import React, { useState } from 'react';
import {
  View,
  StyleSheet,
  KeyboardAvoidingView,
  Platform,
  ScrollView,
} from 'react-native';
import {
  Button,
  Text,
  Surface,
  TextInput,
  Divider,
  HelperText,
} from 'react-native-paper';
import { SafeAreaView } from 'react-native-safe-area-context';
import { useDispatch } from 'react-redux';
import { authApi } from '../../lib/api/auth';
import { setUser, setError, clearError } from '../../store/slices/authSlice';

export function LoginScreen() {
  const dispatch = useDispatch();
  const [loading, setLoading] = useState(false);
  const [email, setEmail] = useState('');
  const [password, setPassword] = useState('');
  const [showPassword, setShowPassword] = useState(false);
  const [localError, setLocalError] = useState('');

  const handleGoogleLogin = async () => {
    setLoading(true);
    setLocalError('');
    dispatch(clearError());
    try {
      const user = await authApi.login();
      dispatch(setUser(user));
    } catch (err) {
      const message =
        err instanceof Error ? err.message : 'Login failed. Please try again.';
      setLocalError(message);
      dispatch(setError(message));
    } finally {
      setLoading(false);
    }
  };

  const handleCredentialLogin = async () => {
    if (!email.trim() || !password) {
      setLocalError('Email and password are required.');
      return;
    }
    setLoading(true);
    setLocalError('');
    dispatch(clearError());
    try {
      const user = await authApi.loginWithCredentials(
        email.trim().toLowerCase(),
        password,
      );
      dispatch(setUser(user));
    } catch (err) {
      const message =
        err instanceof Error ? err.message : 'Login failed. Please try again.';
      setLocalError(message);
      dispatch(setError(message));
    } finally {
      setLoading(false);
    }
  };

  return (
    <SafeAreaView style={styles.container}>
      <KeyboardAvoidingView
        style={styles.flex}
        behavior={Platform.OS === 'ios' ? 'padding' : 'height'}
      >
        <ScrollView
          contentContainerStyle={styles.content}
          keyboardShouldPersistTaps="handled"
        >
          <Surface style={styles.logoContainer} elevation={0}>
            <Text variant="headlineLarge" style={styles.brand}>
              Sea Haven
            </Text>
            <Text variant="titleMedium" style={styles.brandSub}>
              Industries
            </Text>
          </Surface>

          <Text variant="headlineSmall" style={styles.title}>
            Proposal System
          </Text>
          <Text variant="bodyLarge" style={styles.subtitle}>
            Submit and manage proposals from anywhere
          </Text>

          <View style={styles.form}>
            <TextInput
              label="Email"
              value={email}
              onChangeText={setEmail}
              autoCapitalize="none"
              autoComplete="email"
              keyboardType="email-address"
              textContentType="emailAddress"
              mode="outlined"
              disabled={loading}
              style={styles.input}
            />
            <TextInput
              label="Password"
              value={password}
              onChangeText={setPassword}
              secureTextEntry={!showPassword}
              autoCapitalize="none"
              autoComplete="password"
              textContentType="password"
              mode="outlined"
              disabled={loading}
              style={styles.input}
              right={
                <TextInput.Icon
                  icon={showPassword ? 'eye-off' : 'eye'}
                  onPress={() => setShowPassword(!showPassword)}
                />
              }
            />

            {localError ? (
              <HelperText type="error" visible>
                {localError}
              </HelperText>
            ) : null}

            <Button
              mode="contained"
              onPress={handleCredentialLogin}
              loading={loading}
              disabled={loading}
              contentStyle={styles.buttonContent}
              style={styles.button}
            >
              Sign In
            </Button>
          </View>

          <View style={styles.dividerRow}>
            <Divider style={styles.dividerLine} />
            <Text variant="bodySmall" style={styles.dividerText}>
              OR
            </Text>
            <Divider style={styles.dividerLine} />
          </View>

          <Button
            mode="outlined"
            icon="google"
            onPress={handleGoogleLogin}
            loading={loading}
            disabled={loading}
            contentStyle={styles.buttonContent}
            style={styles.button}
          >
            Sign in with Google
          </Button>

          <Text variant="bodySmall" style={styles.footer}>
            Use your Sea Haven email to sign in
          </Text>
        </ScrollView>
      </KeyboardAvoidingView>
    </SafeAreaView>
  );
}

const styles = StyleSheet.create({
  container: {
    flex: 1,
    backgroundColor: '#FAFAFA',
  },
  flex: {
    flex: 1,
  },
  content: {
    flexGrow: 1,
    justifyContent: 'center',
    alignItems: 'center',
    paddingHorizontal: 32,
    paddingVertical: 24,
  },
  logoContainer: {
    alignItems: 'center',
    marginBottom: 32,
    backgroundColor: 'transparent',
  },
  brand: {
    fontWeight: '800',
    color: '#1565C0',
  },
  brandSub: {
    color: '#757575',
    marginTop: -4,
  },
  title: {
    fontWeight: '700',
    color: '#212121',
    marginBottom: 8,
  },
  subtitle: {
    color: '#757575',
    textAlign: 'center',
    marginBottom: 32,
  },
  form: {
    width: '100%',
  },
  input: {
    marginBottom: 12,
  },
  buttonContent: {
    paddingVertical: 8,
  },
  button: {
    borderRadius: 8,
    width: '100%',
  },
  dividerRow: {
    flexDirection: 'row',
    alignItems: 'center',
    width: '100%',
    marginVertical: 20,
  },
  dividerLine: {
    flex: 1,
  },
  dividerText: {
    color: '#9E9E9E',
    marginHorizontal: 16,
  },
  footer: {
    color: '#9E9E9E',
    marginTop: 24,
  },
});