#!/bin/bash

# ==============================================================================
# NGINX CONFIG DEPLOYMENT SCRIPT (v3)
#
# This script securely copies NGINX configuration files to a remote server.
# It handles "Permission Denied" errors by first uploading files to a
# temporary directory, and then using `sudo` to move them to the
# protected /etc/nginx/ directory.
#
# INSTRUCTIONS:
# 1. Edit the `REMOTE_USER` and `REMOTE_HOST` variables.
# 2. Make the script executable: chmod +x <script_name>.sh
# 3. Run the script: ./<script_name>.sh
# ==============================================================================

# --- Configuration ---
# PLEASE EDIT THESE TWO VARIABLES with your server details.
REMOTE_USER="ubuntu"      # Example: ubuntu, ec2-user, root
REMOTE_HOST="3.9.182.122"  # Example: 192.168.1.100 or my-server.com

# --- File & Path Definitions ---
KEY_FILE="~/repos/azeem-macbookair.pem"
SOURCE_NGINX_CONF="nginx.conf"
SOURCE_SITES_DIR="sites-available"

# Destination paths on the remote server
DEST_NGINX_PATH="/etc/nginx/"
DEST_SITES_PATH="/etc/nginx/sites-available/"

# Temporary directory on the remote server (relative to the user's home dir)
# NOTE: Removed the '~' to make it more compatible with scp.
REMOTE_TEMP_DIR="nginx_deploy_temp"

# --- Script Logic ---

echo "🚀 Starting NGINX configuration deployment to $REMOTE_HOST..."
echo "--------------------------------------------------------"

# Expand the tilde (~) in the key file path to an absolute path.
EVAL_KEY_FILE=$(eval echo "$KEY_FILE")

# --- Pre-flight Checks ---
if [ ! -f "$EVAL_KEY_FILE" ]; then
    echo "❌ ERROR: SSH key not found at $EVAL_KEY_FILE"
    exit 1
fi
if [ ! -f "$SOURCE_NGINX_CONF" ]; then
    echo "❌ ERROR: Source file '$SOURCE_NGINX_CONF' not found."
    exit 1
fi
if [ ! -d "$SOURCE_SITES_DIR" ]; then
    echo "❌ ERROR: Source directory '$SOURCE_SITES_DIR' not found."
    exit 1
fi

# --- Remote Operations ---

# Step 1: Create the temporary directory on the remote server.
# This command runs in the user's home directory by default.
echo "-> Creating temporary directory on remote server..."
ssh -i "$EVAL_KEY_FILE" "${REMOTE_USER}@${REMOTE_HOST}" "mkdir -p $REMOTE_TEMP_DIR"
if [ $? -ne 0 ]; then
    echo "❌ ERROR: Failed to create temporary directory on the remote server. Aborting."
    exit 1
fi
echo "  ✅ Remote temporary directory is ready."
echo

# Step 2: Transfer all files to the temporary directory.
# We transfer nginx.conf AND the entire sites-available directory in one command.
echo "- Transferring configuration files to temporary location..."
scp -i "$EVAL_KEY_FILE" -r "$SOURCE_NGINX_CONF" "$SOURCE_SITES_DIR" "${REMOTE_USER}@${REMOTE_HOST}:${REMOTE_TEMP_DIR}/"
if [ $? -ne 0 ]; then
    echo "❌ ERROR: File transfer failed. Aborting."
    exit 1
fi
echo "  ✅ All files successfully transferred to temporary location."
echo

# Step 3: Move files from temp to final destination using sudo and clean up.
echo "- Moving files into place with sudo and cleaning up..."
ssh -i "$EVAL_KEY_FILE" "${REMOTE_USER}@${REMOTE_HOST}" << EOF
    # Move the main config file
    sudo mv "$REMOTE_TEMP_DIR/nginx.conf" "${DEST_NGINX_PATH}nginx.conf"

    # Move the sites-available files
    sudo mv "$REMOTE_TEMP_DIR/sites-available/"* "$DEST_SITES_PATH"

    # Remove the temporary directory
    rm -rf "$REMOTE_TEMP_DIR"

    echo "  -> Verifying Nginx configuration..."
    # Test the Nginx configuration for syntax errors
    sudo nginx -t
EOF

if [ $? -ne 0 ]; then
    echo "⚠️ WARNING: An error occurred on the remote server during the move or config test."
    echo "You may need to log in manually to fix it: ssh -i $EVAL_KEY_FILE ${REMOTE_USER}@${REMOTE_HOST}"
    exit 1
fi

echo "  ✅ Files moved and temporary directory removed."
echo

# Step 4: Ask to reload Nginx
read -p "Nginx config test was successful. Reload Nginx to apply changes? (y/n) " -n 1 -r
echo
if [[ $REPLY =~ ^[Yy]$ ]]; then
    echo "- Reloading Nginx on the server..."
    ssh -i "$EVAL_KEY_FILE" "${REMOTE_USER}@${REMOTE_HOST}" "sudo systemctl reload nginx"
    echo "  ✅ Nginx reloaded."
fi

# --- Completion ---
echo "--------------------------------------------------------"
echo "🎉 Deployment complete!"