package main

import (
	"context"
	"fmt"
	"github.com/charmbracelet/bubbles/progress"
	"github.com/charmbracelet/bubbles/textinput"
	"github.com/charmbracelet/bubbles/viewport"
	tea "github.com/charmbracelet/bubbletea"
	"github.com/charmbracelet/lipgloss"
	"github.com/charmbracelet/wish"
	bm "github.com/charmbracelet/wish/bubbletea"
	lm "github.com/charmbracelet/wish/logging"
	"github.com/gliderlabs/ssh"
	"github.com/muesli/termenv"
	"io/ioutil"
	"log"
	"math"
	"os"
	"os/signal"
	"strconv"
	"strings"
	"syscall"
	"time"
	"unicode/utf8"
)

var (
	titleStyle = func() lipgloss.Style {
		b := lipgloss.RoundedBorder()
		b.Right = "├"
		return lipgloss.NewStyle().BorderStyle(b).Padding(0, 1)
	}()

	infoStyle = func() lipgloss.Style {
		b := lipgloss.RoundedBorder()
		b.Left = "┤"
		return titleStyle.Copy().BorderStyle(b)
	}()
)

func main() {
	log.Println("Welcome on Cemantics!")

	s, err := wish.NewServer(
		wish.WithAddress(fmt.Sprintf("%s:%d", "0.0.0.0", 2200)),
		wish.WithAddress(fmt.Sprintf("%s:%d", "[::]", 2200)),
		wish.WithHostKeyPath(".ssh/term_info_ed25519"),
		wish.WithMiddleware(
			lm.Middleware(),
			bm.MiddlewareWithColorProfile(teaHandler, termenv.TrueColor),
		),
	)
	if err != nil {
		log.Fatalln(err)
	}

	done := make(chan os.Signal, 1)
	signal.Notify(done, os.Interrupt, syscall.SIGINT, syscall.SIGTERM)
	log.Printf("Starting SSH server on %s:%d", "[::]", 2200)
	go func() {
		if err = s.ListenAndServe(); err != nil {
			log.Fatalln(err)
		}
	}()

	<-done
	log.Println("Stopping SSH server")
	ctx, cancel := context.WithTimeout(context.Background(), 30*time.Second)
	defer func() { cancel() }()
	if err := s.Shutdown(ctx); err != nil {
		log.Fatalln(err)
	}
}

func teaHandler(s ssh.Session) (tea.Model, []tea.ProgramOption) {
	_, _, active := s.Pty()
	if !active {
		fmt.Println("no active terminal, skipping")
		return nil, nil
	}
	log.Println(s.RemoteAddr())

	ti := textinput.New()
	ti.Placeholder = "Choisissez un mot ..."
	ti.Focus()
	ti.CharLimit = 26
	ti.Width = 26

	content, err := ioutil.ReadFile("cemantix.txt")

	if err != nil {
		log.Printf("Error while opening cemantix.txt: %s", err)
		return nil, nil
	}

	var dictionary = map[string]word{}

	for i, line := range strings.Split(string(content), "\n") {
		if line == "" || line[0] == '#' {
			continue
		}

		s := strings.SplitN(line, " ", 2)
		w := s[0]
		dist, _ := strconv.ParseFloat(s[1], 64)
		dictionary[w] = word{w, dist, 1000 - i}
	}

	m := model{
		err:         nil,
		dictionary:  dictionary,
		textInput:   ti,
		username:    s.User(),
		ip:          s.RemoteAddr().String(),
		words:       []word{},
		progressBar: progress.New(progress.WithScaledGradient("#FF7CCB", "#FDFF8C")),
	}
	return m, []tea.ProgramOption{tea.WithAltScreen(), tea.WithMouseCellMotion()}
}

type errMsg error

type word struct {
	content  string
	distance float64
	ranking  int
}

type model struct {
	ready         bool
	err           error
	dictionary    map[string]word
	textInput     textinput.Model
	username      string
	ip            string
	words         []word
	wordsViewport viewport.Model
	progressBar   progress.Model
	maxLength     int
	lastWord      string
}

func (m model) Init() tea.Cmd {
	return textinput.Blink
}

func (m model) Update(msg tea.Msg) (tea.Model, tea.Cmd) {
	var cmd tea.Cmd
	var cmds []tea.Cmd

	switch msg := msg.(type) {
	case tea.KeyMsg:
		switch msg.Type {
		case tea.KeyEnter:
			return m.InputWord()
		case tea.KeyCtrlC, tea.KeyEsc:
			return m, tea.Quit
		}
	case tea.WindowSizeMsg:
		headerHeight := lipgloss.Height(m.headerView())
		footerHeight := lipgloss.Height(m.footerView())
		verticalMarginHeight := headerHeight + footerHeight

		if !m.ready {
			m.wordsViewport = viewport.New(msg.Width, msg.Height-verticalMarginHeight)
			m.wordsViewport.YPosition = headerHeight
			m.ready = true
		} else {
			m.wordsViewport.Width = msg.Width
			m.wordsViewport.Height = msg.Height - verticalMarginHeight
		}

		lineWidth := lipgloss.Width(fmt.Sprintf(
			"* %s %s %s %4d ",
			strings.Repeat(" ", m.maxLength),
			"-100.00",
			"    ",
			42,
		))
		m.progressBar.Width = msg.Width - lineWidth
		m.wordsViewport.SetContent(m.wordsView())

	case errMsg:
		m.err = msg
		return m, nil
	}

	m.wordsViewport, cmd = m.wordsViewport.Update(msg)
	cmds = append(cmds, cmd)
	m.textInput, cmd = m.textInput.Update(msg)
	cmds = append(cmds, cmd)

	return m, tea.Batch(cmds...)
}

func InsertWord(arr []word, w word) []word {
	if len(arr) == 0 {
		return append(arr, w)
	}
	w2 := arr[len(arr)-1]
	if w.content == w2.content {
		// The word is already present
		return arr
	}
	if w.distance < w2.distance {
		return append(arr, w)
	}
	return append(InsertWord(arr[:len(arr)-1], w), w2)
}

func (m model) InputWord() (model, tea.Cmd) {
	input := m.textInput.Value()

	w, found := m.dictionary[input]

	if !found {
		m.err = fmt.Errorf("le mot %s n'existe pas", input)
		m.textInput.SetValue("")
		m.textInput.CursorStart()
		return m, nil
	}

	m.lastWord = input
	if utf8.RuneCountInString(input) > m.maxLength {
		m.maxLength = utf8.RuneCountInString(input)
	}
	m.words = InsertWord(m.words, w)

	lineWidth := lipgloss.Width(fmt.Sprintf(
		"* %s %s %s %5d ",
		strings.Repeat(" ", m.maxLength),
		"-00.00",
		"    ",
		1000,
	))
	m.progressBar.Width = m.wordsViewport.Width - lineWidth

	m.wordsViewport.SetContent(m.wordsView())

	m.textInput.SetValue("")
	m.textInput.CursorStart()
	m.err = nil

	return m, nil
}

func (w word) View(m model) string {
	var emoji string
	if w.ranking == 1000 {
		emoji = "\U0001F973"
	} else if w.ranking == 999 {
		emoji = "\U0001F631"
	} else if w.ranking >= 990 {
		emoji = "\U0001F525"
	} else if w.ranking >= 900 {
		emoji = "\U0001F975"
	} else if w.ranking >= 1 {
		emoji = "\U0001F60E"
	} else {
		emoji = "\U0001F976"
	}

	var progressBar string
	var ranking string = "    "
	if w.ranking > 0 {
		progressBar = m.progressBar.ViewAs(float64(w.ranking) / 1000.0)
		ranking = fmt.Sprintf("%4d", w.ranking)
	}

	distStr := fmt.Sprintf("%.02f", w.distance)
	if math.Abs(w.distance) < 10 {
		distStr = " " + distStr
	}
	if w.distance >= 0 {
		distStr = " " + distStr
	}
	if math.Abs(w.distance) < 100 {
		distStr = " " + distStr
	}

	return fmt.Sprintf(
		"* %s %s %s %s %s\n",
		w.content+strings.Repeat(" ", m.maxLength-utf8.RuneCountInString(w.content)),
		distStr,
		emoji,
		ranking,
		progressBar,
	)
}

func (m model) headerView() string {
	var err string

	if m.err != nil {
		err = fmt.Sprintf("Erreur : %s", m.err)
	}

	msg := fmt.Sprintf(
		"Veuillez choisir un mot :\n\n%s\n\nDernier mot essayé : %s%s\n%s\n\n",
		m.textInput.View(),
		m.lastWord,
		strings.Repeat(" ", 26),
		err,
	)

	title := titleStyle.Render("Mots précédents")
	line := strings.Repeat("─", int(math.Max(0, float64(m.wordsViewport.Width-lipgloss.Width(title)))))
	msg += lipgloss.JoinHorizontal(lipgloss.Center, title, line)

	return msg
}

func (m model) wordsView() string {
	var content string
	for _, w := range m.words {
		content += w.View(m)
	}
	return content
}

func (m model) footerView() string {
	info := infoStyle.Render(fmt.Sprintf("%3.f%%", m.wordsViewport.ScrollPercent()*100))
	line := strings.Repeat("─", int(math.Max(0, float64(m.wordsViewport.Width-lipgloss.Width(info)))))
	credits := "Inspiration : https://cemantix.herokuapp.com/ (@enigmathix)\n" +
		"Sources : https://gitlab.crans.org/ynerant/cemantix-charm (@ynerant)\n" +
		"Données : Wikipédia France (+ Word2Vec), Grammalecte"
	return lipgloss.JoinVertical(lipgloss.Center, lipgloss.JoinHorizontal(lipgloss.Center, line, info), credits)
}

func (m model) View() string {
	if !m.ready {
		return "\n\tInitialisation…"
	}

	return fmt.Sprintf("%s\n%s\n%s", m.headerView(), m.wordsViewport.View(), m.footerView())
}