sh-utils

#! /bin/bash

source "$DGL_CONF_HOME/dgl-manage.conf"

DGL_CONF_LOCK_DIR="$DGL_CONF_HOME/locks"

declare -a DGL_LOCKS
DGL_LOCKS=()

PROMPTS_ENABLED=
GIVE_HELP=

help() {
    if [[ -n "$GIVE_HELP" ]]; then
        cat
        echo
        exit 0
    fi
}

dgl-run() {
    "$0" "$@"
}

say() {
    echo ";;;; $@"
}

say-do() {
    echo "[EXEC] $@"
    "$@"
}

running-as-root() {
    [[ "$UID" == "0" ]]
}

assert-running-as-root() {
    if ! running-as-root; then
        abort-saying "$SCRIPT_NAME needs to be run as root"
    fi
}

not-running-as-root() {
    [[ "$UID" != "0" ]]
}

each-do() {
    local cmd="$1"
    shift
    for arg in "$@"; do
        $cmd "$arg"
    done
}

announce() {
    echo
    echo "---------------------------------------------------------------------"
    echo "$@"
    echo "$@" >>$ANNOUNCEMENTS_FILE
}

abort-saying() {
    echo -e "$@, aborting."
    exit 1
}

# Call with any argument to disable prompts
enable-prompts() {
    local opt
    while getopts p opt; do
        PROMPTS_ENABLED=1
    done
    shift $((OPTIND - 1))

    # Would be nice to be able to modify the caller's arguments...
}

prompts-enabled() {
    [[ -n "$PROMPTS_ENABLED" && -t 0 ]]
}

prompt() {
    if prompts-enabled; then
        echo "-- Press RETURN to $@ --"
        read
    else
        say "$@"
    fi
}

unlock-dgl-locks() {
    if (( "${#DGL_LOCKS[@]}" > 0 )); then
        rm -f ${DGL_LOCKS[@]}
    fi
}

unlock-on-error() {
    unlock-dgl-locks
    exit 1
}

trap-lock-hook-cleanup() {
    if [[ -z "$DGL_TRAP_LOCK_CLEANUP_HOOKED" ]]; then
        trap unlock-on-error INT TERM
        trap unlock-dgl-locks EXIT
        DGL_TRAP_LOCK_CLEANUP_HOOKED=1
    fi
}

lock-or-die() {
    local lock_name=$1
    mkdir -p "$DGL_CONF_LOCK_DIR"
    local lock_file="$DGL_CONF_LOCK_DIR/${lock_name}.lock"
    shift || true
    if ( set -o noclobber; echo "$$" > "$lock_file" ) 2>/dev/null; then
        DGL_LOCKS=(${DGL_LOCKS[@]} "$lock_file")
        trap-lock-hook-cleanup
    else
        echo "Could not lock $lock_file: $@"
        exit 1
    fi
}

dgl-today() {
    date +%y%m%d-%H%M
}

cat-error() {
    cat >&2
}

assert-chroot-exists() {
    if [[ ! -d "$DGL_CHROOT" ]]; then
        cat-error <<ERROR
DGL chroot $DGL_CHROOT doesn't exist.

Please create it, or edit $DGL_CONF_HOME/dgl-manage.conf to
point at the real chroot.
ERROR
        exit 1
    fi
}

assert-login-db-exists() {
    if [[ ! -f "$LOGIN_DB" ]]; then
        cat-error <<EOF
DGL login db $LOGIN_DB is missing; please check that the chroot
is correctly setup, and that $DGL_CONF_HOME/dgl-manage.conf points
at the correct chroot path.
EOF
        exit 1
    fi
}

login-query() {
    sqlite3 "$LOGIN_DB"
}

dgl-user-exists() {
    local user="$1"
    local found="$(echo "SELECT username FROM dglusers WHERE username='$user';" |
                   login-query)"
    [[ -n "$found" ]]
}

dgl-user-is-admin() {
    local user="$1"
    local found="$(echo "SELECT username FROM dglusers
                         WHERE username='$user' AND (flags & 1) = 1;" |
                   login-query)"
    [[ -n "$found" ]]
}