package main

import (
	"strings"

	"github.com/gdamore/tcell"
)

type Drawable interface {
	Draw(tcell.Screen)
	SetSize(x, y, h, w int)
}

type offsets struct {
	top    int
	bottom int
	left   int
	right  int
}

type contents []struct {
	offsets   offsets
	container Drawable
}

type box struct {
	x, y      int
	h, w      int
	title     Drawable
	menuItems Drawable
	contents  []struct {
		offsets   offsets
		container Drawable
	}
}

func NewBox(title string, menuItems []string, contents contents) *box {
	return &box{
		title:     NewPaddedText(title),
		menuItems: NewPaddedText(strings.Join(menuItems, " ")),
		contents:  contents,
	}
}

func (b *box) SetSize(x, y, h, w int) {
	b.x, b.y, b.h, b.w = x, y, h, w
	b.title.SetSize(b.x+2, b.y, 0, 0)
	b.menuItems.SetSize(b.x+2, b.y+b.h-1, 0, 0)
	for c := range b.contents {
		x := b.x + b.contents[c].offsets.left
		y := b.y + b.contents[c].offsets.top
		h := b.h - b.contents[c].offsets.bottom
		w := b.w - b.contents[c].offsets.right
		b.contents[c].container.SetSize(x, y, h, w)
	}
}

func (b *box) Draw(s tcell.Screen) {
	for m := 1; m < b.w-1; m++ {
		s.SetContent(m, b.y, tcell.RuneHLine, nil, tcell.StyleDefault)
		s.SetContent(m, b.h-1, tcell.RuneHLine, nil, tcell.StyleDefault)
	}
	for m := 1; m < b.h-1; m++ {
		s.SetContent(b.x, m, tcell.RuneVLine, nil, tcell.StyleDefault)
		s.SetContent(b.w-1, m, tcell.RuneVLine, nil, tcell.StyleDefault)
	}
	s.SetContent(b.x, b.y, tcell.RuneULCorner, nil, tcell.StyleDefault)
	s.SetContent(b.w-1, b.y, tcell.RuneURCorner, nil, tcell.StyleDefault)
	s.SetContent(b.x, b.h-1, tcell.RuneLLCorner, nil, tcell.StyleDefault)
	s.SetContent(b.w-1, b.h-1, tcell.RuneLRCorner, nil, tcell.StyleDefault)

	if b.title != nil {
		b.title.Draw(s)
	}
	if b.menuItems != nil {
		b.menuItems.Draw(s)
	}
	for c := range b.contents {
		b.contents[c].container.Draw(s)
	}
}

type list struct {
	x, y      int
	h, w      int
	selected  int
	listItems []string
}

func NewList(listItems []string, initialSelected int) *list {
	return &list{
		listItems: listItems,
		selected:  initialSelected,
	}
}

func (l *list) SetSize(x, y, h, w int) {
	l.x, l.y, l.h, l.w = x, y, h, w
}

func (l *list) Draw(s tcell.Screen) {
	for i := range l.listItems {
		for j, r := range l.listItems[i] {
			s.SetContent(l.x+j, l.y+i, r, nil, tcell.StyleDefault)
		}
		if i == l.selected {
			s.SetContent(l.x+len(l.listItems[i])+1, l.y+i, '<', nil, tcell.StyleDefault)
		}
	}
}

type paddedText struct {
	x, y int
	h, w int
	text string
}

func NewPaddedText(text string) *paddedText {
	return &paddedText{text: text}
}

func (p *paddedText) SetSize(x, y, _, _ int) {
	p.x, p.y, p.h, p.w = x, y, 1, len(p.text)+2
}

func (p *paddedText) Draw(s tcell.Screen) {
	t := p.x
	s.SetContent(t, p.y, ' ', nil, tcell.StyleDefault)
	t++
	for _, r := range p.text {
		s.SetContent(t, p.y, r, nil, tcell.StyleDefault)
		t++
	}
	s.SetContent(t, p.y, ' ', nil, tcell.StyleDefault)
}