#
# == 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.
# Inside each slide, normal element flow is respected.
# Each slide is the size of a landscape-oriented A4 sheet of paper. Light/dark
# mode settings are respected (of course).
# Currently, this is active only in 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 following this tag is part of a slide. Each slide is
#                   presented in the order it appears in.
# &&/slide          Ends (the last started) slide.
#
# &&clide           Same as &&slide, but everything following is centered
#                   vertically. Uses flexbox.
# &&/slide          Ends (the last started) clide. Not compatible with &&/slide!
#
# &&table           Starts a table, where everything following it is formatted as a
#                   table cell in a row.
# &&ftable          Same as &&table, but all colums have the same width.
# &&tarow           Ends the last started row and begins a new row.
#                   Effectively everything following it is on a new row.
# &&/table          Ends (the last started) (table row and) table or ftable.
#
# &&linebN          Adds a line break (vertical spacing) of N (text) lines.
#                   Spacing is equivalent to N em.
#                   Available values for N: 1, 2, 3, 4, 5, 6, 7, 8, 9
# 
# &&fontSIZE        Changes font size to SIZE, in pixels. Default size is 30px.
#                   Available values for SIZE: 18, 20, 22, 25, 27, 35
# &&/font           Text between &&fontSIZE and &&/font is sized accordingly
#
# &&centered        Center horizontally (only) text.
# &&/centered       Text between &&centered and &&/centered is aligned.
#
# &&fright          Aligns following elements and text to the right.
# &&/fright         Text between &&fright and &&/fright is aligned to the right
#
# &&cont            Basic container with no properties. Useful if you need to group
#                   multiple elements into one table cell.
# &&/cont           Ends (the last started) &&cont
#
# -- 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 and while printing.
#
# -- 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.
#
# -- Regarding flex --
#
# The older versions of the script, prior to commit
# 687ff3652e5695183ba1691e7d4b94470f8407b3
# used extensively flexbox for element alignment. This was done with the hope that
# spacing out elements evenly and centering them would be very easy, which turned
# out to be false.
#
# Now, the only thing that uses flexbox is &&clide, and it only allows to center
# everything in the slide vertically.
# Vertical centerings for portions of elements can be done with &&linebN, which,
# though imperfect, does the job very well and should suffice.
# Evenly spacing out elements next to each other can be done with &&table and
# &&ftable.
#
# -- Example Usage --
#
# Refer to src/talks/demo/index.md

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

	# names is name of ftag, meaning if `names[i] = "examp"` the ftag will be &&examp
	# ended specifies how the HTML tag is ended
	#     `ended[i] = 0` means no closing ftag (so no &&/examp)
	#     `ended[i] = 1` means &&/examp exists
	#     `ended[i] = 2` means self-closing, so no &&/examp, but &&examp includes the closing tag
	#
	# &&examp is usually replaced by `<div class="examp">`
	# &&/examp is usually replaced by `</div>`
	# in case ended[i] = 2, &&examp is replaced by `<div class="examp"></div>`

	# Main elements and exceptions to the normal replace format
	names[ 1] = "presentation"
	ended[ 1] = 0
	names[ 2] = "slide"
	ended[ 2] = 1
	names[ 3] = "clide"
	ended[ 3] = 1
	names[ 4] = "table"
	ended[ 4] = 1
	names[ 5] = "ftable"
	ended[ 5] = 0
	names[ 6] = "tarow"
	ended[ 6] = 0
	names[ 7] = "&#47;font" # all font ftags can be closed with a &&/font
	ended[ 7] = 0

	# Line breaks
	names[ 8] = "lineb1"
	ended[ 8] = 2
	names[ 9] = "lineb2"
	ended[ 9] = 2
	names[10] = "lineb3"
	ended[10] = 2
	names[11] = "lineb4"
	ended[11] = 2
	names[12] = "lineb5"
	ended[12] = 2
	names[13] = "lineb6"
	ended[13] = 2
	names[14] = "lineb7"
	ended[14] = 2
	names[15] = "lineb8"
	ended[15] = 2
	names[16] = "lineb9"
	ended[16] = 2

	# Font sizes
	names[17] = "font18"
	ended[17] = 0
	names[18] = "font20"
	ended[18] = 0
	names[19] = "font22"
	ended[19] = 0
	names[20] = "font25"
	ended[20] = 0
	names[21] = "font27"
	ended[21] = 0
	names[22] = "font35"
	ended[22] = 0

	# Everything else
	names[23] = "centered"
	ended[23] = 1
	names[24] = "fright"
	ended[24] = 1
	names[25] = "cont"
	ended[25] = 1

	pres = ORS \
"<nav id=\"presentCont\">" ORS \
"	<img id=\"prevSlideBtn\" class=\"unzoomable btn setting-btn icon nodisplay\" src=\"/img/arrow-left.svg\" alt=\"Previous\">" ORS \
"	<a id=\"slideIndex\" class=\"nodisplay\" href=\"#slide-0\">0</a>" ORS \
"	<img id=\"nextSlideBtn\" class=\"unzoomable btn setting-btn icon nodisplay\" src=\"/img/arrow-right.svg\" alt=\"Next\">" ORS \
"	<img id=\"articleBtn\" class=\"unzoomable btn setting-btn icon\" src=\"/img/article.svg\" alt=\"Show as article\">" ORS \
"	<img id=\"presentBtn\" class=\"unzoomable btn setting-btn icon\" src=\"/img/presentation.svg\" alt=\"Present\">" ORS \
"	<img id=\"printBtn\" class=\"unzoomable btn setting-btn icon\" src=\"/img/printer.svg\" alt=\"Print\">" ORS \
"		</nav><br><br>" ORS \
"		<script type=\"text/javascript\" src=\"/scripts/presentation.js\" integrity=\"sha512-ZxV9z0W+zUL1SDsojpvUy/IbvXiz2mLUdnTghCkT0Ws5Hi+CE2KbrROnKkhIK4DQP85dAF41Lms4GrAYcNaQrA==\" crossorigin=\"anonymous\"></script>"

	for (i = 1; 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>"
		}
	}

	rep[ 1] = pres
	rep[ 3] = "<div class=\"slide clide\"><div></div><div>" # flex-col + flex:1 + <div>
	crep[3] = "</div><div></div></div>"                     # </div>   + flex:1 + /flex-col
	rep[ 4] = "<div class=\"layout-table\"><div class=\"layout-row\">" # <table><tr>  (layout-row > * is td)
	crep[4] = "</div></div>"                                           # </tr><table>
	rep[ 5] = "<div class=\"layout-table fixed-layout\"><div class=\"layout-row\">" # <table><tr>  (layout-row > * is td)
	rep[ 6] = "</div><div class=\"layout-row\">" # </tr><tr>
	rep[ 7] = "</div>" # &&/font

	presInsideCode = 0
	slideIndex = 0
}

function presentationSubstitute(ind) {
	gsub(/(<p>|<\/p>)/, "")
	if ((ind == 2 || ind == 3) && index($0, pat[ind]) != 0) { # &&slide or &&clide
		gsub(pat[ind], "<div id=\"slide-" slideIndex "\"" substr(rep[ind], 5))
		slideIndex++
	}
	else {
		gsub(pat[ind], rep[ind])
	}
	if (ended[ind] == 1)
		gsub(cpat[ind], crep[ind])
}

nopresentation == 0 && /<code>/ {
	presInsideCode = 1
}

nopresentation == 0 && /<\/code>/ {
	presInsideCode = 0
}

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