/*
sgodup -- File deduplication utility
Copyright (C) 2020-2023 Sergey Matveev <stargrave@stargrave.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, version 3 of the License.

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 main

import (
	"fmt"
	"os"
	"time"

	"github.com/dustin/go-humanize"
)

const (
	ESC = 27
)

var LineClear = fmt.Sprintf("%c[%dA%c[2K", ESC, 2, ESC)

type Progress struct {
	fullFiles   int64
	fullSize    uint64
	fullFilesS  string
	fullSizeS   string
	suffixFiles string
	suffixSize  string
	stop        chan struct{}
}

func NewProgress(
	fullFiles int,
	fullSize int64,
	files *int,
	size *int64,
	suffixFiles, suffixSize string,
) Progress {
	p := Progress{
		int64(fullFiles),
		uint64(fullSize),
		humanize.Comma(int64(fullFiles)),
		humanize.IBytes(uint64(fullSize)),
		suffixFiles,
		suffixSize,
		make(chan struct{}, 0),
	}
	go p.Run(files, size)
	return p
}

func (p Progress) Log(prefix string, files int64, size uint64) {
	percentageFiles := int64(0)
	if p.fullFiles > 0 {
		percentageFiles = 100 * files / p.fullFiles
	}
	percentageSize := uint64(0)
	if p.fullSize > 0 {
		percentageSize = 100 * size / p.fullSize
	}
	now := time.Now().Format("2006/01/02 15:04:05")
	fmt.Fprintf(
		os.Stderr,
		"%s%s %s / %s (%d%%) files%s\n%s %s / %s (%d%%)%s\n",
		prefix,
		now, humanize.Comma(files), p.fullFilesS, percentageFiles, p.suffixFiles,
		now, humanize.IBytes(size), p.fullSizeS, percentageSize, p.suffixSize,
	)
}

func (p Progress) Run(files *int, size *int64) {
	p.Log("", 0, 0)
	ticker := time.NewTicker(250 * time.Millisecond)
	for {
		select {
		case <-ticker.C:
			p.Log(LineClear, int64(*files), uint64(*size))
		case <-p.stop:
			ticker.Stop()
			p.Log(LineClear, int64(*files), uint64(*size))
			close(p.stop)
			return
		}
	}
}

func (p Progress) Stop() {
	p.stop <- struct{}{}
	<-p.stop
}