// mmc -- Mattermost client
// Copyright (C) 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 Affero General Public License as
// published by the Free Software Foundation, either 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 Affero General Public License for more details.
//
// You should have received a copy of the GNU Affero General Public License
// along with this program.  If not, see <http://www.gnu.org/licenses/>.

package main

import (
	"flag"
	"fmt"
	"io"
	"log"
	"os"
	"path"
	"time"

	"github.com/mattermost/mattermost-server/v6/model"
	"go.cypherpunks.ru/recfile"
	"go.stargrave.org/mmc"
)

func printPost(m map[string][]string) {
	var tag string
	if len(m["Event"]) > 0 {
		switch m["Event"][0] {
		case model.WebsocketEventPostEdited:
			tag += "[EDIT] "
		case model.WebsocketEventPostDeleted:
			tag += "[DEL] "
		}
	}
	fmt.Printf("\a%s <%s> %s%s\n", m["Created"][0], m["Sender"][0], tag, m["Text"][0])
	tag += "[FILE] "
	for i, fileId := range m["File"] {
		fmt.Printf(
			"\a%s <%s> %s%s (%s)\n",
			m["Created"][0], m["Sender"][0], tag, fileId, m["FileName"][i],
		)
	}
}

func main() {
	lastNum := flag.Int("last", 10, "Only that number of messages")
	flag.Parse()
	where := flag.Arg(0)
	lockPth := path.Join(where, mmc.OutRecLock)
	unlock, err := mmc.Lock(lockPth)
	if err != nil {
		log.Fatalln(err)
	}
	pth := path.Join(where, mmc.OutRec)
	fd, err := os.Open(pth)
	if err != nil {
		log.Fatalln(err)
	}

	r := recfile.NewReader(fd)
	ms := make([]map[string][]string, 0)
	for {
		m, err := r.NextMapWithSlice()
		if err != nil {
			if err == io.EOF {
				break
			}
			log.Fatalln(err)
		}
		ms = append(ms, m)
	}
	unlock()
	if len(ms) > *lastNum {
		ms = ms[len(ms)-*lastNum:]
	}
	for _, m := range ms {
		printPost(m)
	}
	fi, err := fd.Stat()
	if err != nil {
		log.Fatalln(err)
	}
	size := fi.Size()
	for {
		time.Sleep(mmc.SleepTime)
		fi, err = os.Stat(pth)
		if fi.Size() == size {
			continue
		}
		unlock, err = mmc.Lock(lockPth)
		if err != nil {
			log.Fatalln(err)
		}
		r = recfile.NewReader(fd)
		for {
			m, err := r.NextMapWithSlice()
			if err != nil {
				if err == io.EOF {
					break
				}
				log.Fatalln(err)
			}
			printPost(m)
		}
		size = fi.Size()
		unlock()
	}
}