"use client";

import { signIn } from "next-auth/react";
import { type FormEvent, useState } from "react";
import { precheckLogin } from "@/actions/auth-precheck";
import {
	type CaptchaPublicConfig,
	CaptchaWidget,
	readCaptchaToken,
} from "@/components/auth/captcha-widget";
import { signInWithTransientRetry } from "@/lib/auth/sign-in-retry";

export function HomeLoginForm({
	captcha = { provider: "none" },
	nonce,
}: {
	captcha?: CaptchaPublicConfig;
	nonce?: string;
} = {}) {
	const [username, setUsername] = useState("");
	const [password, setPassword] = useState("");
	const [showPassword, setShowPassword] = useState(false);
	const [code, setCode] = useState("");
	const [needs2fa, setNeeds2fa] = useState(false);
	const [error, setError] = useState<string | null>(null);
	const [pending, setPending] = useState(false);

	async function onSubmit(e: FormEvent<HTMLFormElement>) {
		e.preventDefault();
		setError(null);
		setPending(true);
		try {
			if (!needs2fa) {
				const captchaToken = readCaptchaToken(e.currentTarget, captcha);
				const pre = await precheckLogin(username, password, captchaToken);
				if (pre === "invalid") {
					setError("Invalid username or password");
					return;
				}
				if (pre === "captcha") {
					setError("Captcha verification failed. Please try again.");
					return;
				}
				if (pre === "unverified") {
					setError("Please verify your email before signing in.");
					return;
				}
				if (pre === "twofactor") {
					setNeeds2fa(true);
					return;
				}
			}
			const res = await signInWithTransientRetry(() =>
				signIn("credentials", {
					username,
					password,
					code,
					redirect: false,
				}),
			);
			if (!res || res.error) {
				setError(
					needs2fa ? "Invalid 2FA code" : "Invalid username or password",
				);
				return;
			}
			window.location.href = "/";
		} catch {
			setError(needs2fa ? "Invalid 2FA code" : "Invalid username or password");
		} finally {
			setPending(false);
		}
	}

	return (
		<form onSubmit={onSubmit} className="relative flex flex-col gap-4">
			<div className="space-y-1">
				<label
					htmlFor="login-username"
					className="block text-xs font-bold uppercase tracking-wider"
					style={{ color: "var(--color-text-muted)" }}
				>
					Username
				</label>
				<input
					id="login-username"
					type="text"
					value={username}
					onChange={(e) => setUsername(e.target.value)}
					placeholder="Your username"
					autoComplete="username"
					disabled={needs2fa}
					className="input-glow w-full rounded-xl border-2 px-4 py-3 text-sm font-medium transition-all focus:outline-none disabled:opacity-50"
					style={{
						backgroundColor: "var(--color-background)",
						color: "var(--color-text-readable)",
						borderColor: needs2fa
							? "color-mix(in srgb, var(--color-text-muted) 15%, transparent)"
							: "color-mix(in srgb, var(--color-text-muted) 25%, transparent)",
					}}
					required
				/>
			</div>

			<div className="space-y-1">
				<div className="flex items-center justify-between">
					<label
						htmlFor="login-password"
						className="block text-xs font-bold uppercase tracking-wider"
						style={{ color: "var(--color-text-muted)" }}
					>
						Password
					</label>
				</div>
				<div className="relative">
					<input
						id="login-password"
						type={showPassword ? "text" : "password"}
						value={password}
						onChange={(e) => setPassword(e.target.value)}
						placeholder="Your password"
						autoComplete="current-password"
						disabled={needs2fa}
						className="input-glow w-full rounded-xl border-2 px-4 py-3 text-sm font-medium transition-all focus:outline-none disabled:opacity-50"
						style={{
							backgroundColor: "var(--color-background)",
							color: "var(--color-text-readable)",
							borderColor: needs2fa
								? "color-mix(in srgb, var(--color-text-muted) 15%, transparent)"
								: "color-mix(in srgb, var(--color-text-muted) 25%, transparent)",
						}}
						required
					/>
					<button
						type="button"
						onClick={() => setShowPassword(!showPassword)}
						className="absolute right-3 top-1/2 -translate-y-1/2 text-sm font-bold opacity-60 hover:opacity-100 transition-opacity"
						style={{ color: "var(--color-text-muted)" }}
						tabIndex={-1}
					>
						{showPassword ? "Hide" : "Show"}
					</button>
				</div>
			</div>

			{needs2fa ? (
				<div className="space-y-1 animate-scale-in">
					<label
						htmlFor="login-2fa"
						className="block text-xs font-bold uppercase tracking-wider"
						style={{ color: "var(--color-text-muted)" }}
					>
						2FA Code
					</label>
					<input
						id="login-2fa"
						type="text"
						value={code}
						onChange={(e) => setCode(e.target.value)}
						placeholder="Enter your 2FA code"
						inputMode="numeric"
						autoComplete="one-time-code"
						className="w-full rounded-xl border-2 px-4 py-3 text-sm font-medium transition-all focus:outline-none"
						style={{
							backgroundColor: "var(--color-background)",
							color: "var(--color-text-readable)",
							borderColor:
								"color-mix(in srgb, var(--color-primary) 30%, transparent)",
						}}
					/>
				</div>
			) : (
				<CaptchaWidget captcha={captcha} nonce={nonce} />
			)}

			{error ? (
				<p
					className="animate-fade-in-up m-0 text-center text-sm font-semibold"
					style={{ color: "var(--color-danger)" }}
				>
					{error}
				</p>
			) : null}

			<button
				type="submit"
				disabled={pending}
				className="btn-shine w-full cursor-pointer rounded-xl font-extrabold text-sm py-3.5 transition-all duration-200 hover:scale-[1.02] active:scale-95 shadow-lg disabled:opacity-60"
				style={{
					background: "var(--color-primary)",
					color: "var(--color-primary-foreground)",
					boxShadow:
						"0 4px 20px color-mix(in srgb, var(--color-primary) 30%, transparent)",
				}}
			>
				{pending ? (
					<span className="inline-flex items-center gap-2">
						<svg
							className="animate-spin h-4 w-4"
							viewBox="0 0 24 24"
							fill="none"
							role="img"
							aria-label="Loading"
						>
							<circle
								className="opacity-25"
								cx="12"
								cy="12"
								r="10"
								stroke="currentColor"
								strokeWidth="4"
							/>
							<path
								className="opacity-75"
								fill="currentColor"
								d="M4 12a8 8 0 018-8V0C5.373 0 0 5.373 0 12h4z"
							/>
						</svg>
						Please wait...
					</span>
				) : needs2fa ? (
					"Verify"
				) : (
					"Login"
				)}
			</button>
		</form>
	);
}