using System.Text.Json.Serialization;

namespace StellaOps.Policy.RiskProfile.Models;

/// <summary>
/// Represents a risk profile definition used to score and prioritize findings.
/// </summary>
public sealed class RiskProfileModel
{
    /// <summary>
    /// Stable identifier for the risk profile (slug or URN).
    /// </summary>
    [JsonPropertyName("id")]
    public required string Id { get; set; }

    /// <summary>
    /// SemVer for the profile definition.
    /// </summary>
    [JsonPropertyName("version")]
    public required string Version { get; set; }

    /// <summary>
    /// Human-readable summary of the profile intent.
    /// </summary>
    [JsonPropertyName("description")]
    public string? Description { get; set; }

    /// <summary>
    /// Optional parent profile ID for inheritance.
    /// </summary>
    [JsonPropertyName("extends")]
    public string? Extends { get; set; }

    /// <summary>
    /// Signal definitions used for risk scoring.
    /// </summary>
    [JsonPropertyName("signals")]
    public List<RiskSignal> Signals { get; set; } = new();

    /// <summary>
    /// Weight per signal name; weights are normalized by the consumer.
    /// </summary>
    [JsonPropertyName("weights")]
    public Dictionary<string, double> Weights { get; set; } = new();

    /// <summary>
    /// Override rules for severity and decisions.
    /// </summary>
    [JsonPropertyName("overrides")]
    public RiskOverrides Overrides { get; set; } = new();

    /// <summary>
    /// Free-form metadata with stable keys.
    /// </summary>
    [JsonPropertyName("metadata")]
    public Dictionary<string, object?>? Metadata { get; set; }
}

/// <summary>
/// A signal definition used in risk scoring.
/// </summary>
public sealed class RiskSignal
{
    /// <summary>
    /// Logical signal key (e.g., reachability, kev, exploit_chain).
    /// </summary>
    [JsonPropertyName("name")]
    public required string Name { get; set; }

    /// <summary>
    /// Upstream provider or calculation origin.
    /// </summary>
    [JsonPropertyName("source")]
    public required string Source { get; set; }

    /// <summary>
    /// Signal type.
    /// </summary>
    [JsonPropertyName("type")]
    public required RiskSignalType Type { get; set; }

    /// <summary>
    /// JSON Pointer to the signal in the evidence document.
    /// </summary>
    [JsonPropertyName("path")]
    public string? Path { get; set; }

    /// <summary>
    /// Optional transform applied before weighting.
    /// </summary>
    [JsonPropertyName("transform")]
    public string? Transform { get; set; }

    /// <summary>
    /// Optional unit for numeric signals.
    /// </summary>
    [JsonPropertyName("unit")]
    public string? Unit { get; set; }
}

/// <summary>
/// Signal type enumeration.
/// </summary>
[JsonConverter(typeof(JsonStringEnumConverter<RiskSignalType>))]
public enum RiskSignalType
{
    [JsonPropertyName("boolean")]
    Boolean,

    [JsonPropertyName("numeric")]
    Numeric,

    [JsonPropertyName("categorical")]
    Categorical,
}

/// <summary>
/// Override rules for severity and decisions.
/// </summary>
public sealed class RiskOverrides
{
    /// <summary>
    /// Severity override rules.
    /// </summary>
    [JsonPropertyName("severity")]
    public List<SeverityOverride> Severity { get; set; } = new();

    /// <summary>
    /// Decision override rules.
    /// </summary>
    [JsonPropertyName("decisions")]
    public List<DecisionOverride> Decisions { get; set; } = new();
}

/// <summary>
/// A severity override rule.
/// </summary>
public sealed class SeverityOverride
{
    /// <summary>
    /// Predicate over signals (key/value equals).
    /// </summary>
    [JsonPropertyName("when")]
    public required Dictionary<string, object> When { get; set; }

    /// <summary>
    /// Severity to set when predicate matches.
    /// </summary>
    [JsonPropertyName("set")]
    public required RiskSeverity Set { get; set; }
}

/// <summary>
/// A decision override rule.
/// </summary>
public sealed class DecisionOverride
{
    /// <summary>
    /// Predicate over signals (key/value equals).
    /// </summary>
    [JsonPropertyName("when")]
    public required Dictionary<string, object> When { get; set; }

    /// <summary>
    /// Action to take when predicate matches.
    /// </summary>
    [JsonPropertyName("action")]
    public required RiskAction Action { get; set; }

    /// <summary>
    /// Optional reason for the override.
    /// </summary>
    [JsonPropertyName("reason")]
    public string? Reason { get; set; }
}

/// <summary>
/// Severity levels.
/// </summary>
[JsonConverter(typeof(JsonStringEnumConverter<RiskSeverity>))]
public enum RiskSeverity
{
    [JsonPropertyName("critical")]
    Critical,

    [JsonPropertyName("high")]
    High,

    [JsonPropertyName("medium")]
    Medium,

    [JsonPropertyName("low")]
    Low,

    [JsonPropertyName("informational")]
    Informational,
}

/// <summary>
/// Decision actions.
/// </summary>
[JsonConverter(typeof(JsonStringEnumConverter<RiskAction>))]
public enum RiskAction
{
    [JsonPropertyName("allow")]
    Allow,

    [JsonPropertyName("review")]
    Review,

    [JsonPropertyName("deny")]
    Deny,
}