WIP: Add completion support for bash

pkg/command/completion.go

@@ -5,16 +5,26 @@ import (
 	"fmt"
 )
 
+const (
+	bashBaseDir = "/usr/share/bash-completion/completions/"
+)
+
 //go:embed completion/cfg.zsh
 var zshCompletionScript string
 
+//go:embed completion/cfg.bash
+var bashCompletionScript string
+
 func RunCompletion(args []string) int {
 	if len(args) == 0 {
 		return 1
 	}
 
-	if args[0] == "zsh" {
+	switch args[0] {
+	case "zsh":
 		fmt.Print(zshCompletionScript)
+	case "bash":
+		fmt.Print(bashCompletionScript)
 	}
 	return 0
 }

pkg/command/completion/cfg.bash

@@ -0,0 +1,107 @@
+#!/bin/bash
+
+# $1 The name of the command
+# $2 The current word being completed (empty unless we are in the middle of typing a word).
+# $3 The word before the word being completed.
+# COMP_WORDS: an array of all the words typed after the name of the program the compspec belongs to;
+# COMP_CWORD: the index of the word the cursor was when the tab key was pressed;
+# COMP_LINE: the current command line.
+
+# complete -W "init completion git help" config: adds words to completion
+# complete -A <directory> config: adds directories to completion (can us a command to retrieve the current dirs or something similar)
+
+# We need to find the last subcommand if there was one, ignoring the flags
+# We will do this by working backwards through COMP_WORDS starting at COMP_CWORD until we reach a subcommand
+# While going through the flags, add flags to a list of flags that have already been completed
+# When we determine the subcommand, execute the subcommands function
+# Once in the function, determine the current list of flags that have no been executed yet and return them
+# Complete the flag if we only have one possibility
+# When we have a flag that has not been populated, only completed, provide nothing for args that arent directories, or autocomplete dirs if needed.
+# _cfg_subcommand()
+# {
+#
+# }
+
+_cfg_init() {
+	case "${COMP_WORDS[$COMP_CWORD - 1]}" in
+	--url) # Output the completion file for shell (bash|zsh)
+		;;
+	--git.dir) # Initialise the cfg cli
+		COMPREPLY=($(compgen -W "~/.dotfiles" "${COMP_WORDS[$COMP_CWORD]}"))
+		;;
+	--work.tree) # Run git for managing config files
+		COMPREPLY=($(compgen -W "~/" "${COMP_WORDS[$COMP_CWORD]}"))
+		;;
+	--ssh.key) # Add bash | zsh completion, at this point stop doing completion
+		COMPREPLY=($(compgen -W "~/.ssh/id_rsa" "${COMP_WORDS[$COMP_CWORD]}"))
+		;;
+	*)
+		flags=("--url" "--git.dir" "--work.tree" "--ssh.key")
+		filtered=()
+		for i in "${flags[@]}"; do
+			skip=
+			for j in "${COMP_WORDS[@]}"; do
+				[[ $i == $j ]] && {
+					skip=1
+					break
+				}
+			done
+			[[ -n $skip ]] || filtered+=("$i")
+		done
+		[[ ${#filtered[@]} -ne 0 ]] && COMPREPLY=($(compgen -W "${filtered[*]}" -- "${COMP_WORDS[COMP_CWORD]}"))
+		;;
+	esac
+}
+
+_cfg_completion() {
+	COMPREPLY=($(compgen -W "bash zsh" "${COMP_WORDS[$COMP_CWORD]}"))
+}
+
+_cfg_git() {
+	COMPREPLY=($(compgen -W "--help" "${COMP_WORDS[$COMP_CWORD]}"))
+}
+
+_cfg_completions() {
+	if [ -z "$1" ]; then
+		# display usage and exit when no args
+		cfg -h
+		return
+	fi
+
+	subcommand=""
+	for i in "${COMP_WORDS[@]}"; do
+		if [ "$i" == "$2" ]; then
+			break
+		fi
+		if [ -z "$i" ]; then
+			break
+		fi
+		if [[ "$i" == "-"* ]]; then
+			break
+		fi
+		subcommand="$i"
+	done
+
+	shift
+	case "$subcommand" in
+	completion) # Output the completion file for shell (bash|zsh)
+		_cfg_completion "$@"
+		;;
+	init) # Initialise the cfg cli
+		_cfg_init "$@"
+		;;
+	git) # Run git for managing config files
+		_cfg_git "$@"
+		;;
+	bash | zsh) # Add bash | zsh completion, at this point stop doing completion
+		return $?
+		;;
+	*)
+		subcommand="$1"
+		COMPREPLY=($(compgen -W "init completion git help" "${COMP_WORDS[1]}"))
+		;;
+	esac
+	return $?
+}
+
+complete -F _cfg_completions cfg