sql-utilities/tests/Strata.SqlTools.Markdown.Tests/Snowflake/QueryBreakdownGeneratorTests.cs

using Strata.SqlTools.Breakdowns.Snowflake;
using Strata.SqlTools.Markdown.Snowflake;

namespace Strata.SqlTools.Markdown.Tests.Snowflake;

[TestFixture]
public class QueryBreakdownGeneratorTests
{
    private QueryBreakdownGenerator _generator = null!;

    [SetUp]
    public void Setup()
    {
        _generator = new QueryBreakdownGenerator();
    }

    [Test]
    public void GenerateMermaidDiagram_SimpleSnowflakeQuery_GeneratesValidMermaid()
    {
        // Arrange - Using Snowflake syntax with uppercase identifiers
        var query = new QueryBreakdown("USER_ID, USER_NAME", "USERS");

        // Act
        var result = QueryBreakdownGenerator.GenerateMermaidDiagram(query, "Simple User Query");

        // Assert
        Assert.That(result, Does.Contain("```mermaid"));
        Assert.That(result, Does.Contain("flowchart TD"));
        Assert.That(result, Does.Contain("### Simple User Query"));
        Assert.That(result, Does.Contain("SELECT"));
        Assert.That(result, Does.Contain("FROM"));
        Assert.That(result, Does.Contain("```"));
    }

    [Test]
    public void GenerateMermaidDiagram_WithSnowflakeColonParameters_HandlesParameters()
    {
        // Arrange - Snowflake uses :parameter syntax
        var query = QueryBreakdown.Parse(@"
            SELECT USER_ID, USER_NAME, STATUS
            FROM USERS
            WHERE USER_ID = :userId
              AND STATUS = :status
        ", isMicrosoftSql: false);

        // Act
        var result = QueryBreakdownGenerator.GenerateMermaidDiagram(query);

        // Assert
        Assert.That(result, Does.Contain("WHERE"));
        Assert.That(result, Does.Contain("```mermaid"));
        Assert.That(result, Does.Contain("flowchart TD"));
    }

    [Test]
    public void GenerateMermaidDiagram_WithSnowflakeCTE_ShowsWithClause()
    {
        // Arrange - Snowflake CTE with uppercase naming
        var query = QueryBreakdown.Parse(@"
            WITH ACTIVE_USERS AS (
                SELECT USER_ID, USER_NAME
                FROM USERS
                WHERE STATUS = 'ACTIVE'
            )
            SELECT U.USER_ID, U.USER_NAME, COUNT(O.ORDER_ID) AS ORDER_COUNT
            FROM ACTIVE_USERS U
            JOIN ORDERS O ON U.USER_ID = O.USER_ID
            GROUP BY U.USER_ID, U.USER_NAME
        ", isMicrosoftSql: false);

        // Act
        var result = QueryBreakdownGenerator.GenerateMermaidDiagram(query, "Users with Orders");

        // Assert
        Assert.That(result, Does.Contain("WITH Clause"));
        Assert.That(result, Does.Contain("ACTIVE_USERS"));
        Assert.That(result, Does.Contain("GROUP BY"));
    }

    [Test]
    public void GenerateMermaidDiagram_WithSnowflakeQualify_HandlesQualifyClause()
    {
        // Arrange - Snowflake QUALIFY clause (window function filtering)
        var query = QueryBreakdown.Parse(@"
            SELECT
                CUSTOMER_ID,
                ORDER_DATE,
                ORDER_AMOUNT,
                ROW_NUMBER() OVER (PARTITION BY CUSTOMER_ID ORDER BY ORDER_DATE DESC) AS RN
            FROM ORDERS
            QUALIFY RN = 1
        ", isMicrosoftSql: false);

        // Act
        var result = QueryBreakdownGenerator.GenerateMermaidDiagram(query, "Latest Orders per Customer");

        // Assert
        Assert.That(result, Does.Contain("SELECT"));
        Assert.That(result, Does.Contain("FROM"));
        Assert.That(result, Does.Contain("```mermaid"));
    }

    [Test]
    public void GenerateMermaidDiagram_WithDoubleQuotedIdentifiers_HandlesSnowflakeQuoting()
    {
        // Arrange - Snowflake uses "identifier" for case-sensitive names
        var query = QueryBreakdown.Parse(@"
            SELECT ""userId"", ""userName"", ""emailAddress""
            FROM ""Users""
            WHERE ""status"" = 'ACTIVE'
        ", isMicrosoftSql: false);

        // Act
        var result = QueryBreakdownGenerator.GenerateMermaidDiagram(query);

        // Assert
        Assert.That(result, Does.Contain("SELECT"));
        Assert.That(result, Does.Contain("WHERE"));
        Assert.That(result, Does.Contain("FROM"));
    }

    [Test]
    public void GenerateMermaidDiagram_ComplexSnowflakeQuery_GeneratesCompleteDiagram()
    {
        // Arrange - Complex Snowflake query with multiple clauses
        var query = QueryBreakdown.Parse(@"
            WITH SALES_DATA AS (
                SELECT
                    REGION,
                    PRODUCT_ID,
                    SUM(SALES_AMOUNT) AS TOTAL_SALES,
                    COUNT(*) AS ORDER_COUNT
                FROM SALES
                WHERE SALE_DATE >= :startDate AND SALE_DATE <= :endDate
                GROUP BY REGION, PRODUCT_ID
            )
            SELECT
                SD.REGION,
                P.PRODUCT_NAME,
                SD.TOTAL_SALES,
                SD.ORDER_COUNT
            FROM SALES_DATA SD
            JOIN PRODUCTS P ON SD.PRODUCT_ID = P.PRODUCT_ID
            WHERE SD.TOTAL_SALES > :minSales
            ORDER BY SD.TOTAL_SALES DESC
        ", isMicrosoftSql: false);

        // Act
        var result = QueryBreakdownGenerator.GenerateMermaidDiagram(query, "Regional Sales Analysis");

        // Assert
        Assert.That(result, Does.Contain("### Regional Sales Analysis"));
        Assert.That(result, Does.Contain("WITH Clause"));
        Assert.That(result, Does.Contain("SALES_DATA"));
        Assert.That(result, Does.Contain("SELECT"));
        Assert.That(result, Does.Contain("FROM"));
        Assert.That(result, Does.Contain("WHERE"));
        Assert.That(result, Does.Contain("ORDER BY"));
        Assert.That(result, Does.Contain("flowchart TD"));
    }

    [Test]
    public void GenerateMermaidDiagram_WithGroupByAndHaving_IncludesBothClauses()
    {
        // Arrange
        var query = QueryBreakdown.Parse(@"
            SELECT CATEGORY, COUNT(*) AS PRODUCT_COUNT, AVG(PRICE) AS AVG_PRICE
            FROM PRODUCTS
            GROUP BY CATEGORY
            HAVING COUNT(*) > 10 AND AVG(PRICE) < 100
        ", isMicrosoftSql: false);

        // Act
        var result = QueryBreakdownGenerator.GenerateMermaidDiagram(query);

        // Assert
        Assert.That(result, Does.Contain("GROUP BY"));
        Assert.That(result, Does.Contain("HAVING"));
    }

    [Test]
    public void GenerateMermaidDiagram_NullTitle_GeneratesWithoutTitle()
    {
        // Arrange
        var query = new QueryBreakdown("ID", "ORDERS");

        // Act
        var result = QueryBreakdownGenerator.GenerateMermaidDiagram(query, null);

        // Assert
        Assert.That(result, Does.Not.Contain("###"));
        Assert.That(result, Does.Contain("```mermaid"));
        Assert.That(result, Does.Contain("flowchart TD"));
    }

    [Test]
    public void GenerateMermaidDiagram_EmptyTitle_GeneratesWithoutTitle()
    {
        // Arrange
        var query = new QueryBreakdown("ORDER_ID", "ORDERS");

        // Act
        var result = QueryBreakdownGenerator.GenerateMermaidDiagram(query, "");

        // Assert
        Assert.That(result, Does.Not.Contain("###"));
        Assert.That(result, Does.Contain("SELECT"));
    }

    [Test]
    public void GenerateMermaidDiagram_SnowflakeTypeCasting_PreservesSyntax()
    {
        // Arrange - Snowflake :: casting syntax
        var query = QueryBreakdown.Parse(@"
            SELECT
                ORDER_ID::VARCHAR AS ORDER_CODE,
                AMOUNT::DECIMAL(10,2) AS FORMATTED_AMOUNT,
                CREATE_DATE::TIMESTAMP AS CREATED_AT
            FROM ORDERS
        ", isMicrosoftSql: false);

        // Act
        var result = QueryBreakdownGenerator.GenerateMermaidDiagram(query, "Type Cast Example");

        // Assert
        Assert.That(result, Does.Contain("SELECT"));
        Assert.That(result, Does.Contain("FROM"));
        Assert.That(result, Does.Contain("### Type Cast Example"));
    }

    [Test]
    public void GenerateMermaidDiagram_SnowflakeJsonPath_HandlesJsonNotation()
    {
        // Arrange - Snowflake JSON path notation (: for path access)
        var query = QueryBreakdown.Parse(@"
            SELECT
                JSON_DATA:name::STRING AS NAME,
                JSON_DATA:address.city::STRING AS CITY,
                JSON_DATA:age::NUMBER AS AGE
            FROM USER_JSON
        ", isMicrosoftSql: false);

        // Act
        var result = QueryBreakdownGenerator.GenerateMermaidDiagram(query, "JSON Data");

        // Assert
        Assert.That(result, Does.Contain("SELECT"));
        Assert.That(result, Does.Contain("FROM"));
        Assert.That(result, Does.Contain("```mermaid"));
    }
}