using System.Text.Json;
using YZWater.Core.Models;
using YZWater.Core.Services;

namespace YZWater.Core.Tests.Services;

/// <summary>
/// 配置文件路径锚定 + 敏感项落盘加密的回归测试
/// </summary>
public class ConfigProtectionTests
{
    private const string Token = "Hub-Token-S3cr3t";

    [Fact]
    public void HubToken_SerializedAsCiphertext()
    {
        if (!OperatingSystem.IsWindows()) return; // DPAPI 不可用时按明文降级

        var config = new SystemConfig { HubToken = Token };
        var json = JsonSerializer.Serialize(config);

        Assert.DoesNotContain(Token, json);
        Assert.Contains("enc:", json);
    }

    [Fact]
    public void HubToken_SurvivesJsonRoundTrip()
    {
        if (!OperatingSystem.IsWindows()) return;

        var json = JsonSerializer.Serialize(new SystemConfig { HubToken = Token });

        ProtectedStringJsonConverter.BeginRead();
        var restored = JsonSerializer.Deserialize<SystemConfig>(json);

        Assert.Equal(Token, restored?.HubToken);
        Assert.False(ProtectedStringJsonConverter.NeedsRewrite);
    }

    [Fact]
    public void LegacyPlaintextHubToken_StillReadableAndMarkedForRewrite()
    {
        ProtectedStringJsonConverter.BeginRead();
        var restored = JsonSerializer.Deserialize<SystemConfig>("{\"HubToken\":\"" + Token + "\"}");

        Assert.Equal(Token, restored?.HubToken);
        Assert.True(ProtectedStringJsonConverter.NeedsRewrite);

        // ConfigService 据此回写一次，第二次加载就不该再要求改写
        var rewritten = JsonSerializer.Serialize(restored);
        ProtectedStringJsonConverter.BeginRead();
        var reloaded = JsonSerializer.Deserialize<SystemConfig>(rewritten);

        Assert.Equal(Token, reloaded?.HubToken);
        Assert.False(ProtectedStringJsonConverter.NeedsRewrite);
    }

    [Fact]
    public void UndecryptableCiphertext_FallsBackToEmptyInsteadOfThrowing()
    {
        // 配置文件从别的机器/别的 Windows 用户拷来时会走到这里
        ProtectedStringJsonConverter.BeginRead();
        var restored = JsonSerializer.Deserialize<SystemConfig>("{\"HubToken\":\"enc:not-valid-cipher-text\"}");

        Assert.True(string.IsNullOrEmpty(restored?.HubToken));
        Assert.True(ProtectedStringJsonConverter.DecryptFailed);

        // 关键：解不开不等于"等待迁移"。若此处要求回写，ConfigService 会把这段密文
        // 覆盖成空值（还会顺手污染 .lastgood），操作员原机上配的令牌就彻底没了。
        Assert.False(ProtectedStringJsonConverter.NeedsRewrite);
    }

    [Fact]
    public void LegacyPlaintext_MarksRewriteButNotDecryptFailure()
    {
        ProtectedStringJsonConverter.BeginRead();
        JsonSerializer.Deserialize<SystemConfig>("{\"HubToken\":\"" + Token + "\"}");

        Assert.True(ProtectedStringJsonConverter.NeedsRewrite);
        Assert.False(ProtectedStringJsonConverter.DecryptFailed);
    }

    [Fact]
    public void EmptyHubToken_StaysEmptyAndNeedsNoRewrite()
    {
        ProtectedStringJsonConverter.BeginRead();
        var restored = JsonSerializer.Deserialize<SystemConfig>(
            JsonSerializer.Serialize(new SystemConfig { HubToken = string.Empty }));

        Assert.Equal(string.Empty, restored?.HubToken);
        Assert.False(ProtectedStringJsonConverter.NeedsRewrite);
    }
}