1 files changed, 89 insertions, 0 deletions
diff --git a/background.js b/background.js
new file mode 100644
index 0000000..ff88355
--- /dev/null
+++ b/background.js
@@ -0,0 +1,89 @@
+(async function() {
+
+/*
+
+"init" => what it sounds like, basic setup things
+"tumblr" => ok, we have oauth2 creds, now let's authorize with the user!
+"ready" => alright! main thing!!
+
+*/
+let {system_state, tumblr_expiry_date} = await chrome.storage.local.get({"system_state": "init", "tumblr_expiry_date": 0});
+
+let refreshTimeout = (system_state == "ready") ? setTimeout(refreshToken, Date.now() - tumblr_expiry_date) : null;
+
+async function refreshToken() {
+  const { tumblr_refresh_token, oauth_consumer_key, oauth_secret_key } = await chrome.storage.local.get(["tumblr_refresh_token", "oauth_consumer_key", "oauth_secret_key"]);
+
+  const form = new FormData();
+  form.append("grant_type", "refresh_token");
+  form.append("refresh_token", tumblr_refresh_token);
+  form.append("client_id", oauth_consumer_key);
+  form.append("client_secret", oauth_secret_key);
+  const {expires_in, access_token, refresh_token} = await fetch("https://api.tumblr.com/v2/oauth2/token", {body: form, method: "POST"}).then(a => a.json());
+  const tumblr_expiry_date = expires_in * 1000 + Date.now();
+
+  await chrome.storage.local.set({tumblr_expiry_date, tumblr_access_token: access_token, tumblr_refresh_token: refresh_token});
+
+  refreshTimeout = setTimeout(refreshToken, expires_in * 1000);
+
+}
+
+async function doNextThing(startup) {
+  switch (system_state) {
+    case "init":
+      await chrome.tabs.create({url: "chrome-extension://"+chrome.runtime.id+"/init.html"});
+      break;
+    case "tumblr":
+      let {oauth_consumer_key} = await chrome.storage.local.get(["oauth_consumer_key"]);
+      await chrome.tabs.create({url: "https://tumblr.com/oauth2/authorize?response_type=code&scope=basic%20offline_access%20write&state=NA&client_id="+oauth_consumer_key});
+  }
+}
+
+chrome.runtime.onMessage.addListener(async function({id, type, payload}, sender) {
+  console.debug(`Got message "${type}"@"${id}", payload ${JSON.stringify(payload)}`);
+  switch (type) {
+  case "set_creds":
+    const {oauth_consumer_key, oauth_secret_key} = payload;
+    clearTimeout(refreshTimeout);
+    system_state = "tumblr";
+    await chrome.storage.local.set({system_state, oauth_consumer_key, oauth_secret_key});
+
+    doNextThing();
+
+    if (sender.tab) {
+      await chrome.tabs.sendMessage(sender.tab.id, {id, status: "OK"});
+    }
+    return;
+  default:
+    if (sender.tab) {
+      chrome.tabs.sendMessage(sender.tab.id, {id, status: "ERRUNDEF", message: "No message type `"+type+"`!"});
+    }
+    return;
+  }
+});
+
+chrome.tabs.onUpdated.addListener(async function(tabId, {url}, tab) {
+  if (system_state == "tumblr" && url?.startsWith("https://example.com/tfm_redirect")) {
+    const { oauth_consumer_key, oauth_secret_key } = await chrome.storage.local.get(["oauth_consumer_key", "oauth_secret_key"]);
+
+    const code = /code=([a-fA-F0-9]+)/.exec(url)[1];
+
+    const form = new FormData();
+    form.append("grant_type", "authorization_code");
+    form.append("code", code);
+    form.append("client_id", oauth_consumer_key);
+    form.append("client_secret", oauth_secret_key);
+    const {expires_in, access_token, refresh_token} = await fetch("https://api.tumblr.com/v2/oauth2/token", {body: form, method: "POST"}).then(a => a.json());
+
+    const tumblr_expiry_date = expires_in * 1000 + Date.now();
+    await chrome.storage.local.set({system_state: "ready", tumblr_expiry_date, tumblr_access_token: access_token, tumblr_refresh_token: refresh_token});
+    clearTimeout(refreshTimeout);
+    refreshTimeout = setTimeout(refreshToken, expires_in * 1000);
+
+    await chrome.tabs.update(tabId, {url: "chrome-extension://"+chrome.runtime.id+"/ui.html"});
+  }
+});
+
+doNextThing(true);
+
+})();