using System.Collections.Immutable;
using System.Text.Json.Serialization;
using StellaOps.Policy.RiskProfile.Models;

namespace StellaOps.Policy.Engine.Simulation;

/// <summary>
/// Detailed breakdown of a risk simulation result.
/// Per POLICY-RISK-67-003.
/// </summary>
public sealed record RiskSimulationBreakdown(
    [property: JsonPropertyName("simulation_id")] string SimulationId,
    [property: JsonPropertyName("profile_ref")] ProfileReference ProfileRef,
    [property: JsonPropertyName("signal_analysis")] SignalAnalysis SignalAnalysis,
    [property: JsonPropertyName("override_analysis")] OverrideAnalysis OverrideAnalysis,
    [property: JsonPropertyName("score_distribution")] ScoreDistributionAnalysis ScoreDistribution,
    [property: JsonPropertyName("severity_breakdown")] SeverityBreakdownAnalysis SeverityBreakdown,
    [property: JsonPropertyName("action_breakdown")] ActionBreakdownAnalysis ActionBreakdown,
    [property: JsonPropertyName("component_breakdown")] ComponentBreakdownAnalysis? ComponentBreakdown,
    [property: JsonPropertyName("risk_trends")] RiskTrendAnalysis? RiskTrends,
    [property: JsonPropertyName("determinism_hash")] string DeterminismHash);

/// <summary>
/// Reference to the risk profile used in simulation.
/// </summary>
public sealed record ProfileReference(
    [property: JsonPropertyName("id")] string Id,
    [property: JsonPropertyName("version")] string Version,
    [property: JsonPropertyName("hash")] string Hash,
    [property: JsonPropertyName("description")] string? Description,
    [property: JsonPropertyName("extends")] string? Extends);

/// <summary>
/// Analysis of signal contributions to risk scores.
/// </summary>
public sealed record SignalAnalysis(
    [property: JsonPropertyName("total_signals")] int TotalSignals,
    [property: JsonPropertyName("signals_used")] int SignalsUsed,
    [property: JsonPropertyName("signals_missing")] int SignalsMissing,
    [property: JsonPropertyName("signal_coverage")] double SignalCoverage,
    [property: JsonPropertyName("signal_stats")] ImmutableArray<SignalStatistics> SignalStats,
    [property: JsonPropertyName("top_contributors")] ImmutableArray<SignalContributor> TopContributors,
    [property: JsonPropertyName("missing_signal_impact")] MissingSignalImpact MissingSignalImpact);

/// <summary>
/// Statistics for a single signal across all findings.
/// </summary>
public sealed record SignalStatistics(
    [property: JsonPropertyName("signal_name")] string SignalName,
    [property: JsonPropertyName("signal_type")] string SignalType,
    [property: JsonPropertyName("weight")] double Weight,
    [property: JsonPropertyName("findings_with_signal")] int FindingsWithSignal,
    [property: JsonPropertyName("findings_missing_signal")] int FindingsMissingSignal,
    [property: JsonPropertyName("coverage_percentage")] double CoveragePercentage,
    [property: JsonPropertyName("value_distribution")] ValueDistribution? ValueDistribution,
    [property: JsonPropertyName("total_contribution")] double TotalContribution,
    [property: JsonPropertyName("avg_contribution")] double AvgContribution);

/// <summary>
/// Distribution of values for a signal.
/// </summary>
public sealed record ValueDistribution(
    [property: JsonPropertyName("min")] double? Min,
    [property: JsonPropertyName("max")] double? Max,
    [property: JsonPropertyName("mean")] double? Mean,
    [property: JsonPropertyName("median")] double? Median,
    [property: JsonPropertyName("std_dev")] double? StdDev,
    [property: JsonPropertyName("histogram")] ImmutableArray<HistogramBucket>? Histogram);

/// <summary>
/// Histogram bucket for value distribution.
/// </summary>
public sealed record HistogramBucket(
    [property: JsonPropertyName("range_min")] double RangeMin,
    [property: JsonPropertyName("range_max")] double RangeMax,
    [property: JsonPropertyName("count")] int Count,
    [property: JsonPropertyName("percentage")] double Percentage);

/// <summary>
/// A signal that significantly contributed to risk scores.
/// </summary>
public sealed record SignalContributor(
    [property: JsonPropertyName("signal_name")] string SignalName,
    [property: JsonPropertyName("total_contribution")] double TotalContribution,
    [property: JsonPropertyName("contribution_percentage")] double ContributionPercentage,
    [property: JsonPropertyName("avg_value")] double AvgValue,
    [property: JsonPropertyName("weight")] double Weight,
    [property: JsonPropertyName("impact_direction")] string ImpactDirection);

/// <summary>
/// Impact of missing signals on scoring.
/// </summary>
public sealed record MissingSignalImpact(
    [property: JsonPropertyName("findings_with_missing_signals")] int FindingsWithMissingSignals,
    [property: JsonPropertyName("avg_missing_signals_per_finding")] double AvgMissingSignalsPerFinding,
    [property: JsonPropertyName("estimated_score_impact")] double EstimatedScoreImpact,
    [property: JsonPropertyName("most_impactful_missing")] ImmutableArray<string> MostImpactfulMissing);

/// <summary>
/// Analysis of override applications.
/// </summary>
public sealed record OverrideAnalysis(
    [property: JsonPropertyName("total_overrides_evaluated")] int TotalOverridesEvaluated,
    [property: JsonPropertyName("severity_overrides_applied")] int SeverityOverridesApplied,
    [property: JsonPropertyName("decision_overrides_applied")] int DecisionOverridesApplied,
    [property: JsonPropertyName("override_application_rate")] double OverrideApplicationRate,
    [property: JsonPropertyName("severity_override_details")] ImmutableArray<SeverityOverrideDetail> SeverityOverrideDetails,
    [property: JsonPropertyName("decision_override_details")] ImmutableArray<DecisionOverrideDetail> DecisionOverrideDetails,
    [property: JsonPropertyName("override_conflicts")] ImmutableArray<OverrideConflict> OverrideConflicts);

/// <summary>
/// Details of severity override applications.
/// </summary>
public sealed record SeverityOverrideDetail(
    [property: JsonPropertyName("predicate_hash")] string PredicateHash,
    [property: JsonPropertyName("predicate_summary")] string PredicateSummary,
    [property: JsonPropertyName("target_severity")] string TargetSeverity,
    [property: JsonPropertyName("applications_count")] int ApplicationsCount,
    [property: JsonPropertyName("original_severities")] ImmutableDictionary<string, int> OriginalSeverities);

/// <summary>
/// Details of decision override applications.
/// </summary>
public sealed record DecisionOverrideDetail(
    [property: JsonPropertyName("predicate_hash")] string PredicateHash,
    [property: JsonPropertyName("predicate_summary")] string PredicateSummary,
    [property: JsonPropertyName("target_action")] string TargetAction,
    [property: JsonPropertyName("reason")] string? Reason,
    [property: JsonPropertyName("applications_count")] int ApplicationsCount,
    [property: JsonPropertyName("original_actions")] ImmutableDictionary<string, int> OriginalActions);

/// <summary>
/// Override conflict detected during evaluation.
/// </summary>
public sealed record OverrideConflict(
    [property: JsonPropertyName("finding_id")] string FindingId,
    [property: JsonPropertyName("conflict_type")] string ConflictType,
    [property: JsonPropertyName("override_1")] string Override1,
    [property: JsonPropertyName("override_2")] string Override2,
    [property: JsonPropertyName("resolution")] string Resolution);

/// <summary>
/// Analysis of score distribution.
/// </summary>
public sealed record ScoreDistributionAnalysis(
    [property: JsonPropertyName("raw_score_stats")] ScoreStatistics RawScoreStats,
    [property: JsonPropertyName("normalized_score_stats")] ScoreStatistics NormalizedScoreStats,
    [property: JsonPropertyName("score_buckets")] ImmutableArray<ScoreBucket> ScoreBuckets,
    [property: JsonPropertyName("percentiles")] ImmutableDictionary<string, double> Percentiles,
    [property: JsonPropertyName("outliers")] OutlierAnalysis Outliers);

/// <summary>
/// Statistical summary of scores.
/// </summary>
public sealed record ScoreStatistics(
    [property: JsonPropertyName("count")] int Count,
    [property: JsonPropertyName("min")] double Min,
    [property: JsonPropertyName("max")] double Max,
    [property: JsonPropertyName("mean")] double Mean,
    [property: JsonPropertyName("median")] double Median,
    [property: JsonPropertyName("std_dev")] double StdDev,
    [property: JsonPropertyName("variance")] double Variance,
    [property: JsonPropertyName("skewness")] double Skewness,
    [property: JsonPropertyName("kurtosis")] double Kurtosis);

/// <summary>
/// Score bucket for distribution.
/// </summary>
public sealed record ScoreBucket(
    [property: JsonPropertyName("range_min")] double RangeMin,
    [property: JsonPropertyName("range_max")] double RangeMax,
    [property: JsonPropertyName("label")] string Label,
    [property: JsonPropertyName("count")] int Count,
    [property: JsonPropertyName("percentage")] double Percentage);

/// <summary>
/// Outlier analysis for scores.
/// </summary>
public sealed record OutlierAnalysis(
    [property: JsonPropertyName("outlier_count")] int OutlierCount,
    [property: JsonPropertyName("outlier_threshold")] double OutlierThreshold,
    [property: JsonPropertyName("outlier_finding_ids")] ImmutableArray<string> OutlierFindingIds);

/// <summary>
/// Breakdown by severity level.
/// </summary>
public sealed record SeverityBreakdownAnalysis(
    [property: JsonPropertyName("by_severity")] ImmutableDictionary<string, SeverityBucket> BySeverity,
    [property: JsonPropertyName("severity_flow")] ImmutableArray<SeverityFlow> SeverityFlow,
    [property: JsonPropertyName("severity_concentration")] double SeverityConcentration);

/// <summary>
/// Details for a severity bucket.
/// </summary>
public sealed record SeverityBucket(
    [property: JsonPropertyName("severity")] string Severity,
    [property: JsonPropertyName("count")] int Count,
    [property: JsonPropertyName("percentage")] double Percentage,
    [property: JsonPropertyName("avg_score")] double AvgScore,
    [property: JsonPropertyName("score_range")] ScoreRange ScoreRange,
    [property: JsonPropertyName("top_contributors")] ImmutableArray<string> TopContributors);

/// <summary>
/// Score range for a bucket.
/// </summary>
public sealed record ScoreRange(
    [property: JsonPropertyName("min")] double Min,
    [property: JsonPropertyName("max")] double Max);

/// <summary>
/// Flow from original to final severity after overrides.
/// </summary>
public sealed record SeverityFlow(
    [property: JsonPropertyName("from_severity")] string FromSeverity,
    [property: JsonPropertyName("to_severity")] string ToSeverity,
    [property: JsonPropertyName("count")] int Count,
    [property: JsonPropertyName("is_escalation")] bool IsEscalation);

/// <summary>
/// Breakdown by recommended action.
/// </summary>
public sealed record ActionBreakdownAnalysis(
    [property: JsonPropertyName("by_action")] ImmutableDictionary<string, ActionBucket> ByAction,
    [property: JsonPropertyName("action_flow")] ImmutableArray<ActionFlow> ActionFlow,
    [property: JsonPropertyName("decision_stability")] double DecisionStability);

/// <summary>
/// Details for an action bucket.
/// </summary>
public sealed record ActionBucket(
    [property: JsonPropertyName("action")] string Action,
    [property: JsonPropertyName("count")] int Count,
    [property: JsonPropertyName("percentage")] double Percentage,
    [property: JsonPropertyName("avg_score")] double AvgScore,
    [property: JsonPropertyName("severity_breakdown")] ImmutableDictionary<string, int> SeverityBreakdown);

/// <summary>
/// Flow from original to final action after overrides.
/// </summary>
public sealed record ActionFlow(
    [property: JsonPropertyName("from_action")] string FromAction,
    [property: JsonPropertyName("to_action")] string ToAction,
    [property: JsonPropertyName("count")] int Count);

/// <summary>
/// Breakdown by component/package.
/// </summary>
public sealed record ComponentBreakdownAnalysis(
    [property: JsonPropertyName("total_components")] int TotalComponents,
    [property: JsonPropertyName("components_with_findings")] int ComponentsWithFindings,
    [property: JsonPropertyName("top_risk_components")] ImmutableArray<ComponentRiskSummary> TopRiskComponents,
    [property: JsonPropertyName("ecosystem_breakdown")] ImmutableDictionary<string, EcosystemSummary> EcosystemBreakdown);

/// <summary>
/// Risk summary for a component.
/// </summary>
public sealed record ComponentRiskSummary(
    [property: JsonPropertyName("component_purl")] string ComponentPurl,
    [property: JsonPropertyName("finding_count")] int FindingCount,
    [property: JsonPropertyName("max_score")] double MaxScore,
    [property: JsonPropertyName("avg_score")] double AvgScore,
    [property: JsonPropertyName("highest_severity")] string HighestSeverity,
    [property: JsonPropertyName("recommended_action")] string RecommendedAction);

/// <summary>
/// Summary for a package ecosystem.
/// </summary>
public sealed record EcosystemSummary(
    [property: JsonPropertyName("ecosystem")] string Ecosystem,
    [property: JsonPropertyName("component_count")] int ComponentCount,
    [property: JsonPropertyName("finding_count")] int FindingCount,
    [property: JsonPropertyName("avg_score")] double AvgScore,
    [property: JsonPropertyName("critical_count")] int CriticalCount,
    [property: JsonPropertyName("high_count")] int HighCount);

/// <summary>
/// Risk trend analysis (for comparison simulations).
/// </summary>
public sealed record RiskTrendAnalysis(
    [property: JsonPropertyName("comparison_type")] string ComparisonType,
    [property: JsonPropertyName("score_trend")] TrendMetric ScoreTrend,
    [property: JsonPropertyName("severity_trend")] TrendMetric SeverityTrend,
    [property: JsonPropertyName("action_trend")] TrendMetric ActionTrend,
    [property: JsonPropertyName("findings_improved")] int FindingsImproved,
    [property: JsonPropertyName("findings_worsened")] int FindingsWorsened,
    [property: JsonPropertyName("findings_unchanged")] int FindingsUnchanged);

/// <summary>
/// Trend metric for comparison.
/// </summary>
public sealed record TrendMetric(
    [property: JsonPropertyName("direction")] string Direction,
    [property: JsonPropertyName("magnitude")] double Magnitude,
    [property: JsonPropertyName("percentage_change")] double PercentageChange,
    [property: JsonPropertyName("is_significant")] bool IsSignificant);