#!/bin/bash
# Off-site Backup — rclone cloud sync extension for backup.sh
#
# This script is sourced by backup.sh when CLOUD_ENABLED=true.
# It syncs local backups to a cloud provider via rclone with encryption.
#
# Prerequisites (handled by setup-rclone.sh):
#   1. rclone installed (Docker image: rclone/rclone)
#   2. Cloud remote configured (e.g., `onedrive`, `gdrive`)
#   3. Crypt remote configured (e.g., `nas-backup-crypt`)
#
# Env vars (set in .env or exported before running backup.sh):
#   CLOUD_ENABLED=false          # Set to true to enable cloud sync
#   RCLONE_REMOTE=nas-backup     # Base rclone remote name
#   RCLONE_CRYPT_REMOTE=""       # If set, uses encrypted remote (e.g., nas-backup-crypt:)
#   CLOUD_RETENTION_DAYS=30      # Keep cloud copies for this many days
#   RCLONE_EXTRA_FLAGS=""        # Extra flags for rclone sync (e.g., "--bwlimit 2M")

CLOUD_ENABLED="${CLOUD_ENABLED:-false}"
RCLONE_REMOTE="${RCLONE_REMOTE:-nas-backup}"
RCLONE_CRYPT_REMOTE="${RCLONE_CRYPT_REMOTE:-}"
CLOUD_RETENTION_DAYS="${CLOUD_RETENTION_DAYS:-30}"
CLOUD_ERRORS=0

# Resolve the target remote (plain or crypt)
if [ -n "$RCLONE_CRYPT_REMOTE" ]; then
    _cloud_target="${RCLONE_CRYPT_REMOTE}"
else
    _cloud_target="${RCLONE_REMOTE}:nas-tools"
fi

_rclone() {
    docker run --rm \
        -v "$RCLONE_CONFIG_DIR:/config/rclone" \
        -v "$BACKUP_DIR:/data:ro" \
        rclone/rclone:latest \
        "$@" --config /config/rclone/rclone.conf
}

cloud_backup() {
    log "=== Cloud backup started ==="

    # 1. Sync backup files to cloud
    log "Syncing $BACKUP_DIR to $_cloud_target ..."
    if _rclone sync /data/ "$_cloud_target" \
        --verbose \
        --progress \
        --copy-links \
        $RCLONE_EXTRA_FLAGS; then
        log "Cloud sync OK"
    else
        log "FAILED: cloud sync"
        CLOUD_ERRORS=$((CLOUD_ERRORS + 1))
    fi

    # 2. Cloud retention — delete files older than CLOUD_RETENTION_DAYS
    log "Applying cloud retention: ${CLOUD_RETENTION_DAYS} days ..."
    if _rclone delete "$_cloud_target" \
        --min-age "${CLOUD_RETENTION_DAYS}d" \
        --verbose; then
        log "Cloud retention OK"
    else
        log "FAILED: cloud retention cleanup"
        CLOUD_ERRORS=$((CLOUD_ERRORS + 1))
    fi

    # 3. Show cloud usage summary
    log "Cloud storage summary:"
    _rclone size "$_cloud_target" --json 2>/dev/null | python3 -c "
import json, sys
try:
    d = json.load(sys.stdin)
    print(f'  {d.get(\"count\",0)} files, {d.get(\"bytes\",0)/1024/1024:.1f} MB')
except: pass
" || true

    log "=== Cloud backup finished ($CLOUD_ERRORS errors) ==="
    return $CLOUD_ERRORS
}