#!/usr/bin/env bash

# requires pandoc
#          coreutils
#          uuidgen
#          tidy
#          the_silver_searcher (could use grep instead)

set -o errexit
set -o nounset
set -o pipefail
if [[ "${TRACE-0}" == "1" ]]; then
    set -o xtrace
fi

SITENAME="wiki"
SITEURL="https://elioat.tilde.institute/wiki"
SITEDESCRIPTION="a little wiki"
if [[ -f updated ]]; then
   LASTUPDATE=$(<updated)
fi
TIMESTAMP=$(gdate +"%s")
RFC822=$(gdate -R)
RSSHEADER='<?xml version="1.0" encoding="UTF-8"?>
<rss xmlns:dc="http://purl.org/dc/elements/1.1/" xmlns:content="http://purl.org/rss/1.0/modules/content/" xmlns:atom="http://www.w3.org/2005/Atom" version="2.0">
<channel>
<title>
<![CDATA[ '${SITENAME}']]>
</title>
<link>'${SITEURL}'</link>
<atom:link href="'${SITEURL}'/feed.rss" rel="self" type="application/rss+xml"/>
<description>
<![CDATA[ '${SITEDESCRIPTION}' ]]>
</description>'
RSSEND='</channel></rss>'

build_logs() {
    pandoc changelog.md -o public/changelog.html
    cd content
    rm ../archive.md
    echo -e "# Archive\n" > ../archive.md
    for file in *;
    do
        archive_entry="- [${file%.*}](${SITEURL}/${file%.*}.html)"
        echo -e "$archive_entry" >> ../archive.md
    done
    cd ..
    pandoc archive.md -o public/archive.html
}

build() {
    cd content
    i=0

    rm ../public/feed.xml
    touch ../public/feed.xml
    echo -e "${RSSHEADER}" > ../public/feed.xml

    for file in *; 
    do
        file_last_updated=$(stat -f %m "$file")
        if [ "$file_last_updated" -gt "$LASTUPDATE" ]; 
        then
            (( i++ ))
            updated_at="- [${file%.*}](${SITEURL}/${file%.*}.html), ${RFC822}"
            echo -e "$updated_at\n$(cat ../changelog.md)" > ../changelog.md
            pandoc "${file}" -o ../public/"${file%.*}".html
            rss_entry='<item>
<title>
<![CDATA[ the page "'${file%.*}'" was updated! ]]>
</title>
<link>'${SITEURL}'/'${file%.*}.html'</link>
<guid>'${SITEURL}/${file%.*}.html#$(uuidgen)'</guid>
<pubDate>'${RFC822}'</pubDate>
<description>
<![CDATA[ 
<p><a href="'${SITEURL}/${file%.*}.html'">'${file%.*}'</a> updated!</p><br><br><pre><code>'$(fold -sw 80 <"$file")'</code></pre>  ]]>
</description>
</item>'
            echo -e "$rss_entry" >> ../public/feed.xml
        fi
    done
    cd ..
    echo -e "$RSSEND" >> public/feed.xml
    # this is stupid and superfluous, but I was bugged by the weirdly formatted RSS output
    tidy \
        -xml \
        --show-body-only yes \
        --indent auto \
        --indent-spaces 2 \
        --quiet yes \
        -w 80 \
        -m \
        --force-output y \
        --wrap 0 \
            public/feed.xml
    if [ $i -gt 0 ];
    then
        build_logs "$@"
    fi
    echo "$TIMESTAMP" > updated
    echo "updated" $i "items."
}

help_text() {
    echo '
    mynah, a little wiki bird

    usage: ./mynah
                     -b(uild)....to build the site
                     -s(earch)...to search for a pattern across all wiki entries
                     -d(eploy)...to publish the public directory to a host
                     -h(elp).....to display this message
                     -n(est).....to start a new wiki
'
}

if [[ "${1-}" =~ ^-*h(elp)?$ ]]; then
    help_text "$@"
    exit
elif [[ "${1-}" =~ ^-*b(uild)?$ ]]; then
    build "$@"
    exit
elif [[ "${1-}" =~ ^-*s(earch)?$ ]]; then
    ag "$2" content/*
    exit
elif [[ "${1-}" =~ ^-*d(eploy)?$ ]]; then
    scp -r public/* elioat@tilde.institute:~/public_html/wiki/
    exit
elif [[ "${1-}" =~ ^-*n(est)?$ ]]; then
    if [[ -f content ]]; then
        echo -e "   
            a content directory already exists 
            so you can't build a new nest here
            "
    else
        mkdir content public
        touch archive.md changelog.md updated public/feed.xml
    fi
    exit
fi

cd "$(dirname "$0")"

main() {
    help_text "$@"
}

main "$@"