// Copyright © 2019 Ettore Di Giacinto <mudler@gentoo.org>
//
// This program is free software; you can redistribute it and/or modify
// it under the terms of the GNU General Public License as published by
// the Free Software Foundation; either version 2 of the License, or
// (at your option) any later version.
//
// This program is distributed in the hope that it will be useful,
// but WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
// GNU General Public License for more details.
//
// You should have received a copy of the GNU General Public License along
// with this program; if not, see <http://www.gnu.org/licenses/>.

package backend

import (
	"encoding/json"
	"os/exec"

	"github.com/mudler/luet/pkg/compiler"
	. "github.com/mudler/luet/pkg/logger"

	"github.com/pkg/errors"
)

type SimpleImg struct{}

func NewSimpleImgBackend() compiler.CompilerBackend {
	return &SimpleImg{}
}

// TODO: Missing still: labels, and build args expansion
func (*SimpleImg) BuildImage(opts compiler.CompilerBackendOptions) error {
	name := opts.ImageName
	path := opts.SourcePath
	dockerfileName := opts.DockerFileName

	buildarg := []string{"build", "-t", name, path, "-f ", dockerfileName}
	Spinner(22)
	Debug("Building image "+name+" - running img with: ", buildarg)
	out, err := exec.Command("img", buildarg...).CombinedOutput()
	if err != nil {
		return errors.Wrap(err, "Failed building image: "+string(out))
	}
	SpinnerStop()
	Info(out)
	return nil
}

func (*SimpleImg) RemoveImage(opts compiler.CompilerBackendOptions) error {
	name := opts.ImageName
	buildarg := []string{"rm", name}
	Spinner(22)
	out, err := exec.Command("img", buildarg...).CombinedOutput()
	if err != nil {
		return errors.Wrap(err, "Failed building image: "+string(out))
	}
	SpinnerStop()
	Info(out)
	return nil
}

func (s *SimpleImg) ImageDefinitionToTar(opts compiler.CompilerBackendOptions) error {
	if err := s.BuildImage(opts); err != nil {
		return errors.Wrap(err, "Failed building image")
	}
	if err := s.ExportImage(opts); err != nil {
		return errors.Wrap(err, "Failed exporting image")
	}
	if err := s.RemoveImage(opts); err != nil {
		return errors.Wrap(err, "Failed removing image")
	}
	return nil
}

func (*SimpleImg) ExportImage(opts compiler.CompilerBackendOptions) error {
	name := opts.ImageName
	path := opts.Destination
	buildarg := []string{"save", name, "-o", path}
	Spinner(22)
	Debug("Saving image "+name+" - running img with: ", buildarg)
	out, err := exec.Command("img", buildarg...).CombinedOutput()
	if err != nil {
		return errors.Wrap(err, "Failed building image: "+string(out))
	}
	SpinnerStop()
	Info(out)
	return nil
}

// TODO: Dup in docker, refactor common code in helpers for shared parts

// TODO: Use container-diff (https://github.com/GoogleContainerTools/container-diff) for checking out layer diffs
// Changes uses container-diff (https://github.com/GoogleContainerTools/container-diff) for retrieving out layer diffs
func (*SimpleImg) Changes(fromImage, toImage string) ([]compiler.ArtifactLayer, error) {
	diffargs := []string{"diff", fromImage, toImage, "--type=file", "-j"}
	Spinner(22)
	defer SpinnerStop()

	out, err := exec.Command("container-diff", diffargs...).CombinedOutput()
	if err != nil {
		return []compiler.ArtifactLayer{}, errors.Wrap(err, "Failed Resolving layer diffs: "+string(out))
	}

	var diffs []compiler.ArtifactLayer

	err = json.Unmarshal(out, &diffs)
	if err != nil {
		return []compiler.ArtifactLayer{}, errors.Wrap(err, "Failed unmarshalling json response: "+string(out))
	}
	return diffs, nil
}