#!/usr/bin/env zsh
# Recommended: hg >= 1.0
PDIR="$HOME/packages"
PKG_ROOT="ssh://derf.homelinux.org/var/packages_root"
VCS_CMD="hg"
VCS_OPTIONS="--quiet"
VCS_ADD="clone"
VCS_INCOMING="incoming"
VCS_STATUS="status"
VCS_UPDATE="pull"
VCS_UPDATE_OPTIONS="--update"
CL_OPTIONS="-q"
info=$'\e[0;36m'
error=$'\e[0;31m'
reset=$'\e[0m'

info () {
	echo -ne "${info}$*${reset}"
}

warn () {
	echo -ne "${error}$*${reset}"
}

die () {
	echo -ne "${error}$*${reset}"
	exit 100
}

check_sed () {
	QUUX=$(echo foox | sed -r 's/^fo{2}(.)$/quu\1/' 2> /dev/null)
	if ([ "$QUUX" != 'quux' ]) {
		warn "sed is not working properly. This may produce unexpected behaviour.\n"
	}
}

if ([ -f $HOME/.pkg.conf ]) {
	. $HOME/.pkg.conf
}

if ([ ! -d $PDIR ]) {
	die "$PDIR not found!!"
}

check_deps () {
	[ -r $PDIR/$1/.deps ] || return 0
	DEPS=($(cat $PDIR/$1/.deps))
	INSTALL=()
	for dep in $DEPS; {
		if ([ "$dep" = "$1" ]) {
			warn "This package depends on itself. Therefore, I'm considering it borked. Not installing.\n"
			return 100
		}
		if ([ ! -d $PDIR/$dep ]) {
			echo -n "$1 depends on $dep. Install dependency? [Y/n] "
			read
			if ([ ! "$REPLY" = 'n' ]) {
				INSTALL+="$dep"
			}
		}
	}
	if ([ -n "$INSTALL" ]) {
		for pkg in $INSTALL; {
			pkg_add "$pkg"
		}
	}
}

pkg_add () {
	if ([ -d $PDIR/$1 ]) {
		info "Package '$1' is already installed!\n"
		return 100
	}
	cd $PDIR || return 255
	info "Retrieving package $1...\n"
	$VCS_CMD $VCS_OPTIONS $VCS_ADD $PKG_ROOT/$1 || return 255
	if ([ -f $PDIR/$1/hooks/post-add ]) {
		info 'Executing post-add hook\n'
		. $PDIR/$1/hooks/post-add
	}
	check_deps "$1"
	info 'Checking symlinks...\n'
	cd $PDIR/$1
	checklinks $CL_OPTIONS
	return 0
}

pkg_remove () {
	if ([ ! -d $PDIR/$1 ]) {
		info "Package '$1' is not installed!\n"
		return 100
	}
	if ([ -f $PDIR/$1/hooks/pre-remove ]) {
		info 'Executing pre-remove hook\n'
		. $PDIR/$1/hooks/pre-remove
	}
	rm -r $PDIR/$1
	info "Package removed."
}

pkg_update () {
	cd $PDIR/$1
	info "Checking package $1..."
	NEW=$($VCS_CMD $VCS_OPTIONS $VCS_INCOMING)
	if ([ $? = 0 ]) {
		info "\rUpdating package $1 to $(echo $NEW | tail -n 1)"
		$VCS_CMD $VCS_OPTIONS $VCS_UPDATE $VCS_UPDATE_OPTIONS
		info "\rUpdated package $1 to $(echo $NEW | tail -n 1) \n"
		checklinks $CL_OPTIONS
		if ([ -f hooks/post-update ]) {
			info 'Executing post-update hook\n'
			. hooks/post-update
		}
	} else {
		info "\r                                        \r"
	}
	cd $PDIR
}

pkg_update_wrapper () {
	if ([ -n "$1" ]) {
		pkg_update "$1"
	} else {
		cd $PDIR
		for i in *(/); {
			pkg_update "$i"
		}
	}
}

pkg_changesrc () {
	cd $PDIR
	for i in *(/); {
		if ([ -f $i/.hg/hgrc ]) {
			sed -i "s!default = [^:]*://.*\$!default = $1/$i!" $i/.hg/hgrc
		}
	}
}

pkg_list_installed () {
	=ls -1 $PDIR
}

pkg_list_available () {
	if (grep "^ssh" <<< "$PKG_ROOT" &> /dev/null) {
		ssh -q $(sed 's!^ssh://!!' <<< "$PKG_ROOT" | sed -r 's!^([^/]*)/.*$!\1!') 'ls -1 packages'
	}
}

pkg_status () {
	cd $PDIR/$1
	info "Checking $1 status..."
	check_deps $1
	STATUS=$($VCS_CMD $VCS_STATUS)
	if ([ -n "$STATUS" ]) {
		info "\rLocally modified in $1:\n"
		echo "$STATUS"
	} else {
		info "\r                                        \r"
	}
}

pkg_status_wrapper () {
	if ([ -n "$1" ]) {
		pkg_status "$1"
	} else {
		cd $PDIR
		for i in *(/); {
			pkg_status "$i"
		}
	}
}

check_sed

case "$1" in
	add) pkg_add "$2" ;;
	changeroot) pkg_changesrc "$2" ;;
	delete) pkg_remove "$2" ;;
	install) pkg_add "$2" ;;
	list) pkg_list_installed ;;
	list-all) pkg_list_available ;;
	remove) pkg_remove "$2" ;;
	status) pkg_status_wrapper "$2" ;;
	update) pkg_update_wrapper "$2" ;;
esac