/*
Copyright 2018 The Kubernetes Authors.

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 kube

import (
	"os"
	"path/filepath"
	"strings"

	"sigs.k8s.io/kind/pkg/errors"
	"sigs.k8s.io/kind/pkg/exec"
	"sigs.k8s.io/kind/pkg/log"

	"k8s.io/apimachinery/pkg/util/version"
)

// TODO(bentheelder): plumb through arch

// dockerBuilder implements Bits for a local docker-ized make / bash build
type dockerBuilder struct {
	kubeRoot string
	arch     string
	logger   log.Logger
}

var _ Builder = &dockerBuilder{}

// NewDockerBuilder returns a new Bits backed by the docker-ized build,
// given kubeRoot, the path to the kubernetes source directory
func NewDockerBuilder(logger log.Logger, kubeRoot, arch string) (Builder, error) {
	return &dockerBuilder{
		kubeRoot: kubeRoot,
		arch:     arch,
		logger:   logger,
	}, nil
}

// Build implements Bits.Build
func (b *dockerBuilder) Build() (Bits, error) {
	// cd to k8s source
	cwd, err := os.Getwd()
	if err != nil {
		return nil, err
	}
	// make sure we cd back when done
	defer func() {
		// TODO(bentheelder): set return error?
		_ = os.Chdir(cwd)
	}()
	if err := os.Chdir(b.kubeRoot); err != nil {
		return nil, err
	}

	// capture version info
	sourceVersionRaw, err := sourceVersion(b.kubeRoot)
	if err != nil {
		return nil, err
	}

	// check for version specific workarounds
	ver, err := version.ParseSemantic(sourceVersionRaw)
	if err != nil {
		return nil, errors.Wrap(err, "failed to parse source version")
	}
	// leverage in-tree-cloud-provider-free builds by default
	// https://github.com/kubernetes/kubernetes/pull/80353
	// leverage dockershim free builds by default
	// https://github.com/kubernetes/kubernetes/pull/87746
	goflags := "GOFLAGS=-tags=providerless,dockerless"
	if ver.LessThan(version.MustParseSemantic("v1.19.0")) {
		goflags = "GOFLAGS=-tags=providerless"
	}

	// we will pass through the environment variables, prepending defaults
	// NOTE: if env are specified multiple times the last one wins
	env := append(
		[]string{
			// ensure the build isn't especially noisy..
			"KUBE_VERBOSE=0",
			// we don't want to build these images as we don't use them ...
			"KUBE_BUILD_HYPERKUBE=n",
			"KUBE_BUILD_CONFORMANCE=n",
			// build for the host platform
			"KUBE_BUILD_PLATFORMS=" + dockerBuildOsAndArch(b.arch),
			// pass goflags
			goflags,
		},
		os.Environ()...,
	)
	// build binaries
	what := []string{
		// binaries we use directly
		"cmd/kubeadm",
		"cmd/kubectl",
		"cmd/kubelet",
	}
	cmd := exec.Command(
		"build/run.sh",
		"make", "all", "WHAT="+strings.Join(what, " "),
	).SetEnv(env...)
	exec.InheritOutput(cmd)
	if err := cmd.Run(); err != nil {
		return nil, errors.Wrap(err, "failed to build binaries")
	}

	// build images
	cmd = exec.Command("make", "quick-release-images").SetEnv(env...)
	exec.InheritOutput(cmd)
	if err := cmd.Run(); err != nil {
		return nil, errors.Wrap(err, "failed to build images")
	}

	binDir := filepath.Join(b.kubeRoot,
		"_output", "dockerized", "bin", "linux", b.arch,
	)
	imageDir := filepath.Join(b.kubeRoot,
		"_output", "release-images", b.arch,
	)

	return &bits{
		binaryPaths: []string{
			filepath.Join(binDir, "kubeadm"),
			filepath.Join(binDir, "kubelet"),
			filepath.Join(binDir, "kubectl"),
		},
		imagePaths: []string{
			filepath.Join(imageDir, "kube-apiserver.tar"),
			filepath.Join(imageDir, "kube-controller-manager.tar"),
			filepath.Join(imageDir, "kube-scheduler.tar"),
			filepath.Join(imageDir, "kube-proxy.tar"),
		},
		version: sourceVersionRaw,
	}, nil
}

func dockerBuildOsAndArch(arch string) string {
	return "linux/" + arch
}
