/*
 * Registration page for creating a new user account.
 *
 * Author: Shiv
 * Date: April 2026
 */

"use client";

import dynamic from "next/dynamic";
import Link from "next/link";
import { useState } from "react";
import { useRouter, useSearchParams } from "next/navigation";
import { useAuth } from "@/context/AuthContext";

const labelCls = "flex flex-col gap-[0.35rem] text-[0.9rem] font-semibold text-[#444]";
const inputCls = "px-[0.85rem] py-[0.6rem] border border-[#ddd] rounded-lg text-base outline-none transition-all focus:border-[#e68672] focus:shadow-[0_0_0_3px_rgba(230,134,114,0.2)]";
const submitBtnCls = "mt-2 py-3 bg-[#e68672] text-white border-none rounded-lg text-base font-bold cursor-pointer transition-all hover:bg-[#d4705e] active:scale-[0.98] disabled:opacity-60 disabled:cursor-not-allowed";

function resolveNextPath(candidate) {
  if (!candidate || !candidate.startsWith("/")) {
    return "/";
  }
  if (candidate.startsWith("//") || candidate.startsWith("/login") || candidate.startsWith("/register")) {
    return "/";
  }
  return candidate;
}

//Registration page
//Collects user details, checks passwords match, then creates an account
function RegisterPage() {
  const {register} = useAuth();
  const router = useRouter();
  const searchParams = useSearchParams();

  const [form, setForm] = useState({
    firstName: "",
    lastName: "",
    username: "",
    email: "",
    phone: "",
    password: "",
    confirmPassword: "",
  });

  const [error, setError] = useState("");
  const [loading, setLoading] = useState(false);

  //Updates a single field in the form state
  function handleChange(e) {
    setForm((prev) => ({ ...prev, [e.target.name]: e.target.value }));
  }

  //Validates passwords match then submits the registration form
  async function handleSubmit(e) {
    e.preventDefault();
    setError("");

    if (form.password !== form.confirmPassword) {
      setError("Passwords do not match.");
      return;
    }

    setLoading(true);
    try {
      await register({
        firstName: form.firstName,
        lastName: form.lastName,
        username: form.username,
        email: form.email,
        phone: form.phone,
        password: form.password,
      });
      router.push(resolveNextPath(searchParams.get("next")));
    }

    catch (err) {
      setError(err.message);
    }

    finally {
      setLoading(false);
    }
  }

  return (
    <main className="min-h-[calc(100vh-70px)] flex items-center justify-center py-8 px-4 bg-[#fafafa]">
      <div className="bg-white rounded-2xl shadow-[0_4px_24px_rgba(0,0,0,0.1)] p-10 w-full max-w-[440px] max-[480px]:p-6">
        <h1 className="text-[1.75rem] font-bold text-[#222] m-0 mb-6 text-center">Create Account</h1>

        {error && <p className="bg-[#fff0f0] border border-[#f5c6c6] text-[#c0392b] rounded-lg px-4 py-[0.65rem] text-[0.9rem] mb-2">{error}</p>}

        <form className="flex flex-col gap-4" onSubmit={handleSubmit}>
          <label className={labelCls}>
            First Name
            <input className={inputCls} type="text" name="firstName" value={form.firstName} onChange={handleChange} required />
          </label>

          <label className={labelCls}>
            Last Name
            <input className={inputCls} type="text" name="lastName" value={form.lastName} onChange={handleChange} required />
          </label>

          <label className={labelCls}>
            Username
            <input className={inputCls} type="text" name="username" value={form.username} onChange={handleChange} required minLength={3} />
          </label>

          <label className={labelCls}>
            Email
            <input className={inputCls} type="email" name="email" value={form.email} onChange={handleChange} required />
          </label>

          <label className={labelCls}>
            Phone
            <input className={inputCls} type="tel" name="phone" value={form.phone} onChange={handleChange} required pattern="[0-9\-\+\(\) ]{7,15}" title="Enter a valid phone number" />
          </label>

          <label className={labelCls}>
            Password
            <input className={inputCls} type="password" name="password" value={form.password} onChange={handleChange} required minLength={6} autoComplete="new-password" />
          </label>

          <label className={labelCls}>
            Confirm Password
            <input className={inputCls} type="password" name="confirmPassword" value={form.confirmPassword} onChange={handleChange} required minLength={6} autoComplete="new-password" />
          </label>

          <button className={submitBtnCls} type="submit" disabled={loading}>
            {loading ? "Creating account…" : "Register"}
          </button>
        </form>

        <p className="text-center text-[0.9rem] text-[#666] mt-5">
          Already have an account?{" "}
          <Link href={searchParams.get("next") ? `/login?next=${encodeURIComponent(searchParams.get("next"))}` : "/login"} className="text-[#e68672] font-semibold no-underline hover:underline">Log in here</Link>
        </p>

        <p className="text-center text-[0.9rem] text-[#666] mt-5">
          Forgot your password?{" "}
          <Link href="/forgot-password" className="text-[#e68672] font-semibold no-underline hover:underline">Reset it here</Link>
        </p>
      </div>
    </main>
  );
}

export default dynamic(() => Promise.resolve(RegisterPage), {
  ssr: false,
});