#!/bin/bash
# Comprehensive fix for Waitress port parsing issue on VPS

set -e

echo "=== Fixing Waitress Port Parsing Issue ==="
echo

APP_DIR="/opt/mockapi"
SERVICE_FILE="/etc/systemd/system/mockapi.service"
ENV_FILE="${APP_DIR}/.env"

print_status() {
    echo -e "\033[0;32m[+]\033[0m $1"
}

print_warning() {
    echo -e "\033[1;33m[!]\033[0m $1"
}

print_error() {
    echo -e "\033[0;31m[!]\033[0m $1"
}

# Step 1: Check environment
print_status "Step 1: Checking environment"
if [[ ! -d "$APP_DIR" ]]; then
    print_error "Application directory not found: $APP_DIR"
    exit 1
fi

if [[ ! -f "$SERVICE_FILE" ]]; then
    print_error "Service file not found: $SERVICE_FILE"
    exit 1
fi

cd "$APP_DIR"

# Step 2: Read current port from .env
print_status "Step 2: Reading current configuration"
PORT="8000"
HOST="0.0.0.0"

if [[ -f "$ENV_FILE" ]]; then
    if grep -q "^PORT=" "$ENV_FILE"; then
        PORT=$(grep "^PORT=" "$ENV_FILE" | cut -d'=' -f2)
        print_status "Found PORT in .env: $PORT"
        
        # Validate PORT is numeric
        if [[ ! "$PORT" =~ ^[0-9]+$ ]]; then
            print_error "PORT is not numeric: '$PORT'. Setting to 8000."
            PORT="8000"
            sudo sed -i "s/^PORT=.*/PORT=8000/" "$ENV_FILE"
        fi
    else
        print_warning "PORT not found in .env, adding PORT=8000"
        echo "PORT=8000" | sudo tee -a "$ENV_FILE" > /dev/null
    fi
    
    if grep -q "^HOST=" "$ENV_FILE"; then
        HOST=$(grep "^HOST=" "$ENV_FILE" | cut -d'=' -f2)
        print_status "Found HOST in .env: $HOST"
    else
        print_warning "HOST not found in .env, adding HOST=0.0.0.0"
        echo "HOST=0.0.0.0" | sudo tee -a "$ENV_FILE" > /dev/null
    fi
else
    print_error ".env file not found: $ENV_FILE"
    exit 1
fi

# Step 3: Backup service file
print_status "Step 3: Backing up service file"
BACKUP_FILE="${SERVICE_FILE}.backup.$(date +%s)"
sudo cp "$SERVICE_FILE" "$BACKUP_FILE"
print_status "Backup created: $BACKUP_FILE"

# Step 4: Fix service file - OPTION 1: Use shell expansion
print_status "Step 4: Fixing service file ExecStart command"
print_warning "Current issue: Waitress receives literal string '\$PORT' instead of expanded value"
print_status "Solution 1: Use /bin/sh -c to enable shell variable expansion"

# Get the virtual environment path
VENV_DIR="${APP_DIR}/venv"
if [[ ! -d "$VENV_DIR" ]]; then
    print_error "Virtual environment not found: $VENV_DIR"
    exit 1
fi

# Read current service file to get other settings
CURRENT_USER=$(grep "^User=" "$SERVICE_FILE" | cut -d'=' -f2)
CURRENT_GROUP=$(grep "^Group=" "$SERVICE_FILE" | cut -d'=' -f2)
CURRENT_WORKDIR=$(grep "^WorkingDirectory=" "$SERVICE_FILE" | cut -d'=' -f2)

print_status "Current service settings:"
print_status "  User: $CURRENT_USER"
print_status "  Group: $CURRENT_GROUP"
print_status "  WorkingDirectory: $CURRENT_WORKDIR"

# Create new service file with fixed ExecStart
print_status "Creating fixed service file..."
sudo tee "$SERVICE_FILE" > /dev/null << EOF
[Unit]
Description=Mock API Service
After=network.target
Wants=network.target

[Service]
Type=simple
User=$CURRENT_USER
Group=$CURRENT_GROUP
WorkingDirectory=$CURRENT_WORKDIR
Environment="PATH=$VENV_DIR/bin"
Environment="PYTHONPATH=$APP_DIR"
EnvironmentFile=$APP_DIR/.env
# Use shell to expand environment variables
ExecStart=/bin/sh -c "$VENV_DIR/bin/waitress-serve --host=\$HOST --port=\$PORT wsgi:wsgi_app"
Restart=always
RestartSec=10
StandardOutput=syslog
StandardError=syslog
SyslogIdentifier=mockapi

# Security hardening
NoNewPrivileges=true
PrivateTmp=true
ProtectSystem=strict
ReadWritePaths=$APP_DIR

[Install]
WantedBy=multi-user.target
EOF

print_status "Service file updated with shell expansion."

# Step 5: Alternative simpler fix - hardcode port based on .env value
print_status "Alternative approach available: Hardcode port in service file"
print_warning "Would you like to hardcode port $PORT in service file instead? (y/N)"
read -p "Choice: " -n 1 -r
echo

if [[ $REPLY =~ ^[Yy]$ ]]; then
    print_status "Hardcoding port $PORT in service file..."
    sudo tee "$SERVICE_FILE" > /dev/null << EOF
[Unit]
Description=Mock API Service
After=network.target
Wants=network.target

[Service]
Type=simple
User=$CURRENT_USER
Group=$CURRENT_GROUP
WorkingDirectory=$CURRENT_WORKDIR
Environment="PATH=$VENV_DIR/bin"
Environment="PYTHONPATH=$APP_DIR"
EnvironmentFile=$APP_DIR/.env
# Hardcoded port based on .env value
ExecStart=$VENV_DIR/bin/waitress-serve --host=$HOST --port=$PORT wsgi:wsgi_app
Restart=always
RestartSec=10
StandardOutput=syslog
StandardError=syslog
SyslogIdentifier=mockapi

# Security hardening
NoNewPrivileges=true
PrivateTmp=true
ProtectSystem=strict
ReadWritePaths=$APP_DIR

[Install]
WantedBy=multi-user.target
EOF
    print_status "Service file updated with hardcoded port $PORT."
    print_warning "Note: If you change PORT in .env, you must update service file manually."
fi

# Step 6: Reload and restart
print_status "Step 5: Reloading systemd daemon..."
sudo systemctl daemon-reload

print_status "Step 6: Restarting service..."
sudo systemctl restart mockapi

sleep 3

# Step 7: Verify
print_status "Step 7: Verifying service status..."
if sudo systemctl is-active --quiet mockapi; then
    print_status "✓ Service is running!"
    
    echo
    print_status "Testing health endpoint on port $PORT..."
    if curl -f -s --max-time 10 http://localhost:$PORT/health > /dev/null 2>&1; then
        print_status "✓ Health check passed!"
        echo
        echo "=== Service Fixed Successfully ==="
        echo "MockAPI is now running on:"
        echo "  URL: http://localhost:$PORT"
        echo "  Admin: http://localhost:$PORT/admin/login"
        echo "  Docs: http://localhost:$PORT/docs"
        echo "  Health: http://localhost:$PORT/health"
    else
        print_warning "Health check failed (might be starting up). Checking logs..."
        sleep 2
        if curl -f -s --max-time 5 http://localhost:$PORT/health > /dev/null 2>&1; then
            print_status "✓ Health check passed on second attempt!"
        else
            print_warning "Service running but health check failing. Checking logs..."
            sudo journalctl -u mockapi -n 20 --no-pager
        fi
    fi
else
    print_error "Service failed to start after fix."
    echo
    print_warning "Checking service logs..."
    sudo journalctl -u mockapi -n 30 --no-pager
    echo
    print_warning "Trying alternative approach with simplified service file..."
    
    # Try a simpler approach - just hardcode common values
    print_status "Creating minimal service file..."
    sudo tee "$SERVICE_FILE" > /dev/null << EOF
[Unit]
Description=Mock API Service
After=network.target

[Service]
Type=simple
User=$CURRENT_USER
Group=$CURRENT_GROUP
WorkingDirectory=$APP_DIR
Environment="PATH=$VENV_DIR/bin"
ExecStart=$VENV_DIR/bin/waitress-serve --host=0.0.0.0 --port=8000 wsgi:wsgi_app
Restart=always
RestartSec=10

[Install]
WantedBy=multi-user.target
EOF
    
    sudo systemctl daemon-reload
    sudo systemctl restart mockapi
    
    sleep 3
    
    if sudo systemctl is-active --quiet mockapi; then
        print_status "✓ Service started with hardcoded values!"
        print_warning "Running on default port 8000. Update .env to match."
        sudo sed -i "s/^PORT=.*/PORT=8000/" "$ENV_FILE"
    else
        print_error "All fixes failed. Please check manual configuration."
        sudo journalctl -u mockapi -n 30 --no-pager
    fi
fi

echo
print_status "=== Fix script completed ==="
echo "Backup service file: $BACKUP_FILE"
echo "Current .env PORT: $PORT"
echo "Current .env HOST: $HOST"