package main

import (
	"fmt"
	"io"
	"mkvm/volumes"
	"mkvm/volumes/pools"
	"net/http"
	"strings"

	"github.com/sirupsen/logrus"
	"github.com/spf13/cobra"
)

var (
	debianRelease  string
	debianPackages []string

	debianFilenameSuffix = map[pools.ImageFormat]string{
		pools.ImageFormatRaw:   "-generic-amd64-daily.raw",
		pools.ImageFormatQcow2: "-generic-amd64-daily.qcow2",
	}
)

var debianCmd = cobra.Command{
	Use:  "debian vm-name",
	Args: cobra.ExactArgs(1),
	Run: func(cmd *cobra.Command, args []string) {
		name := args[0]

		conn, pool, err := getLibvirtAndPool()
		if err != nil {
			logrus.WithError(err).Fatal("error connecting to libvirt")
			return
		}
		defer conn.Close()

		diskImageURL, err := debianGetImageURL(debianRelease, pool.ImageFormat())
		if err != nil {
			logrus.WithError(err).Fatal("error getting disk image URL")
		}

		// download disk image
		err = volumes.Create(conn, pool, argDiskSizeGB, diskImageURL, name)
		if err != nil {
			logrus.WithError(err).Fatal("error creating VM disk")
		}

		// prepare cloudconfig and start the http server
		bind, err := getServerListenAddress(conn)
		if err != nil {
			logrus.WithError(err).Fatal("error getting server bind address")
		}

		serverURL := fmt.Sprintf("http://%s", bind)

		err = buildCloudConfig(name, fmt.Sprintf("%s/phone-home", serverURL))
		if err != nil {
			logrus.WithError(err).Fatal("error building cloud config")
		}

		go runHTTPServer(bind)

		smbios := map[int]map[string]string{1: {"serial": fmt.Sprintf("ds=nocloud-net;s=%s/", serverURL)}}

		// create domain
		err = createDomain(conn, pool, name, setSMBIOS(smbios))
		if err != nil {
			logrus.WithError(err).Fatal("error creating domain")
		}

		wg.Add(1)

		logrus.Info("waiting for VM to finish provisioning")
		wg.Wait()
	},
}

func init() {
	debianCmd.Flags().StringVarP(&debianRelease, "release", "r", "bookworm", "debian release to install. Options: bookworm (default), trixie, sid")
	debianCmd.Flags().StringArrayVarP(&debianPackages, "packages", "p", nil, "apt packages to install")

	rootCmd.AddCommand(&debianCmd)
}

func debianGetImageURL(release string, format pools.ImageFormat) (string, error) {
	imageSuffix, ok := debianFilenameSuffix[format]
	if !ok {
		return "", fmt.Errorf("unexpected image format %s from storage pool", format)
	}

	diskImageURLPrefix := fmt.Sprintf("https://cloud.debian.org/images/cloud/%s/daily/latest", release)

	// find image URL + hash
	shaURL := fmt.Sprintf("%s/SHA512SUMS", diskImageURLPrefix)
	shaResp, err := http.Get(shaURL)
	if err != nil {
		return "", err
	}
	defer shaResp.Body.Close()

	shas, err := io.ReadAll(shaResp.Body)
	if err != nil {
		return "", err
	}

	if shaResp.StatusCode != http.StatusOK {
		logrus.WithFields(logrus.Fields{
			"status": shaResp.Status,
			"url":    shaURL,
			"resp":   string(shas),
		}).Fatal("failed to get image hash")
	}

	for _, line := range strings.Split(string(shas), "\n") {
		hash, filename, ok := strings.Cut(strings.TrimSpace(line), "  ")
		if !ok {
			continue
		}

		if !strings.HasSuffix(filename, imageSuffix) {
			continue
		}

		return fmt.Sprintf("%s/%s#hash=sha512:%s", diskImageURLPrefix, filename, hash), nil
	}

	return "", fmt.Errorf("unable to find hash of image in %s", shaURL)
}