// Copyright 2025 The TCell Authors
//
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
//    http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.

package main

import (
	"fmt"
	"os"

	"github.com/gdamore/tcell/v3"
	"github.com/gdamore/tcell/v3/color"
)

func displayHelloWorld(s tcell.Screen) {
	w, h := s.Size()
	s.Clear()
	s.SetTitle("Hello World")
	x := w/2 - 7
	y := h/2 - 1
	style := tcell.StyleDefault.Foreground(color.CadetBlue.TrueColor()).Background(color.White)
	s.PutStrStyled(x, y, "Hello, World!", style)
	x = w/2 - 9
	y += 2
	s.PutStr(x, y, "Press ")
	x += len("Press ")

	s.PutStrStyled(x, y, "ESC", tcell.StyleDefault.Bold(true))
	x += len("ESC")
	s.PutStr(x, y, " to exit.")
	s.Show()
}

// This program just prints "Hello, World!".  Press ESC to exit.
func main() {

	s, e := tcell.NewScreen()
	if e != nil {
		fmt.Fprintf(os.Stderr, "%v\n", e)
		os.Exit(1)
	}
	if e := s.Init(); e != nil {
		fmt.Fprintf(os.Stderr, "%v\n", e)
		os.Exit(1)
	}

	defStyle := tcell.StyleDefault.
		Background(color.Black).
		Foreground(color.White)
	s.SetStyle(defStyle)

	displayHelloWorld(s)

	for {
		ev := <-s.EventQ()
		switch ev := ev.(type) {
		case *tcell.EventResize:
			s.Sync()
			displayHelloWorld(s)
		case *tcell.EventKey:
			if ev.Key() == tcell.KeyEscape {
				s.Fini()
				return
			}
		}
	}
}