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

namespace StellaOps.ElkSharp;

internal static partial class ElkEdgeRouterIterative
{
    private static CandidateSolution ApplyFinalDirectUnderNodePolish(
        CandidateSolution solution,
        ElkPositionedNode[] nodes,
        double minLineClearance)
    {
        var current = solution;
        var underNodeSeverity = new Dictionary<string, int>(StringComparer.Ordinal);
        ElkEdgeRoutingScoring.CountUnderNodeViolations(current.Edges, nodes, underNodeSeverity, 10);
        if (underNodeSeverity.Count == 0)
        {
            return current;
        }

        foreach (var edgeId in underNodeSeverity
                     .OrderByDescending(pair => pair.Value)
                     .ThenBy(pair => pair.Key, StringComparer.Ordinal)
                     .Select(pair => pair.Key))
        {
            var candidateEdges = ElkEdgePostProcessor.ElevateUnderNodeViolations(
                current.Edges,
                nodes,
                minLineClearance,
                [edgeId]);
            var candidateScore = ElkEdgeRoutingScoring.ComputeScore(candidateEdges, nodes);
            var candidateRetryState = BuildRetryState(
                candidateScore,
                HighwayProcessingEnabled
                    ? ElkEdgeRouterHighway.DetectRemainingBrokenHighways(candidateEdges, nodes).Count
                    : 0);
            if (!IsBetterCandidate(candidateScore, candidateRetryState, current.Score, current.RetryState))
            {
                continue;
            }

            current = current with
            {
                Score = candidateScore,
                RetryState = candidateRetryState,
                Edges = candidateEdges,
            };
        }

        return current;
    }

    private static CandidateSolution ApplyFinalProtectedLocalBundlePolish(
        CandidateSolution solution,
        ElkPositionedNode[] nodes,
        double minLineClearance)
    {
        var current = solution;
        var underNodeSeverity = new Dictionary<string, int>(StringComparer.Ordinal);
        ElkEdgeRoutingScoring.CountUnderNodeViolations(current.Edges, nodes, underNodeSeverity, 10);

        var focusSeverity = new Dictionary<string, int>(underNodeSeverity, StringComparer.Ordinal);
        ElkEdgeRoutingScoring.CountTargetApproachJoinViolations(current.Edges, nodes, focusSeverity, 10);
        if (focusSeverity.Count == 0)
        {
            return current;
        }

        foreach (var edgeId in focusSeverity
                     .OrderByDescending(pair => pair.Value)
                     .ThenBy(pair => pair.Key, StringComparer.Ordinal)
                     .Select(pair => pair.Key))
        {
            var focusEdgeIds = ExpandWinningSolutionFocus(current.Edges, [edgeId]).ToArray();
            if (focusEdgeIds.Length == 0)
            {
                continue;
            }

            var focusedRepairSeeds = focusEdgeIds
                .Where(underNodeSeverity.ContainsKey)
                .OrderBy(id => id, StringComparer.Ordinal)
                .ToArray();
            if (focusedRepairSeeds.Length == 0)
            {
                focusedRepairSeeds = [edgeId];
            }

            var candidateEdges = ElkEdgePostProcessor.ElevateUnderNodeViolations(
                current.Edges,
                nodes,
                minLineClearance,
                focusedRepairSeeds);
            candidateEdges = ElkEdgePostProcessor.SpreadTargetApproachJoins(
                candidateEdges,
                nodes,
                minLineClearance,
                focusEdgeIds,
                forceOutwardAxisSpacing: true);
            candidateEdges = ElkEdgePostProcessor.SpreadRectTargetApproachFeederBands(
                candidateEdges,
                nodes,
                minLineClearance,
                focusEdgeIds);
            candidateEdges = ElkEdgePostProcessor.SeparateSharedLaneConflicts(
                candidateEdges,
                nodes,
                minLineClearance,
                focusEdgeIds);
            candidateEdges = ElkEdgePostProcessor.ElevateUnderNodeViolations(
                candidateEdges,
                nodes,
                minLineClearance,
                focusEdgeIds);
            candidateEdges = ElkEdgePostProcessor.SpreadTargetApproachJoins(
                candidateEdges,
                nodes,
                minLineClearance,
                focusEdgeIds,
                forceOutwardAxisSpacing: true);
            candidateEdges = ElkEdgePostProcessor.SpreadRectTargetApproachFeederBands(
                candidateEdges,
                nodes,
                minLineClearance,
                focusEdgeIds);
            candidateEdges = ChoosePreferredHardRuleLayout(current.Edges, candidateEdges, nodes);

            var candidateScore = ElkEdgeRoutingScoring.ComputeScore(candidateEdges, nodes);
            var candidateRetryState = BuildRetryState(
                candidateScore,
                HighwayProcessingEnabled
                    ? ElkEdgeRouterHighway.DetectRemainingBrokenHighways(candidateEdges, nodes).Count
                    : 0);
            if (!IsBetterCandidate(candidateScore, candidateRetryState, current.Score, current.RetryState))
            {
                continue;
            }

            current = current with
            {
                Score = candidateScore,
                RetryState = candidateRetryState,
                Edges = candidateEdges,
            };

            underNodeSeverity.Clear();
            ElkEdgeRoutingScoring.CountUnderNodeViolations(current.Edges, nodes, underNodeSeverity, 10);
        }

        return current;
    }

}