using MeterVault.Core.Domain;

namespace MeterVault.Core.Tests;

public sealed class MeterMetaTests
{
    [Fact]
    public void Role_reads_configured_role()
    {
        Assert.Equal(MeterRoles.GridImport, MeterMeta.Role("{\"role\":\"grid_import\"}"));
    }

    [Theory]
    [InlineData("")]
    [InlineData("   ")]
    [InlineData("{}")]
    [InlineData("not json")]
    [InlineData("{\"role\":123}")]
    [InlineData("[1,2,3]")]
    public void Role_is_null_when_absent_or_malformed(string meta)
    {
        Assert.Null(MeterMeta.Role(meta));
    }

    [Fact]
    public void WithRole_sets_role_and_preserves_other_keys()
    {
        var updated = MeterMeta.WithRole("{\"expression\":\"a-b\"}", MeterRoles.TotalLoad);

        Assert.Equal(MeterRoles.TotalLoad, MeterMeta.Role(updated));
        Assert.Equal("a-b", MeterMeta.ReadString(updated, "expression"));
    }

    [Fact]
    public void WithRole_overwrites_existing_role()
    {
        var updated = MeterMeta.WithRole("{\"role\":\"grid_import\"}", MeterRoles.GridExport);

        Assert.Equal(MeterRoles.GridExport, MeterMeta.Role(updated));
    }

    [Fact]
    public void WithRole_handles_empty_meta()
    {
        var updated = MeterMeta.WithRole("", MeterRoles.GridImport);

        Assert.Equal(MeterRoles.GridImport, MeterMeta.Role(updated));
    }
}