package syscheck

import (
	"bufio"
	"context"
	"fmt"
	"os"
	"runtime"
	"strconv"
	"strings"

	"golang.org/x/sys/cpu"
)

type CPUInfo struct {
	Cores        int64
	FrequencyMHz int64
	SupportAES   bool
	IsX86V2      bool
}

func GetCPUInfo(ctx context.Context) (CPUInfo, error) {
	info := CPUInfo{
		Cores: int64(runtime.NumCPU()),
	}

	// Parse /proc/cpuinfo to get CPU frequency and model info
	file, err := os.Open("/proc/cpuinfo")
	if err != nil {
		return info, fmt.Errorf("failed to open /proc/cpuinfo: %w", err)
	}
	defer file.Close()

	scanner := bufio.NewScanner(file)
	for scanner.Scan() {
		line := scanner.Text()

		// Parse CPU MHz
		if strings.HasPrefix(line, "cpu MHz") {
			parts := strings.Split(line, ":")
			if len(parts) == 2 {
				freqStr := strings.TrimSpace(parts[1])
				if freq, err := strconv.ParseFloat(freqStr, 64); err == nil {
					info.FrequencyMHz = int64(freq)
					break // Get first CPU frequency
				}
			}
		}
	}

	if err := scanner.Err(); err != nil {
		return info, fmt.Errorf("failed to read /proc/cpuinfo: %w", err)
	}

	// Check CPU features using x/sys/cpu package
	if runtime.GOARCH == "amd64" || runtime.GOARCH == "386" {
		// Check AES-NI support
		info.SupportAES = cpu.X86.HasAES

		// Check x86-64-v2 support
		// x86-64-v2 requires: SSE3, SSSE3, SSE4.1, SSE4.2, POPCNT
		info.IsX86V2 = cpu.X86.HasSSE3 &&
			cpu.X86.HasSSSE3 &&
			cpu.X86.HasSSE41 &&
			cpu.X86.HasSSE42 &&
			cpu.X86.HasPOPCNT
	} else {
		// For ARM or other architectures
		info.SupportAES = false
		info.IsX86V2 = false
	}

	return info, nil
}