Add shell completion for --device and --reader

ykman/_cli/__main__.py

@@ -34,10 +34,11 @@
 
 from .. import __version__
 from ..pcsc import list_devices as list_ccid, list_readers
-from ..device import scan_devices, list_all_devices
+from ..device import scan_devices, list_all_devices as _list_all_devices
 from ..util import get_windows_version
 from ..logging import init_logging
 from ..diagnostics import get_diagnostics, sys_info
+from ..settings import AppData
 from .util import YkmanContextObject, click_group, EnumChoice, CliFail, pretty_print
 from .info import info
 from .otp import otp
@@ -52,6 +53,7 @@
 from .hsmauth import hsmauth
 
 import click
+import click.shell_completion
 import ctypes
 import time
 import sys
@@ -114,6 +116,22 @@ def require_reader(connection_types, reader):
         raise CliFail("Not a CCID command.")
 
 
+def list_all_devices(*args, **kwargs):
+    devices = _list_all_devices(*args, **kwargs)
+    with_serial = [(dev, dev_info) for (dev, dev_info) in devices if dev_info.serial]
+    if with_serial:
+        history = AppData("history")
+        cache = history.setdefault("devices", {})
+        for dev, dev_info in with_serial:
+            if dev_info.serial:
+                k = str(dev_info.serial)
+                cache[k] = cache.pop(k, None) or _describe_device(dev, dev_info, False)
+        # 5, chosen by fair dice roll
+        [cache.pop(k) for k in list(cache.keys())[: -max(5, len(with_serial))]]
+        history.write()
+    return devices
+
+
 def require_device(connection_types, serial=None):
     # Find all connected devices
     devices, state = scan_devices()
@@ -126,6 +144,7 @@ def require_device(connection_types, serial=None):
             except TimeoutError:
                 raise CliFail("No YubiKey detected!")
         if n_devs > 1:
+            list_all_devices()  # Update device cache
             raise CliFail(
                 "Multiple YubiKeys detected. Use --device SERIAL to specify "
                 "which one to use."
@@ -151,12 +170,19 @@ def require_device(connection_types, serial=None):
             raise CliFail("Failed to connect to YubiKey.")
         return devs[0]
     else:
-        for _ in (0, 1):  # If no match initially, wait a bit for state change.
+        for retry in (
+            True,
+            False,
+        ):  # If no match initially, wait a bit for state change.
             devs = list_all_devices(connection_types)
-            for dev, nfo in devs:
-                if nfo.serial == serial:
-                    return dev, nfo
-            devices, state = _scan_changes(state)
+            for dev, dev_info in devs:
+                if dev_info.serial == serial:
+                    return dev, dev_info
+            try:
+                if retry:
+                    _, state = _scan_changes(state)
+            except TimeoutError:
+                break
 
         raise CliFail(
             f"Failed connecting to a YubiKey with serial: {serial}.\n"
@@ -171,6 +197,14 @@ def require_device(connection_types, serial=None):
     type=int,
     metavar="SERIAL",
     help="specify which YubiKey to interact with by serial number",
+    shell_complete=lambda ctx, param, incomplete: [
+        click.shell_completion.CompletionItem(
+            serial,
+            help=description,
+        )
+        for serial, description in AppData("history").get("devices", {}).items()
+        if serial.startswith(incomplete)
+    ],
 )
 @click.option(
     "-r",
@@ -179,6 +213,9 @@ def require_device(connection_types, serial=None):
     "(can't be used with --device or list)",
     metavar="NAME",
     default=None,
+    shell_complete=lambda ctx, param, incomplete: [
+        f'"{reader.name}"' for reader in list_readers()
+    ],
 )
 @click.option(
     "-l",
@@ -306,13 +343,8 @@ def list_keys(ctx, serials, readers):
             if dev_info.serial:
                 click.echo(dev_info.serial)
         else:
-            if dev.pid is None:  # Devices from list_all_devices should always have PID.
-                raise AssertionError("PID is None")
-            name = get_name(dev_info, dev.pid.yubikey_type)
-            version = dev_info.version or "unknown"
-            mode = dev.pid.name.split("_", 1)[1].replace("_", "+")
             click.echo(
-                f"{name} ({version}) [{mode}]"
+                _describe_device(dev, dev_info)
                 + (f" Serial: {dev_info.serial}" if dev_info.serial else "")
             )
         pids.add(dev.pid)
@@ -328,6 +360,18 @@ def list_keys(ctx, serials, readers):
                     click.echo(f"{name} [{mode}] <access denied>")
 
 
+def _describe_device(dev, dev_info, include_mode=True):
+    if dev.pid is None:  # Devices from list_all_devices should always have PID.
+        raise AssertionError("PID is None")
+    name = get_name(dev_info, dev.pid.yubikey_type)
+    version = dev_info.version or "unknown"
+    description = f"{name} ({version})"
+    if include_mode:
+        mode = dev.pid.name.split("_", 1)[1].replace("_", "+")
+        description += f" [{mode}]"
+    return description
+
+
 COMMANDS = (
     list_keys,
     info,