#!/bin/ksh
#
########################################################################
#
# snaps - Check if you can upgrade your OpenBSD OS base to
# last -current snapshot
#
# Copyright (c) 2017-2020, Fred Galusik <f AT galusik.fr>
# All rights reserved.
#
# Redistribution and use in source and binary forms, with or without
# modification, are permitted provided that the following conditions are
# met:
#
# 1. Redistributions of source code must retain the above copyright
# notice, this list of conditions and the following disclaimer.
#
# 2. Redistributions in binary form must reproduce the above copyright
# notice, this list of conditions and the following disclaimer in the
# documentation and/or other materials provided with the distribution.
#
# 3. Neither the name of the copyright holder nor the names of its
# contributors may be used to endorse or promote products derived from
# this software without specific prior written permission.
#
# THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
# "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
# LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
# A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
# HOLDER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
# SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
# LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
# DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
# THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
# (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
# OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
#
########################################################################

set -ue

###
### VARS
###

VERSION=2.0

# choose your MIRROR
true "${MIRROR:=$(grep -v "^#" /etc/installurl)}"

# curl is mandatory
if [ ! "$(which curl 2>/dev/null)" ]; then
    echo "WARNING: 'curl' is requested to run this program. Aborting..."
        exit 1
fi
CURL=$(whereis curl)

# 
ARCH=$(uname -m)
SHA=SHA256
BASE=/snapshots/${ARCH}/
BASEF=/snapshots/${ARCH}/${SHA}
PKGSF=/snapshots/packages/${ARCH}/${SHA}

GET='/usr/bin/ftp -n -m -C'

LOGF=/var/log/snaps.log

###
###
###


usage() {
    echo "${0##*/} ${VERSION}"
    echo "Usage: ${0##*/} [-scalfuph]"
    echo ""
    echo "  -s  check \$MIRROR freshness & choose to sysupgrade or not"
    echo "  -c  check BASE and PACKAGES build dates from \$MIRROR"
    echo "  -a  check BASE and PACKAGES build dates from all available mirrors"
    echo "  -l  list date and \$MIRROR of the 3 last upgrade using this script"
    echo "  -f  read the online FAQ : Following -current and using snapshots"
    echo "  -u  upgrade snaps to last version"
    echo "  -p  update ports tree to -current"
    echo "  -h  print this help and exit"
    echo ""
    echo "MIRROR is based upon /etc/installurl and set to: ${MIRROR}"
    echo ""
    echo "You can set it manually:"
    echo "\$ MIRROR=http://mirrors.ircam.fr/pub/OpenBSD snaps -c"
    echo ""
}


s_root() {
    if [[ $(id -u) != "0" ]]; then
        echo "WARNING: You need to be root to do this! Aborting..." 1>&2
        exit 1
    fi
}


s_toupgrade() {
    REMOTESNAPS='https://framagit.org/fredg/snaps/raw/master/snaps'
    LASTSNAPS=/tmp/snaps
    echo "Checking snaps release..."
    if [[ -f "${LASTSNAPS}" ]]; then
      rm -f "${LASTSNAPS}"
    fi
    if $GET -V -o "${LASTSNAPS}" "${REMOTESNAPS}"; then
        REMOTEVERSION=$(awk -F '=' '/^VERSION=/ { print $2 }' "${LASTSNAPS}")
        if [ "${VERSION}" != "${REMOTEVERSION}" ]; then
            echo "WARNING: snaps is not up-to-date !"
            echo "Last version: ${REMOTEVERSION}"
            echo "To upgrade, run 'snaps -u'"
        else
            echo "GOOD: snaps is up-to-date."
        fi
    else
          echo "WARNING: Remote snaps not reachable ! Check the connection."
    fi
    echo ""
}


s_upgrade() {
    SELFPATH=$(dirname "$(readlink -f -- "$0")")
    echo "Downloading last snaps version..."
    $GET -o "${SELFPATH}" "${REMOTESNAPS}"
}


get_log() {
    if [[ -f "${LOGF}" ]]; then
        tail -n 3 ${LOGF}
    else
        echo "No ${LOGF} file. Seems you have not yet played with snaps."
        exit 1
    fi
}


s_upports() {
    echo "Updating Ports tree..."
    cd /usr/ports || exit 1
    /usr/bin/cvs up -Pd || exit 1
    echo "New Ports tree fetched!"
}


s_cur() {
    CURRENTSYS=$(sed q /var/run/dmesg.boot)
    echo "=== LOCAL BASE BUILD DATE ==="
    echo "${CURRENTSYS}"
}


s_when() {
    CURLB="$(${CURL} -sI "${MIRROR}${BASEF}" | grep Last-Modified)"
    CURLP="$(${CURL} -sI "${MIRROR}${PKGSF}" | grep Last-Modified)"
    echo "=== ONLINE BASE AND PACKAGES BUILD DATES ==="
    echo "From ${MIRROR}"
    echo "Base (${ARCH})     => ${CURLB}"
    echo "Packages (${ARCH}) => ${CURLP}"
}


s_sysup() {
    NOW=$(date "+ %Y-%m-%d %R")
    echo ""
    echo -n "Do you want to run 'sysupgrade -s' ? (y/n): "
    read -r _c
    case ${_c} in
        y|Y)
            ;;
        *)
            echo "Aborting..."
            exit 1
            ;;
    esac
    echo "${NOW} FROM ${MIRROR}${BASE}" >> ${LOGF}
    /usr/sbin/sysupgrade -s
}


read_faq() {
    FAQ='https://www.openbsd.org/faq/current.html'
    if [ "$(which links 2>/dev/null)" ]; then
        READ='links -dump'
    elif [ "$(which lynx 2>/dev/null)" ]; then
        READ='lynx --dump'
    else
        echo "WARNING: You need 'links' or 'lynx' to read the online FAQ/CURRENT. Aborting..."
        exit 1
    fi
    ${READ} ${FAQ} | less
}

all_mirrors() {
    echo "Checking mirrors..."
    HTTPSLIST='https://cvsweb.openbsd.org/cgi-bin/cvsweb/~checkout~/www/httpslist'
    MIRRORLIST=$(${CURL} ${HTTPSLIST} | awk '{print $1}')
    echo ""
    for _m in ${MIRRORLIST}
    do
        CB="$(${CURL} -sI "${_m}${BASEF}" | grep Last-Modified |\
            sed 's/Last-Modified: //')"
        CP="$(${CURL} -sI "${_m}${PKGSF}" | grep Last-Modified |\
            sed 's/Last-Modified: //')"
        # only print mirror which give an answer
        # FIXME try to figure out how to print 1 mirror per line
        if [ "${CB}" ]; then
            echo "${_m}"
            echo "${CB}"
            echo "${CP}"
            echo ""
        fi
    done
}


##
## Run
##

if [ $# -eq 0 ]; then
    usage
    exit 1
fi

case $1 in
    -s)
        s_root
        s_toupgrade
        s_cur
        echo ""
        s_when
        s_sysup
        ;;
    -c)
        s_cur
        s_when
        ;;
    -a)
        all_mirrors
        ;;
    -l)
        get_log
        ;;
    -f)
        read_faq
        ;;
    -u)
        s_upgrade
        ;;
    -p)
        s_upports
        ;;
    -h|*)
        usage
        exit 1
        ;;
esac