package main

import (
	"fmt"
	"log"
	"strings"

	"github.com/jroimartin/gocui"
)

var messages []string
var users = []string{"Alice", "Bob", "Charlie"}

func layout(g *gocui.Gui) error {
	maxX, maxY := g.Size()

	if v, err := g.SetView("users", 0, 0, 20, maxY-1); err != nil {
		if err != gocui.ErrUnknownView {
			return err
		}
		v.Title = "Users"
		v.Clear()
		for _, u := range users {
			fmt.Fprintln(v, u)
		}
	}

	if v, err := g.SetView("chat", 21, 0, maxX-1, maxY-5); err != nil {
		if err != gocui.ErrUnknownView {
			return err
		}
		v.Title = "Chat"
		v.Wrap = true
		updateChatView(v)
	}

	if v, err := g.SetView("input", 21, maxY-4, maxX-1, maxY-1); err != nil {
		if err != gocui.ErrUnknownView {
			return err
		}
		v.Title = "Type your message"
		v.Editable = true
		v.Wrap = true
		if _, err := g.SetCurrentView("input"); err != nil {
			return err
		}
	}

	return nil
}
func updateChatView(v *gocui.View) {
	v.Clear()
	for _, msg := range messages {
		fmt.Fprintln(v, msg)
	}
}

func sendMessage(g *gocui.Gui, v *gocui.View) error {
	input := strings.TrimSpace(v.Buffer())
	v.Clear()
	v.SetCursor(0, 0)
	v.SetOrigin(0, 0)

	if input != "" {
		messages = append(messages, "You: "+input)
		if chatView, err := g.View("chat"); err == nil {
			updateChatView(chatView)
		}
	}
	v.Clear()
	v.SetCursor(0, 0)
	return nil
}

func keybindings(g *gocui.Gui) error {
	// Ctrl+C to quit
	if err := g.SetKeybinding("", gocui.KeyCtrlC, gocui.ModNone, quit); err != nil {
		return err
	}

	// Enter to send message
	// Enter adds a new line (multiline input)
	if err := g.SetKeybinding("input", gocui.KeyArrowDown, gocui.ModNone, insertNewline); err != nil {
		return err
	}

	// Ctrl+Enter sends the message
	if err := g.SetKeybinding("input", gocui.KeyEnter, gocui.ModNone, sendMessage); err != nil {
		return err
	}

	return nil
}

func insertNewline(g *gocui.Gui, v *gocui.View) error {
	v.EditNewLine()
	return nil
}

func quit(g *gocui.Gui, v *gocui.View) error {
	return gocui.ErrQuit
}

func main() {
	g, err := gocui.NewGui(gocui.OutputNormal)
	if err != nil {
		log.Panicln(err)
	}
	defer g.Close()

	g.SetManagerFunc(layout)

	if err := keybindings(g); err != nil {
		log.Panicln(err)
	}

	if err := g.MainLoop(); err != nil && err != gocui.ErrQuit {
		log.Panicln(err)
	}
}