shell-git-config

#!/bin/sh -efu
### This file is covered by the GNU General Public License,
### which should be included with libshell as the file LICENSE.
### All copyright information are listed in the COPYING.

if [ -z "${__included_shell_git_config-}" ]; then
__included_shell_git_config=1

. shell-error
. shell-var
. shell-string

GIT_CONFIG_GET_RAW=
GIT_CONFIG_INCLUDE=1

__git_config_git_topdir()
{
	local __p="$2"
	while [ -n "$__p" ]; do
		[ ! -d "$__p/.git" ] ||
			break
		__p="${__p%/*}"
	done
	eval "$1=\"\$__p\""
}

__git_config_lc()
{
	local __lc="$2"
	[ -n "${2##*[A-Z]*}" ] ||
		__lc="$(printf '%s' "$2" |tr '[:upper:]' '[:lower:]')"
	eval "$1=\"\$__lc\""
}

# Parse incoming argument into pieces
__git_config_split()
{
	[ -z "${1##*.*}" ] ||
		fatal " key does not contain a section: $1"

	local sl nl

	__git_config_section="${1%%.*}"
	[ -n "${__git_config_section##*[!A-Za-z0-9-]*}" ] ||
		fatal "bad section name: $__git_config_section"
	__git_config_lc sl "$__git_config_section"

	__git_config_name="${1##*.}"
	[ -n "${__git_config_name##*[!A-Za-z0-9-]*}" ] ||
		fatal "bad variable name: $__git_config_name"
	__git_config_lc nl "$__git_config_name"

	__git_config_subsection="${1#*.}"
	[ "$__git_config_subsection" != "$__git_config_name" ] &&
		__git_config_subsection="${__git_config_subsection%.*}" ||
		__git_config_subsection=

	__git_config_location="$sl${__git_config_subsection:+.$__git_config_subsection}"
	__git_config_fullpath="$__git_config_location.$nl"
}

__git_config_fullpath()
{
	local __git_config_section __git_config_name __git_config_subsection
	__git_config_split "$1"
}

__git_config_value()
{
	local dq='' bq='' c='' m='' l="$1"
	fill_mask m "$l"

	value=
	while [ -n "$l" ]; do
		c="${l%$m}"
		l="${l#?}"
		m="${m#?}"

		case "$c" in
			\\)
				if [ -z "$bq" ]; then
					bq=1
					c=
				else
					bq=
				fi
				;;
			\")
				if [ -z "$bq" ]; then
					[ -z "$dq" ] && dq=1 || dq=
					c=
				else
					bq=
				fi
				;;
			b|n|t)
				if [ -n "$bq" ]; then
					bq=
					# shellcheck disable=SC2059
					# Disable `Don't use variables in the printf format string`
					# because we actually want to interpret data as a format string.
					c="$(printf "\\$c#")"
					c="${c%#}"
				fi
				;;
			*)
				bq=
				;;
		esac
		value="$value$c"
	done

	[ -z "$dq" ] ||
		fatal "bad config file line $nline in $fn"
}

git_config_handler() { :; }
git_config_parse_file()
{
	local fn="$1" name value section='' subsection='' section_lower='' name_lower='' location='' line oline nline=0 eof=''

	__git_config_parse_section()
	{
		local line="$1" invalid='[!A-Za-z0-9-.]'

		if [ -n "$section" ]; then
			location="$section_lower${subsection:+.$subsection}"
			git_config_handler 'section-end'
		fi

		section="$line"
		subsection=

		if [ -z "${line##*[ 	]*}" ]; then
			section="${line%%[ 	]*}"
			subsection="${line#*[ 	]\"}"
			subsection="${subsection%\"}"
			invalid="[!A-Za-z0-9-]"
		fi

		[ -n "${section##*$invalid*}" ] ||
			fatal "bad config file line $nline in $fn"

		__git_config_lc section_lower "$section"

		location="$section_lower${subsection:+.$subsection}"
		git_config_handler 'section-start'
	}
	__git_config_parse_variable()
	{
		shell_var_trim name "${1%%=*}"

		[ -z "${1##*=*}" ] &&
			shell_var_trim value "${1#*=}" ||
			value='true'

		shell_var_unquote value "$value"

		[ -n "${GIT_CONFIG_GET_RAW-}" ] ||
			__git_config_value "$value"

		__git_config_lc name_lower "$name"

		location="$section_lower.${subsection:+$subsection.}$name_lower"
		git_config_handler 'variable'
	}
	__git_config_expend_path()
	{
		local __i="$2"
		[ -n "${__i##./*}" ] || [ "$fn" = "${fn%/*}" ] ||
			__i="${fn%/*}/${__i#./}"

		[ -n "${__i##\~/*}" ] ||
			__i="$HOME/${__i#\~/}"

		[ -n "${__i##\~*}" ] ||
			fatal "expression isn't supported at line $nline in $fn"

		eval "$1=\"\$__i\""
	}
	__git_config_parse_include_or_if()
	{
		local i='' gitdir='' pattern=''

		[ -z "${2-}" ] ||
			case "$2" in
				'gitdir:'*)
					gitdir="${GIT_DIR-}"

					if [ -z "$gitdir" ]; then
						__git_config_git_topdir gitdir "${fn%/*}"
						[ -z "$gitdir" ] ||
							gitdir="$gitdir/.git"
					fi

					__git_config_expend_path pattern "${2#gitdir:}"

					[ -n "${pattern##*/}" ] && [ -n "${pattern##*/\*\*}" ] ||
						pattern="${pattern%/*}/*"

					[ -n "${pattern##\*\*/*}" ] ||
						pattern="*/${pattern#*/}"

					[ -z "${pattern##/*}" ] || [ -z "${pattern##\**}" ] ||
						pattern="*/$pattern"

					[ -z "${gitdir##$pattern}" ] ||
						return 0
					;;
				*)
					fatal "condition is not supported: $2"
					;;
			esac

		__git_config_expend_path i "$1"

		[ ! -e "$i" ] ||
			git_config_parse_file "$i"
	}
	__git_config_parse_include()
	{
		[ "$location" != 'include.path' ] ||
			__git_config_parse_include_or_if "$1"
	}
	__git_config_parse_includeif()
	{
		[ -n "${location##includeif.*.path}" ] || [ -z "$subsection" ] ||
			__git_config_parse_include_or_if "$1" "$subsection"
	}

	oline=
	while [ -z "$eof" ]; do
		nline=$(($nline + 1))

		IFS= read -r line || eof=1

		line="$oline$line"
		oline=

		case "$line" in
			'')
				;;
			*\\)
				oline="$line"
				;;
			'#'*|';'*)
				git_config_handler 'comment'
				;;
			'['*']'[' 	']*[!' 	']*)
				fatal "expression isn't supported at line $nline in $fn"
				;;
			'['*']')
				line="${line#\[}"
				line="${line%\]}"
				__git_config_parse_section "$line"
				;;
			*)
				__git_config_parse_variable "$line"

				if [ -n "$GIT_CONFIG_INCLUDE" ]; then
					__git_config_parse_include "$value"
					__git_config_parse_includeif "$value"
				fi
				;;
		esac
	done < "$fn"

	[ -n "$section" ] ||
		return 0
	location="$section_lower${subsection:+.$subsection}"
	git_config_handler 'section-end'
}

### Checks whether there is a specified variable in the configuration.
### Usage: git_config_location_exists file name
git_config_location_exists()
{
	local __git_config_location_exists=1 __git_config_fullpath __git_config_location
	git_config_handler()
	{
		[ "$__git_config_fullpath" != "$location" ] ||
			__git_config_location_exists=0
	}
	__git_config_fullpath "$2"
	git_config_parse_file "$1"
	return $__git_config_location_exists
}

### Gets variable from specified config file and store result into variable.
### Usage: git_config_get retname file name
git_config_get()
{
	local __git_config_v='' __git_config_fullpath __git_config_location
	git_config_handler()
	{
		[ "$1" != 'variable' ] || [ "$__git_config_fullpath" != "$location" ] ||
			__git_config_v="$value"
	}
	__git_config_fullpath "$3"
	git_config_parse_file "$2"
	eval "$1=\"\$__git_config_v\""
}

### Counts variable occurrences in specified config file and store result into variable.
### Usage: git_config_count retname file name
git_config_count()
{
	local __git_config_v=0 __git_config_fullpath __git_config_location
	git_config_handler()
	{
		[ "$1" != 'variable' ] || [ "$__git_config_fullpath" != "$location" ] ||
			__git_config_v=$(($__git_config_v + 1))
	}
	__git_config_fullpath "$3"
	git_config_parse_file "$2"
	eval "$1=\"\$__git_config_v\""
}

### Lists values of variable in specified config file.
### Usage: git_config_list file [name]
git_config_list()
{
	local __git_config_fullpath='' __git_config_location=''
	git_config_handler()
	{
		[ "$1" = 'variable' ] ||
			return 0
		if [ -n "$__git_config_location" ]; then
			[ "$__git_config_fullpath" != "$location" ] ||
				printf '%s\n' "$value"
		else
			printf '%s=%s\n' "$location" "$value"
		fi
	}
	[ -z "${2-}" ] ||
		__git_config_fullpath "$2"
	git_config_parse_file "$1"
}

### Lists all names and variables in tab separated form.
### Usage: git_config_parse file
git_config_parse()
{
	git_config_handler()
	{
		[ "$1" = 'variable' ] ||
			return 0
		printf '%s\t%s\n' "$location" "$value"
	}
	git_config_parse_file "$1"
}

### Append another value with same name into config file.
### Usage: git_config_append file name value
git_config_append()
{
	local GIT_CONFIG_INCLUDE='' GIT_CONFIG_GET_RAW=1
	local __git_config_section __git_config_name __git_config_subsection __git_config_fullpath __git_config_location
	local __git_config_nvalue="$3"
	local __git_config_state=0 fn

	[ -f "$1" ] || :> "$1"

	__git_config_split "$2"

	git_config_handler()
	{
		case "$1" in
			comment)
				printf '%s\n' "$line"
				;;
			variable)
				printf '\t%s = %s\n' "$name" "$value"
				if [ "$__git_config_fullpath" = "$location" ] && [ $__git_config_state != 1 ]; then
					printf '\t%s = %s\n' "$__git_config_name" "$__git_config_nvalue"
					__git_config_state=1
				fi
				;;
			section-start)
				printf '[%s]\n' "$section${subsection:+ \"$subsection\"}"
				;;
			section-end)
				if [ "$__git_config_location" = "$location" ] && [ $__git_config_state != 1 ]; then
					printf '\t%s = %s\n' "$__git_config_name" "$__git_config_nvalue"
					__git_config_state=1
				fi
				;;
		esac
	}
	fn="$(mktemp "$1.XXXXXX")"
	git_config_parse_file "$1" > "$fn"

	if [ $__git_config_state -eq 0 ]; then
		printf '[%s]\n\t%s = %s\n' \
			"$__git_config_section${__git_config_subsection:+ \"$__git_config_subsection\"}" \
			"$__git_config_name" "$__git_config_nvalue" >> "$1"
		rm -f -- "$fn"
	else
		mv -f -- "$fn" "$1"
	fi
}

### Set or add value into config file.
### Usage: git_config_set file name value
git_config_set()
{
	local GIT_CONFIG_INCLUDE='' GIT_CONFIG_GET_RAW=1
	local __git_config_section __git_config_name __git_config_subsection __git_config_fullpath __git_config_location
	local __git_config_nvalue="$3" __git_config_ovalue=''
	local __git_config_state=0 fn

	[ -f "$1" ] || :> "$1"

	__git_config_split "$2"
	git_config_get __git_config_ovalue "$1" "$2"

	git_config_handler()
	{
		case "$1" in
			comment)
				printf '%s\n' "$line"
				;;
			variable)
				if [ "$__git_config_fullpath" = "$location" ] && [ -n "$__git_config_ovalue" ]; then
					if [ "$__git_config_ovalue" = "$value" ]; then
						printf '\t%s = %s\n' "$__git_config_name" "$__git_config_nvalue"
						__git_config_state=1
					fi
				else
					printf '\t%s = %s\n' "$name" "$value"
				fi
				;;
			section-start)
				printf '[%s]\n' "$section${subsection:+ \"$subsection\"}"
				;;
			section-end)
				if [ "$__git_config_location" = "$location" ] && [ $__git_config_state != 1 ]; then
					printf '\t%s = %s\n' "$__git_config_name" "$__git_config_nvalue"
					__git_config_state=1
				fi
				;;
		esac
	}
	fn="$(mktemp "$1.XXXXXX")"
	git_config_parse_file "$1" > "$fn"

	if [ $__git_config_state -eq 0 ]; then
		printf '[%s]\n\t%s = %s\n' \
			"$__git_config_section${__git_config_subsection:+ \"$__git_config_subsection\"}" \
			"$__git_config_name" "$__git_config_nvalue" >> "$1"
		rm -f -- "$fn"
	else
		mv -f -- "$fn" "$1"
	fi
}

### Usage: git_config_unset file name [value]
git_config_unset()
{
	local GIT_CONFIG_INCLUDE='' GIT_CONFIG_GET_RAW=1
	local __git_config_section __git_config_name __git_config_subsection __git_config_fullpath __git_config_location
	local __git_config_ovalue="${3-}"
	local fn

	[ -f "$1" ] || :> "$1"
	__git_config_split "$2"

	git_config_handler()
	{
		case "$1" in
			comment)
				printf '%s\n' "$line"
				;;
			variable)
				if [ "$__git_config_fullpath" = "$location" ]; then
					[ -z "$__git_config_ovalue" ] || [ "$__git_config_ovalue" = "$value" ] ||
						printf '\t%s = %s\n' "$name" "$value"
				else
					printf '\t%s = %s\n' "$name" "$value"
				fi
				;;
			section-start)
				[ "$__git_config_fullpath" = "$location" ] ||
					printf '[%s]\n' "$section${subsection:+ \"$subsection\"}"
				;;
		esac
	}
	fn="$(mktemp "$1.XXXXXX")"
	git_config_parse_file "$1" > "$fn"
	mv -f -- "$fn" "$1"
}

### Usage: __var_append arrname name value
__var_append()
{
	local n
	eval "n=\${$1:-0}"
	eval "${1}_${n}_n=\"\$2\""
	eval "${1}_${n}_v=\"\$3\""
	eval "$1=$(($n+1))"
}

### Usage: __arr_append retindex arrname value
__arr_append()
{
	local n
	eval "n=\${$2:-0}"
	eval "${2}_${n}=\"\$3\""
	eval "$2=$(($n+1))"
	eval "$1=$n"
}

### Usage: __arr_find retindex arrname value
__arr_find()
{
	local i=0 n='' v=''
	eval "$1="
	eval "n=\${$2:-0}"
	while [ "$i" -lt "$n" ]; do
		eval "v=\"\${${2}_${i}}\""
		if [ "$v" = "$3" ]; then
			eval "$1=$i"
			return
		fi
		i=$(($i+1))
	done
}

### Parses git-config-like file and store the result in memory for future use.
### Usage: git_config_env file
git_config_env()
{
	s=0
	local idx='' sidx=''
	git_config_handler()
	{
		case "$1" in
			section-start)
				case "$section_lower" in
					include|includeif) return ;;
				esac
				__arr_find idx s "$section_lower"
				[ -n "$idx" ] ||
					__arr_append idx s "$section_lower"

				if [ -n "$subsection" ]; then
					__arr_find sidx "ss_$idx" "$subsection"
					[ -n "$sidx" ] ||
						__arr_append sidx "ss_$idx" "$subsection"
				else
					eval "ss_$idx=\${ss_$idx:-0}"
					sidx=
				fi
				;;
			variable)
				[ -n "$idx" ] ||
					fatal "variable outside of section"
				__var_append "v_${idx}${sidx:+_$sidx}_x" "$name_lower" "$value"
				;;
		esac
	}
	git_config_parse_file "$1"
}

### Stores git-config variable into variable 'ret'.
### Usage: git_config_get_var ret section subsection name [{first|last|all=DELIM}]
git_config_get_var()
{
	local __git_config_get_var_ret="$1" __git_config_get_var_v=''
	__git_config_get_var()
	{
		local n='' v='' i=0 idx='' sidx=''

		__arr_find idx s "$2"
		[ "${#idx}" != 0 ] ||
			return 0

		if [ "${#3}" != 0 ]; then
			eval "n=\"\$ss_$idx\""
			[ "${#n}" != 0 ] && [ "$n" != 0 ] &&
				__arr_find sidx "ss_$idx" "$3" ||
				return 0
		fi

		eval "n=\"\${v_$idx${sidx:+_$sidx}_x:-0}\""

		while [ "$i" -lt "$n" ]; do
			eval "v=\"\$v_$idx${sidx:+_$sidx}_x_${i}_n\""
			if [ "$v" = "$4" ]; then
				eval "v=\"\$v_$idx${sidx:+_$sidx}_x_${i}_v\""
				case "${5-}" in
					first)
						eval "__git_config_get_var_v=\"\$v\""
						return
						;;
					all=*)
						eval "__git_config_get_var_v=\"\${__git_config_get_var_v:+\${__git_config_get_var_v}${5#all=}}\$v\""
						;;
					''|last)
						eval "__git_config_get_var_v=\"\$v\""
						;;
				esac
			fi
			i=$(($i+1))
		done
	}
	__git_config_get_var "$@"
	eval "$__git_config_get_var_ret=\"\$__git_config_get_var_v\""
}

### Usage: git_config_foreach [name] [custom_handler]
git_config_foreach_handler()
{
	printf '%s=%s\n' "$1" "$2"
}
git_config_foreach()
{
	local __git_config_foreach_name="${1-}"
	local __git_config_foreach_handler="${2:-git_config_foreach_handler}"

	__arr_foreach()
	{
		local i=0 x=0 n='' v=''
		eval "set -- \"\${$1:-0}\" \"\$@\""
		while [ "$i" -lt "$1" ]; do
			eval "n=\"\${${2}_${i}_n}\""
			eval "v=\"\${${2}_${i}_v}\""
			if [ -z "$__git_config_foreach_name" ] || [ "$__git_config_foreach_name" = "${3:+$3.}$n" ]; then
				"$__git_config_foreach_handler" "${3:+$3.}$n" "$v"
			fi
			i=$(($i+1))
		done
	}

	local i=0 j=0 ss section subsection

	while [ "$i" -lt "${s:-0}" ]; do
		eval "section=\"\$s_${i}\""
		__arr_foreach "v_${i}_x" "$section"

		eval "ss=\"\${ss_${i}:-0}\""

		j=0
		while [ "$j" -lt "$ss" ]; do
			eval "subsection=\"\$ss_${i}_${j}\""
			__arr_foreach "v_${i}_${j}_x" "$section.$subsection"
			j=$(($j+1))
		done

		i=$(($i+1))
	done
}

### Usage: git_config_get_subsections section
git_config_get_subsections_handler() { :; }
git_config_get_subsections()
{
	local __git_config_get_subsections_idx=
	__git_config_get_subsections_idx()
	{
		local n='' v='' i=0

		eval "n=\${s:-0}"
		while [ "$i" -lt "$n" ]; do
			eval "v=\"\${s_${i}}\""
			if [ "$v" = "$1" ]; then
				__git_config_get_subsections_idx=$i
				return 0
			fi
			i=$(($i+1))
		done
		return 1
	}
	__git_config_get_subsections_idx "$1" || return 0
	__git_config_get_subsections_idx()
	{
		__git_config_get_subsections_idx=0
		while [ "$__git_config_get_subsections_idx" -lt "$2" ]; do
			eval "git_config_get_subsections_handler \"\${ss_${1}_${__git_config_get_subsections_idx}}\""
			__git_config_get_subsections_idx=$(($__git_config_get_subsections_idx+1))
		done
	}
	eval "__git_config_get_subsections_idx \"$__git_config_get_subsections_idx\" \"\$ss_$__git_config_get_subsections_idx\""
}

fi # __included_shell_git_config