Add a curl/wget one-line installer and popup setup detection

Add install-remote.sh, which fetches the latest release and runs its
install.sh so setup no longer needs a git clone. The popup now probes
the native host with a "ping" action on open and, if it's not
registered yet, shows the one-liner (with copy-to-clipboard) instead
of the auto-capture toggle -- so a Web Store install can be completed
end-to-end by clicking the extension icon and pasting one command.

README.md

@@ -14,6 +14,8 @@ browser's built-in downloader.
 - Linux with KGet installed and running (or set to autostart)
 - A Chromium-based browser: Chrome, Chromium, Brave, Vivaldi, or Edge
 - `python3`, `dbus-send`
+- `curl` or `wget`, for the one-line remote installer below (skip if you'd
+  rather download and run `install.sh` yourself)
 - `notify-send`, optional, for the completion notification
 - `kwriteconfig6` (KDE Frameworks), optional, silences KGet's own duplicate
   notification
@@ -49,22 +51,26 @@ without them.)
 
 1. Install the extension from the Chrome Web Store: **`<CHROME_WEB_STORE_URL>`**
    *(placeholder, fill in once the listing is live)*.
-2. Install the native messaging host that lets the extension talk to KGet.
-   Download and extract `kget-capture-vX.Y.Z.zip` (the source archive, not
-   `kget-capture-extension-vX.Y.Z.zip`) from the
-   [Releases page](https://github.com/andwati/kget-capture/releases), then
-   from inside that folder:
+2. Click the extension's toolbar icon. The popup detects that the native
+   messaging host isn't set up yet and shows a one-line command; run it in a
+   terminal, then click "I ran it, check again" in the popup:
    ```bash
-   ./install.sh
+   curl -fsSL https://raw.githubusercontent.com/andwati/kget-capture/main/install-remote.sh | bash
    ```
+   (or with `wget`: `wget -qO- https://raw.githubusercontent.com/andwati/kget-capture/main/install-remote.sh | bash`)
+
+   This downloads the latest release and runs its `install.sh`, which
+   registers the native host for every supported browser it finds installed
+   and prints any remaining setup warnings. No git clone required. If you'd
+   rather run it yourself: download and extract `kget-capture-vX.Y.Z.zip`
+   (the source archive, not `kget-capture-extension-vX.Y.Z.zip`) from the
+   [Releases page](https://github.com/andwati/kget-capture/releases), then
+   from inside that folder run `./install.sh` directly.
 3. Open your browser's download settings (`chrome://settings/downloads`,
    `brave://settings/downloads`, etc.) and turn **off** "Ask where to save
    each file before downloading". Chrome shows this dialog itself, before the
    extension gets a chance to intercept the download, so this one-time change
-   is required.
-
-`install.sh` registers the native host for every supported browser it finds
-installed and prints any remaining setup warnings.
+   is required (no extension API can do it for you).
 
 ### Building from source
 
@@ -131,6 +137,9 @@ Prebuilt releases are published on the
 
 ## Troubleshooting
 
+- **`install-remote.sh` fails to look up the latest release?** It queries
+  GitHub's API, which rate-limits unauthenticated requests (60/hour per IP);
+  wait a bit, or fall back to the manual `install.sh` steps in Install above.
 - **Check native host registration:** confirm
   `~/.config/<browser>/NativeMessagingHosts/com.kget_capture.host.json` exists
   and its `path` points at an executable file

extension/popup.css

@@ -1,5 +1,5 @@
 body {
-  width: 240px;
+  width: 320px;
   padding: 12px;
   font-family: system-ui, sans-serif;
   font-size: 13px;
@@ -36,3 +36,38 @@ h1 {
   font-family: inherit;
   cursor: pointer;
 }
+
+.cmd-row {
+  display: flex;
+  align-items: center;
+  gap: 6px;
+  margin-top: 8px;
+}
+
+.cmd-row code {
+  flex: 1;
+  min-width: 0;
+  overflow-x: auto;
+  white-space: nowrap;
+  background: #f0f0f0;
+  padding: 4px 6px;
+  border-radius: 3px;
+  font-size: 11px;
+}
+
+.cmd-row button {
+  flex: none;
+  padding: 4px 8px;
+  font-size: 12px;
+  font-family: inherit;
+  cursor: pointer;
+}
+
+#recheck-setup {
+  display: block;
+  margin-top: 10px;
+  padding: 4px 8px;
+  font-size: 12px;
+  font-family: inherit;
+  cursor: pointer;
+}

extension/popup.html

@@ -6,6 +6,19 @@
 </head>
 <body>
   <h1>KGet Capture</h1>
+
+  <div id="setup-needed" hidden>
+    <p class="hint">One-time setup needed: KGet Capture needs a small local
+      helper installed before it can talk to KGet. Run this in a terminal:</p>
+    <div class="cmd-row">
+      <code id="setup-command"></code>
+      <button id="copy-command" type="button">Copy</button>
+    </div>
+    <p class="status" id="copy-feedback"></p>
+    <button id="recheck-setup" type="button">I ran it, check again</button>
+  </div>
+
+  <div id="ready" hidden>
     <label class="toggle-row">
       <input type="checkbox" id="auto-capture-toggle">
       <span>Auto-capture all downloads</span>
@@ -17,6 +30,8 @@
       dialog itself, before this extension can intercept anything.
       <button id="open-download-settings" type="button">Turn off Chrome's download prompt</button>
     </p>
+  </div>
+
   <script src="popup.js"></script>
 </body>
 </html>

extension/popup.js

@@ -1,14 +1,61 @@
+const NATIVE_HOST = "com.kget_capture.host";
+const INSTALL_COMMAND =
+  "curl -fsSL https://raw.githubusercontent.com/andwati/kget-capture/main/install-remote.sh | bash";
+
+const setupPanel = document.getElementById("setup-needed");
+const readyPanel = document.getElementById("ready");
 const checkbox = document.getElementById("auto-capture-toggle");
 const statusLine = document.getElementById("status-line");
+const copyFeedback = document.getElementById("copy-feedback");
 
 function renderStatus(enabled) {
   statusLine.textContent = `Auto-capture: ${enabled ? "ON" : "OFF"}`;
 }
 
+function showReady() {
+  setupPanel.hidden = true;
+  readyPanel.hidden = false;
   chrome.storage.local.get({ autoCaptureEnabled: true }).then(({ autoCaptureEnabled }) => {
     checkbox.checked = autoCaptureEnabled;
     renderStatus(autoCaptureEnabled);
   });
+}
+
+function showSetupNeeded() {
+  document.getElementById("setup-command").textContent = INSTALL_COMMAND;
+  readyPanel.hidden = true;
+  setupPanel.hidden = false;
+}
+
+// The native host is only reachable once install.sh (or install-remote.sh)
+// has registered it -- sendNativeMessage fails with a lastError like
+// "Specified native messaging host not found" until then, which is exactly
+// the signal we want to gate the rest of the popup on.
+function checkNativeHost() {
+  chrome.runtime.sendNativeMessage(NATIVE_HOST, { action: "ping" }, () => {
+    if (chrome.runtime.lastError) {
+      showSetupNeeded();
+    } else {
+      showReady();
+    }
+  });
+}
+
+checkNativeHost();
+
+document.getElementById("recheck-setup").addEventListener("click", checkNativeHost);
+
+document.getElementById("copy-command").addEventListener("click", async () => {
+  try {
+    await navigator.clipboard.writeText(INSTALL_COMMAND);
+    copyFeedback.textContent = "Copied to clipboard.";
+  } catch (e) {
+    copyFeedback.textContent = "Couldn't copy -- select and copy the command manually.";
+  }
+  setTimeout(() => {
+    copyFeedback.textContent = "";
+  }, 2000);
+});
 
 checkbox.addEventListener("change", () => {
   chrome.storage.local.set({ autoCaptureEnabled: checkbox.checked });

install-remote.sh

@@ -0,0 +1,60 @@
+#!/usr/bin/env bash
+# Fetches the latest release source archive and runs install.sh from it, so
+# setup doesn't require a git clone:
+#
+#   curl -fsSL https://raw.githubusercontent.com/andwati/kget-capture/main/install-remote.sh | bash
+#   wget -qO- https://raw.githubusercontent.com/andwati/kget-capture/main/install-remote.sh | bash
+set -euo pipefail
+
+REPO="andwati/kget-capture"
+
+fetch_stdout() {
+  if command -v curl >/dev/null 2>&1; then
+    curl -fsSL "$1"
+  elif command -v wget >/dev/null 2>&1; then
+    wget -qO- "$1"
+  else
+    echo "ERROR: this installer needs 'curl' or 'wget' on PATH." >&2
+    exit 1
+  fi
+}
+
+fetch_to_file() {
+  if command -v curl >/dev/null 2>&1; then
+    curl -fsSL "$1" -o "$2"
+  else
+    wget -qO "$2" "$1"
+  fi
+}
+
+echo "Looking up the latest release..."
+tag="$(fetch_stdout "https://api.github.com/repos/$REPO/releases/latest" \
+  | grep -m1 '"tag_name"' | sed -E 's/.*"tag_name": *"([^"]+)".*/\1/')"
+if [ -z "$tag" ]; then
+  echo "ERROR: couldn't determine the latest release tag from GitHub." >&2
+  exit 1
+fi
+echo "Latest release: $tag"
+
+if ! command -v python3 >/dev/null 2>&1; then
+  echo "ERROR: 'python3' is required but not found on PATH." >&2
+  exit 1
+fi
+
+tmp_dir="$(mktemp -d)"
+trap 'rm -rf "$tmp_dir"' EXIT
+
+zip_path="$tmp_dir/kget-capture.zip"
+zip_url="https://github.com/$REPO/releases/download/$tag/kget-capture-$tag.zip"
+echo "Downloading $zip_url..."
+fetch_to_file "$zip_url" "$zip_path"
+
+echo "Extracting..."
+src_dir="$tmp_dir/src"
+python3 -c "
+import sys, zipfile
+zipfile.ZipFile(sys.argv[1]).extractall(sys.argv[2])
+" "$zip_path" "$src_dir"
+
+echo "Running install.sh..."
+bash "$src_dir/install.sh"

native-host/kget_capture_host.py

@@ -154,7 +154,17 @@ def spawn_notifier(transfer_path, dest):
 
 def main():
     message = read_message()
-    if not message or message.get("action") != "addTransfer" or "url" not in message:
+    if not message:
+        write_message({"ok": False, "error": "invalid request"})
+        return
+
+    # The extension popup uses this to detect whether the native host is
+    # installed/registered at all, distinct from whether a transfer succeeds.
+    if message.get("action") == "ping":
+        write_message({"ok": True})
+        return
+
+    if message.get("action") != "addTransfer" or "url" not in message:
         write_message({"ok": False, "error": "invalid request"})
         return