#!/bin/sh
# plist --- read or manipulate plist files
# Author: Noah Friedman <friedman@splode.com>
# Created: 2017-12-30
# Public domain

# $Id: plist,v 1.2 2018/05/03 18:32:13 friedman Exp $

# Commentary:
# Code:

opt_x=

get_domain_fqp()
{
    local pl=${1%.plist}.plist  # make sure it ends in .plist
    shift
    case $pl in
        /* | ./* | ../* ) : ;;
        * ) case ${UID-`id -u`} in
                0 )      pl=/Library/Preferences/$pl ;;
                * ) pl=$HOME/Library/Preferences/$pl ;;
            esac ;;
    esac
    domain=$pl

    if ! [ -f "$domain" ] && [ -f "${domain%.plist}" ]; then
        domain=${domain%.plist}
    fi
}

apop() { eval "$1=(\"\${$1[@]:0:\${#$1[@]}-${2-1}}\")"; }
aref() { eval echo "\"\${$1[$2]}\""; }

plb() { /usr/libexec/PlistBuddy $opt_x -c "$*" "$domain"; }

plclear()  { plb clear "$@" ; }
plprint()  { plb print  "\":$*\"" ; }
pldelete() { plb delete "\":$*\"" ; }
plcopy()   { plb copy   "\":$1\""  "\":$2\"" ; }
plmerge()  { plb merge   "\"$1\""  "\":$2\"" ; }
plimport() { plb import "\":$1\""   "\"$2\"" ; }

plset() { plwrite "$@" ; }
pladd() { plwrite "$@" ; }

plwrite()
{
    test -d "${domain%/*}" || mkdir -p "${domain%/*}"

    local verb=
    case $1 in
        add | set ) verb=$1 ; shift ;;
    esac

    local key=$1
    shift

    if ! [ -f "$domain" ] ; then
        plclear > /dev/null 2>&1  # quietly create file
    fi

    case $key in
        *:  ) vivify "$key"
              verb=add ;;

        *:* ) if numberp  "${key##*:}"
              then vivify "${key}"
              else vivify "${key%:*}"
              fi ;;
    esac

    if [ -z "$verb" ]; then
        if plprint "$key" > /dev/null 2>&1; then
            verb=set
        else
            verb=add
        fi
    fi

    local type=
    case $verb:$# in
        add:1 ) case $1 in
                    array | dict ) : ;;
                    true | false ) type=bool    ;;
                    *[^0-9]*     ) type=string  ;;
                    *            ) type=integer ;;
                esac ;;
        set:1 ) case $1 in
                    # container already exists
                    array | dict ) return ;;
                esac ;;
    esac

    plb "$verb \":$key\" $type $*"
}

vivify()
{
    local oIFS=$IFS
    IFS=:
    case "$*" in
        *: ) set . $*: ;;  # to save trailing empty string
        *  ) set . $*  ;;
    esac
    IFS=$oIFS

    local sub=$2  # skip "."
    shift 2

    while [ $# -gt 0 ]; do
        if numberp "$1" && ! plb print ":$sub" ; then
            plb add ":$sub" array 2> /dev/null
        fi
        sub=$sub:$1
        shift
    done > /dev/null 2>&1
}

numberp()
{
    case $1 in
        *[^0-9]* ) return 1 ;;
        * | ''   ) return 0 ;;
    esac
}

usage()
{
    local prog=${0##*/}

    exec 1>&2
    if [ $# -gt 0 ]; then
        echo "$prog: $*"
        echo
    fi

    cat <<- __EOF__
	Usage: $prog [DOMAIN] [COMMAND] {ARGS ...}

	DOMAIN is the plist file to operate on.
	If file is not absolute, the DOMAIN will be looked up under
	~/Library/Preferences or (if root) /Library/Preferences.

	COMMAND and ARGS can be of the form:

	    print   {key}                      # will print whole dict without arg
	    add     [key] {type} [value ...]   # type will be inferenced if missing
	    set     [key] [value ...]          # key will be created if missing
	    delete  [key]

	    clear   [type]                     # see PlistBuddy man page for these
	    copy    [srckey] [dstkey]
	    merge   [file] {entry}
	    import  [entry] [file]

	__EOF__

    exit 1
}

main()
{
    case $#:$1 in
        0: | 1:-[hx] | 1:--help ) usage ;;
        *:-x ) opt_x=-x ; shift ;;
    esac

    get_domain_fqp "$1"
    shift

    local verb=$1
    shift

    case $verb in
        add   | set  | print | delete ) pl$verb "$@" ;;
        clear | copy | merge | import ) pl$verb "$@" ;;

        # Some aliases
        get | read ) plprint     "$@" ;;
        del        ) pldelete    "$@" ;;
        force-add  ) plwrite add "$@" ;;  # force op
        force-set  ) plwrite set "$@" ;;  # force op

        * ) usage "$verb: unknown operator" ;;
    esac
}

main "$@"

# eof