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


##
## Internal functions for displaying stuff
##

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

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

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

check_installed () {
	[ -n "$1" -a -d $PDIR/$1 ] || die "Not installed: $1\n"
}

check_valid () {
	[ -d $PDIR/$1/.hg ] || die "Not a valid package name: '$1'\n"
}

clear_line () {
	echo -ne "\r                                                          \r"
}

# Read local configuration
if ([ -f $HOME/.pkg.conf ]) {
	. $HOME/.pkg.conf
}

export PDIR
export PKG_ROOT


##
## Make sure everything's sane
## Warn otherwise
##

# we need sed -r (and sed -i, but not checking for that here)
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 ([ ! -d $PDIR ]) {
	die "$PDIR not found!!"
}


##
## Some additional variables related to PKG_ROOT
##

# Protocol
if (echo "$PKG_ROOT" | grep "^ssh" &> /dev/null) {
	PKG_PROTO='ssh'
	} elif (echo "$PKG_ROOT" | grep "^/" &> /dev/null) {
	PKG_PROTO='file'
} else {
	false
}

# Host
if ([ "$PKG_PROTO" = "ssh" ]) {
	PKG_HOST=$(echo "$PKG_ROOT" | sed 's!^ssh://!!' | sed -r 's!^([^/]*)/.*$!\1!')
}

# Remote path
if ([ "$PKG_PROTO" = "ssh" ]) {
	PKG_PATH=$(echo "$PKG_ROOT" | sed 's!^ssh://'"$PKG_HOST"'/!!')
} elif ([ "$PKG_PROTO" = "file" ]) {
	PKG_PATH="$PKG_ROOT"
}


##
## Ask the user for confirmation
##

# Default reply: Yes
confirm_yes () {
	echo -n "$* [Y/n] "
	read -k 1
	[ $REPLY != $'\n' ] && echo
	if ([ "$REPLY" = 'y' -o "$REPLY" = 'Y' -o "$REPLY" = $'\n' ]) {
		true
	} else {
		false
	}
}

# Default reply: No
confirm_no () {
	echo -n "$* [y/N] "
	read -q
}


##
## Major internal functions
##

# Return an understandable priority from the numeric one
real_priority () {
	case "$1" in
		6) echo "essential" ;;
		5) echo "important" ;;
		4) echo "required" ;;
		3) echo "standard" ;;
		2) echo "optional" ;;
		1) echo "extra" ;;
		*) echo ;;
	esac
}

# Execute a hook
exec_hook () {
	package="$1"
	hook="$2"
	if ([ -r $PDIR/$package/hooks/$hook ]) {
		info "Executing $hook hook\n"
		cd $PDIR/$package
		. hooks/$hook
	}
}

# Check dependencies and offer to install them
check_deps () {
	[ -r $PDIR/$1/dependencies ] || return 0
	DEPS=($(cat $PDIR/$1/dependencies))
	INSTALL=()
	for dep in $DEPS; {
		if ([ ! -d $PDIR/$dep ]) {
			INSTALL+="$dep"
		}
	}
	if ([ -n "$INSTALL" ]) {
		info "$1 has unmet dependencies: "
		echo "$INSTALL"
		if (confirm_yes "Install dependencies?") {
			for pkg in $INSTALL; {
				pkg_add "$pkg"
			}
		} else {
			die "Installation aborted"
		}
	}
}

check_conflicts () {
	[ -r $PDIR/$1/conflicts ] || return 0
	CONFLICTS=($(cat $PDIR/$1/conflicts))
	REMOVE=()
	for conflict in $CONFLICTS; {
		if ([ -d $PDIR/$conflict ]) {
			REMOVE+="$conflict"
		}
	}
	if ([ -n "$REMOVE" ]) {
		info "$1 conflicts with the following packages: "
		echo "$REMOVE"
		if (confirm_no "Remove conflicting packages and proceed with installation?") {
			for pkg in $REMOVE; {
				pkg_remove "$pkg"
			}
		} else {
			die "Installation aborted"
		}
	}
}

# Write a packages' files to .collected
# Currently, this is only documentation
populate_collected () {
	cd $PDIR/$1 || return
	info "Enabling documentation "
	if ([ -d man ]) {
		for i in man/*/*; {
			section=${i:h:t}
			manpage=${i:t}
			if (podchecker man/$section/$manpage &> /dev/null) {
				pod2man -s $section -c "$1 package" -r "/home/derf" man/$section/$manpage > $PDIR/.collected/man/man$section/$manpage.$section
				echo -n "+"
			} else {
				echo -n "."
			}
		}
	}
	if ([ -d bin ]) {
		for i in bin/*; {
			if (podchecker $i &> /dev/null) {
				pod2man $i > $PDIR/.collected/man/man1/${i:t}.1
				echo -n "+"
			} else {
				echo -n "."
			}
		}
	}
	clear_line
	if ([ -d bin ]) {
		for i in bin/*(*); {
			if ([ "$(readlink $HOME/$i)" != "../$1/$i" ]) {
				rm -f "$HOME/$i"
				ln -s ../${PDIR//$HOME\/}/$1/$i $HOME/$i
			}
		}
	}
}

# Remove a packages' files from .collected
# Assuming there are no packages with colliding files
# TODO: Make sure there are none
genocide_collected () {
	cd $PDIR/$1 || return
	info "Removing documentation"
	if ([ -d man ]) {
		for i in man/*/*; {
			section=${i:h:t}
			manual=${i:t}
			if ([ -e $PDIR/.collected/man/man$section/$manual ]) {
				rm $PDIR/.collected/man/man$section/$manual
			}
		}
	}
	if ([ -d bin ]) {
		for i in bin/*; {
			rm -f $PDIR/.collected/man/man1/${i:t}.1
		}
	}
	clear_line
	if ([ -d bin ]) {
		for i in bin/*(*); {
			if ([ "$(readlink $HOME/$i)" = "../${PDIR//$HOME\/}/$1/$i" ]) {
				rm -f $HOME/$i
			}
		}
	}
}


##
## Finally - the functions actually doing something
##

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_ADD $PKG_ROOT/$1 || return 255
	if ([ -r $PDIR/$1/Makefile ]) {
		info "Building binaries\n"
		cd $PDIR/$1
		make
	}
	exec_hook "$1" "post-add"
	check_deps "$1"
	check_conflicts "$1"
	cd $PDIR/$1
	checklinks $CL_OPTIONS
	populate_collected "$1"
	return 0
}

pkg_remove () {
	check_installed "$1"
	check_valid "$1"
	cd $PDIR/$1
	if ([ -r priority ]) {
		if ([ $(cat priority) -gt 3 ]) {
			confirm_no "Package '$1' is $(real_priority $(cat priority)). Really remove?" || return
		}
	}
	exec_hook "$1" "pre-remove"
	genocide_collected "$1"
	rm -r $PDIR/$1
	info "Package removed.\n"
}

pkg_update () {
	check_installed "$1"
	cd $PDIR/$1
	info "Looking for updates: $1"
	NEW=$($VCS_CMD $VCS_INCOMING)
	if ([ $? = 0 ]) {
		clear_line
		info "Updating: $1 to $(echo $NEW | tail -n 1)"
		$VCS_CMD $VCS_UPDATE
		clear_line
		info "Updated $1 to $(echo $NEW | tail -n 1) \n"
		check_deps "$1"
		if ([ -r Makefile ]) {
			info "Building binaries\n"
			make
		}
		exec_hook "$1" "post-update"
		checklinks $CL_OPTIONS
		populate_collected "$1"
	} else {
		clear_line
	}
	cd $PDIR
}

# If no package was specified, update everything
pkg_update_wrapper () {
	if ([ -n "$1" ]) {
		pkg_update "$1"
	} else {
		cd $PDIR
		for i in *(/); {
			pkg_update "$i"
		}
	}
}

# Change the 'default' url in every package's .hgrc
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 ([ "$PKG_PROTO" = 'ssh' ]) {
		ssh -q "$PKG_HOST" ls -1 "$PKG_PATH"
	} elif ([ "$PKG_PROTO" = 'file' ]) {
		ls -1 "$PKG_PATH"
	}
}

# Local modifications should not be overseen...
pkg_status () {
	check_installed "$1"
	cd $PDIR/$1
	check_deps "$1"
	check_conflicts "$1"
	checklinks $CL_OPTIONS
	STATUS=$($VCS_CMD $VCS_STATUS)
	clear_line
	if ([ -n "$STATUS" ]) {
		info "Locally modified in $1:\n"
		echo "$STATUS"
	}
}

# Same as with update - if no package is specified, check all
pkg_status_wrapper () {
	if ([ -n "$1" ]) {
		pkg_status "$1"
	} else {
		cd $PDIR
		for i in *(/); {
			pkg_status "$i"
		}
	}
}

# Various information related to a package
pkg_info () {
	check_installed "$1"
	cd $PDIR/$1
	[ -z "$1" ] && die "Not enough arguments\n"
	# Fetch the infos
	NAME="$1"
	if ([ -r priority ]) {
		PRIORITY=$(cat priority)
		PRIORITY_NAME=$(real_priority "$PRIORITY")
	}
	LOG=$(hg log)
	VERSION=$(echo $LOG | grep -m1 'changeset:' | grep -Eo '[0-9]{1,}:[0-9a-f]*')
	DATE=$(echo $LOG | grep -m1 'date:' | grep -Eo '[A-Z][a-z]{2}.*')
	if ([ -r dependencies ]) {
		DEPENDENCIES=$(cat dependencies | tr "\n" " " | sed 's/ /, /g' | sed 's/, $//')
	}
	if ([ -r tags ]) {
		TAGS=$(cat tags | tr "\n" " " | sed 's/ /, /g' | sed 's/, $//')
	}
	if ([ -d hooks ]) {
		HOOKS=$(ls hooks)
	}
	if ([ -r Makefile ]) {
		MAKEFILE=1
	}
	SIZE=$(du -sh .hg | grep -o '.*[KMG]')
	if ([ -r description ]) {
		DESCRIPTION=$(cat description)
	}

	show_info () {
		[ -z "$2" ] && return
		info "$1: "
		echo "$2"
	}

	show_info "Package" "$NAME"
	show_info "Priority" "$PRIORITY ($PRIORITY_NAME)"
	show_info "Version" "$VERSION"
	show_info "Date" "$DATE"
	show_info "Depends" "$DEPENDENCIES"
	show_info "Tags" "$TAGS"
	show_info "Hooks" "$HOOKS"
	show_info "Repostiry Size" "$SIZE"
	show_info "Description" "$DESCRIPTION"
}

pkg_log () {
	check_installed "$1"
	hg -R $PDIR/$1 glog | less
}

pkg_changelog () {
	[ -r $PDIR/$1/changelog ] && view $PDIR/$1/changelog
}

# Almost obsoleted by the bin/* -> man/ stuff
pkg_doc () {
	if ([ -r $PDIR/.collected/man/$1 ]) {
		man $PDIR/.collected/man/$1
	} elif ([ -r $PDIR/.collected/doc/$1 ]) {
		less $PDIR/.collected/doc/$1
	} else {
		echo "No documentation found"
	}
}


##
## Now what shall we do...
##

case "$1" in
	add) pkg_add "$2" ;;
	changelog) pkg_changelog "$2" ;;
	changeroot) pkg_changesrc "$2" ;;
	delete) pkg_remove "$2" ;;
	doc) pkg_doc "$2" ;;
	info) pkg_info "$2" ;;
	install) pkg_add "$2" ;;
	list) pkg_list_installed ;;
	list-all) pkg_list_available ;;
	log) pkg_log "$2" ;;
	remove) pkg_remove "$2" ;;
	status) pkg_status_wrapper "$2" ;;
	update) pkg_update_wrapper "$2" ;;
	*) die "wait, what?\n" ;;
esac