package main

import (
	"flag"
	"fmt"
	"io/ioutil"
	"log"
	"os"
	"os/exec"
	"os/user"
	"strconv"
	"strings"
	"time"
)

type OnFail int

const (
	IgnoreOnFail OnFail = iota
	WarnOnFail
	ExitOnFail
)

type arrayFlags []string

// Implemented for flag#Value interface
func (s *arrayFlags) String() string {
	if s == nil {
		return ""
	}
	return fmt.Sprintf("%v", *s)
}

// Implemented for flag#Value interface
func (s *arrayFlags) Set(value string) error {
	*s = append(*s, value)
	return nil
}

// Returns `"foo" "bar"`
func (s *arrayFlags) AsArgs() string {
	var result []string
	for _, value := range *s {
		result = append(result, fmt.Sprintf("%q", value))
	}
	return strings.Join(result, " ")
}

// Returns `--flag="foo" --flag="bar"`
func (s *arrayFlags) AsRepeatedFlag(name string) string {
	var result []string
	for _, value := range *s {
		result = append(result, fmt.Sprintf(`--%s="%s"`, name, value))
	}
	return strings.Join(result, " ")
}

var build_instance string
var build_project string
var build_zone string
var dest_image string
var dest_family string
var dest_project string
var launch_instance string
var arch string
var source_image_family string
var source_image_project string
var repository_url string
var repository_branch string
var version string
var internal_ip_flag string
var INTERNAL_extra_source string
var verbose bool
var username string
var image_disk_size_gb int

// NOTE: For `gcloud compute ssh` command, `ssh_flags` will be used as SSH_ARGS rather than
// as `--ssh_flag` repeated flag. Why? because --ssh_flag is not parsed as expected when
// containing quotes and spaces.
var ssh_flags arrayFlags
var host_orchestration_flag bool

func init() {
	user, err := user.Current()
	if err != nil {
		panic(err)
	}
	username = user.Username

	flag.StringVar(&build_instance, "build_instance",
		username+"-build", "Instance name to create for the build")
	flag.StringVar(&build_project, "build_project",
		mustShell("gcloud config get-value project"), "Project to use for scratch")
	// The new get-value output format is different. The result is in 2nd line.
	str_list := strings.Split(build_project, "\n")
	if len(str_list) == 2 {
		build_project = str_list[1]
	}

	flag.StringVar(&build_zone, "build_zone",
		mustShell("gcloud config get-value compute/zone"),
		"Zone to use for scratch resources")
	// The new get-value output format is different. The result is in 2nd line.
	str_list = strings.Split(build_zone, "\n")
	if len(str_list) == 2 {
		build_zone = str_list[1]
	}

	flag.StringVar(&dest_image, "dest_image",
		"vsoc-host-scratch-"+username, "Image to create")
	flag.StringVar(&dest_family, "dest_family", "",
		"Image family to add the image to")
	flag.StringVar(&dest_project, "dest_project",
		mustShell("gcloud config get-value project"), "Project to use for the new image")
	// The new get-value output format is different. The result is in 2nd line.
	str_list = strings.Split(dest_project, "\n")
	if len(str_list) == 2 {
		dest_project = str_list[1]
	}

	flag.StringVar(&launch_instance, "launch_instance", "",
		"Name of the instance to launch with the new image")
	flag.StringVar(&arch, "arch", "gce_x86_64",
		"Which CPU arch, arm/x86_64/gce_x86_64")
	flag.StringVar(&source_image_family, "source_image_family", "debian-12",
		"Image familty to use as the base")
	flag.StringVar(&source_image_project, "source_image_project", "debian-cloud",
		"Project holding the base image")
	flag.StringVar(&repository_url, "repository_url",
		"https://github.com/google/android-cuttlefish.git",
		"URL to the repository with host changes")
	flag.StringVar(&repository_branch, "repository_branch",
		"v0.9.30", "Branch to check out")
	flag.StringVar(&version, "version", "", "cuttlefish-common version")
	flag.StringVar(&internal_ip_flag, "INTERNAL_IP", "",
		"INTERNAL_IP can be set to --internal-ip run on a GCE instance."+
			"The instance will need --scope compute-rw.")
	flag.StringVar(&INTERNAL_extra_source, "INTERNAL_extra_source", "",
		"INTERNAL_extra_source may be set to a directory containing the source for extra packages to build.")
	flag.BoolVar(&verbose, "verbose", true, "print commands and output (default: true)")
	flag.IntVar(&image_disk_size_gb, "image_disk_size_gb", 10, "Image disk size in GB")
	flag.Var(&ssh_flags, "ssh_flag",
		"Values for --ssh-flag and --scp_flag for gcloud compute ssh/scp respectively. This flag may be repeated")
	flag.BoolVar(&host_orchestration_flag, "host_orchestration", false,
		"assembles image with host orchestration capabilities")
	flag.Parse()
}

func shell(cmd string) (string, error) {
	if verbose {
		fmt.Println(cmd)
	}
	b, err := exec.Command("/bin/sh", "-c", cmd).CombinedOutput()
	if verbose {
		fmt.Println(string(b))
	}
	if err != nil {
		return "", err
	}
	return strings.TrimSpace(string(b)), nil
}

func mustShell(cmd string) string {
	if verbose {
		fmt.Println(cmd)
	}
	out, err := shell(cmd)
	if err != nil {
		panic(err)
	}
	if verbose {
		fmt.Println(out)
	}
	return strings.TrimSpace(out)
}

func gce(action OnFail, gceArg string, errorStr ...string) (string, error) {
	cmd := "gcloud " + gceArg
	out, err := shell(cmd)
	if out != "" {
		fmt.Println(out)
	}
	if err != nil && action != IgnoreOnFail {
		var buf string
		fmt.Sprintf(buf, "gcloud error occurred: %s", err)
		if len(errorStr) > 0 {
			buf += " [" + errorStr[0] + "]"
		}
		if action == ExitOnFail {
			panic(buf)
		}
		if action == WarnOnFail {
			fmt.Println(buf)
		}
	}
	return out, err
}

func waitForInstance(PZ string) {
	for {
		time.Sleep(5 * time.Second)
		_, err := gce(WarnOnFail, `compute ssh `+internal_ip_flag+` `+PZ+` `+
			build_instance+` -- `+ssh_flags.AsArgs()+` uptime `)
		if err == nil {
			break
		}
	}
}

func packageSource(url string, branch string, subdir string) {
	repository_dir := url[strings.LastIndex(url, "/")+1:]
	repository_dir = mustShell(`basename "` + repository_dir + `" .git`)
	debian_dir := repository_dir
	if subdir != "" {
		debian_dir = repository_dir + "/" + subdir
	}
	mustShell("git clone " + url + " -b " + branch)
	mustShell("dpkg-source -b " + debian_dir)
	mustShell("rm -rf " + repository_dir)
	mustShell("ls -l")
	mustShell("pwd")
}

func createInstance(instance string, arg string) {
	_, err := gce(WarnOnFail, `compute instances describe "`+instance+`"`)
	if err != nil {
		gce(ExitOnFail, `compute instances create `+arg+` "`+instance+`"`)
	}
}

func main() {
	gpu_type := "nvidia-tesla-p100-vws"
	PZ := "--project=" + build_project + " --zone=" + build_zone

	if arch != "gce_x86_64" {
		// new path that generate image locally without creating GCE instance

		abt := os.Getenv("ANDROID_BUILD_TOP")
		cmd := `"` + abt + `/device/google/cuttlefish/tools/create_base_image_combined.sh"`
		cmd += " " + arch
		out, err := shell(cmd)
		if out != "" {
			fmt.Println(out)
		}
		if err != nil {
			fmt.Println("create_base_image arch %s error occurred: %s", arch, err)
		}

		// gce operations
		delete_instances := build_instance + " " + dest_image
		if launch_instance != "" {
			delete_instances += " " + launch_instance
		}
		zip_file := "disk_" + username + ".raw.tar.gz"
		gs_file := "gs://cloud-android-testing-esp/" + zip_file
		cloud_storage_file := "https://storage.googleapis.com/cloud-android-testing-esp/" + zip_file
		location := "us"

		// delete all previous instances, images and disks
		gce(WarnOnFail, `compute instances delete -q `+PZ+` `+delete_instances, `Not running`)
		gce(WarnOnFail, `compute disks delete -q `+PZ+` "`+dest_image+`"`, `No scratch disk`)
		gce(WarnOnFail, `compute images delete -q --project="`+build_project+`" "`+dest_image+`"`,
			`Not respinning`)
		gce(WarnOnFail, `alpha storage rm `+gs_file)

		// upload new local host image into GCE storage
		gce(WarnOnFail, `alpha storage cp `+abt+`/`+zip_file+` gs://cloud-android-testing-esp`)

		// create GCE image based on new uploaded host image
		gce(WarnOnFail, `compute images create "`+dest_image+`" --project="`+build_project+
			`" --family="`+source_image_family+`" --source-uri="`+cloud_storage_file+
			`" --storage-location="`+location+`" --guest-os-features=UEFI_COMPATIBLE`)

		// find Nvidia GPU and then create GCE instance
		gce(ExitOnFail, `compute accelerator-types describe "`+gpu_type+`" `+PZ,
			`Please use a zone with `+gpu_type+` GPUs available.`)
		createInstance(build_instance, PZ+
			` --machine-type=n1-standard-16 --network-interface=network-tier=PREMIUM,subnet=default`+
			` --accelerator="type=`+gpu_type+
			`,count=1" --maintenance-policy=TERMINATE --provisioning-model=STANDARD`+
			` --service-account=204446994883-compute@developer.gserviceaccount.com`+
			` --scopes=https://www.googleapis.com/auth/devstorage.read_only,`+
			`https://www.googleapis.com/auth/logging.write,`+
			`https://www.googleapis.com/auth/monitoring.write,`+
			`https://www.googleapis.com/auth/servicecontrol,`+
			`https://www.googleapis.com/auth/service.management.readonly,`+
			`https://www.googleapis.com/auth/trace.append`+
			` --tags=http-server --create-disk=auto-delete=yes,boot=yes,device-name=`+build_instance+
			`,image=projects/cloud-android-testing/global/images/`+dest_image+
			`,mode=rw,size=200,type=projects/cloud-android-testing/zones/`+build_zone+
			`/diskTypes/pd-balanced --no-shielded-secure-boot --shielded-vtpm`+
			` --shielded-integrity-monitoring --reservation-affinity=any`)

		// enable serial-port (console)
		gce(WarnOnFail, `compute instances add-metadata `+build_instance+
			` --metadata serial-port-enable=TRUE`)
		return
	}

	dest_family_flag := ""
	if dest_family != "" {
		dest_family_flag = "--family=" + dest_family
	}

	scratch_dir, err := ioutil.TempDir("", "")
	if err != nil {
		log.Fatal(err)
	}

	oldDir, err := os.Getwd()
	if err != nil {
		log.Fatal(err)
	}
	os.Chdir(scratch_dir)
	packageSource(repository_url, repository_branch, "base")
	packageSource(repository_url, repository_branch, "frontend")
	os.Chdir(oldDir)

	abt := os.Getenv("ANDROID_BUILD_TOP")
	source_files := `"` + abt + `/device/google/cuttlefish/tools/create_base_image_gce.sh"`
	source_files += " " + `"` + abt + `/device/google/cuttlefish/tools/install_nvidia.sh"`
	source_files += " " + `"` + abt + `/device/google/cuttlefish/tools/update_gce_kernel.sh"`
	source_files += " " + `"` + abt + `/device/google/cuttlefish/tools/remove_old_gce_kernel.sh"`
	source_files += " " + scratch_dir + "/*"
	if INTERNAL_extra_source != "" {
		source_files += " " + INTERNAL_extra_source + "/*"
	}

	delete_instances := build_instance + " " + dest_image
	if launch_instance != "" {
		delete_instances += " " + launch_instance
	}

	gce(WarnOnFail, `compute instances delete -q `+PZ+` `+delete_instances,
		`Not running`)
	gce(WarnOnFail, `compute disks delete -q `+PZ+` "`+dest_image+
		`"`, `No scratch disk`)
	gce(WarnOnFail, `compute images delete -q --project="`+build_project+
		`" "`+dest_image+`"`, `Not respinning`)
	gce(WarnOnFail, `compute disks create `+PZ+`  --size=`+strconv.Itoa(image_disk_size_gb)+`G `+
		`--image-family="`+source_image_family+`" --image-project="`+source_image_project+`" "`+dest_image+`"`)
	gce(ExitOnFail, `compute accelerator-types describe "`+gpu_type+`" `+PZ,
		`Please use a zone with `+gpu_type+` GPUs available.`)
	createInstance(build_instance, PZ+
		` --machine-type=n1-standard-16 --image-family="`+source_image_family+
		`" --image-project="`+source_image_project+
		`" --boot-disk-size=200GiB --accelerator="type=`+gpu_type+
		`,count=1" --maintenance-policy=TERMINATE --boot-disk-size=200GiB`)

	waitForInstance(PZ)

	// Ubuntu tends to mount the wrong disk as root, so help it by waiting until
	// it has booted before giving it access to the clean image disk
	gce(WarnOnFail, `compute instances attach-disk `+PZ+` "`+build_instance+
		`" --disk="`+dest_image+`"`)

	// beta for the --internal-ip flag that may be passed via internal_ip_flag
	gce(ExitOnFail, `beta compute scp `+internal_ip_flag+` `+PZ+` `+source_files+
		` "`+build_instance+`:" `+ssh_flags.AsRepeatedFlag("scp-flag"))

	// Update the host kernel before installing any kernel modules
	// Needed to guarantee that the modules in the chroot aren't built for the
	// wrong kernel
	gce(WarnOnFail, `compute ssh `+internal_ip_flag+` `+PZ+` "`+build_instance+
		`"`+` -- `+ssh_flags.AsArgs()+` ./update_gce_kernel.sh`)
	// TODO rammuthiah if the instance is clobbered with ssh commands within
	// 5 seconds of reboot, it becomes inaccessible. Workaround that by sleeping
	// 50 seconds.
	time.Sleep(70 * time.Second)
	gce(ExitOnFail, `compute ssh `+internal_ip_flag+` `+PZ+` "`+build_instance+
		`"`+` -- `+ssh_flags.AsArgs()+` ./remove_old_gce_kernel.sh`)

	ho_arg := ""
	if host_orchestration_flag {
		ho_arg = "-o"
	}
	gce(ExitOnFail, `compute ssh `+internal_ip_flag+` `+PZ+` "`+build_instance+
		`"`+` -- `+ssh_flags.AsArgs()+` ./create_base_image_gce.sh `+ho_arg)

	// Reboot the instance to force a clean umount of the disk's file system.
	gce(WarnOnFail, `compute ssh `+internal_ip_flag+` `+PZ+` "`+build_instance+
		`" -- `+ssh_flags.AsArgs()+` sudo reboot`)
	waitForInstance(PZ)

	gce(ExitOnFail, `compute instances delete -q `+PZ+` "`+build_instance+`"`)
	gce(ExitOnFail, `compute images create --project="`+build_project+
		`" --source-disk="`+dest_image+`" --source-disk-zone="`+build_zone+
		`" --licenses=https://www.googleapis.com/compute/v1/projects/vm-options/global/licenses/enable-vmx `+
		dest_family_flag+` "`+dest_image+`"`)
	gce(ExitOnFail, `compute disks delete -q `+PZ+` "`+dest_image+`"`)

	if launch_instance != "" {
		createInstance(launch_instance, PZ+
			` --image-project="`+build_project+`" --image="`+dest_image+
			`" --machine-type=n1-standard-4 --scopes storage-ro --accelerator="type=`+
			gpu_type+`,count=1" --maintenance-policy=TERMINATE --boot-disk-size=200GiB`)
	}

	fmt.Printf("Test and if this looks good, consider releasing it via:\n"+
		"\n"+
		"gcloud compute images create \\\n"+
		"  --project=\"%s\" \\\n"+
		"  --source-image=\"%s\" \\\n"+
		"  --source-image-project=\"%s\" \\\n"+
		"  \"%s\" \\\n"+
		"  \"%s\"\n",
		dest_project, dest_image, build_project, dest_family_flag, dest_image)
}