using System;
using System.Collections.Generic;
using System.IO;
using System.Text.RegularExpressions;
using System.Threading.Tasks;

namespace InstaSoftOfficeTool.Services
{
    public class LicenseManager
    {
        public string OsppPath { get; private set; }

        public bool FindOspp()
        {
            var searchPaths = new[]
            {
                // Click-to-Run (leggyakoribb — Office 365, 2019, 2021, 2024)
                @"C:\Program Files\Microsoft Office\root\Office16\OSPP.VBS",
                @"C:\Program Files (x86)\Microsoft Office\root\Office16\OSPP.VBS",
                // Hagyományos MSI
                @"C:\Program Files\Microsoft Office\Office16\ospp.vbs",
                @"C:\Program Files (x86)\Microsoft Office\Office16\ospp.vbs",
                @"C:\Program Files\Microsoft Office\Office15\ospp.vbs",
                @"C:\Program Files (x86)\Microsoft Office\Office15\ospp.vbs",
                @"C:\Program Files\Microsoft Office\Office14\ospp.vbs",
                @"C:\Program Files (x86)\Microsoft Office\Office14\ospp.vbs",
            };

            foreach (var path in searchPaths)
            {
                if (File.Exists(path))
                {
                    OsppPath = path;
                    return true;
                }
            }

            try
            {
                var c2rPath = Microsoft.Win32.Registry.LocalMachine.OpenSubKey(
                    @"SOFTWARE\Microsoft\Office\ClickToRun\Configuration")
                    ?.GetValue("InstallationPath") as string;

                if (!string.IsNullOrEmpty(c2rPath))
                {
                    // C2R: root\Office16 vagy sima Office16
                    var candidates = new[]
                    {
                        Path.Combine(c2rPath, "root", "Office16", "OSPP.VBS"),
                        Path.Combine(c2rPath, "Office16", "OSPP.VBS"),
                    };
                    foreach (var candidate in candidates)
                    {
                        if (File.Exists(candidate))
                        {
                            OsppPath = candidate;
                            return true;
                        }
                    }
                }
            }
            catch { }

            return false;
        }

        public async Task<string> GetStatusAsync()
        {
            if (string.IsNullOrEmpty(OsppPath))
                return "Az ospp.vbs nem tal\u00e1lhat\u00f3.";

            var runner = new ProcessRunner();
            return await runner.RunAndCaptureAsync("cscript",
                "//Nologo \"" + OsppPath + "\" /dstatus");
        }

        public List<string> ParseLicenseKeys(string dstatusOutput)
        {
            var keys = new List<string>();
            var regex = new Regex(@"Last 5 characters of installed product key:\s*(\S+)",
                RegexOptions.IgnoreCase);

            foreach (Match match in regex.Matches(dstatusOutput))
            {
                keys.Add(match.Groups[1].Value);
            }

            return keys;
        }

        public async Task<string> RemoveKeyAsync(string last5Chars)
        {
            if (string.IsNullOrEmpty(OsppPath))
                return "Az ospp.vbs nem tal\u00e1lhat\u00f3.";

            var runner = new ProcessRunner();
            return await runner.RunAndCaptureAsync("cscript",
                "//Nologo \"" + OsppPath + "\" /unpkey:" + last5Chars);
        }

        public async Task<string> RemoveAllKeysAsync()
        {
            var status = await GetStatusAsync();
            var keys = ParseLicenseKeys(status);

            if (keys.Count == 0)
                return "Nem tal\u00e1lhat\u00f3 telep\u00edtett term\u00e9kkulcs.";

            var results = new List<string>();
            foreach (var key in keys)
            {
                var result = await RemoveKeyAsync(key);
                results.Add(key + ": " + result.Trim());
            }

            return string.Join("\n", results);
        }
    }
}