using System.Text.Json;
using Lagerbestand.Data;
using Lagerbestand.Models;
using Microsoft.EntityFrameworkCore;

namespace Lagerbestand.Services;

public interface ISiteSettingsService
{
    Task<PromoBannerSettings> GetPromoBannerSettingsAsync();
    Task SavePromoBannerSettingsAsync(PromoBannerSettings settings);
    Task<LexwareApiSettings> GetLexwareApiSettingsAsync();
    Task SaveLexwareApiSettingsAsync(LexwareApiSettings settings);
    Task<TwoFactorSettings> GetTwoFactorSettingsAsync();
    Task SaveTwoFactorSettingsAsync(TwoFactorSettings settings);
    Task<SmtpSettings> GetSmtpSettingsAsync();
    Task SaveSmtpSettingsAsync(SmtpSettings settings);
    Task<SessionSettings> GetSessionSettingsAsync();
    Task SaveSessionSettingsAsync(SessionSettings settings);

    /// <summary>
    /// Gets a raw setting value by key
    /// </summary>
    Task<string?> GetValueAsync(string key);

    /// <summary>
    /// Sets a raw setting value by key
    /// </summary>
    Task SetValueAsync(string key, string value);
}

public class SiteSettingsService : ISiteSettingsService
{
    private const string PromoBannerKey = "PromoBanner";
    private const string LexwareApiKey = "LexwareApi";
    private const string TwoFactorKey = "TwoFactor";
    private const string SmtpKey = "Smtp";
    private const string SessionKey = "Session";
    
    private readonly AppDbContext _context;
    private readonly ILogger<SiteSettingsService> _logger;

    public SiteSettingsService(AppDbContext context, ILogger<SiteSettingsService> logger)
    {
        _context = context;
        _logger = logger;
    }

    public async Task<PromoBannerSettings> GetPromoBannerSettingsAsync()
    {
        try
        {
            // Quick timeout to prevent blocking app startup
            using var cts = new CancellationTokenSource(TimeSpan.FromSeconds(5));
            
            var setting = await _context.SiteSettings
                .AsNoTracking()
                .FirstOrDefaultAsync(s => s.Key == PromoBannerKey, cts.Token);

            if (setting == null)
            {
                return new PromoBannerSettings();
            }

            var settings = JsonSerializer.Deserialize<PromoBannerSettings>(setting.Value);
            return settings ?? new PromoBannerSettings();
        }
        catch (OperationCanceledException)
        {
            _logger.LogDebug("Banner settings query timed out, returning default");
            return new PromoBannerSettings();
        }
        catch (MySqlConnector.MySqlException ex) when (ex.Number == 1146)
        {
            // Table doesn't exist yet - this is normal during first startup
            _logger.LogDebug("SiteSettings table not found, returning default settings");
            return new PromoBannerSettings();
        }
        catch (Exception ex)
        {
            _logger.LogWarning(ex, "Failed to load promo banner settings");
            return new PromoBannerSettings();
        }
    }

    public async Task SavePromoBannerSettingsAsync(PromoBannerSettings settings)
    {
        try
        {
            var existing = await _context.SiteSettings
                .FirstOrDefaultAsync(s => s.Key == PromoBannerKey);

            var json = JsonSerializer.Serialize(settings);

            if (existing != null)
            {
                existing.Value = json;
                existing.UpdatedAt = DateTime.UtcNow;
                _context.SiteSettings.Update(existing);
            }
            else
            {
                var newSetting = new SiteSettings
                {
                    Key = PromoBannerKey,
                    Value = json,
                    CreatedAt = DateTime.UtcNow
                };
                _context.SiteSettings.Add(newSetting);
            }

                                await _context.SaveChangesAsync();
                                _logger.LogInformation("Promo banner settings saved successfully");
                            }
                            catch (Exception ex)
                            {
                                _logger.LogError(ex, "Failed to save promo banner settings");
                                throw;
                            }
                        }

                        public async Task<LexwareApiSettings> GetLexwareApiSettingsAsync()
                        {
                            try
                            {
                                using var cts = new CancellationTokenSource(TimeSpan.FromSeconds(5));

                                var setting = await _context.SiteSettings
                                    .AsNoTracking()
                                    .FirstOrDefaultAsync(s => s.Key == LexwareApiKey, cts.Token);

                                if (setting == null)
                                    return new LexwareApiSettings();

                                var settings = JsonSerializer.Deserialize<LexwareApiSettings>(setting.Value);
                                return settings ?? new LexwareApiSettings();
                            }
                            catch (OperationCanceledException)
                            {
                                _logger.LogDebug("Lexware settings query timed out, returning default");
                                return new LexwareApiSettings();
                            }
                            catch (MySqlConnector.MySqlException ex) when (ex.Number == 1146)
                            {
                                _logger.LogDebug("SiteSettings table not found, returning default Lexware settings");
                                return new LexwareApiSettings();
                            }
                            catch (Exception ex)
                            {
                                _logger.LogWarning(ex, "Failed to load Lexware API settings");
                                return new LexwareApiSettings();
                            }
                        }

                        public async Task SaveLexwareApiSettingsAsync(LexwareApiSettings settings)
                        {
                            try
                            {
                                var existing = await _context.SiteSettings
                                    .FirstOrDefaultAsync(s => s.Key == LexwareApiKey);

                                var json = JsonSerializer.Serialize(settings);

                                if (existing != null)
                                {
                                    existing.Value = json;
                                    existing.UpdatedAt = DateTime.UtcNow;
                                    _context.SiteSettings.Update(existing);
                                }
                                else
                                {
                                    var newSetting = new SiteSettings
                                    {
                                        Key = LexwareApiKey,
                                        Value = json,
                                        CreatedAt = DateTime.UtcNow
                                    };
                                    _context.SiteSettings.Add(newSetting);
                                }

                                await _context.SaveChangesAsync();
                                        _logger.LogInformation("Lexware API settings saved successfully");
                                    }
                                    catch (Exception ex)
                                    {
                                        _logger.LogError(ex, "Failed to save Lexware API settings");
                                        throw;
                                    }
                                }

                                public async Task<TwoFactorSettings> GetTwoFactorSettingsAsync()
                                {
                                    try
                                    {
                                        using var cts = new CancellationTokenSource(TimeSpan.FromSeconds(5));
                                        var setting = await _context.SiteSettings
                                            .AsNoTracking()
                                            .FirstOrDefaultAsync(s => s.Key == TwoFactorKey, cts.Token);

                                        if (setting == null)
                                            return new TwoFactorSettings();

                                        return JsonSerializer.Deserialize<TwoFactorSettings>(setting.Value) ?? new TwoFactorSettings();
                                    }
                                    catch (OperationCanceledException)
                                    {
                                        _logger.LogDebug("TwoFactor settings query timed out, returning default");
                                        return new TwoFactorSettings();
                                    }
                                    catch (MySqlConnector.MySqlException ex) when (ex.Number == 1146)
                                    {
                                        return new TwoFactorSettings();
                                    }
                                    catch (Exception ex)
                                    {
                                        _logger.LogWarning(ex, "Failed to load TwoFactor settings");
                                        return new TwoFactorSettings();
                                    }
                                }

                                public async Task SaveTwoFactorSettingsAsync(TwoFactorSettings settings)
                                {
                                    try
                                    {
                                        var existing = await _context.SiteSettings
                                            .FirstOrDefaultAsync(s => s.Key == TwoFactorKey);

                                        var json = JsonSerializer.Serialize(settings);

                                        if (existing != null)
                                        {
                                            existing.Value = json;
                                            existing.UpdatedAt = DateTime.UtcNow;
                                            _context.SiteSettings.Update(existing);
                                        }
                                        else
                                        {
                                            _context.SiteSettings.Add(new SiteSettings
                                            {
                                                Key = TwoFactorKey,
                                                Value = json,
                                                CreatedAt = DateTime.UtcNow
                                            });
                                        }

                                        await _context.SaveChangesAsync();
                                        _logger.LogInformation("TwoFactor settings saved successfully");
                                    }
                                    catch (Exception ex)
                                    {
                                        _logger.LogError(ex, "Failed to save TwoFactor settings");
                                        throw;
                                    }
                                }

                                public async Task<SmtpSettings> GetSmtpSettingsAsync()
                                {
                                    try
                                    {
                                        using var cts = new CancellationTokenSource(TimeSpan.FromSeconds(5));
                                        var setting = await _context.SiteSettings
                                            .AsNoTracking()
                                            .FirstOrDefaultAsync(s => s.Key == SmtpKey, cts.Token);

                                        if (setting == null)
                                            return new SmtpSettings();

                                        return JsonSerializer.Deserialize<SmtpSettings>(setting.Value) ?? new SmtpSettings();
                                    }
                                    catch (OperationCanceledException)
                                    {
                                        _logger.LogDebug("SMTP settings query timed out, returning default");
                                        return new SmtpSettings();
                                    }
                                    catch (MySqlConnector.MySqlException ex) when (ex.Number == 1146)
                                    {
                                        return new SmtpSettings();
                                    }
                                    catch (Exception ex)
                                    {
                                        _logger.LogWarning(ex, "Failed to load SMTP settings");
                                        return new SmtpSettings();
                                    }
                                }

                                public async Task SaveSmtpSettingsAsync(SmtpSettings settings)
                                {
                                    try
                                    {
                                        var existing = await _context.SiteSettings
                                            .FirstOrDefaultAsync(s => s.Key == SmtpKey);

                                        var json = JsonSerializer.Serialize(settings);

                                        if (existing != null)
                                        {
                                            existing.Value = json;
                                            existing.UpdatedAt = DateTime.UtcNow;
                                            _context.SiteSettings.Update(existing);
                                        }
                                        else
                                        {
                                            _context.SiteSettings.Add(new SiteSettings
                                            {
                                                Key = SmtpKey,
                                                Value = json,
                                                CreatedAt = DateTime.UtcNow
                                            });
                                        }

                                        await _context.SaveChangesAsync();
                                        _logger.LogInformation("SMTP settings saved successfully");
                                    }
                                    catch (Exception ex)
                                    {
                                        _logger.LogError(ex, "Failed to save SMTP settings");
                                        throw;
                                    }
                                }

    public async Task<SessionSettings> GetSessionSettingsAsync()
    {
        try
        {
            using var cts = new CancellationTokenSource(TimeSpan.FromSeconds(5));
            var setting = await _context.SiteSettings
                .AsNoTracking()
                .FirstOrDefaultAsync(s => s.Key == SessionKey, cts.Token);

            if (setting == null)
                return new SessionSettings();

            return JsonSerializer.Deserialize<SessionSettings>(setting.Value) ?? new SessionSettings();
        }
        catch (OperationCanceledException)
        {
            _logger.LogDebug("Session settings query timed out, returning default");
            return new SessionSettings();
        }
        catch (MySqlConnector.MySqlException ex) when (ex.Number == 1146)
        {
            return new SessionSettings();
        }
        catch (Exception ex)
        {
            _logger.LogWarning(ex, "Failed to load Session settings");
            return new SessionSettings();
        }
    }

    public async Task SaveSessionSettingsAsync(SessionSettings settings)
    {
        try
        {
            // Clamp to safe ranges before persisting
            settings.IdleTimeoutMinutes = settings.GetSafeIdleTimeoutMinutes();
            settings.CircuitRetentionHours = settings.GetSafeCircuitRetentionHours();

            var existing = await _context.SiteSettings
                .FirstOrDefaultAsync(s => s.Key == SessionKey);

            var json = JsonSerializer.Serialize(settings);

            if (existing != null)
            {
                existing.Value = json;
                existing.UpdatedAt = DateTime.UtcNow;
                _context.SiteSettings.Update(existing);
            }
            else
            {
                _context.SiteSettings.Add(new SiteSettings
                {
                    Key = SessionKey,
                    Value = json,
                    CreatedAt = DateTime.UtcNow
                });
            }

            await _context.SaveChangesAsync();
            _logger.LogInformation("Session settings saved successfully");
        }
        catch (Exception ex)
        {
            _logger.LogError(ex, "Failed to save Session settings");
            throw;
        }
    }

                        public async Task<string?> GetValueAsync(string key)
                        {
                            try
                            {
                                using var cts = new CancellationTokenSource(TimeSpan.FromSeconds(5));

                                var setting = await _context.SiteSettings
                                    .AsNoTracking()
                                    .FirstOrDefaultAsync(s => s.Key == key, cts.Token);

                                return setting?.Value;
                            }
                            catch (OperationCanceledException)
                            {
                                _logger.LogDebug("Settings query for '{Key}' timed out", key);
                                return null;
                            }
                            catch (MySqlConnector.MySqlException ex) when (ex.Number == 1146)
                            {
                                _logger.LogDebug("SiteSettings table not found for key '{Key}'", key);
                                return null;
                            }
                            catch (Exception ex)
                            {
                                _logger.LogWarning(ex, "Failed to load setting '{Key}'", key);
                                return null;
                            }
                        }

                        public async Task SetValueAsync(string key, string value)
                        {
                            try
                            {
                                var existing = await _context.SiteSettings
                                    .FirstOrDefaultAsync(s => s.Key == key);

                                if (existing != null)
                                {
                                    existing.Value = value;
                                    existing.UpdatedAt = DateTime.UtcNow;
                                    _context.SiteSettings.Update(existing);
                                }
                                else
                                {
                                    var newSetting = new SiteSettings
                                    {
                                        Key = key,
                                        Value = value,
                                        CreatedAt = DateTime.UtcNow
                                    };
                                    _context.SiteSettings.Add(newSetting);
                                }

                                await _context.SaveChangesAsync();
                                _logger.LogInformation("Setting '{Key}' saved successfully", key);
                            }
                            catch (Exception ex)
                            {
                                _logger.LogError(ex, "Failed to save setting '{Key}'", key);
                                throw;
                            }
                        }
                    }