#!/bin/sh
set -f

LOG=""
DEBUG_LEVEL=1
LOG_D="/run/cloud-init"
LOG_F="/run/cloud-init/cloud-init-generator.log"
ENABLE="enabled"
DISABLE="disabled"
RUN_ENABLED_FILE="$LOG_D/$ENABLE"
RUN_DISABLED_FILE="$LOG_D/$DISABLE"
CLOUD_TARGET_NAME="cloud-init.target"
# lxc sets 'container', but lets make that explicitly a global
CONTAINER="${container}"

# start: template section
CLOUD_SYSTEM_TARGET="/lib/systemd/system/cloud-init.target"
    dsidentify="/usr/lib/cloud-init/ds-identify"
# end: template section

debug() {
    local lvl="$1"
    shift
    [ "$lvl" -gt "$DEBUG_LEVEL" ] && return
    if [ -z "$LOG" ]; then
        { [ -d "$LOG_D" ] || mkdir -p "$LOG_D"; } &&
            { : > "$LOG_F"; } >/dev/null 2>&1 && LOG="$LOG_F" ||
            LOG="/dev/kmsg"
    fi
    echo "$@" >> "$LOG"
}

main() {
    local normal_d="$1" early_d="$2" late_d="$3"
    local target_name="multi-user.target" gen_d="$early_d"
    local link_path="$gen_d/${target_name}.wants/${CLOUD_TARGET_NAME}"
    local ds="" ret=""

    debug 1 "$0 normal=$normal_d early=$early_d late=$late_d"
    debug 2 "$0 $*"

    # ds=found => enable
    # ds=notfound => disable
    # <any> => disable
    debug 1 "checking for datasource"

    if [ ! -x "$dsidentify" ]; then
        debug 1 "no ds-identify in $dsidentify"
        ds=0
    fi
    $dsidentify
    ds=$?
    debug 1 "ds-identify rc=$ds"

    if [ "$ds" = "1" -o "$ds" = "2" ]; then
        if [ "$ds" = "1" ]; then
            debug 1 "cloud-init is enabled but no datasource found, disabling"
        else
            debug 1 "cloud-init is disabled by kernel command line or etc_file"
        fi
        if [ -f "$link_path" ]; then
            if rm -f "$link_path"; then
                debug 1 "disabled. removed existing $link_path"
            else
                ret=$?
                debug 0 "[$ret] disable failed, remove $link_path"
            fi
        else
            debug 1 "already disabled: no change needed [no $link_path]"
        fi
        if [ -e "$RUN_ENABLED_FILE" ]; then
            debug 1 "removing $RUN_ENABLED_FILE and creating $RUN_DISABLED_FILE"
            rm -f "$RUN_ENABLED_FILE"
        fi
        : > "$RUN_DISABLED_FILE"

    elif [ "$ds" = "0" ]; then
        if [ -e "$link_path" ]; then
                debug 1 "already enabled: no change needed"
        else
            [ -d "${link_path%/*}" ] || mkdir -p "${link_path%/*}" ||
                debug 0 "failed to make dir $link_path"
            if ln -snf "$CLOUD_SYSTEM_TARGET" "$link_path"; then
                debug 1 "enabled via $link_path -> $CLOUD_SYSTEM_TARGET"
            else
                ret=$?
                debug 0 "[$ret] enable failed:" \
                    "ln $CLOUD_SYSTEM_TARGET $link_path"
            fi
        fi
        if [ -e $RUN_DISABLED_FILE ]; then
            debug 1 "removing $RUN_DISABLED_FILE and creating $RUN_ENABLED_FILE"
            rm -f $RUN_DISABLED_FILE
        fi
        : > "$RUN_ENABLED_FILE"
    else
        debug 0 "unexpected result '$result' 'ds=$ds'"
        ret=3
    fi
    return $ret
}

main "$@"