// Licensed to StellaOps under the BUSL-1.1 license.
using StellaOps.ReachGraph.Schema;

namespace StellaOps.ReachGraph.Deduplication;

/// <summary>
/// Extensions for edge deduplication.
/// </summary>
public static class EdgeDeduplicatorExtensions
{
    /// <summary>
    /// Deduplicates edges using default extractors based on edge properties.
    /// </summary>
    /// <param name="deduplicator">The deduplicator instance.</param>
    /// <param name="edges">The edges to deduplicate.</param>
    /// <param name="vulnerabilityId">The vulnerability ID to associate with edges.</param>
    /// <param name="defaultSource">Default source ID if not specified.</param>
    /// <param name="timeProvider">Time provider for timestamps.</param>
    /// <returns>Deduplicated edges.</returns>
    public static IReadOnlyList<DeduplicatedEdge> DeduplicateWithDefaults(
        this IEdgeDeduplicator deduplicator,
        IEnumerable<ReachGraphEdge> edges,
        string vulnerabilityId,
        string defaultSource = "unknown",
        TimeProvider? timeProvider = null)
    {
        var time = timeProvider ?? TimeProvider.System;
        var now = time.GetUtcNow();

        return deduplicator.Deduplicate(
            edges,
            keyExtractor: e => new EdgeSemanticKey(e.From, e.To, vulnerabilityId),
            sourceExtractor: _ => defaultSource,
            strengthExtractor: e => GetEdgeStrength(e.Why),
            timestampExtractor: _ => now);
    }

    private static double GetEdgeStrength(EdgeExplanation explanation)
    {
        var typeMultiplier = explanation.Type switch
        {
            EdgeExplanationType.DirectCall => 1.0,
            EdgeExplanationType.Import => 0.95,
            EdgeExplanationType.DynamicLoad => 0.9,
            EdgeExplanationType.Ffi => 0.85,
            EdgeExplanationType.Reflection => 0.8,
            EdgeExplanationType.LoaderRule => 0.75,
            EdgeExplanationType.TaintGate => 0.7,
            EdgeExplanationType.EnvGuard => 0.65,
            EdgeExplanationType.FeatureFlag => 0.6,
            EdgeExplanationType.PlatformArch => 0.6,
            EdgeExplanationType.Unknown => 0.5,
            _ => 0.5
        };

        return explanation.Confidence * typeMultiplier;
    }
}