#!/bin/bash
#
# Script Name: openwrtupload.sh
# Description:
#   Backs up OpenWrt configuration archives to a Backblaze B2 repository
#   using Restic. Each .gz archive found in the source directory is
#   extracted to a staging directory, backed up with Restic, and then
#   removed along with the staging directory.
#
# Usage:
#   openwrtupload.sh
#
# Author: Charlie Silverman
# Version: 20261031-01
#
# Requirements:
#   restic, jq, awk, tar, numfmt (optional, for human-readable sizes).
#   Restic environment file: /root/.restic-env
#
# Versioning:
#   Versions use the format YYYYMMDD-xx, where YYYYMMDD is the release date
#   and xx is the release number for that day, starting at 01.
#
# Revision History:
#   20261031-01 - Added script header and YYYYMMDD-xx versioning.
#                 Added strict error handling with error/interrupt logging;
#                 an archive is no longer deleted if its backup fails.
#                 Staging directory is cleaned up on failure or interrupt.
#                 Restic snapshot details (ID, parent, tags, file/dir counts,
#                 data added, snapshot size, duration) are now written to the
#                 log. restic backup now runs with --json and the details are
#                 read from its backup summary. Added totals at end of run.
#                 Added required-command check.
#

set -o errexit
set -o nounset
set -o pipefail

SCRIPT_VERSION="20261031-01"

#------------------------------------------------------------------------------
# Configuration
#------------------------------------------------------------------------------

LOG_FILE="/home/glibackup/openwrt-backup.log"
SOURCE_DIR="/home/glibackup/openwrt"
STAGING_DIR="/home/Backups/openwrt"
TIMESTAMP="$(date +%Y%m%d-%H%M%S)"
HOSTNAME_FQDN="$(hostname -f)"

RESTIC_TAGS=(openwrt backup)

# Restic repository configuration
export RESTIC_REPOSITORY="s3:https://s3.us-west-004.backblazeb2.com/ackitsbucket/openwrt"
export RESTIC_ENV_FILE="/root/.restic-env"

RESTIC_OUTPUT=""
STAGING_IN_USE=""

#------------------------------------------------------------------------------
# Logging Function
#------------------------------------------------------------------------------

log() {

    local message

    message="[$(date '+%F %T')] $*"

    echo "$message"
    echo "$message" >> "$LOG_FILE"
}

#------------------------------------------------------------------------------
# Convert a byte count to a human-readable size (e.g. 1.23GiB)
#------------------------------------------------------------------------------

human_bytes() {

    local bytes="${1:-0}"

    if command -v numfmt >/dev/null 2>&1; then
        numfmt --to=iec-i --suffix=B --format="%.2f" "$bytes" 2>/dev/null \
            || echo "${bytes} B"
    else
        echo "${bytes} B"
    fi
}

#------------------------------------------------------------------------------
# Write Restic snapshot details from a backup summary (JSON) to the log
#------------------------------------------------------------------------------

log_snapshot_info() {

    local summary="$1"

    local snapshot_id parent_id
    local files_new files_changed files_unmodified
    local dirs_new dirs_changed dirs_unmodified
    local data_added data_added_packed
    local total_files total_bytes total_duration
    local tags

    snapshot_id=$(jq -r '.snapshot_id // "none"' <<< "$summary")
    parent_id=$(restic snapshots "$snapshot_id" --json 2>/dev/null \
        | jq -r '.[0].parent // "none"' 2>/dev/null || echo "unknown")

    files_new=$(jq -r '.files_new // 0' <<< "$summary")
    files_changed=$(jq -r '.files_changed // 0' <<< "$summary")
    files_unmodified=$(jq -r '.files_unmodified // 0' <<< "$summary")
    dirs_new=$(jq -r '.dirs_new // 0' <<< "$summary")
    dirs_changed=$(jq -r '.dirs_changed // 0' <<< "$summary")
    dirs_unmodified=$(jq -r '.dirs_unmodified // 0' <<< "$summary")
    data_added=$(jq -r '.data_added // 0' <<< "$summary")
    data_added_packed=$(jq -r '.data_added_packed // empty' <<< "$summary")
    total_files=$(jq -r '.total_files_processed // 0' <<< "$summary")
    total_bytes=$(jq -r '.total_bytes_processed // 0' <<< "$summary")
    total_duration=$(jq -r '.total_duration // 0' <<< "$summary")

    tags=$(IFS=,; echo "${RESTIC_TAGS[*]}" | sed 's/,/, /g')

    log "---------------- Restic Snapshot -----------------"
    log "Snapshot ID:      ${snapshot_id:0:8} (${snapshot_id})"
    log "Parent snapshot:  ${parent_id:0:8}"
    log "Tags:             ${tags}"
    log "Files:            ${files_new} new, ${files_changed} changed, ${files_unmodified} unmodified"
    log "Directories:      ${dirs_new} new, ${dirs_changed} changed, ${dirs_unmodified} unmodified"
    if [[ -n "$data_added_packed" ]]; then
        log "Data added:       $(human_bytes "$data_added") ($(human_bytes "$data_added_packed") stored)"
    else
        log "Data added:       $(human_bytes "$data_added")"
    fi
    log "Snapshot size:    $(human_bytes "$total_bytes") in ${total_files} files"
    log "Duration:         $(awk -v d="$total_duration" 'BEGIN{printf "%.1f", d}') seconds"
    log "--------------------------------------------------"
}

#------------------------------------------------------------------------------
# Cleanup Function
#------------------------------------------------------------------------------

cleanup() {

    if [[ -n "${STAGING_IN_USE:-}" && -d "$STAGING_DIR" ]]; then
        log "Cleaning up staging directory ${STAGING_DIR}"
        rm -rf "$STAGING_DIR" || log "WARNING: Failed to remove ${STAGING_DIR}"
        STAGING_IN_USE=""
    fi

    if [[ -n "${RESTIC_OUTPUT:-}" ]]; then
        rm -f "$RESTIC_OUTPUT"
        RESTIC_OUTPUT=""
    fi
}

#------------------------------------------------------------------------------
# Error Handling
#------------------------------------------------------------------------------

error_handler() {

    local exit_code=$?
    local line_number=$1

    trap - ERR

    log "ERROR: Backup failed on line ${line_number} with exit code ${exit_code}"

    cleanup

    log "----------------------------------------------------"

    exit "${exit_code}"
}

interrupt_handler() {

    trap - SIGINT SIGTERM

    log "ERROR: Backup interrupted by signal"

    cleanup

    log "----------------------------------------------------"

    exit 1
}

trap 'error_handler $LINENO' ERR
trap interrupt_handler SIGINT SIGTERM

#------------------------------------------------------------------------------
# Startup Logging
#------------------------------------------------------------------------------

log "===================================================="
log "OpenWrt Backup Starting (openwrtupload.sh v${SCRIPT_VERSION})"
log "Host: ${HOSTNAME_FQDN}"
log "Source Directory: ${SOURCE_DIR}"
log "Log File: ${LOG_FILE}"
log "===================================================="

#------------------------------------------------------------------------------
# Verify Requirements
#------------------------------------------------------------------------------

for cmd in restic jq awk tar; do

    if ! command -v "$cmd" >/dev/null 2>&1; then
        log "ERROR: Missing required command: $cmd"
        exit 1
    fi

done

#------------------------------------------------------------------------------
# Load Restic Environment
#------------------------------------------------------------------------------

# shellcheck source=/dev/null
source "$RESTIC_ENV_FILE"

#------------------------------------------------------------------------------
# Locate Archives
#------------------------------------------------------------------------------

shopt -s nullglob
ARCHIVES=("$SOURCE_DIR"/*.gz)
shopt -u nullglob

if [[ ${#ARCHIVES[@]} -eq 0 ]]; then
    log "No backup files found."
    log "----------------------------------------------------"
    exit 0
fi

log "Found ${#ARCHIVES[@]} archive(s) to back up"

#------------------------------------------------------------------------------
# Process Each Archive
#------------------------------------------------------------------------------

TAG_ARGS=()
for tag in "${RESTIC_TAGS[@]}"; do
    TAG_ARGS+=(--tag "$tag")
done

total_bytes_all=0
total_added_all=0
archive_count=0

for FILE in "${ARCHIVES[@]}"; do

    log "Backing up archive ${FILE}..."

    # Start from an empty staging directory
    rm -rf "$STAGING_DIR"
    mkdir -p "$STAGING_DIR"
    STAGING_IN_USE="yes"

    log "Extracting archive ${FILE} to ${STAGING_DIR}"

    tar xzf "$FILE" -C "$STAGING_DIR"

    log "Backing up ${STAGING_DIR} with restic"

    # Capture restic's JSON output in a temporary file. Errors and
    # warnings still go to the log via stderr.
    RESTIC_OUTPUT="$(mktemp /tmp/restic-backup-XXXXXX.json)"

    restic backup \
        "$STAGING_DIR" \
        --json \
        "${TAG_ARGS[@]}" \
        > "$RESTIC_OUTPUT" 2>> "$LOG_FILE"

    summary=$(jq -cR 'fromjson? | select(.message_type == "summary")' \
        "$RESTIC_OUTPUT" | tail -n 1)

    rm -f "$RESTIC_OUTPUT"
    RESTIC_OUTPUT=""

    if [[ -n "$summary" ]]; then
        log_snapshot_info "$summary"
        snap_bytes=$(jq -r '.total_bytes_processed // 0' <<< "$summary")
        added_bytes=$(jq -r '.data_added // 0' <<< "$summary")
    else
        log "WARNING: Restic returned no snapshot summary for ${FILE}"
        snap_bytes=0
        added_bytes=0
    fi

    total_bytes_all=$(awk -v a="$total_bytes_all" -v b="$snap_bytes" 'BEGIN{printf "%.0f", a + b}')
    total_added_all=$(awk -v a="$total_added_all" -v b="$added_bytes" 'BEGIN{printf "%.0f", a + b}')
    archive_count=$((archive_count + 1))

    log "Cleaning up staging directory ${STAGING_DIR}"
    rm -rf "$STAGING_DIR"
    STAGING_IN_USE=""

    log "Backup Complete."

    log "Removing archive file ${FILE}"
    rm -f "$FILE"

    log "----------------------------------------------------"

done

#------------------------------------------------------------------------------
# Completion
#------------------------------------------------------------------------------

log "All archives backed up successfully."
log "Archives Processed: ${archive_count}"
log "Total Backup Size: $(human_bytes "$total_bytes_all")"
log "Total New Data Uploaded: $(human_bytes "$total_added_all")"
log "===================================================="

exit 0