using Strata.SqlTools.Breakdowns.SqlServer;
using Strata.SqlTools.Markdown.Common;

namespace Strata.SqlTools.Markdown.SqlServer;

/// <summary>
/// Generates Markdown documentation from QueryBreakdownCollection objects.
/// Creates comprehensive reports including collection summaries, parameter analysis, and batch flow visualization.
/// </summary>
public static class QueryBreakdownCollectionGenerator
{
    private static readonly MarkdownDialectFormat Format = new()
    {
        ParameterTableLabel = name => $"@{name}",
        ParameterNodeLabel = name => $"@{name}",
        ParameterTypeName = GetParameterType,
        ParameterNodeFill = "#e1f5ff",
        QueryNodeFill = "#f3e5f5",
        IncludeHavingRow = true
    };

    /// <summary>
    /// Generates a comprehensive collection report in Markdown format.
    /// </summary>
    /// <param name="collection">The QueryBreakdownCollection to document.</param>
    /// <param name="title">Optional title for the report.</param>
    /// <returns>A string containing the Markdown documentation.</returns>
    public static string GenerateCollectionReport(QueryBreakdownCollection collection, string? title = null)
        => CollectionReportWriter.CollectionReport(title, new[]
        {
            GenerateCollectionSummary(collection),
            GenerateParameterAnalysis(collection),
            GenerateQueryCompositionReport(collection)
        });

    /// <summary>
    /// Generates a summary section for the collection.
    /// </summary>
    /// <param name="collection">The QueryBreakdownCollection to summarize.</param>
    /// <returns>Markdown summary section.</returns>
    public static string GenerateCollectionSummary(QueryBreakdownCollection collection)
        => CollectionReportWriter.CollectionSummary(
            collection.QueryBreakdowns.Count,
            collection.GetAllUniqueParameters().Count(),
            collection.GetTotalSelectedColumns(),
            collection.GetUniqueTableReferences().Count());

    /// <summary>
    /// Generates a parameter analysis report.
    /// </summary>
    /// <param name="collection">The QueryBreakdownCollection to analyze.</param>
    /// <returns>Markdown parameter analysis section.</returns>
    public static string GenerateParameterAnalysis(QueryBreakdownCollection collection)
        => CollectionReportWriter.ParameterAnalysis(MapParameters(collection), collection.QueryBreakdowns, Format);

    /// <summary>
    /// Generates a Mermaid diagram showing parameter dependencies across queries.
    /// </summary>
    /// <param name="collection">The QueryBreakdownCollection to visualize.</param>
    /// <returns>Mermaid diagram markdown.</returns>
    public static string GenerateParameterDependencyDiagram(QueryBreakdownCollection collection)
        => CollectionReportWriter.ParameterDependencyDiagram(collection.QueryBreakdowns, Format);

    /// <summary>
    /// Generates a detailed query composition report.
    /// </summary>
    /// <param name="collection">The QueryBreakdownCollection to report on.</param>
    /// <returns>Markdown composition report section.</returns>
    public static string GenerateQueryCompositionReport(QueryBreakdownCollection collection)
        => CollectionReportWriter.QueryCompositionReport(collection.QueryBreakdowns, Format);

    /// <summary>
    /// Generates a batch execution flow diagram.
    /// </summary>
    /// <param name="collection">The QueryBreakdownCollection to visualize.</param>
    /// <param name="includeTransaction">Whether to show transaction wrapping.</param>
    /// <returns>Mermaid diagram markdown.</returns>
    public static string GenerateBatchFlowDiagram(QueryBreakdownCollection collection, bool includeTransaction = false)
        => CollectionReportWriter.BatchFlowDiagram(
            collection.QueryBreakdowns.Count,
            includeTransaction ? "BEGIN TRANSACTION" : null,
            includeTransaction ? "COMMIT TRANSACTION" : null);

    /// <summary>
    /// Maps the collection's parameter usage report into the writer's dialect-agnostic rows.
    /// </summary>
    private static List<ParameterUsageRow> MapParameters(QueryBreakdownCollection collection)
        => collection.GetParameterUsageReport()
            .Select(p => new ParameterUsageRow
            {
                ParameterName = p.ParameterName,
                IsUsedInAllQueries = p.IsUsedInAllQueries,
                UsedInQueryCount = p.UsedInQueryCount,
                TotalQueries = p.TotalQueries,
                Value = p.Value
            })
            .ToList();

    /// <summary>
    /// Gets the parameter type name from a parameter value.
    /// </summary>
    private static string GetParameterType(object? value)
    {
        return value switch
        {
            null => "NULL",
            bool => "BIT",
            byte => "TINYINT",
            short => "SMALLINT",
            int => "INT",
            long => "BIGINT",
            float => "REAL",
            double => "FLOAT",
            decimal => "DECIMAL",
            string => "NVARCHAR",
            DateTime => "DATETIME2",
            _ => "VARIANT"
        };
    }
}