package main

import (
	"fmt"
	"strings"
)

const (
	boxErrHorLine           = '═'
	boxErrHorDownLine       = '╦'
	boxErrHorUpLine         = '╩'
	boxErrVertLine          = '║'
	boxErrVertRightLine     = '╠'
	boxErrVertLeftLine      = '╣'
	boxErrTopLeftCorner     = '╔'
	boxErrTopRightCorner    = '╗'
	boxErrBottomLeftCorner  = '╚'
	boxErrBottomRightCorner = '╝'

	boxHorLine           = '─'
	boxHorDownLine       = '┬'
	boxHorUpLine         = '┴'
	boxVertLine          = '│'
	boxVertRightLine     = '├'
	boxVertLeftLine      = '┤'
	boxTopLeftCorner     = '┌'
	boxTopRightCorner    = '┐'
	boxBottomLeftCorner  = '└'
	boxBottomRightCorner = '┘'
)

// Returns an error box
func errorBox(message string) (box string) {
	// 2+len because message length doesn't accomodate the spaces between the left and right border
	box += fmt.Sprintf("%c%v%c\n", boxErrTopLeftCorner, repeatRune(boxErrHorLine, 2+len(message)), boxErrTopRightCorner)
	box += fmt.Sprintf("%c %v %c\n", boxErrVertLine, message, boxErrVertLine)
	box += fmt.Sprintf("%c%v%c\n", boxErrBottomLeftCorner, repeatRune(boxErrHorLine, 2+len(message)), boxErrBottomRightCorner)
	return
}

// Returns a normal box, most commonly used for the menu items
func normalBox(railed bool, messages ...string) (box string) {
	message := strings.Join(messages, " │ ")
	var messagesLengths []int

	for i := 0; i < len(messages)-1; i++ {
		messagesLengths = append(messagesLengths, len(messages[i]))
	}

	/* The message is the middle part between the left and right border,
	   so you have to add 2 for the spaces between it and the borders.
	   Since each "│" character adds 3 to the length (and not 1),
	   get the amount of "│" character from number of messages, double the value
	   and finally subtract (so, "││" is len 6, 2 "│" characters * 2 = 4, 6 - 4 = 2).
	*/
	messageLength := 2 + len(message) - 2*(len(messages)-1)

	box += fmt.Sprintf("%c%v%c\n", boxTopLeftCorner, repeatRune(boxHorLine, messageLength), boxTopRightCorner)
	box += fmt.Sprintf("%c %v %c\n", boxVertLine, message, boxVertLine)
	box += fmt.Sprintf("%c%v%c\n", boxBottomLeftCorner, repeatRune(boxHorLine, messageLength), boxBottomRightCorner)

	indTop := 0
	/* messageLength doesn't include the left and right spaces that are in middle part
	   and on each line there are \n characters (hence adding 2 at the end).
	   With this variable, we're practically at index 0 on the third line.
	*/
	indBot := 2*(messageLength+2) + 2

	if railed {
		box = replaceAtIndex(box, boxVertRightLine, indBot)
	}

	for _, val := range messagesLengths {
		/* +1 Because message length doesn't include the " " in the beginning
		   +2 because we're now at the index of the last letter, and need to go to
		   the right border index
		   And that in total means we add 3 to length
		*/
		indTop += val + 3
		indBot += val + 3

		// Replaces the border character on the top with one that connects to the middle border: ┌───────────┬───────────┐
		box = replaceAtIndex(box, boxHorDownLine, indTop)
		// Replaces the border character on the bottom with one that connects to the middle broder: └───────────┴───────────┘
		box = replaceAtIndex(box, boxHorUpLine, indBot)
	}
	return
}