// Copyright 2022 The Casdoor Authors. 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 util

import (
	"path"
	"runtime"
	"time"

	"github.com/go-git/go-git/v5"
	"github.com/go-git/go-git/v5/plumbing"
	"github.com/go-git/go-git/v5/plumbing/object"
	"github.com/shirou/gopsutil/cpu"
	"github.com/shirou/gopsutil/mem"
)

// get cpu usage
func GetCpuUsage() ([]float64, error) {
	usage, err := cpu.Percent(time.Second, true)
	return usage, err
}

var fileDate, version string

// get memory usage
func GetMemoryUsage() (uint64, uint64, error) {
	virtualMem, err := mem.VirtualMemory()
	if err != nil {
		return 0, 0, err
	}

	var m runtime.MemStats
	runtime.ReadMemStats(&m)

	return m.TotalAlloc, virtualMem.Total, nil
}

// get github current commit and repo release version
func GetGitRepoVersion() (string, string, error) {
	_, filename, _, _ := runtime.Caller(0)
	rootPath := path.Dir(path.Dir(filename))
	r, err := git.PlainOpen(rootPath)
	if err != nil {
		return "", "", err
	}
	ref, err := r.Head()
	if err != nil {
		return "", "", err
	}
	tags, err := r.Tags()
	if err != nil {
		return "", "", err
	}
	tagMap := make(map[plumbing.Hash]string)
	err = tags.ForEach(func(t *plumbing.Reference) error {
		// This technique should work for both lightweight and annotated tags.
		revHash, err := r.ResolveRevision(plumbing.Revision(t.Name()))
		if err != nil {
			return err
		}
		tagMap[*revHash] = t.Name().Short()
		return nil
	})
	if err != nil {
		return "", "", err
	}

	cIter, err := r.Log(&git.LogOptions{From: ref.Hash()})

	releaseVersion := ""
	// iterates over the commits
	err = cIter.ForEach(func(c *object.Commit) error {
		tag, ok := tagMap[c.Hash]
		if ok {
			if releaseVersion == "" {
				releaseVersion = tag
			}
		}
		return nil
	})
	if err != nil {
		return "", "", err
	}

	return ref.Hash().String(), releaseVersion, nil
}