#!/bin/bash
################################################################################
# Nextcloud to Backblaze B2 Backup Script - Native Installation
################################################################################

set -euo pipefail

# Source credentials
source /etc/nextcloud-backup/b2-credentials.env || exit 1
source /opt/nextcloud-backup/.env || exit 1

# B2 CLI path
B2="/root/.local/share/pipx/venvs/b2/bin/b2"

# Configuration
BACKUP_DIR="/opt/nextcloud-backup/.backups"
LOG_DIR="${BACKUP_DIR}/logs"
TIMESTAMP=$(date +%Y%m%d_%H%M%S)
LOG_FILE="${LOG_DIR}/backup_${TIMESTAMP}.log"
# Use warm-storage NFS mount for staging (900GB available, separate from data disk)
# /mnt/nextcloud-data is 2TB total with 1.4TB data = can't fit 587GB backup
# /mnt/warm-storage is 900GB NFS with 0% used = sufficient space
STAGING_DIR="/mnt/warm-storage/.backup-staging"
TEMP_DIR="${STAGING_DIR}/nextcloud-backup-${TIMESTAMP}"

# Create directories
mkdir -p "${BACKUP_DIR}" "${LOG_DIR}" "${TEMP_DIR}"

# Backup database
echo "[$(date '+%Y-%m-%d %H:%M:%S')] 📦 Backing up Nextcloud database..." | tee -a "${LOG_FILE}"
DB_BACKUP="${TEMP_DIR}/nextcloud-db-${TIMESTAMP}.sql.zst"

if mysqldump -u"${NEXTCLOUD_DB_USER}" -p"${NEXTCLOUD_DB_PASSWORD}" \
    --single-transaction --lock-tables=false \
    "${NEXTCLOUD_DB_NAME}" 2>/dev/null | zstd -T0 > "$DB_BACKUP"; then
    DB_SIZE=$(du -h "$DB_BACKUP" | cut -f1)
    echo "[$(date '+%Y-%m-%d %H:%M:%S')] ✅ Database backup: $DB_SIZE" | tee -a "${LOG_FILE}"
else
    echo "[$(date '+%Y-%m-%d %H:%M:%S')] ❌ Database backup failed" | tee -a "${LOG_FILE}"
    rm -rf "$TEMP_DIR"
    exit 1
fi

# Backup files
echo "[$(date '+%Y-%m-%d %H:%M:%S')] 📦 Backing up Nextcloud files..." | tee -a "${LOG_FILE}"
FILES_BACKUP="${TEMP_DIR}/nextcloud-files-${TIMESTAMP}.tar.zst"

if tar --zstd -cf "$FILES_BACKUP" \
    -C "${NEXTCLOUD_DATA_PATH}" . \
    --exclude-caches \
    --warning=no-file-removed 2>/dev/null; then
    FILES_SIZE=$(du -h "$FILES_BACKUP" | cut -f1)
    echo "[$(date '+%Y-%m-%d %H:%M:%S')] ✅ Files backup: $FILES_SIZE" | tee -a "${LOG_FILE}"
else
    echo "[$(date '+%Y-%m-%d %H:%M:%S')] ⚠️  Files backup skipped" | tee -a "${LOG_FILE}"
fi

# Upload to B2
echo "[$(date '+%Y-%m-%d %H:%M:%S')] 📤 Uploading to Backblaze B2..." | tee -a "${LOG_FILE}"

if "${B2}" account get >/dev/null 2>&1; then
    echo "[$(date '+%Y-%m-%d %H:%M:%S')] ✅ B2 authenticated" | tee -a "${LOG_FILE}"
    
    # Upload database
    if [ -f "$DB_BACKUP" ]; then
        echo "[$(date '+%Y-%m-%d %H:%M:%S')] 📤 Uploading database..." | tee -a "${LOG_FILE}"
        if "${B2}" file upload "${B2_BUCKET_NAME}" "$DB_BACKUP" "nextcloud-backups/$(basename $DB_BACKUP)" >>/dev/null 2>&1; then
            echo "[$(date '+%Y-%m-%d %H:%M:%S')] ✅ Database uploaded" | tee -a "${LOG_FILE}"
        else
            echo "[$(date '+%Y-%m-%d %H:%M:%S')] ❌ Database upload failed" | tee -a "${LOG_FILE}"
        fi
    fi
    
    # Upload files
    if [ -f "$FILES_BACKUP" ]; then
        echo "[$(date '+%Y-%m-%d %H:%M:%S')] 📤 Uploading files..." | tee -a "${LOG_FILE}"
        if "${B2}" file upload "${B2_BUCKET_NAME}" "$FILES_BACKUP" "nextcloud-backups/$(basename $FILES_BACKUP)" >>/dev/null 2>&1; then
            echo "[$(date '+%Y-%m-%d %H:%M:%S')] ✅ Files uploaded" | tee -a "${LOG_FILE}"
        else
            echo "[$(date '+%Y-%m-%d %H:%M:%S')] ❌ Files upload failed" | tee -a "${LOG_FILE}"
        fi
    fi
else
    echo "[$(date '+%Y-%m-%d %H:%M:%S')] ❌ B2 authentication failed" | tee -a "${LOG_FILE}"
    rm -rf "$TEMP_DIR"
    exit 1
fi

# Cleanup
rm -rf "$TEMP_DIR"
rmdir "$STAGING_DIR" 2>/dev/null || true  # Remove staging directory if empty

echo "[$(date '+%Y-%m-%d %H:%M:%S')] ✅ Backup completed!" | tee -a "${LOG_FILE}"