using System.Linq;
using QuantEngine.Infrastructure.Data;

namespace QuantEngine.Core.Tests;

public class MigrationScriptNameComparerTests
{
    [Fact]
    public void Sorts_DoubleDigit_Version_After_SingleDigit_Versions()
    {
        var scripts = new[]
        {
            "QuantEngine.Infrastructure.Migrations.V10__Normalize_Snapshots_Schema.sql",
            "QuantEngine.Infrastructure.Migrations.V2__Add_Kis_Collections.sql",
            "QuantEngine.Infrastructure.Migrations.V9__Add_Audit_Trail_Tables.sql",
            "QuantEngine.Infrastructure.Migrations.V1__Initial_Schema.sql",
            "QuantEngine.Infrastructure.Migrations.V8__PostgreSQL_History_First_Schema.sql",
        };

        var sorted = scripts.OrderBy(s => s, new MigrationScriptNameComparer()).ToArray();

        Assert.Equal(new[]
        {
            "QuantEngine.Infrastructure.Migrations.V1__Initial_Schema.sql",
            "QuantEngine.Infrastructure.Migrations.V2__Add_Kis_Collections.sql",
            "QuantEngine.Infrastructure.Migrations.V8__PostgreSQL_History_First_Schema.sql",
            "QuantEngine.Infrastructure.Migrations.V9__Add_Audit_Trail_Tables.sql",
            "QuantEngine.Infrastructure.Migrations.V10__Normalize_Snapshots_Schema.sql",
        }, sorted);
    }

    [Fact]
    public void Regression_ZeroPadded_Script_No_Longer_Sorts_Before_V1()
    {
        // This is the exact bug that shipped 2026-07-24: "V003_..." sorted before "V1__..."
        // under plain ordinal comparison, so a migration with unmet table dependencies ran
        // first. The comparer must treat "V003" as version 3, landing it between V2 and V4.
        var scripts = new[]
        {
            "QuantEngine.Infrastructure.Migrations.V003_add_audit_trail_tables.sql",
            "QuantEngine.Infrastructure.Migrations.V1__Initial_Schema.sql",
            "QuantEngine.Infrastructure.Migrations.V4__Add_Initial_Admin.sql",
        };

        var sorted = scripts.OrderBy(s => s, new MigrationScriptNameComparer()).ToArray();

        Assert.Equal("QuantEngine.Infrastructure.Migrations.V1__Initial_Schema.sql", sorted[0]);
        Assert.Equal("QuantEngine.Infrastructure.Migrations.V003_add_audit_trail_tables.sql", sorted[1]);
        Assert.Equal("QuantEngine.Infrastructure.Migrations.V4__Add_Initial_Admin.sql", sorted[2]);
    }
}