#!/usr/bin/env bash

if [[ "$(realpath "$(dirname "$(realpath -s "$0")")/../../../")" == "/" ]]; then
    . /usr/local/libexec/zio/helpers/bash.sh
else
    . "$(dirname "$(realpath -s "$0")")/../libexec/zio/helpers/bash.sh"
fi

me_filename="$(basename "$(realpath -s "$0")")"
backup_scripts_dir="$(get_config_dir "sh.zio.backup")/scripts"
cache_dir="/var/cache/sh.zio.backup/restic"
secrets_dir="$(get_config_dir "sh.zio.backup")/secrets"
host="$(hostname -s)"
restic_path=""
restic_repo_file="$secrets_dir/restic-repo"
restic_repo_passwd_file="$secrets_dir/restic-repo-passwd"

function download_restic() {
    restic_version="$1"

    restic_download_url="https://github.com/restic/restic/releases/download/v${restic_version}/restic_${restic_version}_linux_amd64.bz2"
    restic_path="/tmp/restic-$restic_version"
    restic_archive_path="${restic_path}_$(date +%s).${restic_download_url##*.}"

    if [[ ! -f "$restic_path" ]]; then
        say info "Downloading Restic ($restic_version)..."

        curl -L -s -o "$restic_archive_path" "$restic_download_url"
        bzip2 -dc "$restic_archive_path" > "$restic_path"
        rm -f "$restic_archive_path"

        chmod +x "$restic_path"

        if [[ ! "$(echo "$("$restic_path" version)")" == "restic $restic_version"* ]]; then
            die "Unexpected output from '$restic_path version'"
            rm -f "$restic_path"
        fi
    fi
}

function invoke_restic() {
    command="$1"
    args="${@:2}"

    case "$(cat "$restic_repo_file")" in
        "b2"*)
            b2_account_id_file="$secrets_dir/b2-account-id"
            b2_account_key_file="$secrets_dir/b2-account-key"

            test_file "$b2_account_id_file"
            test_file "$b2_account_key_file"

            export B2_ACCOUNT_ID="$(cat "$b2_account_id_file")"
            export B2_ACCOUNT_KEY="$(cat "$b2_account_key_file")"
            ;;
        *)
            die "Repository unsupported ("$(cat "$restic_repo_file")")"
            ;;
    esac


    if [[ -z $command ]]; then
        say warning "No command specified. Not running"
    elif [[ $command == "self-update" ]]; then
        say warning "Command '$command' not supported. Not running"
    else
        "$restic_path" \
            --cache-dir "$cache_dir" \
            --password-file "$restic_repo_passwd_file" \
            --repo "$(cat $restic_repo_file)" \
            $command $args
    fi
}

function invoke_script() {
    backup_script="$1"

    backup_script_filename="$(basename "$backup_script")"
    backup_script_name="${backup_script_filename%.*}"
    backup_script_name_length="${#backup_script_name}"

    say primary "-[$backup_script_name]$(repeat "-" $((80-3-$backup_script_name_length)))"
    chmod +x "$backup_script"

    export -f backup_dir
    export -f die
    export -f forget_backup
    export -f get_config_dir
    export -f get_real_path
    export -f invoke_restic
    export -f podman_exec
    export -f prune_backup
    export -f say
    export -f start_service
    export -f stop_service
    export -f test_file
    export backup_scripts_dir
    export cache_dir
    export host
    export me_filename
    export restic_repo_file
    export restic_repo_passwd_file
    export restic_path
    export secrets_dir

    "$backup_scripts_dir/$backup_script_filename"
}

function backup_dir() {
    path="$1"
    args="${@:2}"

    if [[ ! -d "$path" ]]; then
        say warning "'$path' does not exist. Not backing up"
    else
        say info "Backing up: $path ➔ $(cat $restic_repo_file)"

        invoke_restic \
            backup \
            --iexclude "__MACOSX" \
            --iexclude ".cache" \
            --iexclude ".DS_Store" \
            --iexclude "cache" \
            --iexclude "CachedData" \
            --iexclude "CachedExtensionVSIXs" \
            --iexclude "Code Cache" \
            --iexclude "GPUCache" \
            --iexclude "GrSharedCache" \
            --iexclude "ShaderCache" \
            --iexclude "system-cache" \
            --iexclude "thumbs.db" \
            --iexclude "tmp" \
            --exclude "containers/storage/overlay" \
            --exclude "containers/storage/overlay-containers" \
            --exclude "containers/storage/overlay-images" \
            --exclude "containers/storage/overlay-layers" \
            --exclude-if-present ".nobackup" \
            --host "$host" \
            --tag "$me_filename" \
            --tag "$(basename "$0")" \
            $args "$path"
    fi
}

function forget_backup() {
    timeframe="$1"

    if [[ -z $timeframe ]]; then
        timeframe="0y0m7d0h"
    fi

    say info "Forgetting: $timeframe ($host)"

    invoke_restic \
        forget \
        --keep-within "$timeframe" \
        --host "$host"
}

function prune_backup() {
    say info "Pruning"

    invoke_restic \
        prune \
        --dry-run
}

function start_service() {
    service="$1"

    say info "Starting service: $service"
    systemctl start $service
}

function stop_service() {
    service="$1"

    say info "Stopping service: $service"
    systemctl stop $service
}

if [[ "$@" == "help" ]]; then
    echo "$me_filename

Usage:
    $me_filename
        Run all backup scripts available in $backup_scripts_dir

    $me_filename <script>
        Run a specific script from a given path

    $me_filename <command> [arguments]
        Execute 'restic' with arbitrary commands and optional arguments.

        This command is bootstrapped with some arguments — which are not
        overridable — as follows:
          * --cache-dir
          * --password-file
          * --repo

    $me_filename help
        Output this usage text. Use '--help' or 'help <command>' to output
        restic's help text.
"
    exit 0
fi

test_root
test_prog "bzip2"
test_prog "curl"
test_prog "grep"
test_prog "hostname"

mkdir -p "$backup_scripts_dir"
mkdir -p "$cache_dir"
mkdir -p "$secrets_dir"

chmod -R 711 "$secrets_dir"

download_restic 0.16.0

test_file "$restic_repo_file"
test_file "$restic_repo_passwd_file"

if [[ -z "$1" ]]; then
    say info "Running backup scripts..."

    if ! [[ "$(ls -A $backup_scripts_dir)" ]]; then
        die "No scripts found in '$backup_scripts_dir'"
    fi

    for backup_script in $backup_scripts_dir/*; do
        invoke_script $backup_script
    done

    say primary "$(repeat "-" 80)"
elif [[ -f "$1" ]]; then
    invoke_script "$1"
else
    command="$1"
    arguments="${@:2}"
    say info "Running: $restic_path $command $arguments"
    invoke_restic $command $arguments
fi