"use client";

import { useState } from "react";

import Link from "next/link";
import { useRouter } from "next/navigation";

import { ArrowLeft, CheckCircle2, Command, GraduationCap, Lock, Mail, Phone, User } from "lucide-react";

import { Button } from "@/components/ui/button";
import { Input } from "@/components/ui/input";
import { Label } from "@/components/ui/label";
import { APP_CONFIG } from "@/config/app-config";
import { type RegisterData, register } from "@/lib/auth";

export default function RegisterPage() {
  const router = useRouter();
  const [form, setForm] = useState<RegisterData>({
    name: "",
    email: "",
    phone: "",
    language: "EN",
    password: "",
  });
  const [confirm, setConfirm] = useState("");
  const [error, setError] = useState("");
  const [loading, setLoading] = useState(false);

  const set = (field: keyof RegisterData, value: string) => {
    setForm((prev) => ({ ...prev, [field]: value }));
    setError("");
  };

  const validate = (): string | null => {
    if (!form.name.trim()) return "Full name is required.";
    if (!form.email.includes("@")) return "Please enter a valid email address.";
    if (!form.phone.trim()) return "Phone number is required.";
    if (form.password.length < 6) return "Password must be at least 6 characters.";
    if (form.password !== confirm) return "Passwords do not match.";
    return null;
  };

  const handleSubmit = (event: React.FormEvent) => {
    event.preventDefault();
    const validationError = validate();
    if (validationError) {
      setError(validationError);
      return;
    }
    setLoading(true);
    setTimeout(() => {
      const result = register(form);
      if ("error" in result) {
        setError(result.error);
        setLoading(false);
        return;
      }
      router.replace("/portal");
    }, 300);
  };

  return (
    <div className="flex min-h-screen bg-background">
      <aside className="hidden w-[42%] flex-col justify-between bg-sidebar p-10 text-sidebar-foreground lg:flex">
        <div className="flex items-center gap-2.5">
          <Command className="size-6 shrink-0" />
          <span className="font-bold text-xl tracking-tight">{APP_CONFIG.name}</span>
        </div>
        <div className="space-y-7">
          <div>
            <h1 className="font-bold text-3xl leading-tight">
              Create a student
              <br />
              portal account.
            </h1>
            <p className="mt-3 max-w-sm text-sidebar-foreground/70 text-sm leading-relaxed">
              This POC creates a mock student session and adds a local registration record for admissions review.
            </p>
          </div>
          {["View enrollment status", "Upload requested documents", "Track payments and sessions"].map((item) => (
            <div key={item} className="flex items-center gap-3 text-sidebar-foreground/80 text-sm">
              <CheckCircle2 className="size-4" />
              {item}
            </div>
          ))}
        </div>
        <p className="text-sidebar-foreground/40 text-xs">{APP_CONFIG.copyright}</p>
      </aside>

      <main className="flex flex-1 items-start justify-center overflow-y-auto px-6 py-10">
        <div className="w-full max-w-md space-y-7">
          <div className="flex items-center gap-2 lg:hidden">
            <Command className="size-5 shrink-0" />
            <span className="font-bold">{APP_CONFIG.name}</span>
          </div>
          <div>
            <h2 className="font-bold text-2xl">Student registration</h2>
            <p className="mt-1 text-muted-foreground text-sm">Create a mock student portal profile.</p>
          </div>

          <form onSubmit={handleSubmit} className="space-y-4">
            <div className="space-y-1.5">
              <Label htmlFor="name">Full name *</Label>
              <div className="relative">
                <User className="absolute top-1/2 left-3 size-4 -translate-y-1/2 text-muted-foreground" />
                <Input
                  id="name"
                  value={form.name}
                  onChange={(event) => set("name", event.target.value)}
                  className="pl-9"
                  autoFocus
                />
              </div>
            </div>
            <div className="space-y-1.5">
              <Label htmlFor="email">Email *</Label>
              <div className="relative">
                <Mail className="absolute top-1/2 left-3 size-4 -translate-y-1/2 text-muted-foreground" />
                <Input
                  id="email"
                  type="email"
                  value={form.email}
                  onChange={(event) => set("email", event.target.value)}
                  className="pl-9"
                />
              </div>
            </div>
            <div className="space-y-1.5">
              <Label htmlFor="phone">Phone *</Label>
              <div className="relative">
                <Phone className="absolute top-1/2 left-3 size-4 -translate-y-1/2 text-muted-foreground" />
                <Input
                  id="phone"
                  value={form.phone}
                  onChange={(event) => set("phone", event.target.value)}
                  className="pl-9"
                />
              </div>
            </div>
            <div className="grid grid-cols-2 gap-2">
              {(["EN", "FR"] as const).map((language) => (
                <Button
                  key={language}
                  type="button"
                  variant={form.language === language ? "default" : "outline"}
                  onClick={() => set("language", language)}
                >
                  {language === "EN" ? "English" : "Francais"}
                </Button>
              ))}
            </div>
            <div className="space-y-1.5">
              <Label htmlFor="password">Password *</Label>
              <div className="relative">
                <Lock className="absolute top-1/2 left-3 size-4 -translate-y-1/2 text-muted-foreground" />
                <Input
                  id="password"
                  type="password"
                  value={form.password}
                  onChange={(event) => set("password", event.target.value)}
                  className="pl-9"
                />
              </div>
            </div>
            <div className="space-y-1.5">
              <Label htmlFor="confirm">Confirm password *</Label>
              <div className="relative">
                <GraduationCap className="absolute top-1/2 left-3 size-4 -translate-y-1/2 text-muted-foreground" />
                <Input
                  id="confirm"
                  type="password"
                  value={confirm}
                  onChange={(event) => setConfirm(event.target.value)}
                  className="pl-9"
                />
              </div>
            </div>
            {error && <div className="rounded-lg bg-destructive/10 px-3 py-2.5 text-destructive text-sm">{error}</div>}
            <Button type="submit" className="w-full" disabled={loading}>
              {loading ? "Creating account..." : "Create student portal"}
            </Button>
          </form>

          <Link
            href="/login"
            className="flex items-center justify-center gap-1 text-muted-foreground text-sm hover:text-foreground"
          >
            <ArrowLeft className="size-3" /> Back to login
          </Link>
        </div>
      </main>
    </div>
  );
}