using System;
using System.Net.Http;
using System.Text;
using System.Threading.Tasks;
using MediaBrowser.Model.Logging;
using MediaBrowser.Model.Serialization;

namespace NFOGuard.Emby.Plugin
{
    public class LicenseManager
    {
        private readonly ILogger _logger;
        private readonly HttpClient _httpClient;
        private const string NFOGUARD_API_URL = "https://nfoguard.com/api"; // Your future API endpoint

        public LicenseManager(ILogger logger)
        {
            _logger = logger;
            _httpClient = new HttpClient();
            _httpClient.Timeout = TimeSpan.FromSeconds(10); // Quick timeout for license checks
        }

        public async Task<bool> CheckLicenseStatusAsync()
        {
            try
            {
                var config = Plugin.Instance.Configuration;
                
                // Get unique identifier for this installation
                var machineId = GetMachineIdentifier();
                
                _logger.Info("NFOGuard :: Checking automatic license status...");
                
                // Check Patreon subscription
                var patreonValid = await CheckPatreonSubscriptionAsync(machineId);
                if (patreonValid)
                {
                    _logger.Info("NFOGuard :: Valid Patreon subscription found");
                    return true;
                }
                
                // Check PayPal recurring payment
                var paypalValid = await CheckPayPalSubscriptionAsync(machineId);
                if (paypalValid)
                {
                    _logger.Info("NFOGuard :: Valid PayPal subscription found");
                    return true;
                }
                
                _logger.Info("NFOGuard :: No active subscription found, using free tier");
                return false;
            }
            catch (Exception ex)
            {
                _logger.ErrorException("NFOGuard :: License validation error", ex);
                return false; // Default to free tier on error
            }
        }

        private async Task<bool> CheckPatreonSubscriptionAsync(string machineId)
        {
            try
            {
                var requestUrl = $"{NFOGUARD_API_URL}/patreon/check?machine_id={machineId}";
                var response = await _httpClient.GetStringAsync(requestUrl);
                
                // Parse response (you'll implement the API to return JSON like {"active": true, "tier": "supporter"})
                return response.Contains("\"active\":true");
            }
            catch (HttpRequestException)
            {
                _logger.Info("NFOGuard :: Cannot reach license server, running in offline mode");
                return false; // Offline mode - use free tier
            }
            catch (Exception ex)
            {
                _logger.ErrorException("NFOGuard :: Patreon check error", ex);
                return false;
            }
        }

        private async Task<bool> CheckPayPalSubscriptionAsync(string machineId)
        {
            try
            {
                var requestUrl = $"{NFOGUARD_API_URL}/paypal/check?machine_id={machineId}";
                var response = await _httpClient.GetStringAsync(requestUrl);
                
                // Parse response
                return response.Contains("\"active\":true");
            }
            catch (HttpRequestException)
            {
                _logger.Info("NFOGuard :: Cannot reach license server, running in offline mode");
                return false;
            }
            catch (Exception ex)
            {
                _logger.ErrorException("NFOGuard :: PayPal check error", ex);
                return false;
            }
        }

        public string GetMachineIdentifier()
        {
            try
            {
                // Create a unique but consistent identifier for this installation
                // Combine multiple factors to create a stable machine ID
                var machineName = Environment.MachineName ?? "unknown";
                var userDomain = Environment.UserDomainName ?? "unknown"; 
                var installPath = Plugin.Instance.ConfigurationFilePath;
                
                var combined = $"{machineName}-{userDomain}-{installPath}".GetHashCode().ToString("X8");
                
                _logger.Info($"NFOGuard :: Machine ID: {combined}");
                return combined;
            }
            catch (Exception ex)
            {
                _logger.ErrorException("NFOGuard :: Error generating machine ID", ex);
                return "FALLBACK-ID";
            }
        }

        public bool IsTrialExpired()
        {
            // Implement trial logic here
            // For example, check installation date vs current date
            var installDate = Plugin.Instance.Configuration.InstallDate;
            if (installDate == DateTime.MinValue)
            {
                Plugin.Instance.Configuration.InstallDate = DateTime.UtcNow;
                Plugin.Instance.SaveConfiguration();
                return false;
            }

            var trialDays = 30; // 30-day trial
            return DateTime.UtcNow > installDate.AddDays(trialDays);
        }

        public bool CanUseFeature()
        {
            // Check if license is valid or trial is still active
            return Plugin.Instance.Configuration.LicenseValid || !IsTrialExpired();
        }

        public async Task<bool> CheckAndActivateLicenseAsync()
        {
            try
            {
                _logger.Info("NFOGuard :: Checking for active subscriptions...");
                
                var isValid = await CheckLicenseStatusAsync();
                var config = Plugin.Instance.Configuration;
                
                if (isValid && !config.LicenseValid)
                {
                    // Activate license
                    config.LicenseValid = true;
                    config.MonthlyProcessingLimit = 0; // Remove limits
                    config.ProcessedThisMonth = 0; // Reset counter
                    Plugin.Instance.SaveConfiguration();
                    
                    var freeTierManager = new FreeTierManager(_logger);
                    freeTierManager.EnableFullVersion();
                    
                    _logger.Info("NFOGuard :: Subscription detected - unlimited processing activated!");
                    return true;
                }
                else if (!isValid && config.LicenseValid)
                {
                    // Deactivate license
                    config.LicenseValid = false;
                    Plugin.Instance.SaveConfiguration();
                    
                    var freeTierManager = new FreeTierManager(_logger);
                    freeTierManager.SetPercentageBasedLimits();
                    
                    _logger.Info("NFOGuard :: No active subscription found - switched to free tier");
                    return false;
                }
                
                return isValid;
            }
            catch (Exception ex)
            {
                _logger.ErrorException("NFOGuard :: License check error", ex);
                return false;
            }
        }

        public async Task<string> RegisterMachineAsync(string userEmail)
        {
            try
            {
                var machineId = GetMachineIdentifier();
                var config = Plugin.Instance.Configuration;
                
                var registrationData = new
                {
                    machine_id = machineId,
                    email = userEmail,
                    emby_version = Environment.OSVersion.ToString(),
                    plugin_version = Plugin.Instance.Description,
                    install_date = config.InstallDate.ToString("yyyy-MM-dd"),
                    library_stats = GetLibraryStats()
                };
                
                var json = System.Text.Json.JsonSerializer.Serialize(registrationData);
                var content = new StringContent(json, Encoding.UTF8, "application/json");
                
                var response = await _httpClient.PostAsync($"{NFOGUARD_API_URL}/register", content);
                var responseText = await response.Content.ReadAsStringAsync();
                
                if (response.IsSuccessStatusCode)
                {
                    _logger.Info($"NFOGuard :: Machine registered successfully: {machineId}");
                    return $"Registration successful!\n\nMachine ID: {machineId}\n\nTo activate unlimited processing:\n• Subscribe on Patreon: https://patreon.com/nfoguard\n• Or PayPal recurring: https://nfoguard.com/paypal\n\nThe plugin will automatically detect your subscription within 24 hours.";
                }
                else
                {
                    _logger.Warn($"NFOGuard :: Registration failed: {responseText}");
                    return $"Registration failed. You can still use the free tier.\n\nMachine ID: {machineId}\nError: {responseText}";
                }
            }
            catch (Exception ex)
            {
                _logger.ErrorException("NFOGuard :: Registration error", ex);
                var machineId = GetMachineIdentifier();
                return $"Registration failed (offline mode).\n\nMachine ID: {machineId}\n\nTo activate later, visit: https://nfoguard.com/register";
            }
        }

        private object GetLibraryStats()
        {
            try
            {
                // This would be used for analytics (anonymized)
                return new
                {
                    episodes_estimated = "unknown",
                    movies_estimated = "unknown",
                    free_tier_usage = Plugin.Instance.Configuration.ProcessedThisMonth
                };
            }
            catch
            {
                return new { error = "stats_unavailable" };
            }
        }

        public void DeactivateLicense()
        {
            try
            {
                var config = Plugin.Instance.Configuration;
                config.LicenseValid = false;
                
                // Reset to percentage-based free tier
                var freeTierManager = new FreeTierManager(_logger);
                freeTierManager.SetPercentageBasedLimits();
                
                Plugin.Instance.SaveConfiguration();
                
                _logger.Info("NFOGuard :: License deactivated - switched to free tier");
            }
            catch (Exception ex)
            {
                _logger.ErrorException("NFOGuard :: License deactivation error", ex);
            }
        }
    }
}