#!/bin/bash
# Laboratori Cloud - Environment Check Script
# Part of: "Corso Soluzioni Cloud"
#
# Description: Verifies Docker Engine >= 24.0, Compose V2, network utilities, and system resources
# Usage: ./scripts/check-env.sh

# Exit on error, but handle command failures gracefully

# Color codes for output
RED='\033[0;31m'
GREEN='\033[0;32m'
YELLOW='\033[1;33m'
NC='\033[0m' # No Color

# Counters for summary
PASS_COUNT=0
FAIL_COUNT=0

# Function to print pass message
print_pass() {
    echo -e "${GREEN}[PASS]${NC} $1"
    ((PASS_COUNT++))
}

# Function to print fail message
print_fail() {
    echo -e "${RED}[FAIL]${NC} $1"
    ((FAIL_COUNT++))
}

# Function to print warn message
print_warn() {
    echo -e "${YELLOW}[WARN]${NC} $1"
}

# Function to print info message
print_info() {
    echo "[INFO] $1"
}

echo "=========================================="
echo "Laboratori Cloud - Environment Check"
echo "=========================================="
echo ""

# 1. Docker Engine version check
print_info "Checking Docker Engine version..."
if command -v docker &> /dev/null; then
    DOCKER_VERSION=$(docker --version | grep -oP '\d+\.\d+\.\d+' | head -1)
    DOCKER_MAJOR=$(echo "$DOCKER_VERSION" | cut -d. -f1)

    print_info "Found Docker Engine version: $DOCKER_VERSION"

    if [ "$DOCKER_MAJOR" -ge 24 ]; then
        print_pass "Docker Engine >= 24.0 (found $DOCKER_VERSION)"
    else
        print_fail "Docker Engine >= 24.0 required. Found: $DOCKER_VERSION"
    fi
else
    print_fail "Docker Engine not found. Please install Docker >= 24.0"
fi
echo ""

# 2. Docker Compose V2 check
print_info "Checking Docker Compose V2..."
if docker compose version &> /dev/null; then
    COMPOSE_VERSION=$(docker compose version | grep -oP 'Docker Compose version v?\K[\d.]+' | head -1)
    print_info "Found Docker Compose V2 version: $COMPOSE_VERSION"
    print_pass "Docker Compose V2 is available (use 'docker compose' not 'docker-compose')"
elif command -v docker-compose &> /dev/null; then
    print_fail "Docker Compose V2 required. Found legacy 'docker-compose'. Please upgrade to Docker Compose V2"
else
    print_fail "Docker Compose V2 required. Use 'docker compose' not 'docker-compose'"
fi
echo ""

# 3. Network utilities check
print_info "Checking network utilities..."
MISSING_UTILS=()

# Check for netcat/nc
if command -v nc &> /dev/null; then
    print_pass "netcat (nc) is available"
elif command -v netcat &> /dev/null; then
    print_pass "netcat is available"
else
    MISSING_UTILS+=("netcat/nc")
    print_fail "netcat (or nc) is required"
fi

# Check for curl
if command -v curl &> /dev/null; then
    print_pass "curl is available"
else
    MISSING_UTILS+=("curl")
    print_fail "curl is required"
fi

# Check for ip (iproute2)
if command -v ip &> /dev/null; then
    print_pass "ip (iproute2) is available"
else
    MISSING_UTILS+=("ip (iproute2)")
    print_fail "ip (iproute2) is required"
fi

if [ ${#MISSING_UTILS[@]} -gt 0 ]; then
    print_fail "Missing network utilities: ${MISSING_UTILS[*]}"
fi
echo ""

# 4. System resources check
print_info "Checking system resources..."

# Check RAM
if [ -f /proc/meminfo ]; then
    TOTAL_MEM_KB=$(grep MemTotal /proc/meminfo | awk '{print $2}')
    TOTAL_MEM_GB=$((TOTAL_MEM_KB / 1024 / 1024))
    print_info "Total RAM: ${TOTAL_MEM_GB}GB"

    if [ "$TOTAL_MEM_GB" -ge 16 ]; then
        print_pass "System has ${TOTAL_MEM_GB}GB RAM (recommended: 16GB)"
    elif [ "$TOTAL_MEM_GB" -ge 8 ]; then
        print_warn "System has ${TOTAL_MEM_GB}GB RAM (recommended: 16GB for all labs)"
    else
        print_fail "System has ${TOTAL_MEM_GB}GB RAM (minimum: 8GB, recommended: 16GB)"
    fi
elif command -v free &> /dev/null; then
    TOTAL_MEM=$(free -h | awk '/^Mem:/ {print $2}')
    print_info "Total RAM: $TOTAL_MEM"
    print_warn "Could not determine exact RAM value. Please verify you have at least 8GB"
else
    print_warn "Could not determine system RAM. Please verify manually"
fi

# Check CPU cores
if command -v nproc &> /dev/null; then
    CPU_CORES=$(nproc)
    print_info "CPU cores: $CPU_CORES"

    if [ "$CPU_CORES" -ge 4 ]; then
        print_pass "System has $CPU_CORES CPU cores"
    else
        print_warn "System has $CPU_CORES CPU cores (recommended: 4+ for best performance)"
    fi
else
    print_warn "Could not determine CPU count"
fi
echo ""

# Summary
echo "=========================================="
echo "Summary: $PASS_COUNT passed, $FAIL_COUNT failed"
echo "=========================================="

if [ "$FAIL_COUNT" -gt 0 ]; then
    echo ""
    print_fail "Environment check failed. Please fix the issues above before starting labs."
    exit 1
else
    echo ""
    print_pass "All environment checks passed! You're ready to start the labs."
    exit 0
fi