#!/bin/bash
# check_resources.sh — Check available system memory before running tests
# Usage: check_resources.sh <required_memory_gb>

set -euo pipefail

REQUIRED_GB="${1:-0}"

# Get available memory using vm_stat on macOS
if [[ "$(uname)" == "Darwin" ]]; then
    PAGE_SIZE=$(vm_stat | head -1 | awk '{print $NF}' | sed 's/\.//')
    FREE_PAGES=$(vm_stat | awk '/free/ {print $NF}' | sed 's/\.//')
    if [[ -z "$FREE_PAGES" ]]; then
        FREE_PAGES=$(vm_stat | awk '/Pages free/ {print $3}' | sed 's/\.//')
    fi
    AVAILABLE_GB=$(( FREE_PAGES * 16384 / 1073741824 ))  # 16384 = page size on Apple Silicon
    echo "Available memory: ~${AVAILABLE_GB}GB (free: ${FREE_PAGES} pages)"
else
    AVAILABLE_GB=$(free -g | awk '/^Mem:/ {print $7}')
    echo "Available memory: ~${AVAILABLE_GB}GB"
fi

if [[ "$AVAILABLE_GB" -lt "$REQUIRED_GB" ]]; then
    echo "ERROR: Need ${REQUIRED_GB}GB but only ${AVAILABLE_GB}GB available"
    echo "Run 'memory_pressure' to check memory status"
    exit 1
fi

echo "OK: ${AVAILABLE_GB}GB >= ${REQUIRED_GB}GB required"
exit 0