#!/bin/bash
# Simple fix: Update service file to use $HOST and $PORT from .env
# No wrapper script, just fix the variable expansion

set -e

echo "=== Fix: Update service to use \$HOST and \$PORT from .env ==="
echo

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

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

print_status() {
    echo -e "${GREEN}[+]${NC} $1"
}

print_warning() {
    echo -e "${YELLOW}[!]${NC} $1"
}

print_error() {
    echo -e "${RED}[!]${NC} $1"
}

# Check if running as root
if [[ $EUID -ne 0 ]]; then
    print_error "This script requires sudo privileges."
    exit 1
fi

# Step 1: Check files
if [[ ! -f "$ENV_FILE" ]]; then
    print_error ".env file not found: $ENV_FILE"
    exit 1
fi

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

# Step 2: Ensure PORT exists in .env
print_status "Checking .env file..."
if ! grep -q "^PORT=" "$ENV_FILE"; then
    print_warning "PORT not found in .env. Adding PORT=8000..."
    echo "PORT=8000" >> "$ENV_FILE"
    print_status "Added PORT=8000"
fi

if ! grep -q "^HOST=" "$ENV_FILE"; then
    print_warning "HOST not found in .env. Adding HOST=0.0.0.0..."
    echo "HOST=0.0.0.0" >> "$ENV_FILE"
fi

# Validate PORT is numeric
PORT_VALUE=$(grep "^PORT=" "$ENV_FILE" | cut -d'=' -f2)
if [[ ! "$PORT_VALUE" =~ ^[0-9]+$ ]]; then
    print_error "PORT is not numeric: '$PORT_VALUE'. Fixing to 8000."
    sed -i "s/^PORT=.*/PORT=8000/" "$ENV_FILE"
    PORT_VALUE="8000"
fi

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

# Step 4: Check current ExecStart
print_status "Checking current ExecStart line..."
CURRENT_EXEC=$(grep "^ExecStart=" "$SERVICE_FILE")
echo "Current: $CURRENT_EXEC"

# Step 5: Update ExecStart to use $HOST and $PORT
print_status "Updating ExecStart to use variables from .env..."
# We need to replace the ExecStart line with one that uses $HOST and $PORT
# But we need to be careful about escaping for sed

# First, get the current venv path from the existing ExecStart or Environment line
VENV_PATH=$(grep 'Environment="PATH=' "$SERVICE_FILE" | cut -d'=' -f2 | cut -d':' -f1 | sed 's/"//g')
if [[ -z "$VENV_PATH" ]]; then
    # Try to extract from ExecStart
    VENV_PATH=$(echo "$CURRENT_EXEC" | sed -n "s|^ExecStart=\(.*\)/waitress-serve.*|\1|p")
    if [[ -z "$VENV_PATH" ]]; then
        VENV_PATH="/opt/mockapi/venv"
        print_warning "Could not detect venv path, using default: $VENV_PATH"
    fi
fi

print_status "Detected venv path: $VENV_PATH"

# Create a temporary file with the updated service configuration
TMP_FILE=$(mktemp)

# Read the current service file and update ExecStart
while IFS= read -r line; do
    if [[ "$line" =~ ^ExecStart= ]]; then
        # Replace with new ExecStart using variables
        echo "ExecStart=$VENV_PATH/bin/waitress-serve --host=\$HOST --port=\$PORT wsgi:wsgi_app"
        print_status "Updated ExecStart line"
    else
        echo "$line"
    fi
done < "$SERVICE_FILE" > "$TMP_FILE"

# Replace the service file
mv "$TMP_FILE" "$SERVICE_FILE"

# Step 6: Verify the change
print_status "Verifying update..."
UPDATED_EXEC=$(grep "^ExecStart=" "$SERVICE_FILE")
echo "Updated: $UPDATED_EXEC"

# Check if we have the escaped \$HOST and \$PORT
if echo "$UPDATED_EXEC" | grep -q "\\\\\$HOST\|\\\\\$PORT"; then
    print_warning "Found escaped variables (\\\$HOST/\\\$PORT). This might still cause issues."
    print_status "Trying alternative: unescaped variables..."
    
    # Create alternative without backslashes
    TMP_FILE2=$(mktemp)
    while IFS= read -r line; do
        if [[ "$line" =~ ^ExecStart= ]]; then
            # Use unescaped variables
            echo "ExecStart=$VENV_PATH/bin/waitress-serve --host=\$HOST --port=\$PORT wsgi:wsgi_app"
        else
            echo "$line"
        fi
    done < "$SERVICE_FILE" > "$TMP_FILE2"
    
    # The issue: $HOST and $PORT in the HERE-document above will expand
    # We need to write literal $HOST and $PORT. Let's use sed instead.
    sed -i 's/--host=\\\$HOST --port=\\\$PORT/--host=$HOST --port=$PORT/' "$TMP_FILE2"
    mv "$TMP_FILE2" "$SERVICE_FILE"
    
    print_status "Updated with unescaped variables"
fi

# Final check
FINAL_EXEC=$(grep "^ExecStart=" "$SERVICE_FILE")
echo "Final ExecStart: $FINAL_EXEC"

# Step 7: Test if it looks correct
if echo "$FINAL_EXEC" | grep -q "--host=\$HOST --port=\$PORT"; then
    print_status "✓ ExecStart looks correct (uses \$HOST and \$PORT)"
elif echo "$FINAL_EXEC" | grep -q "--host=\\\$HOST --port=\\\$PORT"; then
    print_warning "ExecStart has escaped variables (\\\$HOST/\\\$PORT)"
    print_warning "This might still cause the original error."
else
    print_warning "ExecStart format unexpected: $FINAL_EXEC"
fi

# Step 8: Reload and restart
print_status "Reloading systemd..."
systemctl daemon-reload

print_status "Restarting service..."
if systemctl restart mockapi; then
    print_status "Service restart initiated..."
    
    sleep 3
    
    if systemctl is-active --quiet mockapi; then
        print_status "✓ Service is running!"
        
        # Test health endpoint
        print_status "Testing health endpoint on port $PORT_VALUE..."
        if curl -f -s --max-time 10 http://localhost:$PORT_VALUE/health > /dev/null 2>&1; then
            print_status "✓ Health check passed!"
            echo
            echo "=== SUCCESS ==="
            echo "MockAPI service now uses PORT from .env file."
            echo
            echo "To change port:"
            echo "  1. Edit $ENV_FILE"
            echo "  2. Update the PORT value"
            echo "  3. Run: sudo systemctl restart mockapi"
            echo
            echo "Current port: $PORT_VALUE"
            echo "Access: http://localhost:$PORT_VALUE"
        else
            print_warning "Service running but health check failed."
            journalctl -u mockapi -n 10 --no-pager
        fi
    else
        print_error "Service failed to start."
        echo "Checking logs..."
        journalctl -u mockapi -n 20 --no-pager
        
        # Try one more approach: use a simple hardcoded port as fallback
        print_status "Trying fallback: hardcoding port $PORT_VALUE..."
        sed -i "s|--host=\$HOST --port=\$PORT|--host=0.0.0.0 --port=$PORT_VALUE|" "$SERVICE_FILE"
        systemctl daemon-reload
        systemctl restart mockapi
        
        sleep 3
        
        if systemctl is-active --quiet mockapi; then
            print_status "✓ Service running with hardcoded port $PORT_VALUE"
            print_warning "Note: Port is now hardcoded. To change port, update service file."
        else
            print_error "All attempts failed. Restoring backup..."
            cp "$BACKUP_FILE" "$SERVICE_FILE"
            systemctl daemon-reload
            systemctl restart mockapi
        fi
    fi
else
    print_error "Failed to restart service."
    systemctl status mockapi --no-pager -l
fi

echo
print_status "=== Fix completed ==="
echo "Backup: $BACKUP_FILE"
echo "To manually change port in the future:"
echo "  1. Edit $ENV_FILE (update PORT)"
echo "  2. Edit $SERVICE_FILE (update --port value in ExecStart)"
echo "  3. sudo systemctl daemon-reload"
echo "  4. sudo systemctl restart mockapi"