package main

import (
	"context"
	"fmt"
	"os"

	"github.com/containerd/containerd"
	"github.com/containerd/containerd/cio"
	"github.com/containerd/containerd/namespaces"
	"github.com/containerd/containerd/oci"
	specs "github.com/opencontainers/runtime-spec/specs-go"
)

func main() {
	if len(os.Args) < 2 {
		fmt.Println("Usage: go-ctr-run <image-name> <container-name> <command> <args>")
		os.Exit(1)
	}

	imageName := os.Args[1]
	containerName := os.Args[2]
	snapshotName := containerName + "-snapshot"
	command := os.Args[3:]

	ctx := namespaces.WithNamespace(context.Background(), "default") // ---namespace=default

	// connect to containerd
	client, err := containerd.New("/run/containerd/containerd.sock")
	if err != nil {
		panic(err)
	}
	defer client.Close()

	// pull image
	image, err := client.Pull(ctx, imageName, containerd.WithPullUnpack)
	if err != nil {
		panic(err)
	}

	// create a new container
	container, err := client.NewContainer(
		ctx,
		containerName,
		containerd.WithImage(image),
		containerd.WithNewSnapshot(snapshotName, image),
		containerd.WithRuntime("io.containerd.runsc.v1", nil), // --runtime=io.containerd.runsc.v1
		containerd.WithNewSpec(
			oci.WithProcessArgs(command...),
			oci.WithHostNamespace(specs.NetworkNamespace), // --net-host
			oci.WithEnv([]string{"TERM=dump", "PATH=/usr/local/sbin:/usr/local/bin:/usr/sbin:/usr/bin:/sbin:/bin"}),
			// oci.WithTTY, // --tty
		),
	)
	if err != nil {
		panic(err)
	}
	defer container.Delete(ctx, containerd.WithSnapshotCleanup) // --rm

	// create a task
	task, err := container.NewTask(ctx, cio.NewCreator(
		cio.WithStdio,
		// cio.WithTerminal,
	))
	if err != nil {
		panic(err)
	}
	defer task.Delete(ctx)

	// start task
	if err := task.Start(ctx); err != nil {
		panic(err)
	}

	// wait for exit
	statusC, err := task.Wait(ctx)
	if err != nil {
		panic(err)
	}

	// get exit code
	status := <-statusC
	code, _, err := status.Result()
	if err != nil {
		panic(err)
	}
	fmt.Printf("Container exited with code %d\n", code)
}

time="2025-10-06T11:21:16.742479944Z" level=debug msg="Ignoring events in namespace - \"default\""
time="2025-10-06T11:21:16.749041208Z" level=debug msg="prepare snapshot" key=bash-26343-snapshot parent="sha256:418dccb7d85a63a6aa574439840f7a6fa6fd2321b3e2394568a317735e867d35" snapshotter=overlayfs
time="2025-10-06T11:21:16.756494829Z" level=debug msg="get snapshot mounts" key=bash-26343-snapshot snapshotter=overlayfs
time="2025-10-06T11:21:16.850869950Z" level=info msg="connecting to shim bash-26343" address="unix:///run/containerd/s/894e1ca2baeed4e5ba38bea27f2860a20948a993d49db52c4d7662973e98e99c" namespace=default protocol=ttrpc version=2
time="2025-10-06T11:21:16.936539136Z" level=info msg="loading plugin \"io.containerd.event.v1.publisher\"..." runtime=io.containerd.runsc.v1 type=io.containerd.event.v1
time="2025-10-06T11:21:16.936588143Z" level=info msg="loading plugin \"io.containerd.ttrpc.v1.task\"..." runtime=io.containerd.runsc.v1 type=io.containerd.ttrpc.v1
time="2025-10-06T11:21:16.936603028Z" level=debug msg="registering ttrpc service" id=io.containerd.ttrpc.v1.task
time="2025-10-06T11:21:16.936611912Z" level=info msg="loading plugin \"io.containerd.internal.v1.shutdown\"..." runtime=io.containerd.runsc.v1 type=io.containerd.internal.v1
time="2025-10-06T11:21:16.936765347Z" level=debug msg="serving api on socket" socket="[inherited from parent]"
time="2025-10-06T11:21:16.936806074Z" level=info msg="starting signal loop" namespace=default path=/run/containerd/io.containerd.runtime.v2.task/default/bash-26343 pid=1190 runtime=io.containerd.runsc.v1
time="2025-10-06T11:21:16.937075849Z" level=debug msg="Create, id: bash-26343, bundle: \"/run/containerd/io.containerd.runtime.v2.task/default/bash-26343\""
time="2025-10-06T11:21:16.938498574Z" level=debug msg="Executing: [runsc --root=/run/containerd/runsc/default --log=/run/containerd/io.containerd.runtime.v2.task/default/bash-26343/log.json --log-format=json create --bundle /run/containerd/io.containerd.runtime.v2.task/default/bash-26343 --pid-file /run/containerd/io.containerd.runtime.v2.task/default/bash-26343/init.pid bash-26343]"