#!/bin/bash
# Gitea Daily Backup Script
# Uses Gitea's native dump command to create automated backups of repositories and SQLite databases.
# Designed to run on the VPS (Ezra) as part of a daily cron job.
#
# Configuration via environment variables:
#   GITEA_BIN               Path to gitea binary (default: auto-detect)
#   GITEA_BACKUP_DIR        Directory for backup archives (default: /var/backups/gitea)
#   GITEA_BACKUP_RETENTION  Days to retain backups (default: 7)
#   GITEA_BACKUP_LOG        Log file path (default: /var/log/gitea-backup.log)

set -euo pipefail

GITEA_BIN="${GITEA_BIN:-$(command -v gitea 2>/dev/null || echo "/usr/local/bin/gitea")}"
BACKUP_DIR="${GITEA_BACKUP_DIR:-/var/backups/gitea}"
RETENTION_DAYS="${GITEA_BACKUP_RETENTION:-7}"
DATE="$(date +%Y-%m-%d_%H%M%S)"
BACKUP_FILE="${BACKUP_DIR}/gitea-backup-${DATE}.tar.gz"
LOG_FILE="${GITEA_BACKUP_LOG:-/var/log/gitea-backup.log}"

mkdir -p "${BACKUP_DIR}"

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

log "=== Starting Gitea daily backup ==="

# Verify gitea binary exists
if [ ! -x "${GITEA_BIN}" ]; then
  log "ERROR: Gitea binary not found at ${GITEA_BIN}"
  log "Set GITEA_BIN environment variable to the gitea binary path (e.g., /usr/bin/gitea)"
  exit 1
fi

# Detect Gitea WORK_PATH
WORK_PATH=""
APP_INI=""
for path in /etc/gitea/app.ini /home/git/gitea/custom/conf/app.ini ~/gitea/custom/conf/app.ini; do
  if [ -f "$path" ]; then
    APP_INI="$path"
    break
  fi
done

if [ -n "$APP_INI" ]; then
  # Parse [app] WORK_PATH = /var/lib/gitea
  WORK_PATH=$(sed -n 's/^[[:space:]]*WORK_PATH[[:space:]]*=[[:space:]]*//p' "$APP_INI" | head -1)
  log "Detected WORK_PATH from app.ini: ${WORK_PATH}"
fi

# Fallback detection
if [ -z "$WORK_PATH" ]; then
  for d in /var/lib/gitea /home/git/gitea /srv/gitea /opt/gitea; do
    if [ -d "$d" ]; then
      WORK_PATH="$d"
      break
    fi
  done
  log "Inferred WORK_PATH: ${WORK_PATH:-not found}"
fi

if [ -z "$WORK_PATH" ]; then
  log "ERROR: Could not determine Gitea WORK_PATH. Set GITEA_WORK_PATH manually."
  exit 1
fi

# Perform gitea dump
# Flags: --work-path sets the Gitea working directory, --file writes dump to tar.gz
log "Running: gitea dump --work-path ${WORK_PATH} --file ${BACKUP_FILE}"
"${GITEA_BIN}" dump --work-path "${WORK_PATH}" --file "${BACKUP_FILE}" 2>>"${LOG_FILE}"

if [ $? -ne 0 ]; then
  log "ERROR: gitea dump failed — check ${LOG_FILE} for details"
  exit 1
fi

FILE_SIZE=$(du -h "${BACKUP_FILE}" | cut -f1)
log "Backup created: ${BACKUP_FILE} (${FILE_SIZE})"

# Prune old backups (keep last N days)
find "${BACKUP_DIR}" -name "gitea-backup-*.tar.gz" -type f -mtime +$((${RETENTION_DAYS}-1)) -delete 2>/dev/null || true
log "Pruned backups older than ${RETENTION_DAYS} days"

log "=== Backup completed successfully ==="

exit 0