#!/usr/bin/env bash

function err {
    echo "$@" >&2
}

if [ $# -ne 1 ]; then
    err "./gmi2html.sh /path/to/gmi"
    exit 1;
fi

# main method
GMI=$1
list=0
pre=0
quote=0

while read line; do

    # if in pre-mode and not closing - print and skip
    if [ $pre -eq 1 ]; then
	if [ ! -n "$(sed -nE '/^[`]{3}/p' <<< $line)" ]; then
	    echo "$line"
	    continue;
	fi
    fi


    # quotes
    if [ -n "$(sed -nE '/^[>] .+/p' <<< $line)" ]; then
	if [ $quote -eq 0 ]; then
	    echo "<figure><blockquote>"
	fi
       	quote=1;
	text=$(sed -E 's/^[>] (.+)$/\1/g' <<< $line)
	echo "<p>$text</p>"
	continue
    else
	if [ $quote -eq 1 ]; then
	    if [ -z "$(sed -E '/^[#`*]/d' <<< $line)" ]; then
		echo "</blockquote></figure>"
		quote=0
	    fi
	fi
    fi

    if [ -n "$(sed -nE '/^[`]{3}/p' <<< $line)" ]; then
	if [ $pre -eq 0 ]; then
	    echo "<pre>"
	    pre=1
	else
	    echo "</pre>"
	    pre=0
	fi
	continue;
    fi
    
    # lists
    if [ -n "$(sed -nE '/^[*] .+/p' <<< "$line")" ]; then
	if [ $list -eq 0 ]; then
	    echo "<ul>"
	fi
       	list=1;
	text=$(sed -E 's/^[*] (.+)$/\1/g' <<< "$line")
	echo "<li>${text}</li>"
	continue
    else
	if [ $list -eq 1 ]; then
	    echo "</ul>"
	fi
	list=0;
    fi
    
    # single line modifiers
    if [ -n "$(sed -nE '/^# .+/p' <<< $line)" ]; then
	text=$(sed -E 's/^# (.+)$/\1/g' <<< $line)
	echo "<h1>$text</h1>"
	continue
    fi
    if [ -n "$(sed -nE '/^## .+/p' <<< $line)" ]; then
	text=$(sed -E 's/^## (.+)$/\1/g' <<< $line)
	echo "<h2>$text</h2>"
	continue
    fi
    if [ -n "$(sed -nE '/^### .+/p' <<< $line)" ]; then
	text=$(sed -E 's/^### (.+)$/\1/g' <<< $line)
	echo "<h3>$text</h3>"
	continue
    fi
    if [ -n "$(sed -nE '/^=> .+/p' <<< "$line")" ]; then
	href=$(sed -E 's/^=> ([^ ]+)([ ]?.*)/\1/g' <<< "$line")
	if [ -n "$(sed -nE '/^=> [^ ]+ .+$/p' <<< "$line")" ]; then
	    text=$(sed -E 's/^=> [^ ]+ (.+)$/\1/g' <<< "$line")
	else
	    text=$href
	fi

	if [ $quote -eq 1 ]; then
	    echo "<cite>— <a href='${href}' rel='noopener' target='_blank'>$text</a></cite>"
	else
	    echo "<p><a href='${href}' rel='noopener' target='_blank'>$text</a></p>"
	fi
	continue
    fi
    
    # skip blank lines
    if [ -z "$line" ]; then
	continue
    fi

    # default paragraphs
    if [ $quote -eq 1 ]; then
	echo "<cite>— $line</cite>"
    else
	echo "<p>$line</p>"
    fi
    
done < $GMI