Add temporary appview-proxy header toggle (#874)

src/lib/api/debug-appview-proxy-header.ts

@@ -0,0 +1,57 @@
+/**
+ * APP-700
+ *
+ * This is a temporary debug setting we're running on the Web build to
+ * help the protocol team test some changes.
+ *
+ * It should be removed in ~2 weeks. It should only be used on the Web
+ * version of the app.
+ */
+
+import {useState, useCallback} from 'react'
+import {BskyAgent} from '@atproto/api'
+import {isWeb} from 'platform/detection'
+
+export function useDebugHeaderSetting(agent: BskyAgent): [boolean, () => void] {
+  const [enabled, setEnabled] = useState<boolean>(isEnabled())
+
+  const toggle = useCallback(() => {
+    if (!enabled) {
+      localStorage.setItem('set-header-x-appview-proxy', 'yes')
+      agent.api.xrpc.setHeader('x-appview-proxy', 'true')
+      setEnabled(true)
+    } else {
+      localStorage.removeItem('set-header-x-appview-proxy')
+      agent.api.xrpc.unsetHeader('x-appview-proxy')
+      setEnabled(false)
+    }
+  }, [setEnabled, enabled, agent])
+
+  return [enabled, toggle]
+}
+
+export function setDebugHeader(agent: BskyAgent, enabled: boolean) {
+  if (!isWeb) {
+    return
+  }
+  if (enabled) {
+    localStorage.setItem('set-header-x-appview-proxy', 'yes')
+    agent.api.xrpc.setHeader('x-appview-proxy', 'true')
+  } else {
+    localStorage.removeItem('set-header-x-appview-proxy')
+    agent.api.xrpc.unsetHeader('x-appview-proxy')
+  }
+}
+
+export function applyDebugHeader(agent: BskyAgent) {
+  if (!isWeb) {
+    return
+  }
+  if (isEnabled()) {
+    agent.api.xrpc.setHeader('x-appview-proxy', 'true')
+  }
+}
+
+function isEnabled() {
+  return localStorage.getItem('set-header-x-appview-proxy') === 'yes'
+}