#!/bin/sh
# System configuration backup script
# Backs up /etc and dotfiles (lightweight backup)

set -e

# Config
CONFIG_FILE="/etc/backup.conf"
LOG_DIR="${HOME}/.local/var/log"
LOG_FILE="${LOG_DIR}/backup.log"
LOCK_FILE="/tmp/backup-configs.lock"

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

# Colors
RED='\033[0;31m'
GREEN='\033[0;32m'
YELLOW='\033[1;33m'
BLUE='\033[0;34m'
NC='\033[0m'

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

error() {
  printf "${RED}✖${NC} %s\n" "$1"
  log "ERROR: $1"
}

info() {
  printf "${BLUE}ℹ${NC} %s\n" "$1"
  log "INFO: $1"
}

success() {
  printf "${GREEN}✓${NC} %s\n" "$1"
  log "SUCCESS: $1"
}

# Load config
if [ ! -f "$CONFIG_FILE" ]; then
  error "Configuration file not found: $CONFIG_FILE"
  exit 1
fi

# shellcheck source=/dev/null
. "$CONFIG_FILE"

# Create lock file
if [ -f "$LOCK_FILE" ]; then
  error "Config backup already running"
  exit 1
fi

trap 'rm -f "$LOCK_FILE"' EXIT
touch "$LOCK_FILE"

# Start backup
log "=========================================="
log "Starting CONFIGURATION BACKUP"
log "=========================================="

# Check NAS connectivity
info "Checking NAS connectivity..."
if ! ssh -p "$NAS_PORT" -o ConnectTimeout=5 -o BatchMode=yes \
     "${NAS_USER}@${NAS_HOST}" "echo test" >/dev/null 2>&1; then
  error "SSH connection to NAS failed"
  exit 1
fi

success "NAS is reachable"

# Create backup directory name with timestamp
BACKUP_NAME="config-$(date +%Y%m%d-%H%M%S)"
BACKUP_DEST="${NAS_USER}@${NAS_HOST}:${NAS_PATH}/${BACKUP_NAME}"

info "Backup destination: ${BACKUP_DEST}"

# Create temporary directory for staging
TEMP_DIR=$(mktemp -d)
trap 'rm -rf "$TEMP_DIR" 2>/dev/null; rm -f "$LOCK_FILE"' EXIT

CONFIG_STAGE="$TEMP_DIR/configs"
mkdir -p "$CONFIG_STAGE"

# Copy /etc (excluding large/unnecessary files)
info "Copying system configs from /etc..."
rsync -a --delete \
  --exclude='ssl/certs' \
  --exclude='ca-certificates' \
  /etc/ "$CONFIG_STAGE/etc/" 2>/dev/null || true

# Copy important dotfiles from home
info "Copying dotfiles..."
mkdir -p "$CONFIG_STAGE/home"

# Copy select dotfiles and configs
for item in \
  .zshrc .bashrc .gitconfig .gitmux.conf \
  .config/nvim \
  .config/hypr \
  .config/waybar \
  .config/tmux \
  .config/bat \
  .config/starship.toml \
  .config/ghostty \
  .config/alxndrhi \
  .local/share/chezmoi; do

  if [ -e "/home/alexander/$item" ]; then
    mkdir -p "$(dirname "$CONFIG_STAGE/home/$item")"
    cp -r "/home/alexander/$item" "$CONFIG_STAGE/home/$item" 2>/dev/null || true
  fi
done

# Copy portage config
info "Copying Portage configuration..."
if [ -d /etc/portage ]; then
  mkdir -p "$CONFIG_STAGE/portage"
  cp -r /etc/portage/* "$CONFIG_STAGE/portage/" 2>/dev/null || true
fi

# Copy system scripts
info "Copying custom scripts..."
if [ -d /usr/local/bin ]; then
  mkdir -p "$CONFIG_STAGE/scripts"
  cp -r /usr/local/bin/* "$CONFIG_STAGE/scripts/" 2>/dev/null || true
fi

# Create a manifest file
info "Creating backup manifest..."
cat > "$CONFIG_STAGE/MANIFEST.txt" <<EOF
Configuration Backup
Created: $(date)
Hostname: $(hostname)
Kernel: $(uname -r)

Contents:
- /etc (system configuration)
- Dotfiles from /home/alexander
- Portage configuration (/etc/portage)
- Custom scripts (/usr/local/bin)

To restore:
  rsync -av etc/ /etc/
  rsync -av home/ /home/alexander/
  rsync -av portage/ /etc/portage/
  rsync -av scripts/ /usr/local/bin/
EOF

# Run rsync backup to NAS
info "Uploading to NAS..."

if rsync -avz --delete \
  --rsync-path="mkdir -p ${NAS_PATH}/${BACKUP_NAME} && rsync" \
  -e "ssh -p ${NAS_PORT}" \
  "$CONFIG_STAGE/" \
  "$BACKUP_DEST" >> "$LOG_FILE" 2>&1; then

  success "Backup completed successfully!"

  # Update last backup timestamp
  LAST_BACKUP_FILE="${HOME}/.local/var/backup/last-backup"
  mkdir -p "$(dirname "$LAST_BACKUP_FILE")"
  date +%s > "$LAST_BACKUP_FILE"

  # Log backup size
  BACKUP_SIZE=$(ssh -p "$NAS_PORT" "${NAS_USER}@${NAS_HOST}" \
    "du -sh '${NAS_PATH}/${BACKUP_NAME}' 2>/dev/null | cut -f1" || echo "unknown")
  info "Backup size: $BACKUP_SIZE"

  # Clean up old backups
  info "Cleaning up old backups (keeping last ${RETENTION_COUNT})..."
  ssh -p "$NAS_PORT" "${NAS_USER}@${NAS_HOST}" \
    "cd '${NAS_PATH}' && ls -t | grep '^config-' | tail -n +$((RETENTION_COUNT + 1)) | xargs -r rm -rf" \
    >> "$LOG_FILE" 2>&1 || true

else
  error "Backup failed! Check $LOG_FILE for details"
  exit 1
fi

log "=========================================="
log "Backup completed at $(date)"
log "=========================================="