, manifest));
            });
        }

        private static void InstallerActivatesValidatedPayload()
        {
            InTemp(directory =>
            {
                var package = CreatePackage(directory, "new");
                var install = Path.Combine(directory, "install");
                var data = Path.Combine(directory, "data");
                var engine = new InstallerEngine(package, install, data, false, path => File.Exists(path));
                engine.Install(false, null);
                Assert(File.ReadAllText(Path.Combine(install, InstallerEngine.ApplicationExeName)) == "new", "new payload not activated");
                Assert(File.Exists(Path.Combine(install, "install-state.txt")), "install state missing");
            });
        }

        private static void PackageManifestRejectsUndeclaredAndTraversalFiles()
        {
            InTemp(directory =>
            {
                var app = Path.Combine(directory, "application"); Directory.CreateDirectory(app);
                var exe = Path.Combine(app, InstallerEngine.ApplicationExeName);
                File.WriteAllText(exe, "payload");
                File.WriteAllText(Path.Combine(app, InstallerEngine.ApplicationExeName + ".config"), "config");
                var manifest = Path.Combine(directory, "application.manifest");
                PackageManifest.Write(app, manifest);
                File.WriteAllText(Path.Combine(app, "undeclared.dll"), "extra");
                Expect<InvalidDataException>(() => PackageManifest.ValidateAndRead(app, manifest));
                File.Delete(Path.Combine(app, "undeclared.dll"));
                File.WriteAllText(manifest, PackageManifest.Sha256(exe) + "|" + new FileInfo(exe).Length + "|../escape.exe" + Environment.NewLine);
                Expect<InvalidDataException>(() => PackageManifest.ValidateAndRead(app, manifest));
            });
        }

        private static void InstallerDoesNotMutateOnStagingFailure()
        {
            InTemp(directory =>
            {
                var package = CreatePackage(directory, "new");
                var install = Path.Combine(directory, "install"); Directory.CreateDirectory(install);
                File.WriteAllText(Path.Combine(install, InstallerEngine.ApplicationExeName), "old");
                File.WriteAllText(Path.Combine(install, InstallerEngine.ApplicationExeName + ".config"), "old-config");
                var engine = new InstallerEngine(package, install, Path.Combine(directory, "data"), false, path => false);
                Expect<InvalidOperationException>(() => engine.Install(false, null));
                Assert(File.ReadAllText(Path.Combine(install, InstallerEngine.ApplicationExeName)) == "old", "staging failure modified the installed payload");
                Assert(!Directory.GetDirectories(directory, "install.backup.*").Any(), "backup was created before staging passed");
            });
        }

        private static void InstallerRollsBackFailedActivatedSelfTest()
        {
            InTemp(directory =>
            {
                var package = CreatePackage(directory, "new");
                var install = Path.Combine(directory, "install"); Directory.CreateDirectory(install);
                File.WriteAllText(Path.Combine(install, InstallerEngine.ApplicationExeName), "old");
                File.WriteAllText(Path.Combine(install, InstallerEngine.ApplicationExeName + ".config"), "old-config");
                var calls = 0;
                var engine = new InstallerEngine(package, install, Path.Combine(directory, "data"), false, path => ++calls == 1);
                Expect<InvalidOperationException>(() => engine.Install(false, null));
                Assert(File.ReadAllText(Path.Combine(install, InstallerEngine.ApplicationExeName)) == "old", "previous payload was not restored");
                Assert(!Directory.GetDirectories(directory, "install.staging.*").Any(), "staging directory remained");
                Assert(!Directory.GetDirectories(directory, "install.backup.*").Any(), "backup directory remained");
            });
        }

        private static void InstallerUninstallRemovesProgramDirectory()
        {
            InTemp(directory =>
            {
                var package = CreatePackage(directory, "new");
                var install = Path.Combine(directory, "install"); Directory.CreateDirectory(install);
                File.WriteAllText(Path.Combine(install, InstallerEngine.ApplicationExeName), "installed");
                var engine = new InstallerEngine(package, install, Path.Combine(directory, "data"), false, path => true);
                engine.Uninstall(null);
                Assert(!Directory.Exists(install), "program directory still exists after uninstall");
                Assert(!Directory.GetDirectories(directory, "install.removed.*").Any(), "uninstall quarantine directory remained");
            });
        }

        private static BizTalkSnapshot Snapshot(string application, string port, int state)
        {
            var result = new BizTalkSnapshot { ToolVersion = "test", CreatedAt = DateTimeOffset.Now.ToString("o"), Server = Environment.MachineName };
            var app = new ApplicationSnapshot { Application = application };
            app.SendPorts.Add(new SendPortState { Application = application, Name = port, Status = state });
            result.Applications.Add(app);
            return result;
        }

        private static string CreatePackage(string root, string payload)
        {
            var package = Path.Combine(root, "package");
            var app = Path.Combine(package, "application"); Directory.CreateDirectory(app);
            File.WriteAllText(Path.Combine(app, InstallerEngine.ApplicationExeName), payload);
            File.WriteAllText(Path.Combine(app, InstallerEngine.ApplicationExeName + ".config"), "config");
            PackageManifest.Write(app, Path.Combine(package, "application.manifest"));
            return package;
        }

        private static void InTemp(Action<string> action)
        {
            var directory = Path.Combine(Path.GetTempPath(), "BizTalkPlatformManagementTool.Tests." + Guid.NewGuid().ToString("N"));
            Directory.CreateDirectory(directory);
            try { action(directory); }
            finally { if (Directory.Exists(directory)) Directory.Delete(directory, true); }
        }

        private static void Assert(bool condition, string message) { if (!condition) throw new InvalidOperationException(message); }
        private static void Expect<T>(Action action) where T : Exception
        {
            try { action(); }
            catch (T) { return; }
            throw new InvalidOperationException("Expected exception " + typeof(T).Name);
        }
    }
}