using System.Collections.Concurrent;
using System.Diagnostics;
using System.Globalization;

namespace StellaOps.ElkSharp;

internal static partial class ElkEdgeRouterIterative
{
    private static CandidateSolution ApplyWinnerDetourPolish(
        CandidateSolution solution,
        ElkPositionedNode[] nodes,
        double minLineClearance)
    {
        var focusSeverity = new Dictionary<string, int>(StringComparer.Ordinal);
        ElkEdgeRoutingScoring.CountExcessiveDetourViolations(solution.Edges, nodes, focusSeverity, 10);
        ElkEdgeRoutingScoring.CountGatewaySourceExitViolations(solution.Edges, nodes, focusSeverity, 10);

        if (focusSeverity.Count > 0)
        {
            var batchedRootEdgeIds = focusSeverity
                .OrderByDescending(pair => pair.Value)
                .ThenBy(pair => pair.Key, StringComparer.Ordinal)
                .Take(Math.Min(focusSeverity.Count, MaxWinnerPolishBatchedRootEdges + 2))
                .Select(pair => pair.Key)
                .ToArray();
            var batchedFocusEdgeIds = ExpandWinningSolutionFocus(solution.Edges, batchedRootEdgeIds).ToArray();
            if (batchedFocusEdgeIds.Length > 0)
            {
                var batchedCandidateEdges = ComposeTransactionalFinalDetourCandidate(
                    solution.Edges,
                    nodes,
                    minLineClearance,
                    batchedFocusEdgeIds);
                batchedCandidateEdges = ChoosePreferredHardRuleLayout(solution.Edges, batchedCandidateEdges, nodes);
                if (TryPromoteFinalDetourCandidate(
                        solution.Edges,
                        batchedCandidateEdges,
                        nodes,
                        solution.Score,
                        solution.RetryState,
                        out var batchedPromotedEdges))
                {
                    var batchedPromotedScore = ElkEdgeRoutingScoring.ComputeScore(batchedPromotedEdges, nodes);
                    var batchedPromotedRetryState = BuildRetryState(
                        batchedPromotedScore,
                        HighwayProcessingEnabled
                            ? ElkEdgeRouterHighway.DetectRemainingBrokenHighways(batchedPromotedEdges, nodes).Count
                            : 0);

                    solution = new CandidateSolution(
                        batchedPromotedScore,
                        batchedPromotedRetryState,
                        batchedPromotedEdges,
                        solution.StrategyIndex);
                }
            }
        }

        var candidateEdges = ApplyFinalDetourPolish(solution.Edges, nodes, minLineClearance, restrictedEdgeIds: null);
        if (ReferenceEquals(candidateEdges, solution.Edges))
        {
            return solution;
        }

        var candidateScore = ElkEdgeRoutingScoring.ComputeScore(candidateEdges, nodes);
        var candidateRetryState = BuildRetryState(
            candidateScore,
            HighwayProcessingEnabled
                ? ElkEdgeRouterHighway.DetectRemainingBrokenHighways(candidateEdges, nodes).Count
                : 0);

        return new CandidateSolution(candidateScore, candidateRetryState, candidateEdges, solution.StrategyIndex);
    }

}