using System;
using System.Collections.Generic;
using GB5Shared.Deployment;
using Microsoft.Extensions.Configuration;
using Microsoft.Extensions.DependencyInjection;
using Xunit;

namespace GB5SharedTests;

/// <summary>
/// Covers AddGB5Environment's fail-fast posture — an unconfigured GB5:Environment must throw
/// at registration time, not silently resolve to Dev. Mirrors AddGB5Vault's own fail-fast
/// tests for Vault:Address/Token (same pattern, same reasoning: an unconfigured tier is worse
/// than a startup crash in production).
/// </summary>
public class GB5EnvironmentServiceExtensionsTests
{
    private static IConfiguration ConfigFrom(Dictionary<string, string?> values) =>
        new ConfigurationBuilder().AddInMemoryCollection(values).Build();

    [Fact]
    public void AddGB5Environment_MissingSection_Throws()
    {
        var services = new ServiceCollection();
        var config = ConfigFrom(new Dictionary<string, string?>());

        Assert.Throws<InvalidOperationException>(() => services.AddGB5Environment(config));
    }

    [Fact]
    public void AddGB5Environment_EmptyEnvironmentValue_Throws()
    {
        var services = new ServiceCollection();
        var config = ConfigFrom(new Dictionary<string, string?> { ["GB5:Environment"] = "" });

        Assert.Throws<InvalidOperationException>(() => services.AddGB5Environment(config));
    }

    [Fact]
    public void AddGB5Environment_InvalidTierValue_Throws()
    {
        var services = new ServiceCollection();
        var config = ConfigFrom(new Dictionary<string, string?> { ["GB5:Environment"] = "Staging" });

        Assert.Throws<InvalidOperationException>(() => services.AddGB5Environment(config));
    }

    [Theory]
    [InlineData("Dev", GB5Tier.Dev)]
    [InlineData("QC", GB5Tier.QC)]
    [InlineData("Live", GB5Tier.Live)]
    [InlineData("live", GB5Tier.Live)]
    public void AddGB5Environment_ValidTier_ResolvesIGB5Environment(string configuredValue, GB5Tier expectedTier)
    {
        var services = new ServiceCollection();
        var config = ConfigFrom(new Dictionary<string, string?> { ["GB5:Environment"] = configuredValue });

        services.AddGB5Environment(config);
        var provider = services.BuildServiceProvider();

        var env = provider.GetRequiredService<IGB5Environment>();
        Assert.Equal(expectedTier, env.Tier);
    }
}