package main

import (
	"encoding/json"
	"fmt"
	"log"
	"os/exec"
	"runtime"
)

type podmanMachine struct {
	Name    string `json:"name"`
	Running bool   `json:"running"`
	VMType  string `json:"vm_type"`
}

// ensurePodmanMachineDNS configures public DNS resolvers on running Podman
// machines on Windows and macOS. This is required because the Podman VM does
// not always inherit a working DNS from the host, which prevents pulling
// images and reaching api.wordpress.org from containers.
func ensurePodmanMachineDNS() {
	if runtime.GOOS != "windows" && runtime.GOOS != "darwin" {
		return
	}
	if getContainerEngine() != "podman" {
		return
	}

	out, err := exec.Command("podman", "machine", "list", "--format", "json").Output()
	if err != nil {
		log.Printf("ensurePodmanMachineDNS: cannot list machines: %v", err)
		return
	}

	var machines []podmanMachine
	if err := json.Unmarshal(out, &machines); err != nil {
		log.Printf("ensurePodmanMachineDNS: cannot parse machine list: %v", err)
		return
	}

	for _, m := range machines {
		if !m.Running {
			continue
		}
		if err := configurePodmanMachineDNS(m.Name); err != nil {
			log.Printf("ensurePodmanMachineDNS: failed for %s: %v", m.Name, err)
		} else {
			log.Printf("ensurePodmanMachineDNS: DNS configured for %s", m.Name)
		}
	}
}

func configurePodmanMachineDNS(name string) error {
	cmd := exec.Command(
		"podman", "machine", "ssh", name,
		"sudo", "sh", "-c",
		"echo nameserver 8.8.8.8 > /etc/resolv.conf && echo nameserver 1.1.1.1 >> /etc/resolv.conf",
	)
	hideWindow(cmd)
	out, err := cmd.CombinedOutput()
	if err != nil {
		return fmt.Errorf("%w: %s", err, string(out))
	}
	return nil
}