/**
 * PreferencesForm Component
 * User notification preferences management
 */

import React, { useState, useEffect } from 'react';

interface NotificationPreferences {
  email: boolean;
  push: boolean;
  inApp: boolean;
  plantReminders: boolean;
  transportAlerts: boolean;
  farmAlerts: boolean;
  harvestAlerts: boolean;
  demandMatches: boolean;
  weeklyDigest: boolean;
  quietHoursStart?: string;
  quietHoursEnd?: string;
  timezone?: string;
}

interface PreferencesFormProps {
  userId?: string;
  onSave?: (preferences: NotificationPreferences) => void;
}

export function PreferencesForm({ userId = 'demo-user', onSave }: PreferencesFormProps) {
  const [preferences, setPreferences] = useState<NotificationPreferences>({
    email: true,
    push: true,
    inApp: true,
    plantReminders: true,
    transportAlerts: true,
    farmAlerts: true,
    harvestAlerts: true,
    demandMatches: true,
    weeklyDigest: true
  });
  const [isLoading, setIsLoading] = useState(true);
  const [isSaving, setIsSaving] = useState(false);
  const [message, setMessage] = useState<{ type: 'success' | 'error'; text: string } | null>(null);

  useEffect(() => {
    fetchPreferences();
  }, [userId]);

  async function fetchPreferences() {
    try {
      const response = await fetch(`/api/notifications/preferences?userId=${userId}`);
      const data = await response.json();

      if (data.success) {
        setPreferences(data.data);
      }
    } catch (error) {
      console.error('Failed to fetch preferences:', error);
    } finally {
      setIsLoading(false);
    }
  }

  async function handleSubmit(e: React.FormEvent) {
    e.preventDefault();
    setIsSaving(true);
    setMessage(null);

    try {
      const response = await fetch('/api/notifications/preferences', {
        method: 'PUT',
        headers: { 'Content-Type': 'application/json' },
        body: JSON.stringify({ ...preferences, userId })
      });

      const data = await response.json();

      if (data.success) {
        setMessage({ type: 'success', text: 'Preferences saved successfully!' });
        onSave?.(data.data);
      } else {
        setMessage({ type: 'error', text: data.error || 'Failed to save preferences' });
      }
    } catch (error) {
      setMessage({ type: 'error', text: 'Failed to save preferences' });
    } finally {
      setIsSaving(false);
    }
  }

  function handleToggle(key: keyof NotificationPreferences) {
    setPreferences(prev => ({
      ...prev,
      [key]: !prev[key]
    }));
  }

  if (isLoading) {
    return (
      <div className="p-8 text-center">
        <div className="inline-block animate-spin rounded-full h-8 w-8 border-4 border-gray-200 border-t-green-500"></div>
        <p className="mt-2 text-gray-500">Loading preferences...</p>
      </div>
    );
  }

  return (
    <form onSubmit={handleSubmit} className="space-y-6">
      {message && (
        <div
          className={`p-4 rounded-lg ${
            message.type === 'success' ? 'bg-green-50 text-green-800' : 'bg-red-50 text-red-800'
          }`}
        >
          {message.text}
        </div>
      )}

      {/* Notification Channels */}
      <div className="bg-white p-6 rounded-lg border">
        <h3 className="text-lg font-semibold text-gray-900 mb-4">Notification Channels</h3>
        <p className="text-sm text-gray-600 mb-4">Choose how you want to receive notifications</p>

        <div className="space-y-4">
          <ToggleRow
            label="Email notifications"
            description="Receive notifications via email"
            enabled={preferences.email}
            onChange={() => handleToggle('email')}
          />
          <ToggleRow
            label="Push notifications"
            description="Receive browser push notifications"
            enabled={preferences.push}
            onChange={() => handleToggle('push')}
          />
          <ToggleRow
            label="In-app notifications"
            description="See notifications in the app"
            enabled={preferences.inApp}
            onChange={() => handleToggle('inApp')}
          />
        </div>
      </div>

      {/* Notification Types */}
      <div className="bg-white p-6 rounded-lg border">
        <h3 className="text-lg font-semibold text-gray-900 mb-4">Notification Types</h3>
        <p className="text-sm text-gray-600 mb-4">Choose which types of notifications you want to receive</p>

        <div className="space-y-4">
          <ToggleRow
            label="Plant reminders"
            description="Reminders for watering, fertilizing, and plant care"
            enabled={preferences.plantReminders}
            onChange={() => handleToggle('plantReminders')}
          />
          <ToggleRow
            label="Transport alerts"
            description="Updates about plant transport and logistics"
            enabled={preferences.transportAlerts}
            onChange={() => handleToggle('transportAlerts')}
          />
          <ToggleRow
            label="Farm alerts"
            description="Alerts about vertical farm conditions and issues"
            enabled={preferences.farmAlerts}
            onChange={() => handleToggle('farmAlerts')}
          />
          <ToggleRow
            label="Harvest alerts"
            description="Notifications when crops are ready for harvest"
            enabled={preferences.harvestAlerts}
            onChange={() => handleToggle('harvestAlerts')}
          />
          <ToggleRow
            label="Demand matches"
            description="Alerts when your supply matches consumer demand"
            enabled={preferences.demandMatches}
            onChange={() => handleToggle('demandMatches')}
          />
          <ToggleRow
            label="Weekly digest"
            description="Weekly summary of your activity and insights"
            enabled={preferences.weeklyDigest}
            onChange={() => handleToggle('weeklyDigest')}
          />
        </div>
      </div>

      {/* Quiet Hours */}
      <div className="bg-white p-6 rounded-lg border">
        <h3 className="text-lg font-semibold text-gray-900 mb-4">Quiet Hours</h3>
        <p className="text-sm text-gray-600 mb-4">Set times when you don't want to receive notifications</p>

        <div className="grid grid-cols-2 gap-4">
          <div>
            <label className="block text-sm font-medium text-gray-700 mb-1">Start time</label>
            <input
              type="time"
              value={preferences.quietHoursStart || ''}
              onChange={e =>
                setPreferences(prev => ({ ...prev, quietHoursStart: e.target.value }))
              }
              className="w-full px-3 py-2 border border-gray-300 rounded-lg focus:ring-2 focus:ring-green-500 focus:border-green-500"
            />
          </div>
          <div>
            <label className="block text-sm font-medium text-gray-700 mb-1">End time</label>
            <input
              type="time"
              value={preferences.quietHoursEnd || ''}
              onChange={e =>
                setPreferences(prev => ({ ...prev, quietHoursEnd: e.target.value }))
              }
              className="w-full px-3 py-2 border border-gray-300 rounded-lg focus:ring-2 focus:ring-green-500 focus:border-green-500"
            />
          </div>
        </div>

        <div className="mt-4">
          <label className="block text-sm font-medium text-gray-700 mb-1">Timezone</label>
          <select
            value={preferences.timezone || ''}
            onChange={e => setPreferences(prev => ({ ...prev, timezone: e.target.value }))}
            className="w-full px-3 py-2 border border-gray-300 rounded-lg focus:ring-2 focus:ring-green-500 focus:border-green-500"
          >
            <option value="">Select timezone</option>
            <option value="America/New_York">Eastern Time</option>
            <option value="America/Chicago">Central Time</option>
            <option value="America/Denver">Mountain Time</option>
            <option value="America/Los_Angeles">Pacific Time</option>
            <option value="Europe/London">London</option>
            <option value="Europe/Paris">Paris</option>
            <option value="Asia/Tokyo">Tokyo</option>
            <option value="UTC">UTC</option>
          </select>
        </div>
      </div>

      {/* Submit */}
      <div className="flex justify-end">
        <button
          type="submit"
          disabled={isSaving}
          className="px-6 py-2 bg-green-600 text-white rounded-lg hover:bg-green-700 focus:ring-2 focus:ring-green-500 focus:ring-offset-2 disabled:opacity-50 disabled:cursor-not-allowed transition-colors"
        >
          {isSaving ? 'Saving...' : 'Save Preferences'}
        </button>
      </div>
    </form>
  );
}

interface ToggleRowProps {
  label: string;
  description: string;
  enabled: boolean;
  onChange: () => void;
}

function ToggleRow({ label, description, enabled, onChange }: ToggleRowProps) {
  return (
    <div className="flex items-center justify-between">
      <div>
        <p className="font-medium text-gray-900">{label}</p>
        <p className="text-sm text-gray-500">{description}</p>
      </div>
      <button
        type="button"
        role="switch"
        aria-checked={enabled}
        onClick={onChange}
        className={`relative inline-flex h-6 w-11 flex-shrink-0 cursor-pointer rounded-full border-2 border-transparent transition-colors duration-200 ease-in-out focus:outline-none focus:ring-2 focus:ring-green-500 focus:ring-offset-2 ${
          enabled ? 'bg-green-600' : 'bg-gray-200'
        }`}
      >
        <span
          className={`pointer-events-none inline-block h-5 w-5 transform rounded-full bg-white shadow ring-0 transition duration-200 ease-in-out ${
            enabled ? 'translate-x-5' : 'translate-x-0'
          }`}
        />
      </button>
    </div>
  );
}