functions

#! /bin/bash

# Usage: command_sane <command> <package>
# Verify that command exists in the current environment (builtin, alias or
# executable) or display an error message with the recommended package
# providing it on stderr and return 1.
command_sane() {
    local cmd="$1"
    local pkg="$2"

    if ! command -v "$1" >/dev/null; then
        echo "Cannot find \"${cmd}\" command. Install ${pkg} to use this script." >&2
        return 1
    fi
    return 0
}

# Usage: check_cmd_version
# Compares stage/deploy command against OpenXT version and abort if support is
# no longer provided.
check_cmd_version() {
    local cmd="$1"

    # Ignore development/hacked versions.
    if [ "${OPENXT_RELEASE}" = "0.0.0" -o -z "${OPENXT_RELEASE}" ]; then
        return 0
    fi
    if [ "${OPENXT_RELEASE%%.*}" -ge "8" ]; then
        case "${cmd}" in
            *"-old")
                echo "\`${cmd}' is no longer supported with OpenXT 8 and later versions. See \`${cmd%%-old}' command replacement." >&2
                exit 1 ;;
            *) return 0 ;;
        esac
    else
        case "${cmd}" in
            *"-old") return 0 ;;
            "*") echo "\`${cmd}' is not supported with OpenXT 7 and earlier versions. See \`${cmd}-old' legacy support." >&2
               exit 1 ;;
        esac
    fi
}

register_cmds() {
    local cmd_dir=${1}
    local cmds=$(ls ${cmd_dir} | sed -e 's/~.*//g')

    for c in ${cmds}; do
        . ${cmd_dir}/${c}
        if command -v "${c}_dependency" >/dev/null; then
            for d in $(eval "${c}_dependency"); do
                if [ ! -z "${cmds##*${d}*}" ]; then
                    echo "Command ${c} depends on command ${d} which is not currently installed." >&2
                    continue
                fi
            done
        fi

        _CMDS="${_CMDS} ${c}"
    done
}

describe_cmds() {
    for c in ${_CMDS}; do
        if command -v "${c}_describe" >/dev/null; then
            echo -e "  ${c}:\t$(eval "${c}_describe")"
        else
            echo -e "  ${c}:\tis available but provides no description."
        fi
    done
}

valid_cmd() {
    local cmd="${1}"

    [ -z "${_CMDS##*${cmd}*}" ]
}

call_cmd() {
    local cmd=${1}
    shift 1

    "${cmd}_main" $@
}