import React, { useState, useCallback, useEffect } from 'react';
import {
  View,
  Text,
  StyleSheet,
  KeyboardAvoidingView,
  Platform,
  ScrollView,
  TouchableOpacity,
} from 'react-native';
import { router, useLocalSearchParams } from 'expo-router';
import { Ionicons } from '@expo/vector-icons';
import { Button } from '@/components/ui/Button';
import { Input } from '@/components/ui/Input';
import { ErrorMessage } from '@/components/ui/ErrorMessage';
import { AppColors, BorderRadius, FontSizes, Spacing } from '@/constants/theme';
import { api } from '@/services/api';

export default function EnterNameScreen() {
  const params = useLocalSearchParams<{ email: string; inviteCode: string }>();

  const email = params.email || '';
  const inviteCode = params.inviteCode || '';

  const [firstName, setFirstName] = useState('');
  const [lastName, setLastName] = useState('');
  const [isLoading, setIsLoading] = useState(false);
  const [error, setError] = useState<string | null>(null);

  const handleContinue = useCallback(async () => {
    setError(null);

    const trimmedFirstName = firstName.trim();
    const trimmedLastName = lastName.trim();

    if (!trimmedFirstName) {
      setError('Please enter your first name');
      return;
    }

    setIsLoading(true);

    try {
      // Update profile with name via API
      const response = await api.updateProfile({
        firstName: trimmedFirstName,
        lastName: trimmedLastName || undefined,
      });

      if (!response.ok) {
        throw new Error(response.error?.message || 'Failed to update profile');
      }

      // Navigate to add loved one screen (onboarding step 1)
      router.replace({
        pathname: '/(auth)/add-loved-one',
        params: {
          email,
          inviteCode,
        },
      });
    } catch (err) {
      setError(err instanceof Error ? err.message : 'Failed to save name');
    } finally {
      setIsLoading(false);
    }
  }, [firstName, lastName, email, inviteCode]);

  const handleSkip = () => {
    // Skip entering name and go to add loved one
    router.replace({
      pathname: '/(auth)/add-loved-one',
      params: {
        email,
        inviteCode,
      },
    });
  };

  return (
    <KeyboardAvoidingView
      style={styles.container}
      behavior={Platform.OS === 'ios' ? 'padding' : 'height'}
    >
      <ScrollView
        contentContainerStyle={styles.scrollContent}
        keyboardShouldPersistTaps="handled"
        showsVerticalScrollIndicator={false}
      >
        {/* Skip Button */}
        <View style={styles.headerRow}>
          <View style={{ width: 44 }} />
          <TouchableOpacity style={styles.skipButton} onPress={handleSkip}>
            <Text style={styles.skipText}>Skip</Text>
          </TouchableOpacity>
        </View>

        {/* Icon */}
        <View style={styles.iconContainer}>
          <View style={styles.iconCircle}>
            <Ionicons name="person" size={48} color={AppColors.primary} />
          </View>
        </View>

        {/* Header */}
        <View style={styles.header}>
          <Text style={styles.title}>What's your name?</Text>
          <Text style={styles.subtitle}>
            This helps us personalize your experience
          </Text>
        </View>

        {/* Error Message */}
        {error && (
          <ErrorMessage
            message={error}
            onDismiss={() => setError(null)}
          />
        )}

        {/* Form */}
        <View style={styles.form}>
          <Input
            label="First Name"
            placeholder="Enter your first name"
            leftIcon="person-outline"
            value={firstName}
            onChangeText={(text) => {
              setFirstName(text);
              setError(null);
            }}
            autoCapitalize="words"
            autoCorrect={false}
            editable={!isLoading}
            returnKeyType="next"
          />

          <Input
            label="Last Name (optional)"
            placeholder="Enter your last name"
            leftIcon="person-outline"
            value={lastName}
            onChangeText={setLastName}
            autoCapitalize="words"
            autoCorrect={false}
            editable={!isLoading}
            onSubmitEditing={handleContinue}
            returnKeyType="done"
          />
        </View>

        {/* Continue Button */}
        <View style={styles.buttonContainer}>
          <Button
            title="Continue"
            onPress={handleContinue}
            loading={isLoading}
            fullWidth
            size="lg"
          />
        </View>

        {/* Info */}
        <View style={styles.infoContainer}>
          <Text style={styles.infoText}>
            You can update your name later in settings
          </Text>
        </View>
      </ScrollView>
    </KeyboardAvoidingView>
  );
}

const styles = StyleSheet.create({
  container: {
    flex: 1,
    backgroundColor: AppColors.background,
  },
  scrollContent: {
    flexGrow: 1,
    paddingHorizontal: Spacing.lg,
    paddingTop: Spacing.xl,
    paddingBottom: Spacing.xl,
  },
  headerRow: {
    flexDirection: 'row',
    justifyContent: 'space-between',
    alignItems: 'center',
    marginBottom: Spacing.xl,
  },
  skipButton: {
    paddingVertical: Spacing.sm,
    paddingHorizontal: Spacing.md,
  },
  skipText: {
    fontSize: FontSizes.base,
    color: AppColors.textSecondary,
    fontWeight: '500',
  },
  iconContainer: {
    alignItems: 'center',
    marginBottom: Spacing.xl,
  },
  iconCircle: {
    width: 100,
    height: 100,
    borderRadius: 50,
    backgroundColor: `${AppColors.primary}15`,
    justifyContent: 'center',
    alignItems: 'center',
  },
  header: {
    alignItems: 'center',
    marginBottom: Spacing.xl,
  },
  title: {
    fontSize: FontSizes['2xl'],
    fontWeight: '700',
    color: AppColors.textPrimary,
    marginBottom: Spacing.md,
    textAlign: 'center',
  },
  subtitle: {
    fontSize: FontSizes.base,
    color: AppColors.textSecondary,
    textAlign: 'center',
  },
  form: {
    gap: Spacing.md,
  },
  buttonContainer: {
    marginTop: Spacing.xl,
  },
  infoContainer: {
    alignItems: 'center',
    marginTop: Spacing.lg,
    paddingHorizontal: Spacing.md,
  },
  infoText: {
    fontSize: FontSizes.sm,
    color: AppColors.textMuted,
    textAlign: 'center',
  },
});