autocompletion.go

/*
Copyright 2017 WALLIX

Licensed under the Apache License, Version 2.0 (the "License");
you may not use this file except in compliance with the License.
You may obtain a copy of the License at

    http://www.apache.org/licenses/LICENSE-2.0

Unless required by applicable law or agreed to in writing, software
distributed under the License is distributed on an "AS IS" BASIS,
WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
See the License for the specific language governing permissions and
limitations under the License.
*/

package commands

import (
	"bufio"
	"bytes"
	"os"

	"github.com/spf13/cobra"
)

func init() {
	autocompleteCmd.AddCommand(bashAutocompleteCmd)
	autocompleteCmd.AddCommand(zshAutocompleteCmd)

	RootCmd.AddCommand(autocompleteCmd)
}

var autocompleteCmd = &cobra.Command{
	Use:   "completion",
	Short: "Output shell completion code for the given shell (bash or zsh)",
	Long: `
Output shell completion code for bash or zsh
This command prints shell code which must be evaluated to provide interactive
completion of awless commands.

Bash
	$ source <(awless completion bash)
will load the awless completion code for bash. Note that this depends on the
bash-completion framework. It must be sourced before sourcing the awless
completion, e.g. on macOS:
	$ brew install bash-completion
	$ source $(brew --prefix)/etc/bash_completion
	$ source <(awless completion bash)
	(or, if you want to preserve completion within new terminal sessions)
	$ echo 'source <(awless completion bash)\n' >> ~/.bashrc

Zsh
	$ source <(awless completion zsh)
	(or, if you want to preserve completion within new terminal sessions)
	$ echo 'source <(awless completion zsh)\n' >> ~/.zshrc`,
}

var bashAutocompleteCmd = &cobra.Command{
	Use:   "bash",
	Short: "Output shell completion code for bash",
	Long: `
Output shell completion code for bash.
This command prints shell code which must be evaluated to provide interactive
completion of awless commands.
	$ source <(awless completion bash)
will load the awless completion code for bash. Note that this depends on the
bash-completion framework. It must be sourced before sourcing the awless
completion, e.g. on macOS:
	$ brew install bash-completion
	$ source $(brew --prefix)/etc/bash_completion
	$ source <(awless completion bash)
	(or, if you want to preserve completion within new terminal sessions)
	$ echo 'source <(awless completion bash)\n' >> ~/.bashrc`,
	RunE: runCompletionBash,
}

var zshAutocompleteCmd = &cobra.Command{
	Use:   "zsh",
	Short: "List users",
	Long: `
Output shell completion code for zsh.
This command prints shell code which must be evaluated to provide interactive
completion of awless commands.
	$ source <(awless completion zsh)
	(or, if you want to preserve completion within new terminal sessions)
	$ echo 'source <(awless completion zsh)\n' >> ~/.zshrc
zsh completions are only supported in versions of zsh >= 5.2`,
	RunE: runCompletionZsh,
}

func runCompletionBash(cmd *cobra.Command, args []string) error {
	out := bufio.NewWriter(os.Stdout)
	defer out.Flush()
	return RootCmd.GenBashCompletion(out)
}

// Copyright 2016 The Kubernetes Authors.
//
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
//     http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.
func runCompletionZsh(cmd *cobra.Command, args []string) error {
	out := bufio.NewWriter(os.Stdout)
	defer out.Flush()
	zshInitialization := `
__awless_bash_source() {
	alias shopt=':'
	alias _expand=_bash_expand
	alias _complete=_bash_comp
	emulate -L sh
	setopt kshglob noshglob braceexpand
	source "$@"
}
__awless_type() {
	# -t is not supported by zsh
	if [ "$1" == "-t" ]; then
		shift
		# fake Bash 4 to disable "complete -o nospace". Instead
		# "compopt +-o nospace" is used in the code to toggle trailing
		# spaces. We don't support that, but leave trailing spaces on
		# all the time
		if [ "$1" = "__awless_compopt" ]; then
			echo builtin
			return 0
		fi
	fi
	type "$@"
}
__awless_compgen() {
	local completions w
	completions=( $(compgen "$@") ) || return $?
	# filter by given word as prefix
	while [[ "$1" = -* && "$1" != -- ]]; do
		shift
		shift
	done
	if [[ "$1" == -- ]]; then
		shift
	fi
	for w in "${completions[@]}"; do
		if [[ "${w}" = "$1"* ]]; then
			echo "${w}"
		fi
	done
}
__awless_compopt() {
	true # don't do anything. Not supported by bashcompinit in zsh
}
__awless_declare() {
	if [ "$1" == "-F" ]; then
		whence -w "$@"
	else
		builtin declare "$@"
	fi
}
__awless_ltrim_colon_completions()
{
	if [[ "$1" == *:* && "$COMP_WORDBREAKS" == *:* ]]; then
		# Remove colon-word prefix from COMPREPLY items
		local colon_word=${1%${1##*:}}
		local i=${#COMPREPLY[*]}
		while [[ $((--i)) -ge 0 ]]; do
			COMPREPLY[$i]=${COMPREPLY[$i]#"$colon_word"}
		done
	fi
}
__awless_get_comp_words_by_ref() {
	cur="${COMP_WORDS[COMP_CWORD]}"
	prev="${COMP_WORDS[${COMP_CWORD}-1]}"
	words=("${COMP_WORDS[@]}")
	cword=("${COMP_CWORD[@]}")
}
__awless_filedir() {
	local RET OLD_IFS w qw
	__debug "_filedir $@ cur=$cur"
	if [[ "$1" = \~* ]]; then
		# somehow does not work. Maybe, zsh does not call this at all
		eval echo "$1"
		return 0
	fi
	OLD_IFS="$IFS"
	IFS=$'\n'
	if [ "$1" = "-d" ]; then
		shift
		RET=( $(compgen -d) )
	else
		RET=( $(compgen -f) )
	fi
	IFS="$OLD_IFS"
	IFS="," __debug "RET=${RET[@]} len=${#RET[@]}"
	for w in ${RET[@]}; do
		if [[ ! "${w}" = "${cur}"* ]]; then
			continue
		fi
		if eval "[[ \"\${w}\" = *.$1 || -d \"\${w}\" ]]"; then
			qw="$(__awless_quote "${w}")"
			if [ -d "${w}" ]; then
				COMPREPLY+=("${qw}/")
			else
				COMPREPLY+=("${qw}")
			fi
		fi
	done
}
__awless_quote() {
    if [[ $1 == \'* || $1 == \"* ]]; then
        # Leave out first character
        printf %q "${1:1}"
    else
    	printf %q "$1"
    fi
}
autoload -U +X bashcompinit && bashcompinit
# use word boundary patterns for BSD or GNU sed
LWORD='[[:<:]]'
RWORD='[[:>:]]'
if sed --help 2>&1 | grep -q GNU; then
	LWORD='\<'
	RWORD='\>'
fi
__awless_convert_bash_to_zsh() {
	sed \
	-e 's/declare -F/whence -w/' \
	-e 's/local \([a-zA-Z0-9_]*\)=/local \1; \1=/' \
	-e 's/flags+=("\(--.*\)=")/flags+=("\1"); two_word_flags+=("\1")/' \
	-e 's/must_have_one_flag+=("\(--.*\)=")/must_have_one_flag+=("\1")/' \
	-e "s/${LWORD}_filedir${RWORD}/__awless_filedir/g" \
	-e "s/${LWORD}_get_comp_words_by_ref${RWORD}/__awless_get_comp_words_by_ref/g" \
	-e "s/${LWORD}__ltrim_colon_completions${RWORD}/__awless_ltrim_colon_completions/g" \
	-e "s/${LWORD}compgen${RWORD}/__awless_compgen/g" \
	-e "s/${LWORD}compopt${RWORD}/__awless_compopt/g" \
	-e "s/${LWORD}declare${RWORD}/__awless_declare/g" \
	-e "s/\\\$(type${RWORD}/\$(__awless_type/g" \
	<<'BASH_COMPLETION_EOF'
`
	out.Write([]byte(zshInitialization))

	buf := new(bytes.Buffer)
	RootCmd.GenBashCompletion(buf)
	out.Write(buf.Bytes())

	zshTail := `
BASH_COMPLETION_EOF
}
__awless_bash_source <(__awless_convert_bash_to_zsh)
`
	out.Write([]byte(zshTail))
	return nil
}