// Copyright 2022 Linka Cloud  All rights reserved.
//
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
//     http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.

package main

import (
	"fmt"
	"os"
	"strings"

	"github.com/sirupsen/logrus"
	"github.com/spf13/pflag"

	"go.linka.cloud/d2vm"
)

var (
	output           = "disk0.qcow2"
	size             = "1G"
	password         = ""
	force            = false
	raw              bool
	pull             = false
	cmdLineExtra     = ""
	containerDiskTag = ""
	push             bool
	networkManager   string
	bootloader       string
	splitBoot        bool
	bootSize         uint64
	bootFS           string
	luksPassword     string

	keepCache bool
	platform  string
)

func validateFlags() error {
	switch platform {
	case "linux/amd64":
		if bootloader == "" {
			bootloader = "syslinux"
		}
	case "linux/arm64", "linux/aarch64":
		platform = "linux/arm64"
		if bootloader == "" {
			bootloader = "grub-efi"
		}
		if bootloader != "grub-efi" {
			return fmt.Errorf("unsupported bootloader for platform %s: %s, only grub-efi is supported", platform, bootloader)
		}
	default:
		return fmt.Errorf("unexpected platform: %s, supported platforms: linux/amd64, linux/arm64", platform)
	}
	if luksPassword != "" && !splitBoot {
		logrus.Warnf("luks password is set: enabling split boot")
		splitBoot = true
	}
	if bootFS := d2vm.BootFS(bootFS); bootFS != "" && !bootFS.IsSupported() {
		return fmt.Errorf("invalid boot filesystem: %s", bootFS)
	}
	if bootFS != "" && !splitBoot {
		logrus.Warnf("boot filesystem is set: enabling split boot")
		splitBoot = true
	}
	efi := bootloader == "grub-efi" || bootloader == "grub"
	if efi && !splitBoot {
		logrus.Warnf("grub-efi bootloader is set: enabling split boot")
		splitBoot = true
	}
	if efi && bootFS != "" && bootFS != "fat32" {
		return fmt.Errorf("grub-efi bootloader only supports fat32 boot filesystem")
	}
	if efi && bootFS == "" {
		logrus.Warnf("grub-efi bootloader is set: enabling fat32 boot filesystem")
		bootFS = "fat32"
	}
	if push && tag == "" {
		return fmt.Errorf("tag is required when pushing container disk image")
	}
	if _, err := os.Stat(output); err == nil || !os.IsNotExist(err) {
		if !force {
			return fmt.Errorf("%s already exists", output)
		}
	}
	return nil
}

func buildFlags() *pflag.FlagSet {
	flags := pflag.NewFlagSet("build", pflag.ExitOnError)
	flags.StringVarP(&output, "output", "o", output, "The output image, the extension determine the image format, raw will be used if none. Supported formats: "+strings.Join(d2vm.OutputFormats(), " "))
	flags.StringVarP(&password, "password", "p", "", "Optional root user password")
	flags.StringVarP(&size, "size", "s", "10G", "The output image size")
	flags.BoolVar(&force, "force", false, "Override output qcow2 image")
	flags.StringVar(&cmdLineExtra, "append-to-cmdline", "", "Extra kernel cmdline arguments to append to the generated one")
	flags.StringVar(&networkManager, "network-manager", "", "Network manager to use for the image: none, netplan, ifupdown")
	flags.BoolVar(&raw, "raw", false, "Just convert the container to virtual machine image without installing anything more")
	flags.StringVarP(&containerDiskTag, "tag", "t", "", "Container disk Docker image tag")
	flags.BoolVar(&push, "push", false, "Push the container disk image to the registry")
	flags.BoolVar(&splitBoot, "split-boot", false, "Split the boot partition from the root partition")
	flags.Uint64Var(&bootSize, "boot-size", 100, "Size of the boot partition in MB")
	flags.StringVar(&bootFS, "boot-fs", "", "Filesystem to use for the boot partition, ext4 or fat32")
	flags.StringVar(&bootloader, "bootloader", "", "Bootloader to use: syslinux, grub, grub-bios, grub-efi, defaults to syslinux on amd64 and grub-efi on arm64")
	flags.StringVar(&luksPassword, "luks-password", "", "Password to use for the LUKS encrypted root partition. If not set, the root partition will not be encrypted")
	flags.BoolVar(&keepCache, "keep-cache", false, "Keep the images after the build")
	flags.StringVar(&platform, "platform", d2vm.Arch, "Platform to use for the container disk image, linux/arm64 and linux/arm64 are supported")
	flags.BoolVar(&pull, "pull", false, "Always pull docker image")
	return flags
}