/*
Copyright 2021 The KubeVela 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 cli

import (
	"bufio"
	"bytes"
	"context"
	"encoding/json"
	"fmt"
	"io"
	"log"
	"os"
	"strings"

	"github.com/pkg/errors"
	v1 "k8s.io/apimachinery/pkg/apis/meta/v1"
	"k8s.io/client-go/kubernetes"
	"k8s.io/client-go/util/jsonpath"
	"k8s.io/kubectl/pkg/cmd/get"
	"sigs.k8s.io/yaml"

	"github.com/oam-dev/kubevela/apis/core.oam.dev/v1beta1"
	"github.com/oam-dev/kubevela/pkg/utils/common"
)

func getPodNameForResource(ctx context.Context, clientSet kubernetes.Interface, resourceName string, resourceNamespace string) (string, error) {
	podList, err := clientSet.CoreV1().Pods(resourceNamespace).List(ctx, v1.ListOptions{})
	if err != nil {
		return "", err
	}
	var pods []string
	for _, p := range podList.Items {
		if strings.HasPrefix(p.Name, resourceName) {
			pods = append(pods, p.Name)
		}
	}
	if len(pods) < 1 {
		return "", fmt.Errorf("no pods found created by resource %s", resourceName)
	}
	return common.AskToChooseOnePods(pods)
}

// UserInput user input in command
type UserInput struct {
	Writer io.Writer
	Reader *bufio.Reader
}

// UserInputOptions user input options
type UserInputOptions struct {
	AssumeYes bool
}

// NewUserInput new user input util
func NewUserInput() *UserInput {
	return &UserInput{
		Writer: os.Stdout,
		Reader: bufio.NewReader(os.Stdin),
	}
}

// AskBool format the answer to bool type
func (ui *UserInput) AskBool(question string, opts *UserInputOptions) bool {
	fmt.Fprintf(ui.Writer, "%s (y/n)", question)
	if opts.AssumeYes {
		return true
	}
	line, err := ui.read()
	if err != nil {
		log.Fatal(err.Error())
	}
	if input := strings.TrimSpace(strings.ToLower(line)); input == "y" || input == "yes" {
		return true
	}
	return false
}

func (ui *UserInput) read() (string, error) {
	line, err := ui.Reader.ReadString('\n')
	if err != nil && !errors.Is(err, io.EOF) {
		return "", err
	}
	resultStr := strings.TrimSuffix(line, "\n")
	return resultStr, err
}

// formatApplicationString formats an Application to string in yaml/json/jsonpath for printing (without managedFields).
//
// format = "yaml" / "json" / "jsonpath={.field}"
func formatApplicationString(format string, app *v1beta1.Application) (string, error) {
	var ret string

	if format == "" {
		return "", fmt.Errorf("no format provided")
	}

	// No, we don't want managedFields, get rid of it.
	app.ManagedFields = nil

	switch format {
	case "yaml":
		b, err := yaml.Marshal(app)
		if err != nil {
			return "", err
		}
		ret = string(b)
	case "json":
		b, err := json.MarshalIndent(app, "", "  ")
		if err != nil {
			return "", err
		}
		ret = string(b)
	default:
		// format is not any of json/yaml/jsonpath, not supported
		if !strings.HasPrefix(format, "jsonpath") {
			return "", fmt.Errorf("output %s is not supported", format)
		}

		// format = jsonpath
		s := strings.Split(format, "=")
		if len(s) < 2 {
			return "", fmt.Errorf("jsonpath template format specified but no template given")
		}
		path, err := get.RelaxedJSONPathExpression(s[1])
		if err != nil {
			return "", err
		}

		jp := jsonpath.New("").AllowMissingKeys(true)
		err = jp.Parse(path)
		if err != nil {
			return "", err
		}

		buf := &bytes.Buffer{}
		err = jp.Execute(buf, app)
		if err != nil {
			return "", err
		}
		ret = buf.String()
	}

	return ret, nil
}