import { router } from "expo-router";
import { useState } from "react";
import {
  KeyboardAvoidingView,
  Platform,
  Pressable,
  ScrollView,
  StyleSheet,
  Text,
  View,
} from "react-native";
import { FullScreen } from "@/components/Screen";
import { AuthBackground } from "@/components/AppBackground";
import { AuthServerPicker } from "@/components/AuthServerPicker";
import { HeadingText, Logo } from "@/components/Logo";
import { Button } from "@/components/ui/Button";
import { Card } from "@/components/ui/Card";
import { Input } from "@/components/ui/Input";
import { fonts, spacing } from "@/constants/theme";
import { useAppTheme } from "@/contexts/ThemeContext";
import { requestPasswordReset } from "@/lib/auth-api";
import { isValidEmail, useFieldVisibility } from "@/lib/form-validation";

export default function ForgotPasswordScreen() {
  const { colors } = useAppTheme();
  const [email, setEmail] = useState("");
  const [message, setMessage] = useState<string | null>(null);
  const [error, setError] = useState<string | null>(null);
  const [loading, setLoading] = useState(false);
  const [serverReady, setServerReady] = useState(true);
  const { touch, visible, markSubmitted } = useFieldVisibility();

  const emailValidationError = !email.trim()
    ? "Email is required"
    : isValidEmail(email)
      ? undefined
      : "Enter a valid email";
  const canSubmit = isValidEmail(email) && serverReady;

  async function handleSubmit() {
    markSubmitted();
    if (!canSubmit) return;
    setError(null);
    setMessage(null);
    setLoading(true);

    try {
      const result = await requestPasswordReset(email.trim());
      setMessage(result);
    } catch (err) {
      setError(err instanceof Error ? err.message : "Request failed");
    } finally {
      setLoading(false);
    }
  }

  return (
    <AuthBackground>
      <FullScreen style={styles.safe}>
        <KeyboardAvoidingView
          behavior={Platform.OS === "ios" ? "padding" : undefined}
          style={styles.flex}
        >
          <ScrollView contentContainerStyle={styles.container}>
            <Pressable onPress={() => router.back()}>
              <Text style={[styles.back, { color: colors.mutedForeground }]}>← Back</Text>
            </Pressable>

            <AuthServerPicker onReadyChange={setServerReady} />

            <Card style={styles.card}>
              <View style={styles.header}>
                <Logo size="md" />
                <HeadingText style={styles.title}>Reset password</HeadingText>
                <Text style={[styles.subtitle, { color: colors.mutedForeground }]}>
                  Enter your email and we&apos;ll send reset instructions if an account exists.
                </Text>
              </View>

              <View style={styles.form}>
                <Input
                  label="Email"
                  autoCapitalize="none"
                  autoComplete="email"
                  keyboardType="email-address"
                  value={email}
                  onChangeText={setEmail}
                  onBlur={() => touch("email")}
                  placeholder="you@example.com"
                  required
                  error={visible("email") ? emailValidationError : undefined}
                />

                {error ? (
                  <Text style={[styles.error, { color: colors.destructive }]}>{error}</Text>
                ) : null}
                {message ? (
                  <Text style={[styles.success, { color: colors.foreground }]}>{message}</Text>
                ) : null}

                <Button
                  title="Send reset link"
                  loading={loading}
                  disabled={!canSubmit}
                  onPress={handleSubmit}
                />
                <Button
                  title="Have a reset token?"
                  variant="ghost"
                  onPress={() => router.push("/(auth)/reset-password")}
                />
              </View>
            </Card>
          </ScrollView>
        </KeyboardAvoidingView>
      </FullScreen>
    </AuthBackground>
  );
}

const styles = StyleSheet.create({
  safe: { flex: 1 },
  flex: { flex: 1 },
  container: {
    flexGrow: 1,
    padding: spacing.lg,
    paddingBottom: spacing.md,
    gap: spacing.md,
    justifyContent: "center",
  },
  back: {
    fontFamily: fonts.bodyMedium,
    fontSize: 16,
    marginBottom: spacing.sm,
  },
  card: { gap: spacing.lg },
  header: { gap: spacing.sm },
  title: { fontSize: 28 },
  subtitle: {
    fontSize: 14,
    fontFamily: fonts.body,
    lineHeight: 20,
  },
  form: { gap: spacing.md },
  error: {
    fontSize: 14,
    fontFamily: fonts.body,
  },
  success: {
    fontSize: 14,
    fontFamily: fonts.body,
    lineHeight: 20,
  },
});