#!/bin/bash
set -euo pipefail
tag=latest
dummy=false
token=""

function usage() {
    echo "Usage:"
    echo "$(basename "${0}") [-t|--tag <TAG>] [-T|--token <GITHUB_TOKEN>] [-d|--debug]"
    echo ""
    echo "  -d|--debug           Show more debug information."
    echo "  -t|--tag <TAG>       Release tag or 'latest' (default)."
    echo "  -T|--token <TOKEN>   Github token with read access to public repositories."
    echo "  -D|--dummy|--dry-run Run in Dry-mode without actually updating but showing the commands to execute."
}

while [ $# -gt 0 ]
do
    case "${1}" in
        "-h"|"-?"|"--help")
        shift
        usage
        exit 0
        ;;
        "-d"|"--debug")
        shift
        export DEBUG=true
        ;;
        "-t"|"--tag")
        shift
        tag="${1}"
        shift
        ;;
        "-T"|"--token")
        shift
        token="${1}"
        shift
        ;;
        '-D'|'--dummy'|'--dry-run')
        shift
        dummy=true
        ;;
        *)
        message "Unknown parameter '$1'" p
        shift
        ;;
    esac
done

if [ -z "${token}" ]; then
    echo "You must provide a Github token"
    exit 4
fi
if [ "${tag}" == "latest" ]; then
    tag=$(curl -L -s -H "Accept: application/vnd.github+json" -H "Authorization: Bearer ${token}" -H "X-GitHub-Api-Version: 2022-11-28" https://api.github.com/repos/mastodon/mastodon/releases/latest | jq '.tag_name' | sed 's/"//g')
    if [ "${DEBUG}" == "true" ]; then
        echo "Latest tag is '${tag}'"
    fi
else
    if [ "${DEBUG}" == "true" ]; then
        echo "Looking for tag '${tag}'..."
    fi
    next_page=https://api.github.com/repos/mastodon/mastodon/releases
    releases_file=$(mktemp /tmp/tmp.XXXX)
    while [ -z "${next_page}" ]
    do
        tmpfile=$(mktemp /tmp/tmp.XXXXX)
        releases=$(curl -L -v -H "Accept: application/vnd.github+json" -H "Authorization: Bearer ${token}" -H "X-GitHub-Api-Version: 2022-11-28" "${next_page}" | jq '.[]|.tag_name' 2> "${tmpfile}")
        echo "${releases}" >> "${releases_file}"
        next_page=$(grep '< link: ' "${tmpfile}" | sed 's/< link: //g' | sed 's/, /\n/g' | grep 'rel="next"' | grep -o 'https://[^>]*')
    done
    if ! pgrep "${tag}" "${releases_file}"; then
        printf "The tag '%s' is not part of the releases:\n%s" "${tag}" "${releases}"
        exit 1
    fi
fi

mastodon_home="$(grep "^mastodon:" /etc/passwd | awk 'BEGIN {FS=":"} {print($6)}')/live"
if [ ! -d "${mastodon_home}" ]; then
    printf "The home for the user mastodon '%s', doesn't exist." "${mastodon_home}"
    exit 2
fi

if [ "${DEBUG}" == "true" ]; then
    echo "Changing to Mastodon's home directory '${mastodon_home}'..."
fi
cd "${mastodon_home}" || exit 3
current_tag=$(git name-rev --name-only HEAD | awk 'BEGIN {FS="/"} {print($2)}')
if [ "${current_tag}" != "${tag}" ]; then
    if [ "${DEBUG}" == "true" ]; then
        echo "Fetching from repository..."
    fi
    if [ "${dummy}" == "true" ]; then
        echo sudo -u mastodon git fetch
    else
        sudo -u mastodon git fetch
    fi
    if [ "${DEBUG}" == "true" ]; then
        echo "Changing to reference '${tag}'..."
    fi
    if [ "${dummy}" == "true" ]; then
        echo sudo -u mastodon git checkout "${tag}"
    else
        sudo -u mastodon git checkout "${tag}"
    fi
    current_date=$(date +%Y-%m-%d-%H-%M-%S)
    mkdir -p /var/backups/postgres
    backup_file="/var/backups/postgres/pgdump_pre_update_mastodon_to_${tag}_${current_date}.sql.gz"
    if [ "${dummy}" == "true" ]; then
        echo "sudo -u postgres pg_dump mastodon | gzip -c > \"${backup_file}\""
    else
        if [ "${DEBUG}" == "true" ]; then
            echo "Creating a backup of the database in '${backup_file}'..."
        fi
        sudo -u postgres pg_dump mastodon | gzip -c > "${backup_file}"
    fi
    if [ "${DEBUG}" == "true" ]; then
        echo "Running bundle install..."
    fi
    if [ "${dummy}" == "true" ]; then
        echo sudo -u mastodon "${mastodon_home}/bin/bundle" install
    else
        sudo -u mastodon "${mastodon_home}/bin/bundle" install
    fi
    if [ "${DEBUG}" == "true" ]; then
        echo "Running yarm install..."
    fi
    if [ "${dummy}" == "true" ]; then
        echo sudo -u mastodon "${mastodon_home}/bin/yarn" install --frozen-lockfile
    else
        sudo -u mastodon "${mastodon_home}/bin/yarn" install --frozen-lockfile
    fi
    if [ "${DEBUG}" == "true" ]; then
        echo "Restarting Mastodon services..."
    fi
    if [ "${dummy}" == "true" ]; then
        echo sudo systemctl restart mastodon-sidekiq.service mastodon-web.service mastodon-streaming mastodon-streaming@4000.service
    else
        sudo systemctl restart mastodon-sidekiq.service mastodon-web.service mastodon-streaming mastodon-streaming@4000.service
    fi
else
    echo "Current branch is already '${tag}'"
    exit 0
fi