# Common functions shared by LTSP scripts

# Multiple inclusions shouldn't ever happen, but let's prevent them anyway
if [ -n "$sourced_ltsp_common_functions" ]; then
    echo "Warning: $0 tried to include ltsp-common-functions multiple times." >&2
    return 0
else
    sourced_ltsp_common_functions=true
fi

# All tools should support the standard --version option, see
# http://www.gnu.org/prep/standards/html_node/_002d_002dversion.html
ltsp_version()
{
    # Distributions should replace the version mentioned here with the actual
    # version mentioned in the changelog, using `sed` in their packaging code.
    echo "$ltsp_tool 1.0"
}

warn()
{
    printf "%s\n" "$*" >&2
}

die() {
    warn "$@"
    exit 1
}

log()
{
    if [ -x /usr/bin/logger ] && [ -e /dev/log ]; then
        logger -s -t "${0##/}" "$*"
    elif [ -w /dev/kmsg ]; then
        warn "${0##/}: $*" 2>>/dev/kmsg
        warn "${0##/}: $*"
    else
        warn "${0##/}: $*"
    fi
}

# To debug LTSP scripts, set ltsp.debug=<scriptname> in the kernel
# command line, or run debug=<scriptname> <scriptname>.
# $0 is automatically prefixed in debug messages.
# TODO: merge ltsp-build-client's debug with this one.
debug()
{
    local x

    if [ -z "$debug" ]; then
        if [ -f /proc/cmdline ]; then
            for x in $(cat /proc/cmdline); do
                case "$x" in
                    ltsp.debug=*)
                        debug=${x#ltsp.debug=}
                    ;;
                esac
            done
        fi
        debug=${debug:-false}
    fi
    if [ "$debug" = "${0##*/}" ]; then
        log "$@"
    fi
}

boolean_is_true(){
    case $1 in
       # match all cases of true|y|yes
       [Tt][Rr][Uu][Ee]|[Yy]|[Yy][Ee][Ss]) return 0 ;;
       *) return 1 ;;
    esac
}

run_parts()
# Parameters:
# $1: Directory with main scripts
# $2: Directory with override scripts, defaults to ''
# $3: Script matching regex, defaults to '[0-9]*'
{
    if [ ! -d "$1" ]; then
        warn "Not a directory: $1"
        return 1
    fi
    # We do want to source the scripts in a subshell, so that they affect each
    # other, but not the callee script.
    # ${2:+"$2"} means "preserve spaces, but don't pass a parameter if empty"
    find "$1" ${2:+"$2"} -maxdepth 1 -type f -name ${3:-'[0-9]*'} \
        -printf '%f\n' 2>/dev/null | sort | uniq | 
        while read script; do
            if [ -n "$2" ] && [ -f "$2/$script" ]; then
                . "$2/$script"
            else
                . "$1/$script"
            fi
        done
}

# list files in a directory consisting only of alphanumerics, hyphens and
# underscores
# $1 - directory to list
# $2 - optional prefix to limit which files are selected
run_parts_list() {
    test $# -ge 1 || die "ERROR: Usage: run_parts_list <dir>"
    if [ -d "$1" ]; then
        find -L "$1" -mindepth 1 -maxdepth 1 -type f -name "$2*" |
            sed -n '/.*\/[[:alnum:]_\-]\{1,\}$/p' | sort -n
    fi
}

detect_vendor() {
    if [ -e /etc/sysconfig/ltspdist ]; then
        . /etc/sysconfig/ltspdist
        echo "$VENDORDEF"
    else
        lsb_vendor=$(lsb_release --id --short | tr " " "_")
        if [ "$lsb_vendor" = LinuxMint ]; then
            if [ "$(lsb_release -s -c)" = "debian" ]; then
                echo "Debian"
            else
                echo "Ubuntu"
            fi
        else
            echo "$lsb_vendor"
        fi
    fi
}

# Distros may override this function to implement their own
# architecture detection.
detect_arch() {
    echo $(uname -m)
}

require_root()
{
    if [ ${UID:-$(id -u)} -ne 0 ]; then
        die "Superuser privileges are needed."
    fi
}

# Remember mounted dirs so that it's easier to unmount them with a single call
# to umount_marked. They'll be unmounted in reverse order.
# Use the normal mount syntax, e.g.
#   mark_mount -t proc proc "$ROOT/proc"
mark_mount() {
    local dir old_marked_mounts

    # The last parameter is the dir we need to remember to unmount
    dir=$(eval "echo \$$#")
    # If the user presses Ctrl+C while mount is still running, there's
    # a possibility that it will succeed but it won't go inside the if.
    # So mark the dir before mount.
    # Use newlines to separate dirs, in case they contain spaces
    old_marked_mounts="$MARKED_MOUNTS"
    if [ -z "$MARKED_MOUNTS" ]; then
        MARKED_MOUNTS="$dir"
    else
        MARKED_MOUNTS="$dir
$MARKED_MOUNTS"
    fi
    if ! mount "$@"; then
        MARKED_MOUNTS="$old_marked_mounts"
        die "Could not mount $dir."
    fi
}

umount_marked() {
    [ -z "$MARKED_MOUNTS" ] && return 0

    # Wait until all buffers are flushed, otherwise umount might fail
    sync
    echo "$MARKED_MOUNTS" | while read dir; do
        if ! umount "$dir"; then
            warn "Couldn't unmount $dir."
        fi
    done
    unset MARKED_MOUNTS
}

read_prompt() {
    # Shell agnostic "read -p" implementation

    # Only output if on an interactive terminal
    if [ -t 0 ]; then
        echo -n "$1"
    fi
    shift
    read "$@"
}

translator_credits() {
    # Display translation credits 
    eval_gettext "translator-credits"
}

debug "Started"

# Source tool-specific settings and functions, if they're provided
ltsp_tool=${0##*/}
if [ -f "/usr/share/ltsp/$ltsp_tool-functions" ]; then
    . "/usr/share/ltsp/$ltsp_tool-functions"
fi

# Source tool-specific configuration files
if [ -f "/etc/ltsp/$ltsp_tool.conf" ]; then
    . "/etc/ltsp/$ltsp_tool.conf"
fi
if [ -d "/etc/ltsp/$ltsp_tool.conf.d" ]; then
    for file in $(run_parts_list "/etc/ltsp/$ltsp_tool.conf.d") ; do
        . "$file"
    done
fi