package main

import "github.com/nsf/termbox-go"
import "github.com/mattn/go-runewidth"
import "github.com/atotto/clipboard"

import "os"

type Point struct {
	X int
	Y int
}

func fill(lt Point, rb Point, sym rune) {
	if (rb.Y < lt.Y) || (rb.X < lt.X) {
		return
	}
	var x, y int
	for x = lt.X; x <= rb.X; x++ {
		for y = lt.Y; y <= rb.Y; y++ {
			content[x][y] = sym
		}
	}
}

func setContent(x, y int, msg string) {
	for _, c := range msg {
		content[x][y] = c
		x += runewidth.RuneWidth(c)
	}
}

var ltSel, rbSel Point

var content [][]rune

func clearSel() {
	ltSel = Point{-1, -1}
	rbSel = Point{-1, -1}
}

func redraw() {
	var w, h int = termbox.Size()
	var x, y int
	for x = 0; x < w; x++ {
		for y = 0; y < h; y++ {
			var c rune = content[x][y]
			if x >= ltSel.X && x <= rbSel.X && y >= ltSel.Y && y <= rbSel.Y {
				termbox.SetCell(x, y, c, termbox.ColorDefault|termbox.AttrReverse, termbox.ColorDefault)
			} else {
				termbox.SetCell(x, y, c, termbox.ColorDefault, termbox.ColorDefault)
			}
		}
	}
	termbox.Flush()
}

func addToSel(x int, y int) {
	if ltSel.X == -1 {
		ltSel = Point{x, y}
	} else if x < ltSel.X && y < ltSel.Y {
		rbSel = ltSel
		ltSel = Point{x, y}
	} else {
		rbSel = Point{x, y}
	}
}

func copySel() {
	var x, y int
	if ltSel.X < 0 || rbSel.X < 0 {
		return
	}
	var cb string = ""
	// here we have to go line by line to combine everything
	for y = ltSel.Y; y <= rbSel.Y; y++ {
		for x = ltSel.X; x <= rbSel.X; x++ {
			cb += string(content[x][y])
		}
	}
	clipboard.WriteAll(cb)
}

func clearScreen() {
	var w, h int = termbox.Size()
	content = make([][]rune, w)
	var x, y int
	for x = 0; x < w; x++ {
		content[x] = make([]rune, h)
		for y = 0; y < h; y++ {
			content[x][y] = ' '
		}
	}
}

func main() {
	termbox.Init()
	clearSel()
	clearScreen()
	termbox.SetInputMode(termbox.InputEsc | termbox.InputMouse)
	setContent(10, 10, "Error: Could not connect: ")
	setContent(10, 11, "dial tcp 127.0.0.1:3306:")
	setContent(10, 12, "connect: connection refused")
	setContent(22, 14, " OK ")
	fill(Point{8, 8}, Point{38, 8}, 'x')
	fill(Point{8, 16}, Point{38, 16}, 'x')
	fill(Point{7, 8}, Point{7, 16}, 'x')
	fill(Point{39, 8}, Point{39, 16}, 'x')
	redraw()
	for {
		ev := termbox.PollEvent()
		switch ev.Type {
		case termbox.EventMouse:
			addToSel(ev.MouseX, ev.MouseY)
		case termbox.EventKey:
			if ev.Key == termbox.KeyEnter {
				copySel()
				clearSel()
			} else {
				termbox.Close()
				os.Exit(0)
			}
		}
		redraw()
	}
}