feat(dicts): more robust google engine

src/components/dictionaries/google/engine.ts

@@ -21,9 +21,33 @@ export default function search (
     sl = 'en'
     tl = chCode
   }
-  const url = `https://translate.googleapis.com/translate_a/single?client=gtx&sl=${sl}&tl=${tl}&dt=t&q=${encodeURIComponent(text)}`
 
-  return fetch(url)
+  return fetchWithToken('https://translate.google.com', sl, tl, text)
+    .catch(() => fetchWithToken('https://translate.google.cn', sl, tl, text))
+    .catch(() => fetchWithoutToken(sl, tl, text))
+}
+
+function fetchWithToken (base: string, sl: string, tl: string, text: string): Promise<GoogleSearchResult> {
+  return fetch(base)
+    .then(r => r.text())
+    .then<Response>(body => {
+      const tkk = (body.match(/TKK=(.*?)\(\)\)'\);/) || [''])[0]
+        .replace(/\\x([0-9A-Fa-f]{2})/g, '') // remove hex chars
+        .match(/[+-]?\d+/g)
+      if (tkk) {
+        const tk = getTK(text, Number(tkk[2]), (Number(tkk[0]) + Number(tkk[1])))
+        if (tk) {
+          return fetch(`${base}/translate_a/single?client=t&sl=${sl}&tl=${tl}&q=${text}&tk=${tk}&hl=en&dt=at&dt=bd&dt=ex&dt=ld&dt=md&dt=qca&dt=rw&dt=rm&dt=ss&dt=t&ie=UTF-8&oe=UTF-8&otf=1&ssel=0&tsel=0&kc=5`)
+        }
+      }
+      return handleNoResult()
+    })
+    .then(r => r.text())
+    .then(handleText)
+}
+
+function fetchWithoutToken (sl: string, tl: string, text: string): Promise<GoogleSearchResult> {
+  return fetch(`https://translate.googleapis.com/translate_a/single?client=gtx&sl=${sl}&tl=${tl}&dt=t&q=${text}`)
     .then(r => r.text())
     .then(handleText)
 }
@@ -45,3 +69,40 @@ function handleText (
 
   return handleNoResult()
 }
+
+/* tslint:disable */
+
+function getTK (a, b, c) {
+  b = Number(b) || 0
+  let e: any = []
+  let f = 0
+  let g = 0
+  for (; g < a.length; g++) {
+    let l = a.charCodeAt(g)
+    128 > l ? e[f++] = l : (2048 > l ? e[f++] = l >> 6 | 192 : (55296 == (l & 64512) && g + 1 < a.length && 56320 == (a.charCodeAt(g + 1) & 64512) ? (l = 65536 + ((l & 1023) << 10) + (a.charCodeAt(++g) & 1023),
+      e[f++] = l >> 18 | 240,
+      e[f++] = l >> 12 & 63 | 128) : e[f++] = l >> 12 | 224,
+      e[f++] = l >> 6 & 63 | 128),
+      e[f++] = l & 63 | 128)
+  }
+  a = b
+  for (f = 0; f < e.length; f++) {
+    a += e[f], a = _magic(a, '+-a^+6')
+  }
+  a = _magic(a, '+-3^+b+-f')
+  a ^= Number(c) || 0;
+  0 > a && (a = (a & 2147483647) + 2147483648)
+  a %= 1E6
+  return (a.toString() + '.' + (a ^ b))
+}
+
+function _magic (a, b) {
+  for (var c = 0; c < b.length - 2; c += 3) {
+    // @ts-ignore
+    var d = b.charAt(c + 2), d = "a" <= d ? d.charCodeAt(0) - 87 : Number(d), d = "+" == b.charAt(c + 1) ? a >>> d : a << d;
+    a = "+" == b.charAt(c) ? a + d & 4294967295 : a ^ d
+  }
+  return a
+}
+
+/* tslint:enable */