import { useState, useEffect } from 'react';
import {
  Box,
  Paper,
  Typography,
  TextField,
  Button,
  Alert,
  CircularProgress,
  Divider,
  FormControlLabel,
  Checkbox,
  Grid,
} from '@mui/material';
import { Save, Send } from '@mui/icons-material';
import api from '../services/api';

function Settings() {
  const [settings, setSettings] = useState({
    base_url: '',
    frontend_url: '',
    cors_enabled: false,
    gmail_user: '',
    gmail_app_password: '',
    gmail_from_name: '',
    telegram_bot_token: '',
    telegram_chat_id: '',
    ollama_server_url: '',
    ollama_model: '',
  });
  const [adminInfo, setAdminInfo] = useState({
    username: '',
    current_password: '',
    new_password: '',
    confirm_password: '',
  });
  const [loading, setLoading] = useState(true);
  const [testLoading, setTestLoading] = useState({ mail: false, telegram: false, ollama: false });
  const [alerts, setAlerts] = useState({ mail: null, telegram: null, ollama: null, admin: null });
  const [ollamaModels, setOllamaModels] = useState([]);
  const [adminSaving, setAdminSaving] = useState(false);

  useEffect(() => {
    loadSettings();
    loadAdminInfo();
  }, []);

  const loadSettings = async () => {
    try {
      const response = await api.get('/api/settings');
      const data = response.data.data || {};
      
      // Convert array to object
      const settingsObj = {};
      if (Array.isArray(data)) {
        data.forEach(item => {
          settingsObj[item.key] = item.value === '********' ? '' : item.value;
        });
      }
      
      setSettings({
        base_url: settingsObj.base_url || '',
        frontend_url: settingsObj.frontend_url || '',
        cors_enabled: settingsObj.cors_enabled === 'true',
        gmail_user: settingsObj.gmail_user || '',
        gmail_app_password: settingsObj.gmail_password || '',
        gmail_from_name: settingsObj.gmail_from_name || '',
        telegram_bot_token: settingsObj.telegram_bot_token || '',
        telegram_chat_id: settingsObj.telegram_chat_id || '',
        ollama_server_url: settingsObj.ollama_server_url || '',
        ollama_model: settingsObj.ollama_model || '',
      });
    } catch (error) {
      console.error('Failed to load settings:', error);
    } finally {
      setLoading(false);
    }
  };

  const loadAdminInfo = async () => {
    try {
      const response = await api.get('/api/settings/admin');
      if (response.data.success && response.data.data) {
        setAdminInfo({
          username: response.data.data.username || '',
          current_password: '',
          new_password: '',
          confirm_password: '',
        });
      }
    } catch (error) {
      console.error('Failed to load admin info:', error);
    }
  };

  const handleSave = async () => {
    try {
      await Promise.all([
        api.put('/api/settings/system', {
          base_url: settings.base_url,
          frontend_url: settings.frontend_url,
          cors_enabled: settings.cors_enabled,
        }, { withCredentials: true }),
        api.put('/api/settings/gmail', {
          gmail_user: settings.gmail_user,
          gmail_app_password: settings.gmail_app_password,
          gmail_from_name: settings.gmail_from_name,
        }, { withCredentials: true }),
        api.put('/api/settings/telegram', {
          telegram_bot_token: settings.telegram_bot_token,
          telegram_chat_id: settings.telegram_chat_id,
        }, { withCredentials: true }),
        api.put('/api/ollama/settings', {
          ollama_server_url: settings.ollama_server_url,
          ollama_model: settings.ollama_model,
        }, { withCredentials: true }),
      ]);
      alert('Ayarlar kaydedildi!');
    } catch (error) {
      console.error('Failed to save settings:', error);
      alert('Ayarlar kaydedilemedi: ' + (error.response?.data?.error || error.message));
    }
  };

  const handleTestMail = async () => {
    setTestLoading({ ...testLoading, mail: true });
    try {
      const response = await api.post('/api/settings/test-gmail', {});
      setAlerts({ ...alerts, mail: { severity: 'success', message: response.data.message } });
    } catch (error) {
      setAlerts({
        ...alerts,
        mail: { severity: 'error', message: error.response?.data?.error || 'Test başarısız' },
      });
    } finally {
      setTestLoading({ ...testLoading, mail: false });
    }
  };

  const handleTestTelegram = async () => {
    setTestLoading({ ...testLoading, telegram: true });
    try {
      const response = await api.post('/api/settings/test-telegram', {});
      setAlerts({ ...alerts, telegram: { severity: 'success', message: response.data.message } });
    } catch (error) {
      setAlerts({
        ...alerts,
        telegram: {
          severity: 'error',
          message: error.response?.data?.error || 'Test başarısız',
        },
      });
    } finally {
      setTestLoading({ ...testLoading, telegram: false });
    }
  };

  const handleTestOllama = async () => {
    setTestLoading({ ...testLoading, ollama: true });
    setAlerts({ ...alerts, ollama: null });

    try {
      // First save the settings if they are filled
      if (settings.ollama_server_url && settings.ollama_model) {
        await axios.put(`${API_URL}/api/ollama/settings`, {
          ollama_server_url: settings.ollama_server_url,
          ollama_model: settings.ollama_model,
        }, { withCredentials: true });
      }

      const response = await api.get('/api/ollama/test');

      if (response.data.success) {
        setOllamaModels(response.data.data.models || []);
        setAlerts({
          ...alerts,
          ollama: { 
            severity: 'success', 
            message: `${response.data.message} - ${response.data.data.models.length} model bulundu` 
          },
        });
      } else {
        setAlerts({
          ...alerts,
          ollama: { severity: 'error', message: response.data.message },
        });
      }
    } catch (error) {
      setAlerts({
        ...alerts,
        ollama: {
          severity: 'error',
          message: error.response?.data?.error || 'Ollama bağlantısı başarısız',
        },
      });
    } finally {
      setTestLoading({ ...testLoading, ollama: false });
    }
  };

  const handleSaveAdmin = async () => {
    setAdminSaving(true);
    setAlerts({ ...alerts, admin: null });

    try {
      const updateData = {};
      
      // Only include fields that are being changed
      if (adminInfo.username && adminInfo.username.trim() !== '') {
        updateData.username = adminInfo.username.trim();
      }
      
      if (adminInfo.new_password) {
        updateData.new_password = adminInfo.new_password;
        updateData.confirm_password = adminInfo.confirm_password;
        updateData.current_password = adminInfo.current_password;
      }

      const response = await api.put('/api/settings/admin', updateData);

      if (response.data.success) {
        setAlerts({
          ...alerts,
          admin: { severity: 'success', message: response.data.message || 'Admin bilgileri güncellendi' },
        });
        
        // Clear password fields
        setAdminInfo({
          ...adminInfo,
          current_password: '',
          new_password: '',
          confirm_password: '',
        });
        
        // Reload admin info to get updated username
        await loadAdminInfo();
      }
    } catch (error) {
      setAlerts({
        ...alerts,
        admin: {
          severity: 'error',
          message: error.response?.data?.error || 'Admin bilgileri güncellenemedi',
        },
      });
    } finally {
      setAdminSaving(false);
    }
  };

  if (loading) {
    return (
      <Box display="flex" justifyContent="center" alignItems="center" minHeight="400px">
        <CircularProgress />
      </Box>
    );
  }

  return (
    <Box>
      <Typography variant="h4" gutterBottom>
        Sistem Ayarları
      </Typography>

      <Grid container spacing={3}>
        {/* System Settings */}
        <Grid size={12}>
          <Paper sx={{ p: 3 }}>
            <Typography variant="h6" gutterBottom>
              🌐 Genel Ayarlar
            </Typography>
            <Typography variant="body2" color="text.secondary" gutterBottom>
              Domain ve genel sistem ayarları
            </Typography>

            <Typography variant="body2" color="text.secondary" sx={{ mb: 2 }}>
              <strong>Tek Domain (Önerilen):</strong> Frontend ve backend aynı domainde, path ile ayrılır<br/>
              <strong>İki Domain:</strong> Frontend ve backend farklı domainlerde (CORS gerekir)
            </Typography>

            <FormControlLabel
              control={
                <Checkbox
                  checked={settings.cors_enabled}
                  onChange={(e) =>
                    setSettings({ ...settings, cors_enabled: e.target.checked })
                  }
                />
              }
              label="İki Ayrı Domain Kullan (CORS Aktif Et)"
            />

            <TextField
              fullWidth
              margin="normal"
              label={settings.cors_enabled ? "Backend Domain (Base URL)" : "Domain (Base URL)"}
              type="url"
              placeholder="https://yourdomain.com"
              value={settings.base_url}
              onChange={(e) =>
                setSettings({ ...settings, base_url: e.target.value })
              }
              helperText={
                settings.cors_enabled
                  ? "Backend API domain'i. Örnek: https://api.yourdomain.com"
                  : "Hem frontend hem backend için kullanılacak domain. Örnek: https://yourdomain.com"
              }
            />

            {settings.cors_enabled && (
              <TextField
                fullWidth
                margin="normal"
                label="Frontend Domain"
                type="url"
                placeholder="https://panel.yourdomain.com"
                value={settings.frontend_url}
                onChange={(e) =>
                  setSettings({ ...settings, frontend_url: e.target.value })
                }
                helperText="Frontend panel domain'i. CORS için gerekli."
              />
            )}
          </Paper>
        </Grid>

        {/* Gmail Settings */}
        <Grid size={{ xs: 12, md: 6 }}>
          <Paper sx={{ p: 3 }}>
            <Typography variant="h6" gutterBottom>
              📧 Gmail Ayarları
            </Typography>
            <Typography variant="body2" color="text.secondary" gutterBottom>
              Gmail App Password kullanın (2FA aktif olmalı)
            </Typography>

            <TextField
              fullWidth
              margin="normal"
              label="Gmail Adresi"
              type="email"
              value={settings.gmail_user}
              onChange={(e) =>
                setSettings({ ...settings, gmail_user: e.target.value })
              }
            />
            <TextField
              fullWidth
              margin="normal"
              label="App Password"
              type="password"
              value={settings.gmail_app_password}
              onChange={(e) =>
                setSettings({ ...settings, gmail_app_password: e.target.value })
              }
              helperText="Google Hesap → Güvenlik → 2FA → Uygulama Şifreleri"
            />
            <TextField
              fullWidth
              margin="normal"
              label="Gönderen Adı (Varsayılan)"
              value={settings.gmail_from_name}
              onChange={(e) =>
                setSettings({ ...settings, gmail_from_name: e.target.value })
              }
              placeholder="Güvenlik Ekibi"
              helperText="Mail gönderirken görünecek varsayılan isim"
            />

            {alerts.mail && (
              <Alert severity={alerts.mail.severity} sx={{ mt: 2 }}>
                {alerts.mail.message}
              </Alert>
            )}

            <Box mt={2} display="flex" gap={2}>
              <Button
                variant="contained"
                startIcon={<Save />}
                onClick={handleSave}
              >
                Kaydet
              </Button>
              <Button
                variant="outlined"
                startIcon={<Send />}
                onClick={handleTestMail}
                disabled={testLoading.mail}
              >
                Test Mail Gönder
              </Button>
            </Box>
          </Paper>
        </Grid>

        <Grid size={{ xs: 12, md: 6 }}>
          <Paper sx={{ p: 3 }}>
            <Typography variant="h6" gutterBottom>
              Telegram Ayarları
            </Typography>
            <Typography variant="body2" color="text.secondary" gutterBottom>
              @BotFather'dan bot token alın, @userinfobot'dan chat ID öğrenin
            </Typography>

            <TextField
              fullWidth
              margin="normal"
              label="Bot Token"
              type="password"
              value={settings.telegram_bot_token}
              onChange={(e) =>
                setSettings({ ...settings, telegram_bot_token: e.target.value })
              }
            />
            <TextField
              fullWidth
              margin="normal"
              label="Chat ID"
              value={settings.telegram_chat_id}
              onChange={(e) =>
                setSettings({ ...settings, telegram_chat_id: e.target.value })
              }
            />

            {alerts.telegram && (
              <Alert severity={alerts.telegram.severity} sx={{ mt: 2 }}>
                {alerts.telegram.message}
              </Alert>
            )}

            <Box mt={2} display="flex" gap={2}>
              <Button
                variant="contained"
                startIcon={<Save />}
                onClick={handleSave}
              >
                Kaydet
              </Button>
              <Button
                variant="outlined"
                startIcon={<Send />}
                onClick={handleTestTelegram}
                disabled={testLoading.telegram}
              >
                Test Bildirimi
              </Button>
            </Box>
          </Paper>
        </Grid>

        {/* Admin User Settings */}
        <Grid size={12}>
          <Paper sx={{ p: 3 }}>
            <Typography variant="h6" gutterBottom>
              🔐 Admin Kullanıcı Bilgileri
            </Typography>
            <Typography variant="body2" color="text.secondary" gutterBottom>
              Kullanıcı adı ve şifrenizi değiştirebilirsiniz
            </Typography>

            <TextField
              fullWidth
              margin="normal"
              label="Kullanıcı Adı"
              value={adminInfo.username}
              onChange={(e) =>
                setAdminInfo({ ...adminInfo, username: e.target.value })
              }
              helperText="En az 3 karakter olmalıdır"
            />

            <Divider sx={{ my: 2 }} />
            <Typography variant="subtitle2" gutterBottom>
              Şifre Değiştir (Opsiyonel)
            </Typography>

            <TextField
              fullWidth
              margin="normal"
              label="Mevcut Şifre"
              type="password"
              value={adminInfo.current_password}
              onChange={(e) =>
                setAdminInfo({ ...adminInfo, current_password: e.target.value })
              }
              helperText="Yeni şifre belirlemek için mevcut şifrenizi girin"
            />

            <TextField
              fullWidth
              margin="normal"
              label="Yeni Şifre"
              type="password"
              value={adminInfo.new_password}
              onChange={(e) =>
                setAdminInfo({ ...adminInfo, new_password: e.target.value })
              }
              helperText="En az 8 karakter olmalıdır"
            />

            <TextField
              fullWidth
              margin="normal"
              label="Yeni Şifre (Tekrar)"
              type="password"
              value={adminInfo.confirm_password}
              onChange={(e) =>
                setAdminInfo({ ...adminInfo, confirm_password: e.target.value })
              }
              helperText="Yeni şifreyi tekrar girin"
            />

            {alerts.admin && (
              <Alert severity={alerts.admin.severity} sx={{ mt: 2 }}>
                {alerts.admin.message}
              </Alert>
            )}

            <Box mt={2}>
              <Button
                variant="contained"
                startIcon={adminSaving ? <CircularProgress size={20} /> : <Save />}
                onClick={handleSaveAdmin}
                disabled={adminSaving}
              >
                {adminSaving ? 'Kaydediliyor...' : 'Admin Bilgilerini Kaydet'}
              </Button>
            </Box>
          </Paper>
        </Grid>

        {/* Ollama Settings */}
        <Grid size={12}>
          <Paper sx={{ p: 3 }}>
            <Typography variant="h6" gutterBottom>
              🤖 Ollama AI Ayarları
            </Typography>
            <Typography variant="body2" color="text.secondary" gutterBottom>
              AI ile mail şablonu oluşturmak için Ollama yapılandırması
            </Typography>

            <TextField
              fullWidth
              margin="normal"
              label="Ollama Server URL"
              type="url"
              placeholder="http://localhost:11434"
              value={settings.ollama_server_url}
              onChange={(e) =>
                setSettings({ ...settings, ollama_server_url: e.target.value })
              }
              helperText="Ollama sunucu adresi (varsayılan: http://localhost:11434)"
            />

            <TextField
              fullWidth
              margin="normal"
              label="Model"
              placeholder="llama3.2"
              value={settings.ollama_model}
              onChange={(e) =>
                setSettings({ ...settings, ollama_model: e.target.value })
              }
              helperText="Kullanılacak Ollama model adı (örn: llama3.2, mistral, gemma)"
            />

            {alerts.ollama && (
              <Alert severity={alerts.ollama.severity} sx={{ mt: 2 }}>
                {alerts.ollama.message}
              </Alert>
            )}

            {ollamaModels.length > 0 && (
              <Alert severity="info" sx={{ mt: 2 }}>
                <Typography variant="body2" fontWeight="bold">
                  Mevcut Modeller (tıklayarak seçin):
                </Typography>
                {ollamaModels.map((model, idx) => (
                  <Typography 
                    key={idx} 
                    variant="body2"
                    sx={{ 
                      cursor: 'pointer', 
                      '&:hover': { backgroundColor: 'action.hover' },
                      p: 0.5,
                      borderRadius: 1,
                    }}
                    onClick={() => setSettings({ ...settings, ollama_model: model.name })}
                  >
                    • {model.name} ({(model.size / 1024 / 1024 / 1024).toFixed(1)} GB)
                  </Typography>
                ))}
              </Alert>
            )}

            <Box mt={2} display="flex" gap={2}>
              <Button
                variant="contained"
                startIcon={<Save />}
                onClick={handleSave}
              >
                Kaydet
              </Button>
              <Button
                variant="outlined"
                startIcon={<Send />}
                onClick={handleTestOllama}
                disabled={testLoading.ollama}
              >
                {testLoading.ollama ? <CircularProgress size={20} /> : 'Bağlantıyı Test Et'}
              </Button>
            </Box>
          </Paper>
        </Grid>
      </Grid>

      <Paper sx={{ p: 3, mt: 3 }}>
        <Typography variant="h6" gutterBottom>
          Tracking URL Bilgisi
        </Typography>
        <Divider sx={{ my: 2 }} />
        <Typography variant="body2" color="text.secondary">
          Tracking URL formatı: <strong>http://your-domain.com/t/TOKEN</strong>
        </Typography>
        <Typography variant="body2" color="text.secondary" mt={1}>
          Bu URL'ler mail şablonlarında otomatik olarak oluşturulur ve gönderilir.
        </Typography>
      </Paper>
    </Box>
  );
}

export default Settings;