fix(linux): repair FieldLens CUPS queues with one privilege prompt

src-tauri/src/printers.rs

@@ -99,6 +99,75 @@ finally:
             pass
 "#;
 
+#[cfg(target_os = "linux")]
+const FIELDLENS_CUPS_REPAIR_HELPER: &str = r#"#!/usr/bin/python3
+import os
+import subprocess
+import sys
+import tempfile
+
+target_printer = sys.argv[1]
+target_port = sys.argv[2]
+temp_filter = sys.argv[3]
+filter_path = sys.argv[4]
+
+source_ppd = os.path.join("/etc/cups/ppd", f"{target_printer}.ppd")
+spool_dir = "/var/cache/cups/fieldlens-print"
+
+with open(source_ppd, "r", encoding="utf-8", errors="replace") as source:
+    original = source.read()
+
+cleaned = "\n".join(
+    line for line in original.splitlines()
+    if "fieldlens-capture" not in line
+) + "\n"
+
+prefilter = (
+    "*% FieldLens original-document capture before cups-filters universal conversion\n"
+    "*cupsPreFilter: \"application/vnd.universal-input 0 fieldlens-capture\"\n"
+)
+
+index = cleaned.rfind("*% End")
+if index >= 0:
+    cleaned = cleaned[:index] + prefilter + cleaned[index:]
+else:
+    cleaned += prefilter
+
+fd, ppd_path = tempfile.mkstemp(prefix="fieldlens-", suffix=".ppd")
+os.close(fd)
+
+try:
+    with open(ppd_path, "w", encoding="utf-8") as target:
+        target.write(cleaned)
+
+    subprocess.run(["install", "-m", "0755", temp_filter, filter_path], check=True)
+    subprocess.run(["install", "-d", "-m", "0777", spool_dir], check=True)
+
+    subprocess.run([
+        "lpadmin", "-p", "FieldLens-Print", "-E",
+        "-v", target_port,
+        "-P", ppd_path,
+        "-D", "FieldLens Print",
+    ], check=True)
+
+    subprocess.run([
+        "lpadmin", "-p", "FieldLens-Test-Capture", "-E",
+        "-v", "socket://127.0.0.1:9101",
+        "-P", ppd_path,
+        "-D", "FieldLens Test Capture",
+    ], check=True)
+
+    for queue in ("FieldLens-Print", "FieldLens-Test-Capture"):
+        subprocess.run(["cupsenable", queue], check=True)
+        subprocess.run(["cupsaccept", queue], check=True)
+finally:
+    try:
+        os.unlink(ppd_path)
+    except OSError:
+        pass
+"#;
+
+
 #[derive(Debug, Clone, Serialize, Deserialize)]
 #[serde(rename_all = "camelCase")]
 pub struct SystemPrinter {
@@ -603,51 +672,42 @@ fn install_linux_virtual_printer(target_printer: &str) -> Result<()> {
             "selected printer '{target_printer}' is not installed or available in CUPS"
         ))?;
 
-    install_linux_capture_filter()?;
-    let ppd_path = build_fieldlens_ppd(target_printer)?;
+    let filter_dir = cups_filter_dir()?;
+    let filter_path = filter_dir.join("fieldlens-capture");
 
-    let production_args = vec![
-        "-p".to_string(),
-        "FieldLens-Print".to_string(),
-        "-E".to_string(),
-        "-v".to_string(),
-        target.port.clone(),
-        "-P".to_string(),
-        ppd_path.to_string_lossy().into_owned(),
-        "-D".to_string(),
-        VIRTUAL_PRINTER_NAME.to_string(),
-    ];
-    run_linux_admin(
-        "lpadmin",
-        &production_args,
-        "configure FieldLens production CUPS printer",
-    )?;
+    let temp_filter = std::env::temp_dir().join(format!(
+        "fieldlens-capture-{}.py",
+        uuid::Uuid::new_v4()
+    ));
+    let temp_helper = std::env::temp_dir().join(format!(
+        "fieldlens-cups-repair-{}.py",
+        uuid::Uuid::new_v4()
+    ));
 
-    let test_args = vec![
-        "-p".to_string(),
-        TEST_VIRTUAL_PRINTER_QUEUE.to_string(),
-        "-E".to_string(),
-        "-v".to_string(),
-        TEST_CAPTURE_DEVICE_URI.to_string(),
-        "-P".to_string(),
-        ppd_path.to_string_lossy().into_owned(),
-        "-D".to_string(),
-        TEST_VIRTUAL_PRINTER_NAME.to_string(),
-    ];
-    let test_result = run_linux_admin(
-        "lpadmin",
-        &test_args,
-        "configure FieldLens test-capture CUPS printer",
-    );
-    let _ = fs::remove_file(&ppd_path);
-    test_result?;
+    fs::write(&temp_filter, FIELDLENS_CUPS_FILTER)
+        .context("write FieldLens CUPS capture filter")?;
+    fs::write(&temp_helper, FIELDLENS_CUPS_REPAIR_HELPER)
+        .context("write FieldLens CUPS repair helper")?;
 
-    // Explicitly repair both CUPS state flags because Chromium disables Print
-    // when either is stale.
-    for queue in ["FieldLens-Print", TEST_VIRTUAL_PRINTER_QUEUE] {
-        run_cups_repair_command("cupsenable", &[queue])?;
-        run_cups_repair_command("cupsaccept", &[queue])?;
+    let status = Command::new("pkexec")
+        .arg("python3")
+        .arg(&temp_helper)
+        .arg(target_printer)
+        .arg(&target.port)
+        .arg(&temp_filter)
+        .arg(&filter_path)
+        .status()
+        .context("run elevated FieldLens CUPS repair")?;
+
+    let _ = fs::remove_file(&temp_filter);
+    let _ = fs::remove_file(&temp_helper);
+
+    if !status.success() {
+        return Err(anyhow!(
+            "FieldLens printer repair failed; administrator approval may be required"
+        ));
     }
+
     Ok(())
 }