using System.Threading;
using AcDream.Launcher.Core.Profiles;

namespace AcDream.Launcher.Core.Tests.Profiles;

public sealed class LauncherProfileStoreTests : IDisposable
{
    private readonly string _root;
    private readonly string _filePath;

    public LauncherProfileStoreTests()
    {
        _root = Path.Combine(
            Path.GetTempPath(),
            "acdream-launcher-profile-tests",
            Guid.NewGuid().ToString("N"));
        Directory.CreateDirectory(_root);
        _filePath = Path.Combine(_root, "launcher-profiles.json");
    }

    public void Dispose()
    {
        if (Directory.Exists(_root))
        {
            Directory.Delete(_root, recursive: true);
        }
    }

    [Fact]
    public void LoadOnMissingFileYieldsEmptyDocumentWithoutTouchingDisk()
    {
        var store = new LauncherProfileStore(_filePath);

        bool loaded = store.Load();

        Assert.False(loaded);
        Assert.False(File.Exists(_filePath));
        Assert.Equal(1, store.Document.Version);
        Assert.Empty(store.Document.Servers);
    }

    [Fact]
    public void AddServerThenSaveThenReloadRoundTrips()
    {
        var store = new LauncherProfileStore(_filePath);
        store.Load();

        store.AddServer("Local ACE", "127.0.0.1", 9000);
        store.Save();

        Assert.True(File.Exists(_filePath));

        var reloaded = new LauncherProfileStore(_filePath);
        reloaded.Load();

        ServerProfile server = Assert.Single(reloaded.Document.Servers);
        Assert.Equal("Local ACE", server.Name);
        Assert.Equal("127.0.0.1", server.Host);
        Assert.Equal(9000, server.Port);
        Assert.Empty(server.Accounts);
    }

    [Fact]
    public void AddServerRejectsDuplicateName()
    {
        var store = new LauncherProfileStore(_filePath);
        store.Load();
        store.AddServer("Local ACE", "127.0.0.1", 9000);

        var ex = Assert.Throws<LauncherProfileException>(
            () => store.AddServer("Local ACE", "127.0.0.1", 9001));
        Assert.Contains("Local ACE", ex.Message);
    }

    [Theory]
    [InlineData(0)]
    [InlineData(65536)]
    [InlineData(-1)]
    public void AddServerRejectsOutOfRangePort(int port)
    {
        var store = new LauncherProfileStore(_filePath);
        store.Load();

        Assert.Throws<LauncherProfileException>(
            () => store.AddServer("Local ACE", "127.0.0.1", port));
    }

    [Fact]
    public void EditServerRenamesAndUpdatesHostAndPort()
    {
        var store = new LauncherProfileStore(_filePath);
        store.Load();
        store.AddServer("Local ACE", "127.0.0.1", 9000);

        store.EditServer("Local ACE", newName: "Home ACE", newHost: "10.0.0.5", newPort: 9001);

        ServerProfile server = Assert.Single(store.Document.Servers);
        Assert.Equal("Home ACE", server.Name);
        Assert.Equal("10.0.0.5", server.Host);
        Assert.Equal(9001, server.Port);
    }

    [Fact]
    public void EditServerOnUnknownNameThrows()
    {
        var store = new LauncherProfileStore(_filePath);
        store.Load();

        Assert.Throws<LauncherProfileException>(
            () => store.EditServer("Nope", newHost: "1.2.3.4"));
    }

    [Fact]
    public void RemoveServerRemovesIt()
    {
        var store = new LauncherProfileStore(_filePath);
        store.Load();
        store.AddServer("Local ACE", "127.0.0.1", 9000);

        store.RemoveServer("Local ACE");

        Assert.Empty(store.Document.Servers);
    }

    [Fact]
    public void AddEditRemoveAccountRoundTrip()
    {
        var store = new LauncherProfileStore(_filePath);
        store.Load();
        store.AddServer("Local ACE", "127.0.0.1", 9000);

        store.AddAccount("Local ACE", "testaccount", "testpassword");
        AccountProfile account = Assert.Single(
            store.Document.Servers.Single().Accounts);
        Assert.Equal("testaccount", account.Account);
        Assert.Equal("testpassword", account.Password);

        store.EditAccount(
            "Local ACE",
            "testaccount",
            newAccount: "renamed",
            newPassword: "newpass");
        account = Assert.Single(store.Document.Servers.Single().Accounts);
        Assert.Equal("renamed", account.Account);
        Assert.Equal("newpass", account.Password);

        store.RemoveAccount("Local ACE", "renamed");
        Assert.Empty(store.Document.Servers.Single().Accounts);
    }

    [Fact]
    public void AddAccountRejectsDuplicateAccountOnSameServer()
    {
        var store = new LauncherProfileStore(_filePath);
        store.Load();
        store.AddServer("Local ACE", "127.0.0.1", 9000);
        store.AddAccount("Local ACE", "testaccount", "pw");

        Assert.Throws<LauncherProfileException>(
            () => store.AddAccount("Local ACE", "testaccount", "pw2"));
    }

    [Fact]
    public void EditCharacterUpdatesLaunchModePluginsAndLoginCommandsOnly()
    {
        var store = new LauncherProfileStore(_filePath);
        store.Load();
        store.AddServer("Local ACE", "127.0.0.1", 9000);
        store.AddAccount("Local ACE", "testaccount", "pw");
        store.MergeRoster(
            "Local ACE",
            "testaccount",
            [new CharacterRosterEntry(0x5000000A, "+Acdream", 0)]);

        store.EditCharacter(
            "Local ACE",
            "testaccount",
            "+Acdream",
            launchMode: LaunchMode.Headless,
            plugins: ["ExamplePlugin"],
            loginCommands: ["/tell someone, hi"]);

        CharacterProfile character = Assert.Single(
            store.Document.Servers.Single().Accounts.Single().Characters);
        Assert.Equal(LaunchMode.Headless, character.LaunchMode);
        Assert.Equal(["ExamplePlugin"], character.Plugins);
        Assert.Equal(["/tell someone, hi"], character.LoginCommands);
        Assert.Equal("0x5000000A", character.Id);
    }

    [Fact]
    public void FullProfileWithServersAccountsAndCharactersRoundTripsThroughDisk()
    {
        var store = new LauncherProfileStore(_filePath);
        store.Load();
        store.AddServer("Local ACE", "127.0.0.1", 9000);
        store.AddAccount("Local ACE", "testaccount", "testpassword");
        store.MergeRoster(
            "Local ACE",
            "testaccount",
            [new CharacterRosterEntry(0x5000000A, "+Acdream", 0)]);
        store.EditCharacter(
            "Local ACE",
            "testaccount",
            "+Acdream",
            launchMode: LaunchMode.Gui,
            plugins: ["ExamplePlugin"],
            loginCommands: ["/vt start"]);
        store.Save();

        // Direct proof of the on-disk enum casing — a round-trip alone
        // could mask a PascalCase regression if the reader ever became
        // case-insensitive on enum values.
        string text = File.ReadAllText(_filePath);
        Assert.Contains("\"launchMode\":\"gui\"", text.Replace(" ", string.Empty));

        var reloaded = new LauncherProfileStore(_filePath);
        reloaded.Load();

        ServerProfile server = Assert.Single(reloaded.Document.Servers);
        AccountProfile account = Assert.Single(server.Accounts);
        CharacterProfile character = Assert.Single(account.Characters);
        Assert.Equal("+Acdream", character.Name);
        Assert.Equal("0x5000000A", character.Id);
        Assert.Equal(LaunchMode.Gui, character.LaunchMode);
        Assert.Equal(["ExamplePlugin"], character.Plugins);
        Assert.Equal(["/vt start"], character.LoginCommands);
    }

    [Fact]
    public void LoadRejectsUnsupportedVersion()
    {
        File.WriteAllText(_filePath, """{"version":2,"servers":[]}""");
        var store = new LauncherProfileStore(_filePath);

        Assert.Throws<LauncherProfileException>(() => store.Load());
    }

    [Fact]
    public void LoadRejectsUnmappedMembersStrictly()
    {
        File.WriteAllText(
            _filePath,
            """{"version":1,"servers":[],"unexpectedField":true}""");
        var store = new LauncherProfileStore(_filePath);

        Assert.Throws<LauncherProfileException>(() => store.Load());
    }

    [Fact]
    public void SaveWritesCamelCaseJson()
    {
        var store = new LauncherProfileStore(_filePath);
        store.Load();
        store.AddServer("Local ACE", "127.0.0.1", 9000);
        store.Save();

        string text = File.ReadAllText(_filePath);
        Assert.Contains("\"version\"", text);
        Assert.Contains("\"servers\"", text);
        Assert.Contains("\"host\"", text);
        Assert.DoesNotContain("\"Version\"", text);
        Assert.DoesNotContain("\"Servers\"", text);
    }

    [Fact]
    public void SaveSetsOwnerOnlyPermissionsOnLinux()
    {
        // Linux-conditional: 0600 is a Linux-only hygiene step (spec §5,
        // decisions log item "Windows profile-file permissions"). A no-op
        // pass on Windows/macOS, matching the repo's established
        // OperatingSystem.IsLinux() early-return pattern (e.g.
        // HeadlessCredentialResolverTests.LinuxRejectsGroupOrOtherCredentialPermissions).
        if (!OperatingSystem.IsLinux())
            return;

        var store = new LauncherProfileStore(_filePath);
        store.Load();
        store.AddServer("Local ACE", "127.0.0.1", 9000);
        store.AddAccount("Local ACE", "testaccount", "testpassword");
        store.Save();

        UnixFileMode mode = File.GetUnixFileMode(_filePath);
        Assert.Equal(
            UnixFileMode.UserRead | UnixFileMode.UserWrite,
            mode);
    }

    [Fact]
    public void SaveNeverLeavesTheTempFileWorldOrGroupReadableDuringTheWrite()
    {
        // Review finding F4: the temp file used to be created with the
        // process's default umask and only chmod'd AFTER the atomic
        // rename, leaving a window where the plaintext-credential temp
        // file could be world/group-readable. The fix chmods the temp
        // file immediately after creation, BEFORE any content (including
        // the password) is serialized into it. A large document makes
        // the write take long enough for a concurrent poller to have a
        // real chance at observing a regression.
        if (!OperatingSystem.IsLinux())
            return;

        var store = new LauncherProfileStore(_filePath);
        store.Load();
        store.AddServer("Local ACE", "127.0.0.1", 9000);
        for (int i = 0; i < 300; i++)
        {
            store.AddAccount("Local ACE", $"account{i}", new string('x', 4096));
        }

        string tempPath = _filePath + ".tmp";
        bool observedLooseMode = false;
        bool stop = false;
        var poller = new Thread(() =>
        {
            while (!Volatile.Read(ref stop))
            {
                if (File.Exists(tempPath))
                {
                    try
                    {
                        // The platform-compat analyzer can't see the
                        // enclosing test method's `OperatingSystem.IsLinux()`
                        // guard across this lambda boundary; suppressed
                        // rather than restructured, since the guard is
                        // real and this whole method is a no-op off Linux.
#pragma warning disable CA1416
                        UnixFileMode mode = File.GetUnixFileMode(tempPath);
#pragma warning restore CA1416
                        if ((mode & ~(UnixFileMode.UserRead | UnixFileMode.UserWrite)) != 0)
                        {
                            observedLooseMode = true;
                        }
                    }
                    catch (IOException)
                    {
                        // Renamed/deleted between the Exists check and
                        // GetUnixFileMode — not a finding, just keep
                        // polling.
                    }
                }
            }
        });
        poller.Start();

        store.Save();

        Volatile.Write(ref stop, true);
        poller.Join();

        Assert.False(observedLooseMode);
    }

    [Fact]
    public void SaveDeletesTheStaleTempFileWhenTheFinalRenameFails()
    {
        // Review finding F4: force the rename step to fail (the
        // destination path names an existing DIRECTORY, which
        // File.Move(..., overwrite: true) refuses to replace — Windows
        // reports this as UnauthorizedAccessException, Linux as
        // IOException, so the assertion below accepts either) and assert
        // the temp file — which still carries the just-serialized
        // plaintext credentials — doesn't linger on disk afterward.
        Directory.CreateDirectory(_filePath);
        var store = new LauncherProfileStore(_filePath);
        store.Load();
        store.AddServer("Local ACE", "127.0.0.1", 9000);
        store.AddAccount("Local ACE", "testaccount", "testpassword");

        Assert.ThrowsAny<Exception>(() => store.Save());

        Assert.False(File.Exists(_filePath + ".tmp"));
    }

    [Fact]
    public void LoadDeletesAStaleTempFileLeftBehindByACrashedSave()
    {
        // Review finding F4: a Save() that crashed between creating the
        // temp file and the atomic rename leaves a ".tmp" carrying the
        // same plaintext credentials as the real store. Load() cleans it
        // up opportunistically the next time the store is opened.
        File.WriteAllText(_filePath + ".tmp", """{"version":1,"servers":[]}""");

        var store = new LauncherProfileStore(_filePath);
        store.Load();

        Assert.False(File.Exists(_filePath + ".tmp"));
    }
}