Wrapper around bluetoothctl

btctl

#!/usr/bin/env python3
import sys
import re
import pexpect


class QuitError(Exception):
    pass


class InvalidInputError(Exception):
    pass


def decode(bstr):
    if bstr:
        return bstr.decode("ascii")
    return ""


PROMPT_PREFIX = "\x1b[0;94m["
PROMPT_ALIAS_END = "]"
PROMPT_SUFFIX = "\x1b[0m# "


def get_output(proc):
    try:
        proc.expect_exact(PROMPT_PREFIX)
        stdout = decode(proc.before)

        alias_chars = []
        while True:
            char = decode(proc.read(1))
            if char == PROMPT_ALIAS_END:
                break
            alias_chars.append(char)
        alias = "".join(alias_chars)

        proc.expect_exact(PROMPT_SUFFIX)

    except pexpect.EOF:
        raise QuitError()
    except pexpect.TIMEOUT:
        print("[btctl] Error: bluetootctl timed out")
        raise QuitError()

    try:
        while True:
            proc.expect("\n", timeout=0.01)
            stdout += decode(proc.before)
    except pexpect.EOF:
        raise QuitError()
    except pexpect.TIMEOUT:
        pass

    return alias, stdout


def get_stdin(proc, alias, stdin=False):
    if not stdin:
        stdin = input(f"{PROMPT_PREFIX}{alias}{PROMPT_ALIAS_END}{PROMPT_SUFFIX}")

    if "{" in stdin:
        proc.sendline("paired-devices")

        _, out = get_output(proc)
        aliases = {}
        for line in out.split("\r\n"):
            if not line.startswith("Device "):
                continue

            parts = line.split(" ")
            line_addr = parts[1]
            line_alias = " ".join(parts[2:])

            aliases[line_alias] = line_addr

    def replace_alias(match):
        to_replace = match.group(1)
        if to_replace in aliases:
            return aliases[to_replace]
        raise InvalidInputError(f"Alias \"{to_replace}\" does not exist")

    try:
        stdin = re.sub(r"\{(.*?)\}", replace_alias, stdin)
    except InvalidInputError as err:
        print(f"Invalid input: {err}")
        stdin = get_stdin(proc, alias)

    if stdin.strip() == "exit":
        raise QuitError()

    return stdin


proc = pexpect.spawn("bluetoothctl")

if __name__ == "__main__":
    try:
        if sys.__stdin__.isatty():
            while True:
                alias, stdout = get_output(proc)
                print(stdout)
                stdin = get_stdin(proc, alias)
                proc.sendline(stdin)
        else:
            for stdin in sys.__stdin__.readlines():
                alias, stdout = get_output(proc)
                print(stdout)
                proc.sendline(get_stdin(proc, alias, stdin=stdin))
            while "successful" not in stdout.lower() and "failed" not in stdout.lower():
                alias, stdout = get_output(proc)
                print(stdout.strip())

    except KeyboardInterrupt:
        pass
    except QuitError:
        pass

Necroing from, with my take on the issue, pure shell script to utilize the aliases.