using System;
using System.Linq;
using System.Text.RegularExpressions;

namespace Gott.Services;

/// <summary>
/// Zentrale Definition aller Key-Patterns für den Secret Scanner.
/// Wird von KeyScannerService und GitHubEventScannerService gemeinsam genutzt.
/// </summary>
public static class KeyPatterns
{
    // ── Pattern-Definitionen ──
    // (Regex-Pattern, Suchbegriff für GitHub Code Search / Serper, Key-Typ)

    public static readonly (string Pattern, string SearchTerm, string Type)[] All =
    {
        // Anthropic
        (@"sk-ant-oat01-[A-Za-z0-9_\-]{95}", "sk-ant-oat01", "anthropic_oauth"),
        (@"sk-ant-api03-[A-Za-z0-9_\-]{95}", "sk-ant-api03", "anthropic_api"),

        // OpenAI
        (@"sk-proj-[A-Za-z0-9_\-]{80,200}", "sk-proj-", "openai_project"),
        (@"sk-svcacct-[A-Za-z0-9_\-]{80,200}", "sk-svcacct-", "openai_service"),
        (@"sk-[A-Za-z0-9]{48}", "sk-", "openai_legacy"),

        // Google / Gemini
        (@"AIza[0-9A-Za-z_\-]{35}", "AIzaSy", "google_api"),

        // AWS
        (@"AKIA[0-9A-Z]{16}", "AKIA", "aws_access_key"),

        // GitHub
        (@"ghp_[A-Za-z0-9]{36}", "ghp_", "github_pat"),
        (@"gho_[A-Za-z0-9]{36}", "gho_", "github_oauth"),

        // GitLab
        (@"glpat-[A-Za-z0-9_\-]{20}", "glpat-", "gitlab_pat"),

        // HuggingFace
        (@"hf_[A-Za-z0-9]{34}", "hf_", "huggingface"),

        // Stripe
        (@"sk_live_[0-9a-zA-Z]{24,}", "sk_live_", "stripe_live"),
        (@"sk_test_[0-9a-zA-Z]{24,}", "sk_test_", "stripe_test"),

        // SendGrid
        (@"SG\.[A-Za-z0-9_\-]{22}\.[A-Za-z0-9_\-]{43}", "SG.", "sendgrid"),

        // Slack (xoxb ist häufigster Typ)
        (@"xoxb-[0-9]{10,13}-[A-Za-z0-9\-]{20,}", "xoxb-", "slack"),
    };

    /// <summary>
    /// Patterns die für GitHub Code Search / Serper geeignet sind.
    /// Filtert zu generische Suchterme aus (z.B. "sk-", "SG.", "SK").
    /// </summary>
    public static readonly (string Pattern, string SearchTerm, string Type)[] ForCodeSearch =
        All.Where(p => p.SearchTerm.Length >= 5).ToArray();

    // ── Kompilierte Regexe (einmalig, alle Patterns) ──

    public static readonly Regex[] Compiled = All
        .Select(p => new Regex(p.Pattern, RegexOptions.Compiled))
        .ToArray();

    /// <summary>Erkennt den Key-Typ anhand des Prefixes.</summary>
    public static string DetectType(string key)
    {
        // Spezifischere Patterns zuerst prüfen (Reihenfolge wichtig!)
        if (key.StartsWith("sk-ant-oat01-", StringComparison.Ordinal)) return "anthropic_oauth";
        if (key.StartsWith("sk-ant-api03-", StringComparison.Ordinal)) return "anthropic_api";
        if (key.StartsWith("sk-ant-", StringComparison.Ordinal)) return "anthropic_unknown";
        if (key.StartsWith("sk-proj-", StringComparison.Ordinal)) return "openai_project";
        if (key.StartsWith("sk-svcacct-", StringComparison.Ordinal)) return "openai_service";
        if (key.StartsWith("sk_live_", StringComparison.Ordinal)) return "stripe_live";
        if (key.StartsWith("sk_test_", StringComparison.Ordinal)) return "stripe_test";
        if (key.StartsWith("sk-", StringComparison.Ordinal)) return "openai_legacy";
        if (key.StartsWith("AIza", StringComparison.Ordinal)) return "google_api";
        if (key.StartsWith("AKIA", StringComparison.Ordinal)) return "aws_access_key";
        if (key.StartsWith("ghp_", StringComparison.Ordinal)) return "github_pat";
        if (key.StartsWith("gho_", StringComparison.Ordinal)) return "github_oauth";
        if (key.StartsWith("glpat-", StringComparison.Ordinal)) return "gitlab_pat";
        if (key.StartsWith("hf_", StringComparison.Ordinal)) return "huggingface";
        if (key.StartsWith("SG.", StringComparison.Ordinal)) return "sendgrid";
        if (key.StartsWith("xoxb-", StringComparison.Ordinal)) return "slack";
        return "unknown";
    }

    /// <summary>Prüft ob ein Key-Typ zu Anthropic gehört (für automatische Validierung).</summary>
    public static bool IsAnthropic(string type)
    {
        return type == "anthropic_oauth" || type == "anthropic_api" || type == "anthropic_unknown";
    }

    /// <summary>Menschenlesbarer Name für den Key-Typ.</summary>
    public static string DisplayName(string type)
    {
        return type switch
        {
            "anthropic_oauth" => "Anthropic OAuth",
            "anthropic_api" => "Anthropic API",
            "anthropic_unknown" => "Anthropic",
            "openai_project" => "OpenAI Project",
            "openai_service" => "OpenAI Service",
            "openai_legacy" => "OpenAI Legacy",
            "google_api" => "Google / Gemini",
            "aws_access_key" => "AWS Access Key",
            "github_pat" => "GitHub PAT",
            "github_oauth" => "GitHub OAuth",
            "gitlab_pat" => "GitLab PAT",
            "huggingface" => "HuggingFace",
            "stripe_live" => "Stripe Live",
            "stripe_test" => "Stripe Test",
            "sendgrid" => "SendGrid",
            "slack" => "Slack",
            _ => type
        };
    }
}