#!/bin/bash

RED='\033[0;31m'
GREEN='\033[0;32m'
YELLOW='\033[1;33m'
CYAN='\033[0;36m'
NC='\033[0m' # No Color

echo -e "${CYAN}--- System Swap Space Check ---${NC}"

SWAP_SIZE=$(free -m | awk '/^Swap:/ {print $2}')

if [ "$SWAP_SIZE" -gt "0" ]; then
    echo -e "${GREEN}[OK] Swap space is already configured ($SWAP_SIZE MB). Skipping creation.${NC}"
    exit 0
fi

RAM_SIZE=$(free -m | awk '/^Mem:/ {print $2}')

echo -e "${YELLOW}[WARNING] No swap space detected on this server!${NC}"
echo -e "GitLab requires at least 4GB of RAM. If your server runs out of memory, GitLab will crash."

if [ "$RAM_SIZE" -le "4500" ]; then
    echo -e "${RED}[CRITICAL] Your server has ~4GB RAM ($RAM_SIZE MB). A 4GB swap file is HIGHLY recommended.${NC}"
else
    echo -e "${CYAN}Your server has plenty of RAM ($RAM_SIZE MB), but adding a swap file is still a safe fallback.${NC}"
fi

echo ""
read -p "Do you want to automatically create a 4GB swap file now? (Requires sudo password) (y/n): " -n 1 -r
echo ""

if [[ ! $REPLY =~ ^[Yy]$ ]]; then
    echo -e "${YELLOW}Skipping swap creation. If GitLab crashes, please create swap manually.${NC}"
    exit 0
fi

echo -e "${CYAN}Allocating 4GB swap file... This may take a moment.${NC}"
sudo fallocate -l 4G /swapfile

if [ $? -ne 0 ]; then
    echo -e "${RED}[ERROR] Failed to allocate space. Your disk might be full.${NC}"
    exit 1
fi

echo -e "${CYAN}Securing file permissions...${NC}"
sudo chmod 600 /swapfile

echo -e "${CYAN}Formatting as swap...${NC}"
sudo mkswap /swapfile

echo -e "${CYAN}Enabling swap...${NC}"
sudo swapon /swapfile

if grep -q "/swapfile" /etc/fstab; then
    echo -e "${YELLOW}[INFO] /swapfile entry already exists in /etc/fstab.${NC}"
else
    echo -e "${CYAN}Adding swap to /etc/fstab to survive reboots...${NC}"
    echo '/swapfile none swap sw 0 0' | sudo tee -a /etc/fstab > /dev/null
fi

NEW_SWAP=$(free -m | awk '/^Swap:/ {print $2}')
if [ "$NEW_SWAP" -gt "0" ]; then
    echo -e "${GREEN}[SUCCESS] 4GB Swap space successfully created and enabled!${NC}"
else
    echo -e "${RED}[ERROR] Something went wrong. Swap is still reporting 0 MB.${NC}"
fi