#
# == About ==
#
# This is my way of making slide-based presentations. In short, it just groups
# Markdown formatting into rectangles and adds options for layout formatting.
# Each slide is the size of a landscape-oriented A4 sheet of paper. Light/dark
# mode settings are respected (of course).
# Currently, this appliest only to pages under the "talks" folder.

#
# == ftags ==
#
# &&presentation    Must appear before any other presentation ftags.
#                   It "loads" everything necessary for a presentation, that being
#                   the navigation bar and logic script (which also inserts the
#                   custom stylesheet).
#                   Can be only one per page. Also refer to -- Surroundings --
# 
# &&slide           Everything below this tag is part of a slide. Each slide is
#                   presented in the order it appears in.
# &&/slide          Ends (the last started) slide.
#
# &&frow            A row of paragraphs, where each item is evenly sized and is
#                   spaced out horizontally. In the HTML, it is a simple flexbox.
#                   This is one of the two main ways to configure how content is
#                   laid out on a slide.
# &&/frow           Every HTML element/paragraph between &&frow and &&/frow is an
#                   item that will be laid out.
#
# &&fcol            A column of paragraphs, where each item is evenly sized and is
#                   spaced out vertically. In the HTML, it is a simple flexbox.
#                   This is one of the two main ways to configure how content is
#                   laid out on a slide.
# &&/fcol           Every HTML element/paragraph between &&fcol and &&/fcol is an
#                   item that will be laid out.
# 
# &&flexer          An empty container, which can be used as a blank space item
#                   inside &&frow or &&fcol. In the styling, it just has `flex: 1`.
#
# &&centered        Aligns text to the center, literally.
# &&/centered       Text between &&centered and &&/centered is aligned.
#
# &&fright          Aligns element and the text inside to the right. In the styling,
#                   it just has text-align and float set to right.
# &&/fright         Text between &&fright and &&/fright is aligned to the right
#
# &&fontSIZE        Changes to font size to SIZE, in pixels. Default size is 24px.
#                   Available values for SIZE: 18, 20, 27, 30, 37
# &&/font           Text between &&fontSIZE and &&/font is sized accordingly
#
# -- Surroundings --
#
# As stated, there can only be one presentation per page.
# Everything that is around a presentation and it's slides is normally hidden
# during presenting mode, but will show up if you try to print the presentation.
# Exceptions to this rule are headings and paragraphs, which won't show up in
# presenting mode or during print.
#
# -- Placement/Flow --
#
# All ftags can be placed on their own line, or in a line with other ftags.
# The only requirement is that such a line must start with an ftag, ftags in the
# middle of text aren't recognized.
#
# -- Example Usage --
#
# Refer to src/talks/demo.md

BEGIN {
	if (substr(ARGV[1], "talks") == 0) exit # FILENAME isn't available yet

	# Exceptions to the normal format
	names[ 1] = "presentation"
	ended[ 1] = 0
	names[ 2] = "/font" # all font ftags can be closed with a &&/font
	ended[ 2] = 0

	names[ 3] = "slide"
	ended[ 3] = 1
	names[ 4] = "centered"
	ended[ 4] = 1
	names[ 5] = "flexer"
	ended[ 5] = 2
	names[ 6] = "frow"
	ended[ 6] = 1
	names[ 7] = "fcol"
	ended[ 7] = 1
	names[ 8] = "font18"
	ended[ 8] = 0
	names[ 9] = "font20"
	ended[ 9] = 0
	names[10] = "font27"
	ended[10] = 0
	names[11] = "font30"
	ended[11] = 0
	names[12] = "font35"
	ended[12] = 0
	names[13] = "fright"
	ended[13] = 1

	pres = ORS \
"<nav id=\"presentCont\">" ORS \
"	<img id=\"prevSlideBtn\" class=\"unzoomable btn setting-btn icon nodisplay\" src=\"/img/arrow-left-tabler.svg\" alt=\"Previous\">" ORS \
"	<img id=\"nextSlideBtn\" class=\"unzoomable btn setting-btn icon nodisplay\" src=\"/img/arrow-right-tabler.svg\" alt=\"Next\">" ORS \
"	<img id=\"presentBtn\" class=\"unzoomable btn setting-btn icon\" src=\"/img/presentation-tabler.svg\" alt=\"Present\">" ORS \
"	<img id=\"printBtn\" class=\"unzoomable btn setting-btn icon\" src=\"/img/printer-tabler.svg\" alt=\"Print\">" ORS \
"		</nav>" ORS \
"		<script type=\"text/javascript\" src=\"/scripts/presentation.js\" integrity=\"sha512-79MwfB0EQJMdVjVnd3PA0Cn9fo4JaMUmNuyZNEGSbaMEGcqdE8sWWAbMLheaoptDyb/KuYgNw0pKwvR5Dw+lJw==\" crossorigin=\"anonymous\"></script>"

	pat[1] = "&#38;&#38;presentation"
	rep[1] = pres
	pat[2] = "&#38;&#38;&#47;font"
	rep[2] = "</div>"

	for (i = 3; i <= length(names); i++) {
		pat[i] = "&#38;&#38;" names[i]
		rep[i] = "<div class=\"" names[i] "\">"

		if (ended[i] == 1) {
			cpat[i] = "&#38;&#38;&#47;" names[i]
			crep[i] = "</div>"
		}
		else if (ended[i] == 2) {
			rep[i] = rep[i] "</div>"
		}
	}
}

function substitute(ind) {
	gsub(/(<p>|<\/p>)/, "")
	gsub(pat[ind], rep[ind])
	if (ended[ind] == 1)
		gsub(cpat[ind], crep[ind])
}

/^[ \t]*(<p>|)&#38;&#38;/ {
	for (i = 1; i <= length(names); i++) {
		if (index($0, names[i]) != 0)
			substitute(i)
	}
}

{
	print
}