#!/bin/bash

CONFIG_FILE=~/.mysql_telegram_backup.conf

# Prevent running via pipe
if [ ! -t 0 ]; then
  echo "❌ Error: This script is interactive and cannot be run with a pipe."
  echo "Please download and run it locally:"
  echo "curl -L https://raw.githubusercontent.com/zamibd/database-backup-telegram/main/install.sh -o install.sh"
  echo "chmod +x install.sh"
  echo "./install.sh"
  exit 1
fi

# If config file exists, delete it unconditionally for fresh setup
if [ -f "${CONFIG_FILE}" ]; then
  echo "⚠️ Existing config file found. Deleting it for fresh setup..."
  rm -f "${CONFIG_FILE}"
fi

# Setup: get user input and save config
echo "--- MySQL Telegram Backup: Fresh Setup ---"
read -p "Enter your Telegram Bot Token: " BOT_TOKEN
read -p "Enter your Telegram Chat ID: " CHAT_ID
read -p "Enter your MySQL Username (e.g., root): " DB_USER
read -sp "Enter your MySQL Password: " DB_PASS
echo
read -p "Enter full path for backup directory (default: /root/backups): " BACKUP_DIR

# Use default backup directory if none provided
if [ -z "$BACKUP_DIR" ]; then
  BACKUP_DIR="/root/backups"
  echo "No backup directory entered. Using default: $BACKUP_DIR"
fi

cat > "${CONFIG_FILE}" << EOF
# MySQL Telegram Backup Configuration
BOT_TOKEN='${BOT_TOKEN}'
CHAT_ID='${CHAT_ID}'
DB_USER='${DB_USER}'
DB_PASS='${DB_PASS}'
BACKUP_DIR='${BACKUP_DIR}'
DAYS_TO_KEEP=7
EOF

chmod 600 "${CONFIG_FILE}"
echo "✅ Configuration saved to ${CONFIG_FILE}"

# Add cronjob for daily backup at 2 AM if not already added
SCRIPT_PATH=$(realpath "$0")
CRON_CMD="0 2 * * * bash $SCRIPT_PATH >> /var/log/mysql_telegram_backup.log 2>&1"
(crontab -l 2>/dev/null | grep -Fv "$SCRIPT_PATH"; echo "$CRON_CMD") | crontab -
echo "✅ Cronjob added to run daily at 2 AM"

# Run backup immediately after setup
echo "--> Running backup now..."

source "${CONFIG_FILE}"
BACKUP_DIR=$(eval echo "${BACKUP_DIR}")
mkdir -p "${BACKUP_DIR}"

BACKUP_FILE="${BACKUP_DIR}/all_db_backup_$(date +%F).sql.gz"
CAPTION="✅ MySQL Backup | Host: $(hostname) | Date: $(date +%d-%b-%Y)"

export MYSQL_PWD="${DB_PASS}"

echo "Step 1: Creating database backup..."
if ! mysqldump -u "${DB_USER}" --all-databases | gzip > "${BACKUP_FILE}"; then
  echo "❌ MySQL dump failed."
  unset MYSQL_PWD
  exit 1
fi
unset MYSQL_PWD

if [ ! -s "${BACKUP_FILE}" ]; then
  echo "❌ Backup file not created or empty."
  exit 1
fi

echo "Step 2: Sending backup to Telegram..."
curl -s -X POST "https://api.telegram.org/bot${BOT_TOKEN}/sendDocument" \
  -F "chat_id=${CHAT_ID}" \
  -F "document=@${BACKUP_FILE}" \
  -F "caption=${CAPTION}" > /dev/null

echo "Step 3: Removing backups older than ${DAYS_TO_KEEP} days..."
find "${BACKUP_DIR}" -type f -name "*.sql.gz" -mtime +${DAYS_TO_KEEP} -delete

echo "--> ✅ Backup complete!"