using System;
using System.Text.RegularExpressions;
using CycloneDX;
using CycloneDX.Models;

namespace StellaOps.Scanner.Emit.Composition;

/// <summary>
/// Helpers and media type constants for CycloneDX 1.7.
/// </summary>
/// <remarks>
/// Sprint: SPRINT_5000_0001_0001 - Advisory Alignment (CycloneDX 1.7 Upgrade)
/// Keep upgrade helpers for backward-compatibility with 1.6 inputs.
/// </remarks>
public static class CycloneDx17Extensions
{
    /// <summary>
    /// CycloneDX 1.7 media types.
    /// </summary>
    public static class MediaTypes
    {
        public const string InventoryJson = "application/vnd.cyclonedx+json; version=1.7";
        public const string UsageJson = "application/vnd.cyclonedx+json; version=1.7; view=usage";
        public const string InventoryProtobuf = "application/vnd.cyclonedx+protobuf; version=1.7";
        public const string UsageProtobuf = "application/vnd.cyclonedx+protobuf; version=1.7; view=usage";
    }

    // Regex patterns for version replacement in serialized output
    private static readonly Regex JsonSpecVersionPattern = new(
        @"""specVersion""\s*:\s*""1\.6""",
        RegexOptions.Compiled);

    private static readonly Regex XmlSpecVersionPattern = new(
        @"specVersion=""1\.6""",
        RegexOptions.Compiled);

    /// <summary>
    /// Upgrades a CycloneDX 1.6 JSON string to 1.7 format.
    /// </summary>
    /// <param name="json1_6">The JSON serialized with v1_6.</param>
    /// <returns>The JSON with specVersion updated to 1.7.</returns>
    public static string UpgradeJsonTo17(string json1_6)
    {
        if (string.IsNullOrEmpty(json1_6))
        {
            return json1_6;
        }

        return JsonSpecVersionPattern.Replace(json1_6, @"""specVersion"": ""1.7""");
    }

    /// <summary>
    /// Upgrades a CycloneDX 1.6 XML string to 1.7 format.
    /// </summary>
    /// <param name="xml1_6">The XML serialized with v1_6.</param>
    /// <returns>The XML with specVersion updated to 1.7.</returns>
    public static string UpgradeXmlTo17(string xml1_6)
    {
        if (string.IsNullOrEmpty(xml1_6))
        {
            return xml1_6;
        }

        return XmlSpecVersionPattern.Replace(xml1_6, @"specVersion=""1.7""");
    }

    /// <summary>
    /// Upgrades a media type string from 1.6 to 1.7.
    /// </summary>
    public static string UpgradeMediaTypeTo17(string mediaType)
    {
        if (string.IsNullOrEmpty(mediaType))
        {
            return mediaType;
        }

        return mediaType.Replace("version=1.6", "version=1.7", StringComparison.OrdinalIgnoreCase);
    }

    /// <summary>
    /// Checks if CycloneDX.Core supports v1_7 natively.
    /// Returns true when the library is updated and this workaround can be removed.
    /// </summary>
    public static bool IsNativeV17Supported()
    {
        // Check if v1_7 enum value exists via reflection
        var values = Enum.GetNames(typeof(SpecificationVersion));
        foreach (var value in values)
        {
            if (value.Equals("v1_7", StringComparison.OrdinalIgnoreCase))
            {
                return true;
            }
        }
        return false;
    }
}