#!/bin/bash
# Makefile.d/downloader: A downloader script that handles all kinds of
#                        funny VCS URLs.
# Very heavily based on Pacman's 'makepkg' script.

# Usage: Makefile.d/downloader ARCH DEPNAME::URL [DEPNAME::URL...]

#   Copyright (c) 2014 Luke Shumaker <lukeshu@sbcglobal.net>
#   Copyright (c) 2006-2013 Pacman Development Team <pacman-dev@archlinux.org>
#   Copyright (c) 2002-2006 by Judd Vinet <jvinet@zeroflux.org>
#   Copyright (c) 2005 by Aurelien Foret <orelien@chez.com>
#   Copyright (c) 2006 by Miklos Vajna <vmiklos@frugalware.org>
#   Copyright (c) 2005 by Christian Hamar <krics@linuxforum.hu>
#   Copyright (c) 2006 by Alex Smith <alex@alex-smith.me.uk>
#   Copyright (c) 2006 by Andras Voroskoi <voroskoi@frugalware.org>
#
#   This program is free software; you can redistribute it and/or modify
#   it under the terms of the GNU General Public License as published by
#   the Free Software Foundation; either version 2 of the License, or
#   (at your option) any later version.
#
#   This program is distributed in the hope that it will be useful,
#   but WITHOUT ANY WARRANTY; without even the implied warranty of
#   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
#   GNU General Public License for more details.
#
#   You should have received a copy of the GNU General Public License
#   along with this program.  If not, see <http://www.gnu.org/licenses/>.

export TEXTDOMAIN='pacman-scripts'
export TEXTDOMAINDIR='/usr/share/locale'

shopt -s extglob
set -u -e -E

# check if messages are to be printed using color
declare ALL_OFF= BOLD= BLUE= GREEN= RED= YELLOW=
if [[ -t 2 ]]; then
	# prefer terminal safe colored and bold text when tput is supported
	if tput setaf 0 &>/dev/null; then
		ALL_OFF="$(tput sgr0)"
		BOLD="$(tput bold)"
		BLUE="${BOLD}$(tput setaf 4)"
		GREEN="${BOLD}$(tput setaf 2)"
		RED="${BOLD}$(tput setaf 1)"
		YELLOW="${BOLD}$(tput setaf 3)"
	else
		ALL_OFF="\e[1;0m"
		BOLD="\e[1;1m"
		BLUE="${BOLD}\e[1;34m"
		GREEN="${BOLD}\e[1;32m"
		RED="${BOLD}\e[1;31m"
		YELLOW="${BOLD}\e[1;33m"
	fi
fi
readonly ALL_OFF BOLD BLUE GREEN RED YELLOW

### SUBROUTINES ###

plain() {
	local mesg=$1; shift
	printf "${BOLD}    ${mesg}${ALL_OFF}\n" "$@" >&2
}

msg() {
	local mesg=$1; shift
	printf "${GREEN}==>${ALL_OFF}${BOLD} ${mesg}${ALL_OFF}\n" "$@" >&2
}

msg2() {
	local mesg=$1; shift
	printf "${BLUE}  ->${ALL_OFF}${BOLD} ${mesg}${ALL_OFF}\n" "$@" >&2
}

warning() {
	local mesg=$1; shift
	printf "${YELLOW}==> $(gettext "WARNING:")${ALL_OFF}${BOLD} ${mesg}${ALL_OFF}\n" "$@" >&2
}

error() {
	local mesg=$1; shift
	printf "${RED}==> $(gettext "ERROR:")${ALL_OFF}${BOLD} ${mesg}${ALL_OFF}\n" "$@" >&2
}

dir_is_empty() {
	(
		shopt -s dotglob nullglob
		files=("$1"/*)
		(( ${#files} == 0 ))
	)
}

# a "netfile" has the form:
#    "depname::url"
get_url()     { printf -- "%s\n" "${1#*::}"; }
get_depname() {	printf -- "%s\n" "${1%%::*}"; }

get_protocol() {
	local url="$(get_url "$1")"
	local proto="${url%%://*}"
	proto=${proto%%+*}
	printf -- "%s\n" "$proto"
}

get_urlname() {
	local netfile=$1
	local url="$(get_url "$netfile")"
	local proto=$(get_protocol "$netfile")
	urlname=${netfile%%#*} # Strip a fragment
	urlname=${urlname%/}   # Strip a trailing slash
	urlname=${urlname##*/} # Strip leading components
	urlname=${urlname%.$proto} # Strip .git
	printf -- "%s\n" "${urlname}"
}

get_downloadname() {
	local netfile=$1
	local depname="$(get_depname "$netfile")"
	local urlname="$(get_urlname "$netfile")"
	local proto="$(get_protocol "$netfile")"

	local name
	case $proto in
		git|hg|svn) name="$depname.$proto";;
		http|https) name="$urlname";;
		*)          return 1;;
	esac

	printf -- "%s\n" "$name"
}

####

get_downloadclient() {
	local proto=$1

	# loop through DOWNLOAD_AGENTS variable looking for protocol
	local i
	for i in "${DLAGENTS[@]}"; do
		local handler="${i%%::*}"
		if [[ $proto = "$handler" ]]; then
			local agent="${i##*::}"
			break
		fi
	done

	# if we didn't find an agent, return an error
	if [[ -z $agent ]]; then
		error "$(gettext "Unknown download protocol: %s")" "$proto"
		plain "$(gettext "Aborting...")"
		exit 1 # $E_CONFIG_ERROR
	fi

	# ensure specified program is installed
	local program="${agent%% *}"
	if [[ ! -x $program ]]; then
		local baseprog="${program##*/}"
		error "$(gettext "The download program %s is not installed.")" "$baseprog"
		plain "$(gettext "Aborting...")"
		exit 1 # $E_MISSING_PROGRAM
	fi

	printf "%s\n" "$agent"
}

download_file() {
	local netfile=$1
	local filename="$(get_downloadname "$netfile")"

	pushd "$SRCDEST" &>/dev/null

	if [[ -f "$filename" ]]; then
		msg2 "$(gettext "Found %s")" "${filename}"
		return
	fi

	local proto=$(get_protocol "$netfile")

	# find the client we should use for this URL
	local dlcmd
	dlcmd=$(get_downloadclient "$proto") || exit $?

	local url=$(get_url "$netfile")

	msg2 "$(gettext "Downloading %s...")" "$filename"

	# temporary download file, default to last component of the URL
	local dlfile=$filename

	# replace %o by the temporary dlfile if it exists
	if [[ $dlcmd = *%o* ]]; then
		dlcmd=${dlcmd//\%o/\"$filename.part\"}
		dlfile="$filename.part"
	fi
	# add the URL, either in place of %u or at the end
	if [[ $dlcmd = *%u* ]]; then
		dlcmd=${dlcmd//\%u/\"$url\"}
	else
		dlcmd="$dlcmd \"$url\""
	fi

	local ret=0
	eval "$dlcmd || ret=\$?"
	if (( ret )); then
		[[ ! -s $dlfile ]] && rm -f -- "$dlfile"
		error "$(gettext "Failure while downloading %s")" "$filename"
		plain "$(gettext "Aborting...")"
		exit 1
	fi

	# rename the temporary download file to the final destination
	if [[ $dlfile != "$filename" ]]; then
		mv -f "$dlfile" "$filename"
	fi
}

extract_file() {
	local netfile=$1
	local depname="$(get_depname "$netfile")"
	local filename="$(get_downloadname "$netfile")"
	local filepath="$SRCDEST/$filename"
	local filetype=$(file -bizL "$filepath") # fix Arch flyspray #6246
	local ext=${filename##*.}
	local cmd=bsdtar

	local ret=0
	msg2 "$(gettext "Extracting %s with %s")" "$filename" "$cmd"
	rm -rf "$srcdir/$depname"
	mkdir "$srcdir/$depname" && $cmd -xf "$filepath" -C "$srcdir/$depname" --strip-components 1 || ret=$?
	if (( ret )); then
		error "$(gettext "Failed to extract %s")" "$file"
		plain "$(gettext "Aborting...")"
		exit 1
	fi
}

download_git() {
	local netfile=$1

	local repo="$(get_downloadname "$netfile")"
	local dir="$SRCDEST/$repo"

	local url="$(get_url "$netfile")"
	url=${url##git+}
	url=${url%%#*}

	if [[ ! -d "$dir" ]] || dir_is_empty "$dir" ; then
		msg2 "$(gettext "Cloning %s %s repo...")" "${repo}" "git"
		if ! git clone --mirror "$url" "$dir"; then
			error "$(gettext "Failure while downloading %s %s repo")" "${repo}" "git"
			plain "$(gettext "Aborting...")"
			exit 1
		fi
	elif (( ! HOLDVER )); then
		pushd "$dir" &>/dev/null
		# Make sure we are fetching the right repo
		if [[ "$url" != "$(git config --get remote.origin.url)"  ]] ; then
			error "$(gettext "%s is not a clone of %s")" "$dir" "$url"
			plain "$(gettext "Aborting...")"
			exit 1
		fi
		msg2 "$(gettext "Updating %s %s repo...")" "${repo}" "git"
		if ! git fetch --all -p; then
			# only warn on failure to allow offline builds
			warning "$(gettext "Failure while updating %s %s repo")" "${repo}" "git"
		fi
		popd &>/dev/null
	fi
}

extract_git() {
	local netfile=$1

	local url="$(get_url "$netfile")"
	local fragment=
	if [[ $url = *#* ]]; then
		fragment=${url#*#}
	fi

	local repo="$(get_downloadname "$netfile")"
	local src="$SRCDEST/$repo"
	local dst="$srcdir/$(get_depname "$netfile")"

	msg2 "$(gettext "Creating working copy of %s %s repo...")" "${repo}" "git"
	rm -rf "${dst}"

	if ! git clone "$src" "$dst"; then
		error "$(gettext "Failure while creating working copy of %s %s repo")" "${repo}" "git"
		plain "$(gettext "Aborting...")"
		exit 1
	fi

	local ref=
	if [[ -n $fragment ]]; then
		case ${fragment%%=*} in
			commit|tag)
				ref=${fragment##*=}
				;;
			branch)
				ref=origin/${fragment##*=}
				;;
			*)
				error "$(gettext "Unrecognized reference: %s")" "${fragment}"
				plain "$(gettext "Aborting...")"
				exit 1
		esac
	fi

	if [[ -n $ref ]]; then
		pushd "${dst}" &>/dev/null
		if ! git checkout -b makepkg $ref; then
			error "$(gettext "Failure while creating working copy of %s %s repo")" "${repo}" "git"
			plain "$(gettext "Aborting...")"
			exit 1
		fi
		popd &>/dev/null
	fi
}

download_hg() {
	local netfile=$1

	local repo=$(get_downloadname "$netfile")
	local dir="$SRCDEST/$repo"

	local url=$(get_url "$netfile")
	url=${url##hg+}
	url=${url%%#*}

	if [[ ! -d "$dir" ]] || dir_is_empty "$dir" ; then
		msg2 "$(gettext "Cloning %s %s repo...")" "${repo}" "hg"
		if ! hg clone -U "$url" "$dir"; then
			error "$(gettext "Failure while downloading %s %s repo")" "${repo}" "hg"
			plain "$(gettext "Aborting...")"
			exit 1
		fi
	elif (( ! HOLDVER )); then
		msg2 "$(gettext "Updating %s %s repo...")" "${repo}" "hg"
		pushd "$dir" &>/dev/null
		if ! hg pull; then
			# only warn on failure to allow offline builds
			warning "$(gettext "Failure while updating %s %s repo")" "${repo}" "hg"
		fi
		popd &>/dev/null
	fi
}

extract_hg() {
	local netfile=$1

	local url="$(get_url "$netfile")"
	local fragment=
	if [[ $url = *#* ]]; then
		fragment=${url#*#}
	fi

	local repo="$(get_downloadname "$netfile")"
	local src="$SRCDEST/$repo"
	local dst="$srcdir/$(get_depname "$netfile")"

	msg2 "$(gettext "Creating working copy of %s %s repo...")" "${repo}" "hg"
	rm -rf "${dst}"

	local ref=
	if [[ -n $fragment ]]; then
		case ${fragment%%=*} in
			branch|revision|tag)
				ref=('-u' "${fragment##*=}")
				;;
			*)
				error "$(gettext "Unrecognized reference: %s")" "${fragment}"
				plain "$(gettext "Aborting...")"
				exit 1
		esac
	fi

	if ! hg clone "${ref[@]}" "$src" "$dst"; then
		error "$(gettext "Failure while creating working copy of %s %s repo")" "${repo}" "hg"
		plain "$(gettext "Aborting...")"
		exit 1
	fi

}

download_svn() {
	local netfile=$1

	local url="$(get_url "$netfile")"
	url=${url##svn+}
	local fragment=
	if [[ $url = *#* ]]; then
		fragment=${url#*#}
	fi
	url=${url%%#*}

	local repo=$(get_downloadname "$netfile")
	local dir="$SRCDEST/$repo"

	if [[ ! -d "$dir" ]] || dir_is_empty "$dir" ; then
		msg2 "$(gettext "Cloning %s %s repo...")" "${repo}" "svn"
		mkdir -p "$dir/.makepkg"
		if ! svn checkout --config-dir "$dir/.makepkg" "$url" "$dir"; then
			error "$(gettext "Failure while downloading %s %s repo")" "${repo}" "svn"
			plain "$(gettext "Aborting...")"
			exit 1
		fi
	elif (( ! HOLDVER )); then
		msg2 "$(gettext "Updating %s %s repo...")" "${repo}" "svn"
		pushd "$dir" &>/dev/null
		if ! svn update; then
			# only warn on failure to allow offline builds
			warning "$(gettext "Failure while updating %s %s repo")" "${repo}" "svn"
		fi
		popd &>/dev/null
	fi
}

extract_svn() {
	local netfile=$1

	local url="$(get_url "$netfile")"
	url=${url##svn+}
	local fragment=
	if [[ $url = *#* ]]; then
		fragment=${url#*#}
	fi

	local repo="$(get_downloadname "$netfile")"
	local src="$SRCDEST/$repo"
	local dst="$srcdir/$(get_depname "$netfile")"

	msg2 "$(gettext "Creating working copy of %s %s repo...")" "${repo}" "svn"
	rm -rf "${dst}"

	local ref=
	if [[ -n $fragment ]]; then
		case ${fragment%%=*} in
			revision)
				ref="${fragment##*=}"
				;;
			*)
				error "$(gettext "Unrecognized reference: %s")" "${fragment}"
				plain "$(gettext "Aborting...")"
				exit 1
		esac
	fi

	cp -a "$src" "$dst"

	if [[ -n ${ref} ]]; then
		pushd "$dst" &>/dev/null
		if ! svn update -r ${ref}; then
			error "$(gettext "Failure while creating working copy of %s %s repo")" "${repo}" "svn"
			plain "$(gettext "Aborting...")"
		fi
		popd &>/dev/null
	fi
}

download_sources() {
	msg "$(gettext "Retrieving sources...")"

	local netfile
	for netfile in "$@"; do
		local proto=$(get_protocol "$netfile")
		case "$proto" in
			git)
				download_git "$netfile"
				extract_git "$netfile"
				;;
			hg)
				download_hg "$netfile"
				extract_hg "$netfile"
				;;
			svn)
				download_svn "$netfile"
				extract_svn "$netfile"
				;;
			http|https)
				download_file "$netfile"
				extract_file "$netfile"
				;;
			*)
				error "$(gettext "Unrecognized protocol: %s")" "$proto"
				return 1
				;;
		esac
	done
}

declare -r HOLDVER=0
declare -r srcdir="$PWD/src/$1"; shift
declare -r SRCDEST="$PWD/src/downloads"
declare -r DLAGENTS=('http::/usr/bin/curl -fLC - --retry 3 --retry-delay 3 -o %o %u'
                     'https::/usr/bin/curl -fLC - --retry 3 --retry-delay 3 -o %o %u')

mkdir -p "$srcdir" "$SRCDEST"
download_sources "$@"