#!/usr/bin/env bash

# tar.sh - backup files via tar.
# Copyright (c) 2022 ge <https://nixhacks.net/>
#
# This program is free software: you can redistribute it and/or modify
# it under the terms of the GNU General Public License as published by
# the Free Software Foundation, either version 3 of the License, or
# (at your option) any later version.
#
# This program is distributed in the hope that it will be useful,
# but WITHOUT ANY WARRANTY; without even the implied warranty of
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
# GNU General Public License for more details.
#
# You should have received a copy of the GNU General Public License
# along with this program.  If not, see <https://www.gnu.org/licenses/>.

handler::tar() {
    # Backup local files with tar(1). Handle 'file' URI scheme.
    #
    # Usage: handler::tar URI

    log "Run handler handler::tar() ..."

    local uri
    local src_path
    local dst_path
    local opts
    local archive
    local compr
    local exclude
    local file_ext

    uri="$1"
    dst_path="$__main_target_path"

    parse_uri "$uri"

    if [ -f "$path" ] || [ -d "$path" ]; then
        src_path="$path"
    else
        echo "Error: Path '$path' from URI '$uri' does not exists" >&2
        exit 1
    fi

    if [[ "$src_path" == "$dst_path" ]]; then
        echo "Error: Source and destination paths is the same: $src_path; $dst_path" >&2
        exit 1
    fi

    # Exit if tar is not installed
    is_installed tar

    # Overwrire __tar_options
    if [ -n "$tar_options" ]; then
        opts="$tar_options"
    else
        opts="$__tar_options"
    fi

    # Overwrite __tar_exclude
    if [ "$tar_exclude" ]; then
        for item in "${tar_exclude[@]}"; do
            exclude+=" --exclude $item"
        done
    else
        exclude=
    fi

    # Overwrite __compression
    if [ "$compression" ]; then
        compr="$compression"
    else
        compr="$__compression"
    fi

    # Select filename extension by compression type.
    # Make sure for the `--auto-compress` is enabled in __tar_options
    # Refference: https://www.gnu.org/software/tar/manual/html_node/gzip.html
    case "$compr" in
        gzip|gz)    file_ext='.tar.gz';;    # gzip
        tgz)        file_ext='.tgz';;       # gzip
        taz)        file_ext='.taz';;       # gzip
        compress|Z) file_ext='.tar.Z';;     # compress
        taZ)        file_ext='.taZ';;       # compress
        bzip2|bz2)  file_ext='.tar.bz2';;   # bzip2
        tz2)        file_ext='.tz2';;       # bzip2
        tbz2)       file_ext='.tbz2';;      # bzip2
        tbz)        file_ext='.tbz';;       # bzip2
        lzip|lz)    file_ext='.tar.lz';;    # lzip
        lzma)       file_ext='.tar.lzma';;  # lzma
        tlz)        file_ext='.tlz';;       # lzma
        lzop|lzo)   file_ext='.tar.lzo';;   # lzop
        xz)         file_ext='.tar.xz';;    # xz
        zstd|zst)   file_ext='.tar.zst';;   # zstd
        tzst)       file_ext='.tzst';;      # zstd
        *)          file_ext='.tar.gz';;    # Force gzip
    esac

    archive="${dst_path}/$(gen_backup_name "$file_ext")"

    [ "$__verbose" ] && {
        echo "Source path: $src_path"
        echo "Destination path: $dst_path"
        echo "Command: tar $exclude $opts $archive $src_path"
    }

    log "Archiving $src_path to $archive ..."
    log "Command: tar $exclude $opts $archive $src_path"

    # Run tar
    try tar "$exclude" "$opts" "$archive" "$src_path"

    # Append path to 'backups' array
    backups+=("$archive")
}