using Strata.SqlTools.SqlBreakdown.Classes;
using Strata.SqlTools.SqlBreakdown.Expressions;
using Strata.SqlTools.SqlBreakdown.Expressions.Conditional;
using Strata.SqlTools.Query;
using Strata.SqlTools.SqlBreakdown.Tests.RegisteredTables;
using Strata.SqlTools.Visitors.Snowflake;
using ExpressionFactoryBase = Strata.SqlTools.SqlServer.ExpressionFactory.ExpressionFactory;

namespace Strata.SqlTools.SqlBreakdown.Tests.ExpressionTests;

/// <summary>
/// Test implementation of ExpressionFactory for unit testing.
/// Uses July 1 as the fiscal year start date.
/// </summary>
internal class TestExpressionFactory : ExpressionFactoryBase
{
    protected override DateTime GetCurrentFiscalYearStart()
    {
        return new DateTime(DateTime.UtcNow.Year, 7, 1, 0, 0, 0, DateTimeKind.Utc);
    }

    protected override RegisteredTableColumnExpression GetColumnExpression(int dataColumnId)
    {
        return RegisteredTableColumns.GetColumn(dataColumnId);
    }

    // Public wrappers for testing protected methods
    public new BooleanExpression CreateBooleanExpression(Filter filter) => base.CreateBooleanExpression(filter);
    public static new Expression GetFiscalYearMonthExpression(Expression dateColumnExpr, int fiscalYearStartMonth, int fiscalYearStartDay)
        => ExpressionFactoryBase.GetFiscalYearMonthExpression(dateColumnExpr, fiscalYearStartMonth, fiscalYearStartDay);
}

/// <summary>
/// Base class for expression tests with common setup.
/// </summary>
public abstract class ExpressionTestsBase
{
    protected RegisteredTableSource _table = null!;
    protected RegisteredTableColumnExpression _nameColumnExp = null!;
    protected RegisteredTableColumnExpression _revenueColumnExp = null!;
    protected RegisteredTableColumnExpression _costColumnExp = null!;
    protected RegisteredTableColumnExpression _dischargeDateColumnExp = null!;
    protected CommandVisitor _sqlVisitor = null!;

    [SetUp]
    public void SetUp()
    {
        _table = new RegisteredTableSource(101, "CLIENT_DSS", "FACT_PATIENT_ENCOUNTER_SUMMARY", "PES");
        _nameColumnExp = new RegisteredTableColumnExpression(1, "DEPARTMENT_NAME", _table);
        _revenueColumnExp = new RegisteredTableColumnExpression(2, "NET_REVENUE", _table);
        _costColumnExp = new RegisteredTableColumnExpression(3, "COST", _table);
        _dischargeDateColumnExp = new RegisteredTableColumnExpression(4, "DISCHARGE_DATE", _table);
        _sqlVisitor = new CommandVisitor();
    }

    /// <summary>
    /// Executes an expression test case with arrange, act, and assert phases.
    /// </summary>
    /// <param name="testCase">The test case to execute.</param>
    protected void ExecuteExpressionTest(ExpressionTestCase testCase)
    {
        // Arrange
        var visitor = new CommandVisitor();
        var arrange = testCase.Arrange;

        // Act
        var result = testCase.Act(arrange, visitor);

        // Assert
        Assert.That(testCase.Assertions(result));
    }
}