// -----------------------------------------------------------------------------
// TriageInboxEndpoints.cs
// Sprint: SPRINT_3900_0003_0001_exploit_path_inbox_proof_bundles
// Description: HTTP endpoints for triage inbox with grouped exploit paths.
// -----------------------------------------------------------------------------

using System.Text.Json;
using System.Text.Json.Serialization;
using Microsoft.AspNetCore.Http;
using Microsoft.AspNetCore.Mvc;
using Microsoft.AspNetCore.Routing;
using StellaOps.Scanner.Triage.Models;
using StellaOps.Scanner.Triage.Services;
using StellaOps.Scanner.WebService.Security;

namespace StellaOps.Scanner.WebService.Endpoints.Triage;

/// <summary>
/// Endpoints for triage inbox - grouped exploit paths.
/// </summary>
internal static class TriageInboxEndpoints
{
    private static readonly JsonSerializerOptions SerializerOptions = new(JsonSerializerDefaults.Web)
    {
        DefaultIgnoreCondition = JsonIgnoreCondition.WhenWritingNull,
        Converters = { new JsonStringEnumConverter() }
    };

    /// <summary>
    /// Maps triage inbox endpoints.
    /// </summary>
    public static void MapTriageInboxEndpoints(this RouteGroupBuilder apiGroup)
    {
        ArgumentNullException.ThrowIfNull(apiGroup);

        var triageGroup = apiGroup.MapGroup("/triage")
            .WithTags("Triage");

        // GET /v1/triage/inbox?artifactDigest={digest}&filter={filter}
        triageGroup.MapGet("/inbox", HandleGetInboxAsync)
            .WithName("scanner.triage.inbox")
            .WithDescription("Retrieves triage inbox with grouped exploit paths for an artifact.")
            .Produces<TriageInboxResponse>(StatusCodes.Status200OK)
            .Produces(StatusCodes.Status400BadRequest)
            .RequireAuthorization(ScannerPolicies.TriageRead);
    }

    private static async Task<IResult> HandleGetInboxAsync(
        [FromQuery] string artifactDigest,
        [FromQuery] string? filter,
        [FromServices] IExploitPathGroupingService groupingService,
        [FromServices] IFindingQueryService findingService,
        CancellationToken cancellationToken)
    {
        ArgumentNullException.ThrowIfNull(groupingService);
        ArgumentNullException.ThrowIfNull(findingService);

        if (string.IsNullOrWhiteSpace(artifactDigest))
        {
            return Results.BadRequest(new
            {
                type = "validation-error",
                title = "Invalid artifact digest",
                detail = "Artifact digest is required."
            });
        }

        var findings = await findingService.GetFindingsForArtifactAsync(artifactDigest, cancellationToken);
        var paths = await groupingService.GroupFindingsAsync(artifactDigest, findings, cancellationToken);

        var filteredPaths = ApplyFilter(paths, filter);

        var response = new TriageInboxResponse
        {
            ArtifactDigest = artifactDigest,
            TotalPaths = paths.Count,
            FilteredPaths = filteredPaths.Count,
            Filter = filter,
            Paths = filteredPaths,
            GeneratedAt = DateTimeOffset.UtcNow
        };

        return Results.Ok(response);
    }

    private static IReadOnlyList<ExploitPath> ApplyFilter(
        IReadOnlyList<ExploitPath> paths,
        string? filter)
    {
        if (string.IsNullOrWhiteSpace(filter))
            return paths;

        return filter.ToLowerInvariant() switch
        {
            "actionable" => paths.Where(p => !p.IsQuiet && p.Reachability is ReachabilityStatus.StaticallyReachable or ReachabilityStatus.RuntimeConfirmed).ToList(),
            "noisy" => paths.Where(p => p.IsQuiet).ToList(),
            "reachable" => paths.Where(p => p.Reachability is ReachabilityStatus.StaticallyReachable or ReachabilityStatus.RuntimeConfirmed).ToList(),
            "runtime" => paths.Where(p => p.Reachability == ReachabilityStatus.RuntimeConfirmed).ToList(),
            "critical" => paths.Where(p => p.RiskScore.CriticalCount > 0).ToList(),
            "high" => paths.Where(p => p.RiskScore.HighCount > 0).ToList(),
            _ => paths
        };
    }
}

/// <summary>
/// Response for triage inbox endpoint.
/// </summary>
public sealed record TriageInboxResponse
{
    public required string ArtifactDigest { get; init; }
    public required int TotalPaths { get; init; }
    public required int FilteredPaths { get; init; }
    public string? Filter { get; init; }
    public required IReadOnlyList<ExploitPath> Paths { get; init; }
    public required DateTimeOffset GeneratedAt { get; init; }
}

public interface IFindingQueryService
{
    Task<IReadOnlyList<Finding>> GetFindingsForArtifactAsync(string artifactDigest, CancellationToken ct);
}