#!/bin/bash
# Automated rollback script for Foxhunt HFT Trading System
# Version: 3.0.0
# Wave 75 Agent 9

set -euo pipefail

BACKUP_DIR="${1:-}"
if [ -z "$BACKUP_DIR" ]; then
    echo "Usage: $0 <backup_directory>"
    echo "Example: $0 /opt/foxhunt/backups/20251003_120000"
    echo ""
    echo "Available backups:"
    ls -1dt /opt/foxhunt/backups/* 2>/dev/null | head -5 || echo "  No backups found in /opt/foxhunt/backups"
    exit 1
fi

if [ ! -d "$BACKUP_DIR" ]; then
    echo "Error: Backup directory $BACKUP_DIR does not exist"
    exit 1
fi

echo "━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━"
echo "       FOXHUNT HFT ROLLBACK PROCEDURE"
echo "━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━"
echo "       $(date '+%Y-%m-%d %H:%M:%S')"
echo "━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━"
echo ""
echo "Rollback source: $BACKUP_DIR"
echo ""

# Display backup manifest if available
if [ -f "$BACKUP_DIR/manifest.txt" ]; then
    echo "Backup details:"
    cat "$BACKUP_DIR/manifest.txt"
    echo ""
fi

read -p "This will STOP all services and restore from backup. Continue? (yes/no): " confirm

if [ "$confirm" != "yes" ]; then
    echo "Rollback cancelled"
    exit 0
fi

# Step 1: Stop all services
echo ""
echo "[1/5] Stopping all services..."
sudo systemctl stop foxhunt-trading 2>/dev/null || true
sudo systemctl stop foxhunt-backtesting 2>/dev/null || true
sudo systemctl stop foxhunt-ml-training 2>/dev/null || true
echo "✅ Services stopped"

# Step 2: Restore binaries
echo ""
echo "[2/5] Restoring binaries from backup..."
if [ -d "$BACKUP_DIR/bin" ]; then
    sudo cp -r "$BACKUP_DIR/bin/"* /opt/foxhunt/bin/
    sudo chmod 755 /opt/foxhunt/bin/*
    sudo chown foxhunt:foxhunt /opt/foxhunt/bin/* 2>/dev/null || true
    echo "✅ Binaries restored"
else
    echo "⚠️  No binaries found in backup, skipping"
fi

# Step 3: Restore configuration
echo ""
echo "[3/5] Restoring configuration from backup..."
if [ -d "$BACKUP_DIR/config" ]; then
    sudo cp -r "$BACKUP_DIR/config/"* /opt/foxhunt/config/ 2>/dev/null || true
    sudo chown -R foxhunt:foxhunt /opt/foxhunt/config 2>/dev/null || true
    echo "✅ Configuration restored"
else
    echo "⚠️  No configuration found in backup, skipping"
fi

# Step 4: Restore database (optional, requires manual confirmation)
echo ""
echo "[4/5] Database rollback..."
read -p "Restore database from backup? (yes/no): " restore_db

if [ "$restore_db" = "yes" ]; then
    if [ -f "$BACKUP_DIR/database.sql.gz" ]; then
        echo "Restoring database (this may take several minutes)..."

        # Get database connection info
        DB_NAME="${POSTGRES_DB:-foxhunt_production}"
        DB_USER="${POSTGRES_USER:-foxhunt_user}"

        # Drop and recreate database
        sudo -u postgres psql <<EOF 2>/dev/null || echo "Warning: Database drop failed (may not exist)"
DROP DATABASE IF EXISTS $DB_NAME;
CREATE DATABASE $DB_NAME OWNER $DB_USER;
EOF

        # Restore from backup
        gunzip -c "$BACKUP_DIR/database.sql.gz" | sudo -u postgres psql $DB_NAME
        echo "✅ Database restored"
    else
        echo "❌ Database backup file not found: $BACKUP_DIR/database.sql.gz"
        echo "Continuing without database restore..."
    fi
else
    echo "⚠️  Database rollback skipped"
fi

# Step 5: Restart services
echo ""
echo "[5/5] Restarting services..."
sudo systemctl start foxhunt-trading
sleep 5  # Wait for trading service to initialize

sudo systemctl start foxhunt-backtesting 2>/dev/null || echo "⚠️  Backtesting service failed to start"
sudo systemctl start foxhunt-ml-training 2>/dev/null || echo "⚠️  ML training service failed to start"

echo "✅ Services restarted"

# Verify health
echo ""
echo "Running health checks (waiting 10 seconds for initialization)..."
sleep 10

if [ -x "/opt/foxhunt/bin/health_check.sh" ]; then
    /opt/foxhunt/bin/health_check.sh
elif [ -x "$(dirname $0)/health_check.sh" ]; then
    $(dirname $0)/health_check.sh
else
    echo "⚠️  Health check script not found, manual verification required"
fi

echo ""
echo "━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━"
echo "  ✅ ROLLBACK COMPLETE"
echo "━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━"
echo ""
echo "Next steps:"
echo "  1. Verify all services are healthy"
echo "  2. Check logs for errors: journalctl -u foxhunt-* --since '5 minutes ago'"
echo "  3. Monitor performance for 30 minutes"
echo "  4. Document incident and rollback in postmortem"