#!/usr/bin/env bash
# DictIA — Backup script
#
# Creates a timestamped backup of data, env, and Docker volumes.
# Keeps the last N backups (default: 5).
#
# Usage: bash backup.sh [BACKUP_DIR]
set -euo pipefail

SCRIPT_DIR="$(cd "$(dirname "$0")" && pwd)"
PROJECT_DIR="$(cd "$SCRIPT_DIR/../.." && pwd)"
BACKUP_BASE="${1:-$PROJECT_DIR/backups}"
KEEP_COUNT=5
TIMESTAMP=$(date +%Y%m%d-%H%M%S)
BACKUP_DIR="$BACKUP_BASE/dictia-$TIMESTAMP"

echo "=== DictIA Backup ==="
echo "Project: $PROJECT_DIR"
echo "Backup:  $BACKUP_DIR"
echo

mkdir -p "$BACKUP_DIR"

# 1. Data directory
if [ -d "$PROJECT_DIR/data" ]; then
    echo "[1/4] Backing up data/..."
    cp -a "$PROJECT_DIR/data" "$BACKUP_DIR/data"
else
    echo "[1/4] No data/ directory found, skipping."
fi

# 2. Environment file
if [ -f "$PROJECT_DIR/.env" ]; then
    echo "[2/4] Backing up .env..."
    cp "$PROJECT_DIR/.env" "$BACKUP_DIR/dot-env"
else
    echo "[2/4] No .env found, skipping."
fi

# 3. ASR Proxy stats
ASR_STATS="$PROJECT_DIR/deployment/asr-proxy/usage-stats.json"
if [ -f "$ASR_STATS" ]; then
    echo "[3/4] Backing up ASR proxy stats..."
    cp "$ASR_STATS" "$BACKUP_DIR/asr-usage-stats.json"
else
    echo "[3/4] No ASR proxy stats, skipping."
fi

# 4. Docker volumes (if using managed volumes)
echo "[4/4] Checking Docker volumes..."
if docker volume ls --format '{{.Name}}' 2>/dev/null | grep -q "whisperx-cache"; then
    echo "  Exporting whisperx-cache volume..."
    docker run --rm -v whisperx-cache:/source -v "$BACKUP_DIR":/backup \
        alpine tar czf /backup/whisperx-cache.tar.gz -C /source . 2>/dev/null || true
fi

# Write manifest
cat > "$BACKUP_DIR/manifest.json" <<MANIFEST
{
    "timestamp": "$TIMESTAMP",
    "project_dir": "$PROJECT_DIR",
    "hostname": "$(hostname)",
    "contents": {
        "data": $([ -d "$BACKUP_DIR/data" ] && echo "true" || echo "false"),
        "env": $([ -f "$BACKUP_DIR/dot-env" ] && echo "true" || echo "false"),
        "asr_stats": $([ -f "$BACKUP_DIR/asr-usage-stats.json" ] && echo "true" || echo "false"),
        "whisperx_cache": $([ -f "$BACKUP_DIR/whisperx-cache.tar.gz" ] && echo "true" || echo "false")
    }
}
MANIFEST

# Compress
echo
echo "Compressing backup..."
ARCHIVE="$BACKUP_BASE/dictia-$TIMESTAMP.tar.gz"
tar czf "$ARCHIVE" -C "$BACKUP_BASE" "dictia-$TIMESTAMP"
rm -rf "$BACKUP_DIR"
echo "Archive: $ARCHIVE ($(du -h "$ARCHIVE" | cut -f1))"

# Rotate old backups
BACKUP_COUNT=$(ls -1 "$BACKUP_BASE"/dictia-*.tar.gz 2>/dev/null | wc -l)
if [ "$BACKUP_COUNT" -gt "$KEEP_COUNT" ]; then
    echo
    echo "Rotating backups (keeping last $KEEP_COUNT)..."
    ls -1t "$BACKUP_BASE"/dictia-*.tar.gz | tail -n +"$((KEEP_COUNT + 1))" | xargs rm -f
fi

echo
echo "=== Backup complete ==="