#!/bin/bash


. /etc/shlib

[[ "${BASH_SOURCE[0]}" != "${0}" ]] && SOURCED=true

include common
include pretty
include cmdline

desc='Adds YAML key quite crudely in given compose.yml.'
help="\

$WHITE$exname$NORMAL will find a add or replace SSH key to
given identifier for rsync-backup-target charm.

For now, it only use detection of '## INSERTION-POINT' to manage
edition of 'compose.yml', and verification it didn't break anything
before overwriting.

"


[ "$SOURCED" ] && return 0

##
## Command line processing
##


# remove all lines from regex to regex (not included).
remove_lines_from_to() {
    local from="$1" to="$2"
    sed -r "/$from/,/$to/{/$to/"'!'"d};/$from/d"
}

check_valid_yaml() {
    shyaml get-value >/dev/null 2>&1;
}


cmdline.spec.gnu
cmdline.spec.reporting

service_name=${SERVICE_NAME:-rsync-backup-target}
compose_file=${COMPOSE_FILE:-/etc/compose/compose.yml}

cmdline.spec::valued:--compose-file,-f:usage() {
    echo "Compose file location. Defaults to '/etc/compose/compose.yml'"; }
cmdline.spec::valued:--compose-file,-f:run() { compose_file="$1"; }

cmdline.spec::valued:--service-name,-s:usage() {
    echo "YAML service name in compose file to check for existence of key. Defaults to 'rsync-backup-target'"; }
cmdline.spec::valued:--service-name,-s:run() { service_name="$1"; }

cmdline.spec::cmd:__main__:run() {

    : :posarg: DOMAIN           'domain identifier'
    : :posarg: SSH_PUBLIC_KEY   'ssh public key'

    if ! existing_domains=$(shyaml keys "${service_name//./\\.}.options.keys" < "$compose_file"); then
        err "Couldn't query file '$compose_file' for keys of" \
            "service ${DARKYELLOW}${service_name}${NORMAL}."
        exit 1
    fi

    content=$(cat "$compose_file")
    if echo "$existing_domains" | grep "^${DOMAIN}$" >/dev/null 2>&1; then

        if ! prev_key=$(shyaml get-value "${service_name//./\\.}.options.keys.${DOMAIN//./\\.}" \
                        < "$compose_file"); then
            err "Couldn't query file '$compose_file' for key of domain '$DOMAIN'."
            exit 1
        fi

        if [ "${prev_key}" == "$SSH_PUBLIC_KEY" ]; then
            echo "Key was already setup."
            exit 0
        fi

        content=$(echo "$content" | remove_lines_from_to '^      '"${DOMAIN//./\\.}"': ".*\\$' \
                                                         '^      ([A-Za-z0-9.-]+: "|## END MARKER)')

        if [ -z "$content" ]; then
            err "Didn't manage to remove key to compose file '$DOMAIN' in '$compose_file'."
            exit 1
        fi

        if [ "$content" == "$(cat "$compose_file")" ]; then
            err "Couldn't remove previous key for '$DOMAIN' in '$compose_file'."
            exit 1
        fi
        ## check we didn't break yaml
        if ! echo "$content" | check_valid_yaml; then
            err "Couldn't safely remove previous key for '$DOMAIN' in '$compose_file'."
            exit 1
        fi
    fi

    excerpt=$(cat <<EOF
      $DOMAIN: "$(
    echo "$SSH_PUBLIC_KEY" |
        fold -w 67 | sed -r 's/$/\\/g;2,$ s/^/        /g;$,$ s/\\$//g')"

EOF
           )
    excerpt="${excerpt//\\/\\\\\\}"
    content="$(echo "$content" | sed -r '/^      ## INSERTION-POINT/a\'"${excerpt}")"

    if [ -z "$content" ]; then
        err "Didn't manage to add key to compose file '$DOMAIN' in '$compose_file'."
        exit 1
    fi

    if ! echo "$content" | check_valid_yaml; then
        err "Couldn't safely add key to compose file '$DOMAIN' in '$compose_file'."
        exit 1
    fi

    if diff=$(diff -u "$compose_file" <(echo "$content")); then
        err "No difference, this is not expected, and something went wrong."
        exit 1
    fi
    echo "${WHITE}Applying these changes:${NORMAL}"
    echo "$diff"

    cp "$compose_file" "${compose_file}.old"
    echo "$content" > "$compose_file"

    ## reloading (could be much faster)
    compose --debug down && compose --debug up

    if [ "$?" == 0 ]; then
        echo "Added key, and restarted service ${DARKYELLOW}$service_name${NORMAL}."
    else
        echo "something went wrong ! Should check the state of '$DOMAIN' !!"
        exit 1
    fi
}


cmdline::parse "$@"