using ZB.MOM.WW.ScadaBridge.DelmiaNotifier;

namespace ZB.MOM.WW.ScadaBridge.DelmiaNotifier.Tests;

public class ConfigLoaderTests
{
    /// <summary>Verifies that invalid endpoint lists are rejected when the configuration loads.</summary>
    /// <param name="urls">The base URL list to load.</param>
    [Theory]
    [InlineData("relative")]
    [InlineData("ftp://example.com")]
    [InlineData("https://good.example,broken")]
    [InlineData("http://")]
    public void Load_RejectsInvalidEndpointsBeforeDispatch(string urls)
    {
        var error = Assert.Throws<InvalidOperationException>(() =>
            ConfigLoader.Load(System.Text.Json.JsonSerializer.Serialize(new { ScadaBridge = new { BaseUrls = urls } })));
        Assert.Contains("ScadaBridge:BaseUrls", error.Message);
        Assert.Contains("HTTP", error.Message);
    }

    /// <summary>Verifies that splitting base URLs trims entries and drops empty ones.</summary>
    [Fact]
    public void SplitBaseUrls_trims_and_drops_empties()
    {
        var urls = ConfigLoader.SplitBaseUrls("a, b ,,c");
        Assert.Equal(new[] { "a", "b", "c" }, urls);
    }

    /// <summary>Verifies that a null or whitespace base URL list yields no URLs.</summary>
    [Fact]
    public void SplitBaseUrls_null_or_whitespace_returns_empty()
    {
        Assert.Empty(ConfigLoader.SplitBaseUrls(null));
        Assert.Empty(ConfigLoader.SplitBaseUrls("   "));
    }

    /// <summary>Verifies that the timeout defaults to 30 seconds when it is omitted.</summary>
    [Fact]
    public void Load_defaults_timeout_to_30_when_omitted()
    {
        var cfg = ConfigLoader.Load("{\"ScadaBridge\":{\"BaseUrls\":\"http://x\"}}");
        Assert.Equal(30, cfg.ScadaBridge.TimeoutSeconds);
        Assert.Equal("http://x", cfg.ScadaBridge.BaseUrls);
    }

    /// <summary>Verifies that loading reads every configured field.</summary>
    [Fact]
    public void Load_reads_all_fields()
    {
        var cfg = ConfigLoader.Load("{\"ScadaBridge\":{\"BaseUrls\":\"https://a,http://b\",\"TimeoutSeconds\":5,\"LogPath\":\"l.log\"}}");
        Assert.Equal("https://a,http://b", cfg.ScadaBridge.BaseUrls);
        Assert.Equal(5, cfg.ScadaBridge.TimeoutSeconds);
        Assert.Equal("l.log", cfg.ScadaBridge.LogPath);
    }

    /// <summary>Verifies that an unset or whitespace environment key resolves to null.</summary>
    [Fact]
    public void ResolveApiKey_returns_null_when_unset_or_whitespace()
    {
        Assert.Null(ConfigLoader.ResolveApiKey(_ => null, new NotifierConfig()));
        Assert.Null(ConfigLoader.ResolveApiKey(_ => "   ", new NotifierConfig()));
    }

    /// <summary>Verifies that a key present in the environment is returned.</summary>
    [Fact]
    public void ResolveApiKey_returns_value_when_present()
    {
        Assert.Equal("sbk_x", ConfigLoader.ResolveApiKey(n => n == "SCADABRIDGE_API_KEY" ? "sbk_x" : null, new NotifierConfig()));
    }

    /// <summary>Verifies that the API key is read from the ScadaBridge configuration section.</summary>
    [Fact]
    public void Load_reads_ApiKey_from_ScadaBridge_section()
    {
        var cfg = ConfigLoader.Load("{\"ScadaBridge\":{\"BaseUrls\":\"http://x\",\"ApiKey\":\"sbk_file\"}}");
        Assert.Equal("sbk_file", cfg.ScadaBridge.ApiKey);
    }

    /// <summary>Verifies that the environment key takes precedence over the configured key.</summary>
    [Fact]
    public void ResolveApiKey_prefers_env_over_config()
    {
        var cfg = ConfigLoader.Load("{\"ScadaBridge\":{\"ApiKey\":\"sbk_file\"}}");
        Assert.Equal("sbk_env", ConfigLoader.ResolveApiKey(n => n == "SCADABRIDGE_API_KEY" ? "sbk_env" : null, cfg));
    }

    /// <summary>Verifies that the configured key is used when the environment key is unset or blank.</summary>
    [Fact]
    public void ResolveApiKey_falls_back_to_config_when_env_unset_or_blank()
    {
        var cfg = ConfigLoader.Load("{\"ScadaBridge\":{\"ApiKey\":\"  sbk_file \"}}");
        Assert.Equal("sbk_file", ConfigLoader.ResolveApiKey(_ => null, cfg));
        Assert.Equal("sbk_file", ConfigLoader.ResolveApiKey(_ => "   ", cfg));
    }

    /// <summary>Verifies that the environment key is trimmed the same way as the configured key.</summary>
    [Fact]
    public void ResolveApiKey_trims_env_value_like_the_file_value()
    {
        Assert.Equal("sbk_env", ConfigLoader.ResolveApiKey(_ => "  sbk_env \t", new NotifierConfig()));
    }

    /// <summary>Verifies that key resolution reports whether the environment or the file supplied the key.</summary>
    [Fact]
    public void ResolveApiKey_reports_which_source_supplied_the_key()
    {
        var cfg = ConfigLoader.Load("{\"ScadaBridge\":{\"ApiKey\":\"sbk_file\"}}");
        ConfigLoader.ResolveApiKey(_ => "sbk_env", cfg, out var fromEnv);
        ConfigLoader.ResolveApiKey(_ => null, cfg, out var fromFile);
        ConfigLoader.ResolveApiKey(_ => null, new NotifierConfig(), out var none);
        Assert.Equal(ConfigLoader.ApiKeySourceEnvironment, fromEnv);
        Assert.Equal(ConfigLoader.ApiKeySourceFile, fromFile);
        Assert.Null(none);
    }

    /// <summary>Verifies that the API key stays null when the configuration omits it.</summary>
    [Fact]
    public void Load_leaves_ApiKey_null_when_absent()
    {
        var cfg = ConfigLoader.Load("{\"ScadaBridge\":{\"BaseUrls\":\"http://x\"}}");
        Assert.Null(cfg.ScadaBridge.ApiKey);
    }

    /// <summary>Verifies that key resolution returns null when neither source supplies a key.</summary>
    [Fact]
    public void ResolveApiKey_returns_null_when_neither_source_set()
    {
        var cfg = ConfigLoader.Load("{\"ScadaBridge\":{\"ApiKey\":\"   \"}}");
        Assert.Null(ConfigLoader.ResolveApiKey(_ => null, cfg));
    }
}