"use client";

import { useState, useEffect, useCallback } from "react";

interface DeviceTokenData {
  clawId: string;
  apiKey: string;
  name: string;
  deviceId: string;
}

interface UseDeviceTokenReturn {
  token: string | null;
  clawId: string | null;
  name: string | null;
  isLoading: boolean;
  error: string | null;
  updateName: (newName: string) => Promise<boolean>;
}

const STORAGE_KEY = "openclaw_device";

function generateUUID(): string {
  if (typeof crypto !== "undefined" && crypto.randomUUID) {
    return crypto.randomUUID();
  }
  return "xxxxxxxx-xxxx-4xxx-yxxx-xxxxxxxxxxxx".replace(/[xy]/g, (c) => {
    const r = (Math.random() * 16) | 0;
    const v = c === "x" ? r : (r & 0x3) | 0x8;
    return v.toString(16);
  });
}

function getDeviceInfo(): {
  platform: string;
  browser: string;
  screen: string;
  language: string;
} {
  if (typeof navigator === "undefined") {
    return { platform: "unknown", browser: "unknown", screen: "unknown", language: "en" };
  }

  const ua = navigator.userAgent;
  let browser = "Unknown";
  if (ua.includes("Chrome") && !ua.includes("Edg")) browser = "Chrome";
  else if (ua.includes("Firefox")) browser = "Firefox";
  else if (ua.includes("Safari") && !ua.includes("Chrome")) browser = "Safari";
  else if (ua.includes("Edg")) browser = "Edge";

  return {
    platform: navigator.platform || "unknown",
    browser,
    screen:
      typeof screen !== "undefined"
        ? `${screen.width}x${screen.height}`
        : "unknown",
    language: navigator.language || "en",
  };
}

function getCachedData(): DeviceTokenData | null {
  if (typeof localStorage === "undefined") return null;
  try {
    const raw = localStorage.getItem(STORAGE_KEY);
    if (!raw) return null;
    return JSON.parse(raw) as DeviceTokenData;
  } catch {
    return null;
  }
}

function setCachedData(data: DeviceTokenData): void {
  if (typeof localStorage === "undefined") return;
  localStorage.setItem(STORAGE_KEY, JSON.stringify(data));
}

function updateCachedName(newName: string): void {
  const data = getCachedData();
  if (data) {
    setCachedData({ ...data, name: newName });
  }
}

export function useDeviceToken(): UseDeviceTokenReturn {
  const [token, setToken] = useState<string | null>(null);
  const [clawId, setClawId] = useState<string | null>(null);
  const [name, setName] = useState<string | null>(null);
  const [isLoading, setIsLoading] = useState(true);
  const [error, setError] = useState<string | null>(null);

  useEffect(() => {
    const init = async () => {
      // Check cache first
      const cached = getCachedData();
      if (cached) {
        setToken(cached.apiKey);
        setClawId(cached.clawId);
        setName(cached.name);
        setIsLoading(false);
        return;
      }

      // Register new device
      try {
        const deviceId = generateUUID();
        const deviceInfo = getDeviceInfo();

        const res = await fetch("/api/v1/device/register", {
          method: "POST",
          headers: { "Content-Type": "application/json" },
          body: JSON.stringify({
            deviceId,
            ...deviceInfo,
          }),
        });

        if (!res.ok) {
          throw new Error(`Registration failed: ${res.status}`);
        }

        const data = await res.json();
        const tokenData: DeviceTokenData = {
          clawId: data.clawId,
          apiKey: data.apiKey,
          name: data.name,
          deviceId,
        };

        setCachedData(tokenData);
        setToken(data.apiKey);
        setClawId(data.clawId);
        setName(data.name);
      } catch (err) {
        setError(err instanceof Error ? err.message : "Registration failed");
      } finally {
        setIsLoading(false);
      }
    };

    init();
  }, []);

  const updateName = useCallback(
    async (newName: string): Promise<boolean> => {
      if (!token) return false;

      try {
        const res = await fetch("/api/v1/device/name", {
          method: "PUT",
          headers: {
            "Content-Type": "application/json",
            Authorization: `Bearer ${token}`,
          },
          body: JSON.stringify({ name: newName }),
        });

        if (!res.ok) return false;

        setName(newName);
        updateCachedName(newName);
        return true;
      } catch {
        return false;
      }
    },
    [token]
  );

  return { token, clawId, name, isLoading, error, updateName };
}