/**
 * Mobile wallet detection and deep-link helpers.
 *
 * On mobile browsers (Safari / Chrome) there is no injected `window.ethereum`,
 * so the `injected()` wagmi connector returns nothing and the user sees
 * "No wallet provider found". The fix is to detect this state early and offer
 * deep links that open MetaMask / Trust / Coinbase / OKX and land the user
 * inside the wallet's in-app browser at the current dApp URL.
 *
 * Deep-link patterns used:
 *   MetaMask  https://metamask.app.link/dapp/<host><path>   (universal link → iOS/Android)
 *   Trust     https://link.trustwallet.com/open_url?coin_id=60&url=<encoded>
 *   Coinbase  https://go.cb-wallet.com/dapp?url=<encoded>
 *   OKX       https://www.okx.com/download?deeplink=okx%3A%2F%2Fmain%2Fdapp%2Fbrowser%3Furl%3D<encoded>
 *
 * All links open in a new tab (_blank) so if the user doesn't have the app
 * installed they land on the wallet's download page without breaking nav.
 */

/** True when the JS runtime has access to browser APIs. */
const isBrowser = typeof window !== 'undefined'

/**
 * Rough mobile UA check — covers iOS (iPhone/iPad) and Android.
 * Intentionally excludes desktop Chrome/Firefox even if the viewport is narrow.
 */
export function isMobileDevice(): boolean {
  if (!isBrowser) return false
  return /Android|webOS|iPhone|iPad|iPod|BlackBerry|IEMobile|Opera Mini/i.test(navigator.userAgent)
}

/**
 * Returns true when an injected EIP-1193 provider is present in the window
 * (i.e. the user is already inside MetaMask's browser, has a browser extension,
 * or Coinbase Wallet's in-app browser).
 */
export function hasInjectedWallet(): boolean {
  if (!isBrowser) return false
  // window.ethereum is the canonical EIP-1193 injection point.
  // Some wallets also inject under their own namespace but all reputable ones
  // also set window.ethereum (or window.web3 as a fallback).
  return !!(window as unknown as { ethereum?: unknown }).ethereum
}

/**
 * True when the user is on mobile AND has no injected wallet — the state
 * where we should show the mobile wallet picker instead of a bare error.
 */
export function needsMobileWallet(): boolean {
  return isMobileDevice() && !hasInjectedWallet()
}

export interface WalletLink {
  name: string
  /** Short subtitle shown under the name */
  hint: string
  /** URL that opens the wallet app and navigates to `dappUrl` */
  href: string
  /** CSS color for the icon background */
  color: string
  /** Short letter(s) displayed when no SVG icon is available */
  abbr: string
}

/**
 * Build the deep-link set for the given dApp URL.
 * Pass `window.location.href` (or a canonical URL) as `dappUrl`.
 */
export function getWalletLinks(dappUrl: string): WalletLink[] {
  const enc = encodeURIComponent(dappUrl)
  // MetaMask universal link: strip the protocol and pass host+path
  // e.g. "https://trumpsignal.com/en" → "trumpsignal.com/en"
  const hostPath = dappUrl.replace(/^https?:\/\//, '')

  return [
    {
      name: 'MetaMask',
      hint: 'Most popular — iOS & Android',
      href: `https://metamask.app.link/dapp/${hostPath}`,
      color: '#E8831D',
      abbr: '🦊',
    },
    {
      name: 'Trust Wallet',
      hint: 'Binance-backed, iOS & Android',
      href: `https://link.trustwallet.com/open_url?coin_id=60&url=${enc}`,
      color: '#3375BB',
      abbr: '🛡',
    },
    {
      name: 'Coinbase Wallet',
      hint: 'No Coinbase account needed',
      href: `https://go.cb-wallet.com/dapp?url=${enc}`,
      color: '#1652F0',
      abbr: '🔵',
    },
    {
      name: 'OKX Wallet',
      hint: 'iOS & Android',
      href: `https://www.okx.com/download?deeplink=${encodeURIComponent(`okx://main/dapp/browser?url=${enc}`)}`,
      color: '#000000',
      abbr: 'OKX',
    },
  ]
}