"use client";

import React, { useState } from 'react';
import {
    TextInput,
    Button,
    Select,
    Title,
    Paper,
    Grid,
    Group,
    Radio,
    Text,
} from '@mantine/core';
import { notifications } from '@mantine/notifications';

const bankOptions = [
    { value: 'KCCB', label: 'KCCB - The Kangra Central Co-Operative Bank' },
];

const AddBeneficiary: React.FC = () => {
    const [bankName, setBankName] = useState('');
    const [bankType, setBankType] = useState('own');
    const [accountNo, setAccountNo] = useState('');
    const [confirmAccountNo, setConfirmAccountNo] = useState('');
    const [payeeName, setPayeeName] = useState('');
    const [nickName, setNickName] = useState('');
    const [otp, setOtp] = useState('');
    const [generatedOtp, setGeneratedOtp] = useState('');
    const [otpSent, setOtpSent] = useState(false);
    const [otpVerified, setOtpVerified] = useState(false);
    const [validationStatus, setValidationStatus] = useState<'success' | 'error' | null>(null);
    const [beneficiaryName, setBeneficiaryName] = useState<string | null>(null);
    const [isVisibilityLocked, setIsVisibilityLocked] = useState(false);
    const [showPayeeAcc, setShowPayeeAcc] = useState(true);

    const getFullMaskedAccount = (acc: string) => { return "X".repeat(acc.length); };

    const handleGenerateOtp = async () => {
        const value = "123456"; // Or generate a random OTP
        setGeneratedOtp(value);
        return value;
    };

    const validateAndSendOtp = async () => {
        if (!bankName || !accountNo || !confirmAccountNo) {
            notifications.show({
                withBorder: true,
                color: "red",
                title: "Missing Field",
                message: "All fields must be completed.",
                autoClose: 5000,
            });
            return;
        }

        if (accountNo.length < 10 || accountNo.length > 17) {
            notifications.show({
                withBorder: true,
                color: "red",
                title: "Invalid Account Number",
                message: "Enter a valid account number (10–17 digits).",
                autoClose: 5000,
            });
            return;
        }

        if (accountNo !== confirmAccountNo) {
            notifications.show({
                withBorder: true,
                color: "red",
                title: "Mismatch",
                message: "Account numbers do not match.",
                autoClose: 5000,
            });
            return;
        }

        try {
            const token = localStorage.getItem("access_token");
            const response = await fetch(`/api/beneficiary/validate/within-bank?accountNumber=${accountNo}`, {
                method: "GET",
                headers: {
                    "Content-Type": "application/json",
                    Authorization: `Bearer ${token}`,
                },
            });

            const data = await response.json();

            if (response.ok && data?.name) {
                setBeneficiaryName(data.name);
                setValidationStatus("success");
                setIsVisibilityLocked(true);
                setOtpSent(true);
                await handleGenerateOtp();

                notifications.show({
                    withBorder: true,
                    color: "green",
                    title: "OTP Sent",
                    message: "OTP has been sent to your registered mobile number.",
                    autoClose: 5000,
                });
            } else {
                setBeneficiaryName("Invalid beneficiary account number");
                setValidationStatus("error");
                setAccountNo("");
                setConfirmAccountNo("");
            }
        } catch (error) {
            setBeneficiaryName("Invalid beneficiary account number");
            setValidationStatus("error");

            notifications.show({
                withBorder: true,
                color: "red",
                title: "Error",
                message: "Could not validate account number.",
                autoClose: 5000,
            });
        }
    };

    const verifyOtp = () => {
        if (otp === generatedOtp) {
            setOtpVerified(true);
            notifications.show({
                withBorder: true,
                color: "green",
                title: "OTP Verified",
                message: "OTP validated successfully.",
                autoClose: 5000,
            });
        } else {
            notifications.show({
                withBorder: true,
                color: "red",
                title: "OTP Error",
                message: "OTP does not match.",
                autoClose: 5000,
            });
        }
    };

    return (
        <Paper shadow="sm" radius="md" p="md" withBorder>
            <Title order={3} mb="md">Add Beneficiary</Title>

            <Radio.Group value={bankType} onChange={setBankType} name="bankType" withAsterisk mb="md">
                <Group justify="center">
                    <Radio value="own" label="Own Bank" />
                    <Radio value="outside" label="Outside Bank" />
                </Group>
            </Radio.Group>

            {bankType === "own" ? (
                <Grid gutter="md">
                    <Grid.Col span={4}>
                        <Select
                            label="Bank Name"
                            placeholder="Select bank"
                            data={bankOptions}
                            value={bankName}
                            onChange={(value) => setBankName(value || '')}
                            required
                        />
                    </Grid.Col>

                    <Grid.Col span={4}>
                        <TextInput
                            label="Beneficiary Account Number"
                            placeholder="Enter account number"
                            value={showPayeeAcc ? accountNo : getFullMaskedAccount(accountNo)}
                            onChange={(e) => {
                                const value = e.currentTarget.value;
                                if (/^\d*$/.test(value) && value.length <= 17) {
                                    setAccountNo(value);
                                    setShowPayeeAcc(true);
                                }
                            }}
                            onBlur={() => setShowPayeeAcc(false)}
                            onFocus={() => setShowPayeeAcc(true)}
                            readOnly={isVisibilityLocked}
                            maxLength={17}
                           // disabled={isVisibilityLocked}
                            required
                        />
                    </Grid.Col>

                    <Grid.Col span={4}>
                        <TextInput
                            label="Confirm Beneficiary Account Number"
                            placeholder="Re-enter account number"
                            value={confirmAccountNo}
                            onChange={(e) => {
                                const value = e.currentTarget.value;
                                if (/^\d*$/.test(value) && value.length <= 17) {
                                    setConfirmAccountNo(value);
                                }
                            }}
                            maxLength={17}
                           // disabled={isVisibilityLocked}
                            readOnly={isVisibilityLocked}
                            required
                            onCopy={(e) => e.preventDefault()}
                            onPaste={(e) => e.preventDefault()}
                            onCut={(e) => e.preventDefault()}
                        />

                        {validationStatus === "error" && (
                            <Text c="red" size="sm" style={{ marginLeft: '1rem', whiteSpace: 'nowrap' }}>
                                {beneficiaryName}
                            </Text>
                        )}
                    </Grid.Col>

                    <Grid.Col span={6}>
                        <TextInput
                            label="Nick Name (Optional)"
                            placeholder="Enter nickname (optional)"
                            value={nickName}
                            onChange={(e) => setNickName(e.currentTarget.value)}
                        />
                    </Grid.Col>

                    <Grid.Col span={6}>
                        <TextInput
                            label="Beneficiary Name"
                            value={validationStatus === "success" && beneficiaryName ? beneficiaryName : ""}
                            disabled
                            maxLength={100}
                            required
                        />
                    </Grid.Col>


                    {!otpSent && (
                        <Grid.Col>
                            <Button onClick={validateAndSendOtp}>Validate</Button>
                        </Grid.Col>
                    )}

                    {otpSent && (
                        <>
                            <Grid.Col span={3}>
                                <TextInput
                                    label="Enter OTP"
                                    placeholder="Enter OTP"
                                    value={otp}
                                    onChange={(e) => setOtp(e.currentTarget.value)}
                                    maxLength={6}
                                    disabled={otpVerified} // ✅ Disable after verified
                                />
                            </Grid.Col >
                            <Grid.Col >
                                {!otpVerified ? (
                                    <Button onClick={verifyOtp}>Validate OTP</Button>
                                ) : (


                                    <Button color="blue" size="sm" onClick={() => { /* handle add here */ }}>
                                        Add
                                    </Button>
                                )}
                            </Grid.Col>
                        </>
                    )}
                </Grid>
            ) : (
                <Text size="lg" mt="md">
                    Outside Bank feature coming soon.
                </Text>
            )}
        </Paper>
    );
};

export default AddBeneficiary;