/*
 Orion --- Speech to text bot

   Copyright (c) 2022  Sameer Rahmani <lxsameer@gnu.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, either version 2 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 core

import (
	"fmt"
	"io"
	"io/ioutil"
	"log"
	"os"
	"path/filepath"
	"strings"
	"time"

	"github.com/asticode/go-asticoqui"
	"github.com/cryptix/wav"
	tele "gopkg.in/telebot.v3"
)

type Bot struct {
	Owner string
	StoragePath string
	VoiceStorage string
	Token string
	Model *asticoqui.Model
	ExtendedMetaData bool
	MaxResults uint
	db *DB
}

type Entry struct {
	FilePath string
	Transcript string
	Visited bool
}

func CreateBot(storage *string) (*Bot,error) {
	voiceStorage := filepath.Join(*storage, "voices")
	dbpath := filepath.Join(*storage, "db")
	err := os.MkdirAll(voiceStorage, 0750)

	if err != nil {
		return nil, err
	}

	db, err := CreateDB(&dbpath)

	if err != nil {
		return nil, err
	}

	return &Bot{
		Token: os.Getenv("BOT_TOKEN"),
		MaxResults: 5,
		ExtendedMetaData: false,
		StoragePath: *storage,
		VoiceStorage: voiceStorage,
		db: db,
	}, nil
}

func (bot *Bot) ShutDown() error {
	log.Println("[info] Shutting down...")
	bot.db.Close()
	bot.Model.Close()
	return nil
}

func (bot *Bot) StartBot() {
	pref := tele.Settings{
		Token:  bot.Token,
		// TODO: Move this to the config
		Poller: &tele.LongPoller{Timeout: 10 * time.Second},
	}

	b, err := tele.NewBot(pref)
	if err != nil {
		log.Fatal(err)
		return
	}

	b.Handle(tele.OnVoice, func(c tele.Context) error {
		if !bot.isOwner(c) {
			return nil
		}
		c.Send("...")
		log.Println("Got a voice!")
		filepath, err := bot.StoreVoice(c)
		if err != nil {
			return err
		}
		text, err := bot.ConvertToText(filepath)

		if err != nil {
			return err
		}

		s := strings.Join(*text, " ")

		err = bot.SaveTranscript(filepath, &s)

		if err != nil {
			return err
		}

		c.Send(s)
		fmt.Println(s)

		return nil
	})

	b.Start()
}

func (bot *Bot) SaveTranscript(filepath *string, text *string) error {
	return ioutil.WriteFile(*filepath + ".txt", []byte(*text), 0600)
}

func (bot *Bot) isOwner(c tele.Context) bool {
	me := c.Sender().Username
	log.Printf("[Info] User '%s' is trying to connect!", me)

	if me != bot.Owner {
		c.Send("Get lost!")
		return false
	}
	return true
}

func (bot *Bot) StoreVoice(c tele.Context) (*string, error) {
	v := c.Message().Voice.File
	time := c.Message().Time().Format("2006-01-02_15:04:05")

	path := filepath.Join(bot.VoiceStorage, time + ".ogg")
	wavePath := filepath.Join(bot.VoiceStorage, time + ".wav")

	if err := c.Bot().Download(&v, path); err != nil {
		return nil, err
	}

	if err := ConvertOggtoWav(&path, &wavePath); err != nil {
		return nil, err
	}

	if err := os.Remove(path); err != nil {
		return nil, err
	}

	return &wavePath, nil
}


func (bot *Bot) ConvertToText(voice *string) (*[]string, error) {
	// Stat audio
	i, err := os.Stat(*voice)

	if err != nil {
		return nil, fmt.Errorf("stating %s failed: %w", *voice, err)
	}

	// Open audio
	f, err := os.Open(*voice)
	if err != nil {
		return nil, fmt.Errorf("opening %s failed: %w", *voice, err)
	}

	// Create reader
	r, err := wav.NewReader(f, i.Size())
	if err != nil {
		return nil, fmt.Errorf("creating new reader failed: %w", err)
	}

	// Read
	var d []int16
	for {
		// Read sample
		s, err := r.ReadSample()
		if err == io.EOF {
			break
		} else if err != nil {
			return nil, fmt.Errorf("reading sample failed: %w", err)
		}

		// Append
		d = append(d, int16(s))
	}

	// Speech to text
	var results []string

	if bot.ExtendedMetaData {
		metadata, err := bot.Model.SpeechToTextWithMetadata(d, bot.MaxResults)
		if err != nil {
			return nil, fmt.Errorf("failed converting speech to text: ", err)
		}
		defer metadata.Close()
		results = metadataToStrings(metadata)
	} else {
		res, err := bot.Model.SpeechToText(d)
		if err != nil {
			return nil, fmt.Errorf("failed converting speech to text: ", err)
		}
		results = []string{res}
	}

	// for _, res := range results {
	// 	fmt.Println("Text:", res)
	// }
	return &results, nil
}


func metadataToStrings(m *asticoqui.Metadata) []string {
	results := make([]string, 0, m.NumTranscripts())
	for _, tr := range m.Transcripts() {
		var res string
		for _, tok := range tr.Tokens() {
			res += tok.Text()
		}
		res += fmt.Sprintf(" [%0.3f]", tr.Confidence())
		results = append(results, res)
	}
	return results
}