import React, { useEffect } from "react";
import {
  Text,
  View,
  TextInput,
  StyleSheet,
  TouchableOpacity,
  TouchableWithoutFeedback,
  Keyboard,
  KeyboardAvoidingView,
  StatusBar,
} from "react-native";
import { useRouter } from "expo-router";
import { Formik } from "formik";
import * as Yup from "yup";
import { sendOTP, clearSendOTPError } from "../../store/authSlice";
import { useDispatch } from "react-redux";
import { AppDispatch } from "../../store";
import { useSelector } from "react-redux";
import { RootState } from "../../store";
import { AUTH_STATUSES } from "@/constants/config";

// type VerifyOTPNavigationProp = StackNavigationProp<
//   RootStackParamList,
//   "VerifyOTP"
// >;

// import OTPInputView from "@twotalltotems/react-native-otp-input";
//handleblue => when input field looses focus (mark as touched)
// handleBlur marks the field as touched, when field looses focus
export default function WelcomeScreen() {
  const {
    status,
    otpId,
    phone: phoneNumber,
    sendOTPError,
  } = useSelector((state: RootState) => state.auth);

  const dispatch = useDispatch<AppDispatch>();
  const router = useRouter();

  const phoneValidationSchema = Yup.object().shape({
    phone: Yup.string()
      .required("Phone number is required")
      .matches(/^\d{10}$/, "Phone number must be exactly 10 digits"),
  });

  useEffect(() => {
    if (status === AUTH_STATUSES.SUCCESS && otpId) {
      router.push({
        pathname: "/auth/verifyOtp",
        params: { otpId, phoneNumber },
      });
    }
  }, [status, otpId, router]);

  return (
    <KeyboardAvoidingView style={styles.container} behavior="padding">
      <StatusBar barStyle="dark-content" backgroundColor="#F3F5F8" />
      <TouchableWithoutFeedback onPress={Keyboard.dismiss}>
        <View style={styles.inner}>
          <Text style={styles.title}>Welcome to Driver Saathi</Text>

          <Formik
            initialValues={{ phone: "" }}
            onSubmit={(values) => dispatch(sendOTP({ phone: values.phone }))}
            validationSchema={phoneValidationSchema}
          >
            {({
              handleChange,
              handleBlur,
              handleSubmit,
              values,
              errors,
              touched,
            }) => (
              <View style={styles.form}>
                <Text style={styles.label}>Phone Number</Text>
                <TextInput
                  style={{
                    ...styles.input,
                    color: values.phone ? "black" : "#949CAC",
                  }}
                  onChangeText={(text) => {
                    handleChange("phone")(text);
                    if (sendOTPError) {
                      dispatch(clearSendOTPError());
                    }
                  }}
                  onBlur={handleBlur("phone")}
                  value={values.phone}
                  keyboardType="numeric"
                  placeholder="Enter your registered phone number"
                />
                <View style={styles.errorContainer}>
                  {touched.phone && errors.phone && (
                    <Text style={styles.error}>{errors.phone}</Text>
                  )}
                  {sendOTPError && (
                    <Text style={styles.error}>{sendOTPError}</Text>
                  )}
                </View>
                <TouchableOpacity
                  onPress={handleSubmit as unknown as () => void}
                  style={{
                    ...styles.button,
                    backgroundColor:
                      values.phone.length === 10 &&
                      !errors.phone &&
                      status !== AUTH_STATUSES.LOADING
                        ? "#008761"
                        : "#B0B7C5",
                  }}
                  disabled={
                    values.phone.length !== 10 ||
                    !!errors.phone ||
                    status === AUTH_STATUSES.LOADING
                  }
                >
                  <Text style={styles.buttonText}>Send OTP</Text>
                </TouchableOpacity>
              </View>
            )}
          </Formik>
        </View>
      </TouchableWithoutFeedback>
    </KeyboardAvoidingView>
  );
}

const styles = StyleSheet.create({
  errorContainer: {
    flexDirection: "column",
    gap: 8,
    marginTop: 8,
  },
  error: {
    color: "#D51D10",
    fontFamily: "Inter",
    fontSize: 12,
    fontWeight: "bold",
    lineHeight: 20,
  },
  inner: {
    flex: 1,
    justifyContent: "flex-start",
    position: "relative",
  },
  form: {
    height: "90%",
    position: "relative",
  },
  button: {
    height: 48,
    borderRadius: 4,
    alignItems: "center",
    justifyContent: "center",
    marginTop: 20,
    width: "100%",
    position: "absolute",
    bottom: 50,
  },
  buttonText: {
    color: "#FCFCFC",
    fontFamily: "Inter",
    fontSize: 14,
    fontWeight: "bold",
    lineHeight: 20,
  },
  container: {
    flex: 1,
    padding: 16,
    backgroundColor: "#F3F5F8",
    paddingTop: 0,
  },
  title: {
    fontSize: 28,
    fontWeight: "bold",
    marginBottom: 16,
    color: "#1A1C1E",
    fontStyle: "normal",
    lineHeight: 36,
    letterSpacing: -0.56,
    width: "70%",
  },
  label: {
    fontSize: 14,
    marginBottom: 8,
    color: "#717B8C",
    fontFamily: "Inter",
    fontStyle: "normal",
    fontWeight: "bold",
    lineHeight: 20,
  },
  input: {
    borderRadius: 4,
    borderTopColor: "#D8DDE7",
    borderBottomColor: "#D8DDE7",
    borderLeftColor: "#D8DDE7",
    borderRightColor: "#D8DDE7",
    height: 40,
    borderColor: "gray",
    borderWidth: 1,
    paddingHorizontal: 8,
    fontSize: 14,
    overflow: "hidden",
    fontFamily: "Inter",
    fontStyle: "normal",
    lineHeight: 20,
    fontWeight: "bold",
    backgroundColor: "#ffffff",
  },
});