✏ EDIT: _bluetoothctl

#compdef bluetoothctl

__bluetoothctl() {
	bluetoothctl "$@" 2>/dev/null
}

_bluezcomp_controller() {
	local -a controllers
	bluetoothctl list |
	while read _ MAC NAME; do
		controllers+="${MAC//:/\\:}:${NAME//:/\\:}"
	done
	_describe -t controllers 'controller' controllers
}

_bluezcomp_device() {
	local -a devices
	bluetoothctl devices |
	while read _ MAC NAME; do
		devices+="${MAC//:/\\:}:${NAME//:/\\:}"
	done
	_describe -t devices 'device' devices
}

_bluezcomp_agentcap() {
	local -a agent_options=(${(f)"$(__bluetoothctl agent help)"})
	agent_options=( "${(@)agent_options:#(on|off)}" )
	compadd -a agent_options
}

_bluetoothctl_agent() {
	local -a agent_options=(${(f)"$(__bluetoothctl agent help)"})
	agent_options+=help
	compadd -a agent_options
}

_bluetoothctl_advertise() {
	local -a ad_options=(${(f)"$(__bluetoothctl advertise help)"})
	ad_options+=help
	compadd -a ad_options
}

_bluetoothctl() {
	local -a toggle_commands=(
		"discoverable" "pairable" "power" "scan"
	)

local -a controller_commands=(
		"select" "show"
	)

local -a device_commands=(
		"block" "connect" "disconnect" "info"
		"pair" "remove" "trust" "unblock" "untrust"
	)

# Other commands may be handled by _bluetoothctl_$command
	local -a all_commands=( "${(@f)$(__bluetoothctl --zsh-complete help)}" )

local curcontext=$curcontext state line ret=1
	_arguments -C \
		+ '(info)' \
		{-h,--help}'[Show help message and exit]' \
		{-v,--version}'--version[Show version info and exit]' \
		+ 'mod' \
		'(info)'{-a+,--agent=}'[Register agent handler]:agent:_bluezcomp_agentcap' \
		'(info)'{-t,--timeout}'[Timeout in seconds for non-interactive mode]' \
		'(info)'{-m,--monitor}'[Enable monitor output]' \
		+ 'command' \
		'(info):command:->command' \
		'(info):: :->argument' \
		': :_message "no more arguments"'

if [[ $state == "command" ]]; then
		_describe -t commands 'command' all_commands
	elif [[ $state == "argument" ]]; then
		if (( ! ${"${(@)all_commands%%:*}"[(I)${line[1]}]} )); then
			_message "Unknown bluetoothctl command: $line[1]"
			return 1;
		fi

curcontext="${curcontext%:*:*}:bluetoothctl-$line[1]:"
		if ! _call_function ret _bluetoothctl_$line[1]; then
			case $line[1] in
				(${(~j.|.)toggle_commands})
					compadd on off
					;;
				(${(~j.|.)device_commands})
					_bluezcomp_device
					;;
				(${(~j.|.)controller_commands})
					_bluezcomp_controller
					;;
			esac
		fi
		return ret
	fi
} && _bluetoothctl

[✗] CANCEL