#!/usr/bin/awk -f
# -*- indent-tabs-mode: t; -*-
# HAT TRICK
# (C) 2022 C. Duckworth

### Commentary:

# OLDIFS=$IFS; IFS=$'\n';
# for line in `cat testfile`; do
# test=`echo "$line" | grep -E '[\]$'`;
# if [ $test ]; then
# newline=`echo $line | rev | cut -c 2- | rev`;
# echo -n "$newline"; else echo "$line";
# fi; done;
# IFS=$OLDIFS

### Code:
BEGIN {
	width = 72
	default_htag = "p"
	default_gtag = ""
	default_ftag = ""
}

### Raw formatting
/^>>>/ {
	getline first_raw
	if (raw_fmt_p("html")) {
		raw_html = 1
		html[++hpar] = "<pre><code>" html_escape(first_raw)
	}
	if (raw_fmt_p("gemini")) {
		raw_gemini = 1
		gemini[++gpar] = "```"
		gemini[++gpar] = first_raw
	}
	if (raw_fmt_p("gopher")) {
		raw_gopher = 1
		gopher[++fpar] = first_raw
	}
	raw = 1
	next
}

/^<<</ {
	if (raw_html) {
		html[hpar] = html[hpar] "</code></pre>"
	}
	if (raw_gemini) {
		gemini[++gpar] = "```"
		gemini[++gpar] = ""
	}
	if (raw_gopher) {
		gopher[++fpar] = ""
	}
	raw_html = 0
	raw_gemini = 0
	raw_gopher = 0
	raw = 0
	next
}

raw {
	if (raw_html) {
		html_empty = 0
		html[++hpar] = html_escape($0)
	}
	if (raw_gemini) {
		gemini_empty = 0
		gemini[++gpar] = $0
	}
	if (raw_gopher) {
		gopher_empty = 0
		gopher[++fpar] = $0
	}
	next
}

# Block types
/^#/ {
	match($0, /#+/)
	htag = "h" (RLENGTH > 6 ? 6 : RLENGTH)
	gtag = substr($0, RSTART, (RLENGTH > 3 ? 3 : RLENGTH)) " "
	ftag = substr($0, RSTART, RLENGTH) " "
	sub(/^#+[ \t]*/, "", $0)
}

# Line types
/^=>/ {
	title = ""
	for (i = 3; i <= NF; i++) {
		title = title (title ? " " : "") $i
	}
	hbuf[++hline] = "<a href=\"" $2 "\">" title "</a>"
	gbuf[++gline] = "\ngemini\t" $0
	# TODO: gopher
	next
}

### Everything else
/./ {
	html_empty = 0
	gemini_empty = 0
	gopher_empty = 0
	hbuf[++hline] = $0
	gbuf[++gline] = $0
	fbuf[++fline] = $0
}

/^$/ {
	bufput()
}

END {
	bufput()
	printarr(html, "html")
	printarr(gemini, "gemini")
	printarr(gopher, "gopher")
}


function bufput()
{
	hbufput()
	gbufput()
	fbufput()
}

function clear(arr)
{
	for (x in arr) {
		delete arr[x]
	}
}

function fbufput()
{
	if (! length(fbuf)) {
		next
	}
	for (ln in fbuf) {	# XXX: gopher line types
		paragraph = paragraph (paragraph ? " " : "") fbuf[ln]
	}
	fill(paragraph)
	for (ln in fp) {
		gopher[++fpar] = ((ln == 1) ? ftag : "") fp[ln]
	}
	gopher[++fpar] = ""
	paragraph = ""
	ftag = default_ftag
	clear(fp)
	clear(fbuf)
}

function fill(paragraph)
{
	char = 0
	ln = 1
	split(paragraph, words, FS)
	for (word in words) {
		char += length(words[word])
		if (char <= width) {
			fp[ln] = fp[ln] (fp[ln] ? " " : "") words[word]
		} else {
			fp[++ln] = words[word]
			char = length(words[word])
		}
	}
}

function gbufput()
{
	if (! length(gbuf)) {
		next
	}
	for (ln in gbuf) {
		paragraph = paragraph (paragraph ? " " : "") gbuf[ln]
	}
	gemini[++gpar] = gtag paragraph
	gemini[++gpar] = ""
	gtag = default_gtag
	paragraph = ""
	clear(gbuf)
}

function gopher_line(type, display, selector, hostname, port)
{
	return (type display "\t" selector "\t" hostname "\t" port)
}

function hbufput()
{
	if (! length(hbuf)) {
		next
	}
	for (ln in hbuf) {
		paragraph = paragraph (paragraph ? " " : "") hbuf[ln]
	}
	fill(paragraph)
	for (ln in fp) {
		html[++hpar] = ((ln == 1) ? "<" (htag ? htag : default_htag) ">" : "") fp[ln]
	}
	html[hpar] = html[hpar] (htag_end ? htag_end : "</" (htag ? htag : default_htag) ">")
	paragraph = ""
	htag = default_htag
	clear(fp)
	clear(hbuf)
}

function html_escape(text)
{
	gsub(/&/, "\\&amp;", text)
	gsub(/</, "\\&lt;", text)
	gsub(/>/, "\\&gt;", text)
	return text
}

function printarr(arr, prefix)
{
	if (prefix) {
		fmt = "%s\t%s\n"
	} else {
		fmt = "%s%s\n"
	}
	for (x in arr) {
		printf fmt, prefix, arr[x]
	}
}

function raw_fmt_p(format)
{
	if (NF < 2) {
		return 1
	}
	if ($2 ~ /-/) {
		if ($2 ~ ("-" format)) {
			return 0
		} else {
			return 1
		}
	}
	if ($2 ~ format) {
		return 1
	}
	return 0
}