#!/bin/bash

# Exit on error
set -e

# Validate input parameters
if [ "$#" -ne 2 ]; then
    echo "Usage: $0 <RESTIC_PASSWORD> <CUSTOM_TAG>"
    exit 1
fi

# Assign arguments to variables
RESTIC_PASSWORD="$1"
CUSTOM_TAG="$2"

# Configuration
APP_PATH='/var/www/webroot/ROOT'
BACKUP_PATH='/mnt/backups'
PASSWORD_FILE="/etc/restic-password"
LOG_DIR="/home/jelastic/mb-backups/logs/manual/media"
LOG_FILE="${LOG_DIR}/backup_media_$(date +'%Y-%m-%d').log"
INCLUDE_PATHS=("$APP_PATH/wp-content/uploads")
LOCK_FILE="/tmp/restic_global.lock"

# Ensure log directory exists
mkdir -p "$LOG_DIR"

# Logging function
log() {
    echo "[$(date +'%Y-%m-%d %H:%M:%S')] $1" | tee -a "$LOG_FILE"
}

log "Starting Media Backup process with tags: media_themes, $CUSTOM_TAG."

# Verify password file exists
if [ ! -f "$PASSWORD_FILE" ]; then
    log "ERROR: Password file not found at $PASSWORD_FILE."
    exit 1
fi

# Export the password from the file to ensure Restic uses it automatically
export RESTIC_PASSWORD=$(cat "$PASSWORD_FILE")

# Verify repository access
if ! restic -r "$BACKUP_PATH" snapshots > /dev/null 2>&1; then
    log "ERROR: Unable to access the Restic repository. Aborting backup."
    exit 1
fi

# Acquire a global lock to serialize Restic operations
log "Acquiring global lock for Restic operations..."
exec 9>"$LOCK_FILE"
if ! flock -n 9; then
    log "Another Restic operation is running. Exiting."
    exit 1
fi
log "Global lock acquired."

# Check and remove stale locks
log "Checking for stale locks in the repository..."
if restic -r "$BACKUP_PATH" list locks | grep -q "lock"; then
    log "Stale locks detected. Unlocking the repository..."
    restic -r "$BACKUP_PATH" unlock
    log "Repository unlocked successfully."
else
    log "No stale locks found."
fi

# Check and fix permissions on /mnt/backups
if [ ! -w "$BACKUP_PATH/locks" ]; then
    log "Fixing permissions on $BACKUP_PATH/locks"
    sudo chown -R litespeed:litespeed "$BACKUP_PATH/locks"
    sudo chmod -R u+rw "$BACKUP_PATH/locks"
fi

# Perform the backup
for path in "${INCLUDE_PATHS[@]}"; do
    log "Starting backup for $path..."
    if restic -r "$BACKUP_PATH" backup "$path" \
        --tag media_themes \
        --tag "$CUSTOM_TAG" \
        --force \
        --option b2.connections=4; then
        log "Backup completed successfully for $path with tags: media_themes, $CUSTOM_TAG."
    else
        log "ERROR: Backup failed for $path."
        exit 1
    fi
done

# Release global lock
exec 9>&-

# End logging
log "Media Backup process finished successfully."