// Copyright 2014 The gocui Authors. All rights reserved.
// Use of this source code is governed by a BSD-style
// license that can be found in the LICENSE file.

package main

import (
	"fmt"
	"io"
	"io/ioutil"
	"log"
	"strings"

	"github.com/jroimartin/gocui"
)

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

func keybindings(g *gocui.Gui) error {
	if err := g.SetKeybinding("", gocui.KeyCtrlC, gocui.ModNone, quit); err != nil {
		return err
	}
	if err := g.SetKeybinding("main", gocui.KeyCtrlS, gocui.ModNone, save); err != nil {
		return err
	}
	if err := g.SetKeybinding("main", gocui.KeyCtrlW, gocui.ModNone, saveVisual); err != nil {
		return err
	}
	return nil
}

func save(g *gocui.Gui, v *gocui.View) error {
	f, err := ioutil.TempFile("", "gocui_demo_internal")
	if err != nil {
		return err
	}
	defer f.Close()

	vb := v.Buffer()
	if _, err := io.Copy(f, strings.NewReader(vb)); err != nil {
		return err
	}
	return nil
}

func saveVisual(g *gocui.Gui, v *gocui.View) error {
	f, err := ioutil.TempFile("", "gocui_demo_visual")
	if err != nil {
		return err
	}
	defer f.Close()

	vb := v.ViewBuffer()
	if _, err := io.Copy(f, strings.NewReader(vb)); err != nil {
		return err
	}
	return nil
}

func layout(g *gocui.Gui) error {
	maxX, maxY := g.Size()
	if v, err := g.SetView("main", 0, 0, maxX-1, maxY-1); err != nil {
		if err != gocui.ErrUnknownView {
			return err
		}
		b, err := ioutil.ReadFile("Mark.Twain-Tom.Sawyer.txt")
		if err != nil {
			panic(err)
		}
		fmt.Fprintf(v, "%s", b)
		v.Editable = true
		v.Wrap = true
		if err := g.SetCurrentView("main"); err != nil {
			return err
		}
	}
	return nil
}

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

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

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