//go:build linux

package qemu

import (
	"fmt"
	"os"
	"os/exec"
	"path/filepath"
)

type Config struct {
	Name       string
	TapID      int
	Mac        string
	VolumePath string
	Memory     int
	CPUs       int
	UEFICodePath string
	UEFIVarsPath string
	SerialDir  string
	MonitorDir string
	QMPDir     string
}

func Start(cfg Config) error {
	memory := cfg.Memory
	if memory == 0 {
		memory = 512
	}

	cpus := cfg.CPUs
	if cpus == 0 {
		cpus = 1
	}

	for _, dir := range []string{cfg.SerialDir, cfg.MonitorDir, cfg.QMPDir} {
		if dir != "" {
			if err := os.MkdirAll(dir, 0755); err != nil {
				return fmt.Errorf("mkdir %s: %w", dir, err)
			}
		}
	}

	serialSock := filepath.Join(cfg.SerialDir, cfg.Name+".sock")
	monitorSock := filepath.Join(cfg.MonitorDir, cfg.Name+".sock")
	qmpSock := filepath.Join(cfg.QMPDir, cfg.Name+".sock")

	args := []string{
		"-enable-kvm",
		"-cpu", "host",
		"-m", fmt.Sprintf("%d", memory),
		"-smp", fmt.Sprintf("%d", cpus),
		"-serial", fmt.Sprintf("unix:%s,server,nowait", serialSock),
		"-monitor", fmt.Sprintf("unix:%s,server,nowait", monitorSock),
		"-qmp", fmt.Sprintf("unix:%s,server,nowait", qmpSock),
		"-display", "none",
	}

	if cfg.UEFICodePath != "" && cfg.UEFIVarsPath != "" {
		args = append(args,
			"-drive", fmt.Sprintf("if=pflash,format=raw,readonly=on,file=%s", cfg.UEFICodePath),
			"-drive", fmt.Sprintf("if=pflash,format=raw,file=%s", cfg.UEFIVarsPath),
		)
	}

	args = append(args,
		"-drive", fmt.Sprintf("file=%s,if=virtio", cfg.VolumePath),
		"-netdev", fmt.Sprintf("tap,id=net0,ifname=tap%d,script=no,downscript=no", cfg.TapID),
		"-device", fmt.Sprintf("virtio-net-pci,netdev=net0,mac=%s", cfg.Mac),
		"-daemonize",
	)

	cmd := exec.Command("qemu-system-x86_64", args...)
	if err := cmd.Run(); err != nil {
		return fmt.Errorf("qemu-system-x86_64: %w", err)
	}
	return nil
}