#!/bin/sh -ef
# shellcheck source=/dev/null

log() {
    # Print a message prettily.
    #
    # All messages are printed to stderr to allow the user to hide build
    # output which is the only thing printed to stdout.
    #
    # '${3:-->}':         If the 3rd argument is missing, set prefix to '->'.
    # '${2:+colorb}':     If the 2nd argument exists, set text style of '$1'.
    printf '%b%s %b%b%s%b %s\n' \
           "$colory" "${3:-->}" "$colre" "${2:+$colorb}" "$1" "$colre" "$2" >&2
}

version() {
    log "Carbs Packaging Tools" @VERSION@
    exit 0
}

trap_set() {
    # Function to set the trap value.
    case ${1:-cleanup} in
        cleanup) trap pkg_clean EXIT INT ;;
        block)   trap '' INT ;;
        unset)   trap - EXIT INT ;;
    esac
}

_readlinkf() {
    # Public domain POSIX sh readlink function by Koichi Nakashima
    [ "${1:-}" ] || return 1
    max_symlinks=40
    CDPATH='' # to avoid changing to an unexpected directory

    target=$1
    [ -e "${target%/}" ] || target=${1%"${1##*[!/]}"} # trim trailing slashes
    [ -d "${target:-/}" ] && target="$target/"

    cd -P . 2>/dev/null || return 1
    while [ "$max_symlinks" -ge 0 ] && max_symlinks=$((max_symlinks - 1)); do
        if [ ! "$target" = "${target%/*}" ]; then
            case $target in
                /*) cd -P "${target%/*}/" 2>/dev/null || break ;;
                *) cd -P "./${target%/*}" 2>/dev/null || break ;;
            esac
            target=${target##*/}
        fi

        if [ ! -L "$target" ]; then
            target="${PWD%/}${target:+/}${target}"
            printf '%s\n' "${target:-/}"
            return 0
        fi

        # `ls -dl` format: "%s %u %s %s %u %s %s -> %s\n",
        #   <file mode>, <number of links>, <owner name>, <group name>,
        #   <size>, <date and time>, <pathname of link>, <contents of link>
        # https://pubs.opengroup.org/onlinepubs/9699919799/utilities/ls.html
        link=$(ls -dl -- "$target" 2>/dev/null) || break
        target=${link#*" $target -> "}
    done
    return 1
}

# CPT Library does "lazy loading" of its functions. Meaning that functions are
# defined, but the libraries containing the functions aren't loaded until one of
# those functions are called. This should theoretically decrease the time it
# takes to execute some script that uses only minimal amount of library
# functions. When a function listed below is called, its definition is replaced
# by the one in the loaded library, and executed with the same arguments.
# @AUTOLOADS@

# main()
{
    set -ef

    # Set the library directory if unset, assuming that it shares the same
    # prefix with the tool.
    [ "$CPT_LIBDIR" ] || CPT_LIBDIR=$(_readlinkf "$(command -v cpt-lib)") CPT_LIBDIR=${CPT_LIBDIR%/*}

    # If a parser definition exists, let's run it ourselves. This makes sure we
    # get the variables as soon as possible.
    command -v parser_definition >/dev/null && {
        eval "$(getoptions parser_definition parse "$0")"
        parse "$@"
        eval set -- "$REST"
    }

    # Create the cache directories for CPT and set the variables which point
    # to them. This is seperate from temporary directories created in
    # create_cache(). That's because we need these variables set on most
    # occasions.
    mkdir -p "${cac_dir:=${CPT_CACHE:=${XDG_CACHE_HOME:-$HOME/.cache}/cpt}}" \
             "${src_dir:=$cac_dir/sources}" \
             "${log_dir:=$cac_dir/logs}" \
             "${bin_dir:=$cac_dir/bin}"

    # Set the location to the repository and package database.
    pkg_db=var/db/cpt/installed

    # The PID of the current shell process is used to isolate directories
    # to each specific CPT instance. This allows multiple package manager
    # instances to be run at once. Store the value in another variable so
    # that it doesn't change beneath us.
    pid=${CPT_PID:-$$}

    # Force the C locale to speed up things like 'grep' which disable unicode
    # etc when this is set. We don't need unicode and a speed up is always
    # welcome.
    export LC_ALL=C LANG=C

    # Catch errors and ensure that build files and directories are cleaned
    # up before we die. This occurs on 'Ctrl+C' as well as success and error.
    trap_set cleanup

    # Prefer GNU grep if installed as it is much much faster than busybox's
    # implementation. Very much worth it if you value performance over
    # POSIX correctness (grep quoted to avoid shellcheck false-positive).
    grep=$(command -v ggrep) || grep='grep'

    # Prefer libarchive tar or GNU tar if installed as they are  much
    # much faster than busybox's implementation. Very much worth it if
    # you value performance.
    tar=$(command -v bsdtar || command -v gtar) || tar=tar

    # Figure out which 'sudo' command to use based on the user's choice or
    # what is available on the system.
    su=${CPT_SU:-$(command -v sls    ||
                   command -v sudo   ||
                   command -v doas)} || su=su

    # Store the date and time of script invocation to be used as the name
    # of the log files the package manager creates during builds.
    time=$(date '+%Y-%m-%d-%H:%M')

    # Use readelf for fixing dependencies if it is available, fallback to
    # ldd. readelf shows only the actual dependencies and doesn't include
    # the libraries required by the dependencies.
    elf_prog=${CPT_ELF:="$(
               command -v readelf       ||
               command -v llvm-readelf  ||
               command -v eu-readelf)"} || elf_prog=ldd

    # Make note of the user's current ID to do root checks later on.
    # This is used enough to warrant a place here.
    uid=$(id -u)

    # Save IFS, so we can restore it back to what it was before.
    old_ifs=$IFS

    # Make sure that the CPT_ROOT doesn't end with a '/'. This might
    # break some operations.
    CPT_ROOT=${CPT_ROOT%"${CPT_ROOT##*[!/]}"}

    # Define an optional sys_arch variable in order to provide
    # information to build files with architectural information.
    sys_arch=$(uname -m 2>/dev/null) ||:

    # Define this variable but don't create its directory structure from
    # the get go. It will be created as needed by package installation.
    sys_db=$CPT_ROOT/$pkg_db

    # This allows for automatic setup of a CPT chroot and will
    # do nothing on a normal system.
    mkdir -p "$CPT_ROOT/" 2>/dev/null ||:

    # Set a value for CPT_COMPRESS if it isn't set.
    : "${CPT_COMPRESS:=gz}"

    # Unless being piped or the user specifically doesn't want colors, set
    # colors. This can of course be overriden if the user specifically want
    # colors during piping.
    if { [ "$CPT_COLOR" != 0 ] && [ -t 1 ] ;} || [ "$CPT_COLOR" = 1 ]; then
        colory="\033[1;33m" colorb="\033[1;36m" colre="\033[m"
    fi

}