package gold

import (
	"bytes"
)

type BlockStack []BlockElement

func (s *BlockStack) Len() int {
	return len(*s)
}

func (s *BlockStack) Push(e BlockElement) {
	*s = append(*s, e)
}

func (s *BlockStack) Pop() {
	stack := *s
	if len(stack) == 0 {
		return
	}

	stack = stack[0 : len(stack)-1]
	*s = stack
}

func (s BlockStack) Indent() uint {
	var i uint

	for _, v := range s {
		if v.Style.Indent == nil {
			continue
		}
		i += *v.Style.Indent
	}

	return i
}

func (s BlockStack) Margin() uint {
	var i uint

	for _, v := range s {
		if v.Style.Margin == nil {
			continue
		}
		i += *v.Style.Margin
	}

	return i
}

func (s BlockStack) Width(ctx RenderContext) uint {
	if s.Indent()+s.Margin()*2 > uint(ctx.options.WordWrap) {
		return 0
	}
	return uint(ctx.options.WordWrap) - s.Indent() - s.Margin()*2
}

func (s BlockStack) Parent() BlockElement {
	if len(s) == 1 {
		return BlockElement{
			Block: &bytes.Buffer{},
		}
	}

	return s[len(s)-2]
}

func (s BlockStack) Current() BlockElement {
	if len(s) == 0 {
		return BlockElement{
			Block: &bytes.Buffer{},
		}
	}

	return s[len(s)-1]
}

func (s BlockStack) With(child ElementStyle) ElementStyle {
	return cascadeStyle(s.Current().Style, child, true)
}