using JdeScoping.DataSync.Services;

namespace JdeScoping.DataSync.Tests.Services;

public class MergeSqlBuilderTests
{
    #region BuildCreateTempTable Tests

    [Fact]
    public void BuildCreateTempTable_ValidInputs_ReturnsSelectInto()
    {
        // Act
        var sql = MergeSqlBuilder.BuildCreateTempTable("#TEMP_WorkOrder", "WorkOrder");

        // Assert
        Assert.Equal("SELECT TOP 0 * INTO [#TEMP_WorkOrder] FROM [WorkOrder]", sql);
    }

    [Theory]
    [InlineData(null, "WorkOrder")]
    [InlineData("", "WorkOrder")]
    [InlineData("#TEMP", null)]
    [InlineData("#TEMP", "")]
    public void BuildCreateTempTable_InvalidInputs_ThrowsArgumentException(string? tempTable, string? sourceTable)
    {
        // Act & Assert
        Assert.ThrowsAny<ArgumentException>(() =>
            MergeSqlBuilder.BuildCreateTempTable(tempTable!, sourceTable!));
    }

    #endregion

    #region BuildMergeSimple Tests

    [Fact]
    public void BuildMergeSimple_SingleMatchColumn_BuildsCorrectMerge()
    {
        // Arrange
        var matchColumns = new[] { "Id" };
        var updateColumns = new[] { "Name", "Amount" };
        var insertColumns = new[] { "Id", "Name", "Amount" };

        // Act
        var sql = MergeSqlBuilder.BuildMergeSimple(
            "TestTable", "#TEMP_TestTable",
            matchColumns, updateColumns, null, insertColumns);

        // Assert
        Assert.Contains("MERGE INTO [TestTable] AS target", sql);
        Assert.Contains("USING [#TEMP_TestTable] AS source", sql);
        Assert.Contains("ON target.[Id] = source.[Id]", sql);
        Assert.Contains("WHEN MATCHED THEN", sql);
        Assert.Contains("UPDATE SET target.[Name] = source.[Name], target.[Amount] = source.[Amount]", sql);
        Assert.Contains("WHEN NOT MATCHED THEN", sql);
        Assert.Contains("INSERT ([Id], [Name], [Amount])", sql);
        Assert.Contains("VALUES (source.[Id], source.[Name], source.[Amount])", sql);
    }

    [Fact]
    public void BuildMergeSimple_CompositeKey_BuildsCorrectOnClause()
    {
        // Arrange
        var matchColumns = new[] { "WorkOrderNumber", "BranchCode" };
        var updateColumns = new[] { "Status" };
        var insertColumns = new[] { "WorkOrderNumber", "BranchCode", "Status" };

        // Act
        var sql = MergeSqlBuilder.BuildMergeSimple(
            "WorkOrder", "#TEMP",
            matchColumns, updateColumns, null, insertColumns);

        // Assert
        Assert.Contains("ON target.[WorkOrderNumber] = source.[WorkOrderNumber] AND target.[BranchCode] = source.[BranchCode]", sql);
    }

    [Fact]
    public void BuildMergeSimple_WithUpdateWhen_IncludesCondition()
    {
        // Arrange
        var matchColumns = new[] { "Id" };
        var updateColumns = new[] { "Name" };
        var insertColumns = new[] { "Id", "Name" };
        var updateWhen = "source.[LastUpdateDt] > target.[LastUpdateDt]";

        // Act
        var sql = MergeSqlBuilder.BuildMergeSimple(
            "TestTable", "#TEMP",
            matchColumns, updateColumns, updateWhen, insertColumns);

        // Assert
        Assert.Contains("WHEN MATCHED AND source.[LastUpdateDt] > target.[LastUpdateDt] THEN", sql);
    }

    [Fact]
    public void BuildMergeSimple_NoUpdateColumns_OmitsUpdateClause()
    {
        // Arrange
        var matchColumns = new[] { "Id" };
        var updateColumns = Array.Empty<string>();
        var insertColumns = new[] { "Id", "Name" };

        // Act
        var sql = MergeSqlBuilder.BuildMergeSimple(
            "TestTable", "#TEMP",
            matchColumns, updateColumns, null, insertColumns);

        // Assert
        Assert.DoesNotContain("WHEN MATCHED", sql);
        Assert.Contains("WHEN NOT MATCHED THEN", sql);
    }

    [Fact]
    public void BuildMergeSimple_EmptyMatchColumns_ThrowsArgumentException()
    {
        // Arrange
        var matchColumns = Array.Empty<string>();
        var updateColumns = new[] { "Name" };
        var insertColumns = new[] { "Id", "Name" };

        // Act & Assert
        Assert.Throws<ArgumentException>(() =>
            MergeSqlBuilder.BuildMergeSimple(
                "TestTable", "#TEMP",
                matchColumns, updateColumns, null, insertColumns));
    }

    [Fact]
    public void BuildMergeSimple_EmptyInsertColumns_ThrowsArgumentException()
    {
        // Arrange
        var matchColumns = new[] { "Id" };
        var updateColumns = new[] { "Name" };
        var insertColumns = Array.Empty<string>();

        // Act & Assert
        Assert.Throws<ArgumentException>(() =>
            MergeSqlBuilder.BuildMergeSimple(
                "TestTable", "#TEMP",
                matchColumns, updateColumns, null, insertColumns));
    }

    #endregion

    #region BuildTruncateTempTable Tests

    [Fact]
    public void BuildTruncateTempTable_ValidInput_ReturnsTruncate()
    {
        // Act
        var sql = MergeSqlBuilder.BuildTruncateTempTable("#TEMP_WorkOrder");

        // Assert
        Assert.Equal("TRUNCATE TABLE [#TEMP_WorkOrder]", sql);
    }

    #endregion

    #region BuildDropTempTable Tests

    [Fact]
    public void BuildDropTempTable_ValidInput_ReturnsDropWithCheck()
    {
        // Act
        var sql = MergeSqlBuilder.BuildDropTempTable("#TEMP_WorkOrder");

        // Assert
        Assert.Contains("IF OBJECT_ID('tempdb..#TEMP_WorkOrder') IS NOT NULL", sql);
        Assert.Contains("DROP TABLE [#TEMP_WorkOrder]", sql);
    }

    #endregion
}