// SPDX-License-Identifier: BUSL-1.1
// Sprint: SPRINT_6000_0004_0001 - Scanner Worker Integration
// Task: T5 - Add Configuration and DI Registration

using Microsoft.Extensions.Configuration;
using Microsoft.Extensions.DependencyInjection;
using Microsoft.Extensions.Logging;
using StellaOps.BinaryIndex.Core.Services;
using StellaOps.BinaryIndex.Persistence.Services;
using StellaOps.Scanner.Worker.Processing;

namespace StellaOps.Scanner.Worker.Extensions;

/// <summary>
/// Extension methods for registering BinaryIndex integration services.
/// </summary>
public static class BinaryIndexServiceExtensions
{
    /// <summary>
    /// Adds BinaryIndex integration services to the service collection.
    /// </summary>
    public static IServiceCollection AddBinaryIndexIntegration(
        this IServiceCollection services,
        IConfiguration configuration)
    {
        var options = configuration
            .GetSection("BinaryIndex")
            .Get<BinaryIndexOptions>() ?? new BinaryIndexOptions();

        if (!options.Enabled)
        {
            services.AddSingleton<IBinaryVulnerabilityService, NullBinaryVulnerabilityService>();
            return services;
        }

        services.AddSingleton(options);
        services.AddScoped<IBinaryVulnerabilityService, BinaryVulnerabilityService>();
        services.AddScoped<IBinaryFeatureExtractor, ElfFeatureExtractor>();
        services.AddScoped<BinaryVulnerabilityAnalyzer>();
        services.AddScoped<Processing.BinaryFindingMapper>();

        return services;
    }
}

/// <summary>
/// Configuration options for BinaryIndex integration.
/// </summary>
public sealed class BinaryIndexOptions
{
    /// <summary>
    /// Whether binary vulnerability analysis is enabled.
    /// </summary>
    public bool Enabled { get; init; } = true;

    /// <summary>
    /// Batch size for binary lookups.
    /// </summary>
    public int BatchSize { get; init; } = 100;

    /// <summary>
    /// Timeout in milliseconds for binary lookups.
    /// </summary>
    public int TimeoutMs { get; init; } = 5000;

    /// <summary>
    /// Minimum confidence threshold for reporting matches.
    /// </summary>
    public decimal MinConfidence { get; init; } = 0.7m;
}

/// <summary>
/// Null implementation of IBinaryVulnerabilityService for when binary analysis is disabled.
/// </summary>
internal sealed class NullBinaryVulnerabilityService : IBinaryVulnerabilityService
{
    public Task<System.Collections.Immutable.ImmutableArray<BinaryVulnMatch>> LookupByIdentityAsync(
        StellaOps.BinaryIndex.Core.Models.BinaryIdentity identity,
        LookupOptions? options = null,
        CancellationToken ct = default)
    {
        return Task.FromResult(System.Collections.Immutable.ImmutableArray<BinaryVulnMatch>.Empty);
    }

    public Task<System.Collections.Immutable.ImmutableDictionary<string, System.Collections.Immutable.ImmutableArray<BinaryVulnMatch>>> LookupBatchAsync(
        IEnumerable<StellaOps.BinaryIndex.Core.Models.BinaryIdentity> identities,
        LookupOptions? options = null,
        CancellationToken ct = default)
    {
        return Task.FromResult(System.Collections.Immutable.ImmutableDictionary<string, System.Collections.Immutable.ImmutableArray<BinaryVulnMatch>>.Empty);
    }

    public Task<FixStatusResult?> GetFixStatusAsync(
        string distro,
        string release,
        string sourcePkg,
        string cveId,
        CancellationToken ct = default)
    {
        return Task.FromResult<FixStatusResult?>(null);
    }

    public Task<System.Collections.Immutable.ImmutableDictionary<string, FixStatusResult>> GetFixStatusBatchAsync(
        string distro,
        string release,
        string sourcePkg,
        IEnumerable<string> cveIds,
        CancellationToken ct = default)
    {
        return Task.FromResult(System.Collections.Immutable.ImmutableDictionary<string, FixStatusResult>.Empty);
    }

    public Task<System.Collections.Immutable.ImmutableArray<BinaryVulnMatch>> LookupByFingerprintAsync(
        byte[] fingerprint,
        FingerprintLookupOptions? options = null,
        CancellationToken ct = default)
    {
        return Task.FromResult(System.Collections.Immutable.ImmutableArray<BinaryVulnMatch>.Empty);
    }

    public Task<System.Collections.Immutable.ImmutableDictionary<string, System.Collections.Immutable.ImmutableArray<BinaryVulnMatch>>> LookupByFingerprintBatchAsync(
        IEnumerable<(string Key, byte[] Fingerprint)> fingerprints,
        FingerprintLookupOptions? options = null,
        CancellationToken ct = default)
    {
        return Task.FromResult(System.Collections.Immutable.ImmutableDictionary<string, System.Collections.Immutable.ImmutableArray<BinaryVulnMatch>>.Empty);
    }

    public Task<System.Collections.Immutable.ImmutableArray<BinaryVulnMatch>> LookupByDeltaSignatureAsync(
        Stream binaryStream,
        DeltaSigLookupOptions? options = null,
        CancellationToken ct = default)
    {
        return Task.FromResult(System.Collections.Immutable.ImmutableArray<BinaryVulnMatch>.Empty);
    }

    public Task<System.Collections.Immutable.ImmutableArray<BinaryVulnMatch>> LookupBySymbolHashAsync(
        string symbolHash,
        string symbolName,
        DeltaSigLookupOptions? options = null,
        CancellationToken ct = default)
    {
        return Task.FromResult(System.Collections.Immutable.ImmutableArray<BinaryVulnMatch>.Empty);
    }

    public Task<System.Collections.Immutable.ImmutableArray<CorpusFunctionMatch>> IdentifyFunctionFromCorpusAsync(
        FunctionFingerprintSet fingerprints,
        CorpusLookupOptions? options = null,
        CancellationToken ct = default)
    {
        return Task.FromResult(System.Collections.Immutable.ImmutableArray<CorpusFunctionMatch>.Empty);
    }

    public Task<System.Collections.Immutable.ImmutableDictionary<string, System.Collections.Immutable.ImmutableArray<CorpusFunctionMatch>>> IdentifyFunctionsFromCorpusBatchAsync(
        IEnumerable<(string Key, FunctionFingerprintSet Fingerprints)> functions,
        CorpusLookupOptions? options = null,
        CancellationToken ct = default)
    {
        return Task.FromResult(System.Collections.Immutable.ImmutableDictionary<string, System.Collections.Immutable.ImmutableArray<CorpusFunctionMatch>>.Empty);
    }
}