From 771888599ec7c1fad208d19fa3a3162905a12456 Mon Sep 17 00:00:00 2001
From: glacambre <code@lacamb.re>
Date: Thu, 17 May 2018 08:23:25 +0200
Subject: [PATCH] native_background.ts: implement writePref()

---
 src/native_background.ts | 69 ++++++++++++++++++++++++++--------------
 1 file changed, 46 insertions(+), 23 deletions(-)

diff --git a/src/native_background.ts b/src/native_background.ts
index b35d620b..f2ed0ee7 100644
--- a/src/native_background.ts
+++ b/src/native_background.ts
@@ -326,6 +326,29 @@ export async function getProfileDir() {
     }
 }
 
+export async function parsePrefs(prefFileContent: string) {
+    //  This RegExp currently only deals with " but for correctness it should
+    //  also deal with ' and `
+    //  We could also just give up on parsing and eval() the whole thing
+    const regex = new RegExp(
+        /^(user_|sticky_|lock)?[pP]ref\("([^"]+)",\s*"?([^\)]+?)"?\);$/,
+    )
+    // Fragile parsing
+    let allPrefs = prefFileContent.split("\n").reduce((prefs, line) => {
+        let matches = line.match(regex)
+        if (!matches) {
+            return prefs
+        }
+        const key = matches[2]
+        let value = matches[3]
+        // value = " means that it should be an empty string
+        if (value == '"') value = ""
+        prefs[key] = value
+        return prefs
+    }, {})
+    return allPrefs
+}
+
 /** When given the name of a firefox preference file, will load said file and
  *  return a promise for an object the keys of which correspond to preference
  *  names and the values of which correspond to preference values.
@@ -334,27 +357,8 @@ export async function getProfileDir() {
  */
 export async function loadPrefs(filename): Promise<{ [key: string]: string }> {
     const result = await read(filename)
-    if (result.code == 2) return {}
-    //  This RegExp currently only deals with " but for correctness it should
-    //  also deal with ' and `
-    //  We could also just give up on parsing and eval() the whole thing
-    const regex = new RegExp(
-        /^(user_|sticky_|lock)?[pP]ref\("([^"]+)",\s*"?([^\)]+?)"\);$/,
-    )
-    // Fragile parsing
-    let allPrefs = result.content.split("\n").reduce((prefs, line) => {
-        let matches = line.match(regex)
-        if (!matches) {
-            return prefs
-        }
-        const key = matches[2]
-        let value = matches[3]
-        // value = "" means that it should be an empty string
-        if (value == '"') value = ""
-        prefs[key] = value
-        return prefs
-    }, {})
-    return allPrefs
+    if (result.code != 0) return {}
+    return parsePrefs(result.content)
 }
 
 /** Returns a promise for an object that should contain every about:config
@@ -366,7 +370,6 @@ export async function getPrefs(): Promise<{ [key: string]: string }> {
     const profile = (await getProfileDir()) + "/"
     const prefFiles = [
         // Debian has these
-        "/etc/firefox/firefox.js",
         "/usr/share/firefox/browser/defaults/preferences/firefox.js",
         "/usr/share/firefox/browser/defaults/preferences/debugger.js",
         "/usr/share/firefox/browser/defaults/preferences/devtools-startup-prefs.js",
@@ -374,6 +377,7 @@ export async function getPrefs(): Promise<{ [key: string]: string }> {
         "/usr/share/firefox/browser/defaults/preferences/firefox-branding.js",
         "/usr/share/firefox/browser/defaults/preferences/vendor.js",
         "/usr/share/firefox/browser/defaults/preferences/firefox.js",
+        "/etc/firefox/firefox.js",
         // Pref files can be found here:
         // https://developer.mozilla.org/en-US/docs/Mozilla/Preferences/A_brief_guide_to_Mozilla_preferences
         profile + "grepref.js",
@@ -387,7 +391,6 @@ export async function getPrefs(): Promise<{ [key: string]: string }> {
         profile + "user.js",
     ]
     let promises = []
-    let prers = {}
     // Starting all promises before awaiting because we want the calls to be
     // made in parallel
     for (let file of prefFiles) {
@@ -400,3 +403,23 @@ export async function getPrefs(): Promise<{ [key: string]: string }> {
 export async function getPref(name: string): Promise<string> {
     return (await getPrefs())[name]
 }
+
+/** Writes a preference to user.js */
+export async function writePref(name: string, value: any) {
+    if (typeof value == "string") value = `"${value}"`
+    const file = (await getProfileDir()) + "/user.js"
+    // No need to check the return code because read returns "" when failing to
+    // read a file
+    const text = (await read(file)).content
+    let prefPos = text.indexOf(`pref("${name}",`)
+    if (prefPos < 0) {
+        write(file, `${text}\nuser_pref("${name}", ${value});\n`)
+    } else {
+        let substr = text.substring(prefPos)
+        let prefEnd = substr.indexOf(";\n")
+        console.log(text, substr, prefPos, prefEnd)
+        substr = text.substring(prefPos, prefPos + prefEnd)
+        console.log(substr)
+        write(file, text.replace(substr, `pref("${name}", ${value})`))
+    }
+}