functions

# -*- shell-script[bash] -*-

# Copyright 2022 Amazon.com, Inc. or its affiliates. All Rights Reserved.
# SPDX-License-Identifier: Apache-2.0

###################
# Logging helpers #
###################

# Naming things is hard
ARG0=${BASH_SOURCE[-1]}
MY_NAME="Firecracker $(basename "$ARG0")"

# Send a decorated message to stdout, followed by a new line
#
say() {
    [ -t 1 ] && [ -n "$TERM" ] \
        && echo "$(tput setaf 2)[$MY_NAME $(date -Iseconds)]$(tput sgr0) $*" \
        || echo "[$MY_NAME] $*"
}

# Send a decorated message to stdout, without a trailing new line
#
say_noln() {
    [ -t 1 ] && [ -n "$TERM" ] \
        && echo -n "$(tput setaf 2)[$MY_NAME]$(tput sgr0) $*" \
        || echo "[$MY_NAME] $*"
}

# Send a text message to stderr
#
say_err() {
    [ -t 2 ] && [ -n "$TERM" ] \
        && echo -e "$(tput setaf 1)[$MY_NAME] $*$(tput sgr0)" 1>&2 \
        || echo -e "[$MY_NAME] $*" 1>&2
}

# Send a warning-highlighted text to stdout
say_warn() {
    [ -t 1 ] && [ -n "$TERM" ] \
        && echo "$(tput setaf 3)[$MY_NAME] $*$(tput sgr0)" \
        || echo "[$MY_NAME] $*"
}

# Exit with an error message and (optional) code
# Usage: die [-c <error code>] <error message>
#
die() {
    code=1
    [[ "$1" = "-c" ]] && {
        code="$2"
        shift 2
    }
    say_err "$@"
    exit $code
}

# Exit with an error message if the last exit code is not 0
#
ok_or_die() {
    code=$?
    [[ $code -eq 0 ]] || die -c $code "$@"
}

# ANSI output helper
# https://en.wikipedia.org/wiki/ANSI_escape_code
function SGR {
    local codes=$*
    printf "\e[%sm" "${codes// /;}"
}

# Prompt the user for confirmation before proceeding.
# Args:
#   $1  prompt text.
#       Default: Continue? (y/n)
#   $2  confirmation input.
#       Default: y
# Return:
#   exit code 0 for successful confirmation
#   exit code != 0 if the user declined
#
OPT_UNATTENDED=false
get_user_confirmation() {

    # Pass if running unattended
    [[ "$OPT_UNATTENDED" = true ]] && return 0

    # Fail if STDIN is not a terminal (there's no user to confirm anything)
    [[ -t 0 ]] || return 1

    # Otherwise, ask the user
    #
    msg=$([ -n "${1:-}" ] && echo -n "$1" || echo -n "Continue? (y/n) ")
    yes=$([ -n "${2:-}" ] && echo -n "$2" || echo -n "y")
    say_noln "$msg"
    read c && [ "$c" = "$yes" ] && return 0
    return 1
}

#######################################
# Release automation common functions #
#######################################

# Get version from the swagger file
function get_swagger_version {
    local file=${1:-"$FC_ROOT_DIR/src/api_server/swagger/firecracker.yaml"}
    grep -oP 'version: \K.*' "$file"
}

function check_local_branch_is_release_branch {
    local LOCAL_BRANCH=$(git rev-parse --abbrev-ref HEAD)
    local RELEASE_BRANCH=firecracker-v$(echo "$version" |cut -d. -f-2)

    if [ "$LOCAL_BRANCH" != "$RELEASE_BRANCH" ]; then
        cat <<EOF
ERROR: The current branch '$LOCAL_BRANCH' should be '$RELEASE_BRANCH'
Bailing out.
You can fix this by checking out the expected release branch and rerunning:

    git checkout -B $RELEASE_BRANCH
EOF
        exit 1
    fi
}

# Validate the user supplied version number.
# It must start with 3 groups of integers separated by dot and
# must not contain `wip` or `dirty`.
function validate_version {
    declare version_regex="^([0-9]+\.){2}[0-9]+"
    local version="$1"

    if [ -z "$version" ]; then
        die "Version cannot be empty."
    elif [[ ! "$version" =~ $version_regex ]]; then
        die "Invalid version number: $version. Version should start with \$Major.\$Minor.\$Build, see
        https://github.com/firecracker-microvm/firecracker/blob/main/docs/RELEASE_POLICY.md for more information."
    elif [[ "$version" == *"wip"* ]] || [[ "$version" == *"dirty"* ]]; then
        die "Invalid version number: $version. Version should not contain \`wip\` or \`dirty\`."
    fi
}

#########################
# Firecracker functions #
#########################

# Check if /dev/kvm exists. Exit if it doesn't.
# Upon returning from this call, the caller can be certain /dev/kvm is
# available.
#
ensure_kvm() {
    [[ -c /dev/kvm ]] || die "/dev/kvm not found. Aborting."
}