"use client";

import { type FormEvent, useEffect, useState } from "react";
import { getApiBase, setToken } from "../lib/auth";
import { loginErrorMessage } from "../lib/login-errors";
import AuthLayout from "../ui/AuthLayout";

type LoginMode = "jellyfin" | "local";
type LoginOptions = {
  showJellyfinLogin: boolean;
  showLocalLogin: boolean;
  showForgotPassword: boolean;
  showSignupLink: boolean;
};
const DEFAULT_OPTIONS: LoginOptions = {
  showJellyfinLogin: true,
  showLocalLogin: true,
  showForgotPassword: true,
  showSignupLink: true,
};

export default function LoginPage() {
  const [username, setUsername] = useState("");
  const [password, setPassword] = useState("");
  const [showPassword, setShowPassword] = useState(false);
  const [mode, setMode] = useState<LoginMode>("jellyfin");
  const [options, setOptions] = useState<LoginOptions>(DEFAULT_OPTIONS);
  const [optionsReady, setOptionsReady] = useState(false);
  const [loginMessage, setLoginMessage] = useState("");
  const [error, setError] = useState("");
  const [loading, setLoading] = useState(false);
  const canSignIn = options.showJellyfinLogin || options.showLocalLogin;
  const selectedMode: LoginMode =
    mode === "jellyfin" && options.showJellyfinLogin ? "jellyfin" : options.showLocalLogin ? "local" : "jellyfin";

  useEffect(() => {
    const controller = new AbortController();
    const load = async () => {
      try {
        const response = await fetch(`${getApiBase()}/site/public`, { signal: controller.signal });
        if (!response.ok) throw new Error("Options unavailable");
        const data = await response.json();
        if (controller.signal.aborted) return;
        setOptions({
          showJellyfinLogin: data?.login?.showJellyfinLogin !== false,
          showLocalLogin: data?.login?.showLocalLogin !== false,
          showForgotPassword: data?.login?.showForgotPassword !== false,
          showSignupLink: data?.login?.showSignupLink !== false,
        });
        setLoginMessage(typeof data?.login?.message === "string" ? data.login.message.trim() : "");
      } catch {
        // Keep the normal sign-in methods available during a settings outage.
      } finally {
        if (!controller.signal.aborted) setOptionsReady(true);
      }
    };
    void load();
    return () => controller.abort();
  }, []);

  const submit = async (event: FormEvent<HTMLFormElement>) => {
    event.preventDefault();
    if (loading || !canSignIn || !optionsReady) return;
    setError("");
    setLoading(true);
    try {
      const response = await fetch(
        `${getApiBase()}${selectedMode === "jellyfin" ? "/auth/jellyfin/login" : "/auth/login"}`,
        {
          method: "POST",
          headers: { "Content-Type": "application/x-www-form-urlencoded" },
          body: new URLSearchParams({ username: username.trim(), password }),
          credentials: "include",
        },
      );
      if (!response.ok) {
        setError(await loginErrorMessage(response));
        return;
      }
      const data = await response.json();
      if (!data?.authenticated) {
        setError("Could not sign in. Please try again.");
        return;
      }
      setToken("cookie");
      const next = new URLSearchParams(window.location.search).get("next") || "";
      const allowedNext =
        [
          "/insights",
          "/insights/reports",
          "/profile",
          "/profile#monthly-recaps",
          "/profile#newsletters",
          "/admin/recaps",
          "/admin/newsletters",
          "/setup",
          "/admin/backups",
        ].includes(next) ||
        /^\/insights\/reports\?month=[0-9]{4}-(?:0[1-9]|1[0-2])$/.test(next) ||
        /^\/issues\/confirm\/\d+$/.test(next);
      window.location.assign(allowedNext ? next : "/welcome");
    } catch {
      setError("Could not reach Magent. Check your connection and try again.");
    } finally {
      setLoading(false);
    }
  };

  return (
    <AuthLayout
      title="Welcome back."
      description="Sign in to your media workspace."
      footer={
        optionsReady &&
        options.showSignupLink && (
          <>
            Have an invite?{" "}
            <a href="/signup">
              Create an account <span aria-hidden="true">↗</span>
            </a>
          </>
        )
      }
    >
      {loginMessage && (
        <p className="account-notice account-login-message" role="status">
          {loginMessage}
        </p>
      )}
      {optionsReady && options.showJellyfinLogin && options.showLocalLogin && (
        <fieldset className="login-methods" aria-label="Sign-in account">
          <button
            type="button"
            aria-pressed={selectedMode === "jellyfin"}
            disabled={loading}
            onClick={() => {
              setMode("jellyfin");
              setError("");
            }}
          >
            Grizzlyflix
          </button>
          <button
            type="button"
            aria-pressed={selectedMode === "local"}
            disabled={loading}
            onClick={() => {
              setMode("local");
              setError("");
            }}
          >
            Magent
          </button>
        </fieldset>
      )}
      {!optionsReady ? (
        <p className="account-hint" role="status">
          Loading sign-in…
        </p>
      ) : !canSignIn ? (
        <p className="account-notice is-error" role="alert">
          Sign-in is currently unavailable. Please contact an administrator.
        </p>
      ) : (
        <form className="account-form login-form" onSubmit={submit}>
          <p className="login-method-help">
            {selectedMode === "jellyfin" ? "Use your Grizzlyflix / Jellyfin account." : "Use your Magent account."}
          </p>
          <label htmlFor="login-username">Username</label>
          <input
            id="login-username"
            name="username"
            value={username}
            onChange={(event) => setUsername(event.target.value)}
            autoComplete="username"
            autoCapitalize="none"
            spellCheck={false}
            required
            disabled={loading}
          />
          <div className="login-password-label">
            <label htmlFor="login-password">Password</label>
            {options.showForgotPassword && <a href="/forgot-password">Forgot password?</a>}
          </div>
          <div className="login-password-field">
            <input
              id="login-password"
              name="password"
              type={showPassword ? "text" : "password"}
              value={password}
              onChange={(event) => setPassword(event.target.value)}
              autoComplete="current-password"
              required
              disabled={loading}
            />
            <button
              type="button"
              className="password-visibility"
              aria-label={showPassword ? "Hide password" : "Show password"}
              aria-pressed={showPassword}
              onClick={() => setShowPassword(!showPassword)}
            >
              <svg viewBox="0 0 24 24" fill="none" stroke="currentColor" strokeWidth="1.7" aria-hidden="true">
                <path d="M2 12s3.5-7 10-7 10 7 10 7-3.5 7-10 7S2 12 2 12Z" />
                <circle cx="12" cy="12" r="3" />
                {showPassword && <path d="m3 3 18 18" />}
              </svg>
            </button>
          </div>
          {error && (
            <p className="account-notice is-error" role="alert">
              {error}
            </p>
          )}
          <button type="submit" className="account-primary login-submit" disabled={loading}>
            {loading ? "Signing in…" : "Sign in"}
            <span aria-hidden="true">→</span>
          </button>
        </form>
      )}
    </AuthLayout>
  );
}