#!/bin/sh

export author="Liv"
web_url="https://liv.envs.net/"

# All files in static dir will be copied directly to public dir, files in assets will not be copied
base_dirs="./static ./assets ./public ./content ./layouts ./assets"
root_file="./layouts/root.html"
head_file="./layouts/head.html"
header_file="./layouts/header.html"
footer_file="./layouts/footer.html"

temp_list=$(mktemp)
temp_xml=$(mktemp)
trap 'rm "$temp_list" "$temp_xml"' EXIT

show_help() {
    cat << EOF
Usage: $0 [options]
-h, --help     Show this help message
-i, --init     Create default directories and templates
EOF
}

process_template() {
    if [ -n "$css" ]; then
        css_content=$(cat << EOF
<style>
$(cat "$css")
</style>
EOF
)
    fi
    awk -v css="$css_content" '
    BEGIN {
        split("title description keywords author", keys)
    }
    /^\+\+\+$/ { in_p = !in_p; next }
    in_p { next }
    {
        line = $0
        for (i in keys) {
            k = keys[i]; v = ENVIRON[k]; pat = "{{ *" k " *}}"
            if (v != "") gsub(pat, v, line)
            else if (line ~ pat) next
        }
        if (css != "") sub("</head>", css "\n</head>", line)
        print line
    }' "$1" > "$2"
}

extract_preamble() {
    unset title date description keywords css
    eval "$(awk '/^\+\+\+$/{if(++c==2) exit; next} c==1' "$1")"
    export title date description keywords css
}

apply_layout() {
    sed "
        /{{ *main *}}/ { r ${1}
        d; }
        /{{ *head *}}/ { r ${head_file}
        d; }
        /{{ *header *}}/ { r ${header_file}
        d; }
        /{{ *footer *}}/ { r ${footer_file}
        d; }
    " "$root_file" > "${2}.tmp"
    process_template "$2.tmp" "$2"
    rm "$2.tmp"
}

compile_rss() {
    extract_preamble "./content/index.html"
    cat << EOF > "./public/index.xml"
<rss version="2.0" xmlns:atom="http://www.w3.org/2005/Atom">
<channel>
<title>${title}</title>
<link>${web_url}</link>
<image>
<url>${web_url}favicon.ico</url>
</image>
<description>${description}</description>
<language>en</language>
<lastBuildDate>$(date -u -R)</lastBuildDate>
<atom:link href="${web_url}index.xml" rel="self" type="application/rss+xml"/>
EOF
    if [ -s "$temp_xml" ]; then
        sort -r "$temp_xml" | sed 's/^[^|]*|//' | tr '\001' '\n' | sed '/^$/d' >> "./public/index.xml"
    fi
    cat << EOF >> "./public/index.xml"
</channel>
</rss>
EOF
}

compile_content() {
    item_count=0
    find "./content/" -type f -name "*.html" ! -name "index.html" | while IFS= read -r file; do
        extract_preamble "$file"
        
        temp="${file#./content/}"
        dest_path="./public/${temp%.html}/"
        dest="${dest_path}index.html"
        url="./${temp%.html}/"

        mkdir -p "$dest_path"
        apply_layout "$file" "$dest"

        item_count=$((item_count + 1))
        sortable_date=$(date -d "$date" +%Y%m%d%H%M%S)$(printf "%04d" "$item_count")

        if [ -n "$description" ]; then
            echo "<dt>${date} <a href='${url}'>${title}</a></dt><dd>${description}</dd>" >> "$temp_list"
        else
            echo "<dt>${date} <a href='${url}'>${title}</a></dt>" >> "$temp_list"
        fi
        
        {
            cat << EOF
<item>
<title>${title}</title>
<link>${web_url}${url#./}</link>
<pubDate>$(date -d "${date}" -u -R)</pubDate>
<guid>${web_url}${url#./}</guid>
EOF
            if [ -n "$description" ]; then
                cat << EOF
<description>
${description}
</description>
EOF
            fi
            echo "</item>"
        } | tr '\n' '\001' | awk -v key="$sortable_date" '{print key "|" $0}' >> "$temp_xml"
    done
}

compile_index() {
    find "./content/" -type f -name "index.html" | sort | while IFS= read -r file; do
        extract_preamble "$file"
        temp="${file#./content/}"
        dest_path="./public/${temp%index.html}"
        dest="${dest_path}index.html"

        mkdir -p "$dest_path"

        sorted_list=$(mktemp)

        {
            cat "$file"
            echo "<dl>"
            if [ "$dest" = "./public/index.html" ]; then
                sort -r "$temp_list" | head -n 5
                cat << EOF
</dl>
<p><a href='./blogs'>More blogs</a></p>
EOF
            else
                sort -r "$temp_list" | sed "s|/blogs/|/|g"
                echo "</dl>"
            fi
        } > "$sorted_list"

        apply_layout "$sorted_list" "$dest"
        rm "$sorted_list"
    done
}

init() {
    for dir in $base_dirs; do
        mkdir -p "$dir"
    done
    
    [ ! -f "$root_file" ] && cat << 'EOF' > "$root_file"
<!DOCTYPE html>
<html lang="en">
  <head>
    {{head}}
  </head>
  <body>
    <header>
      {{header}}
    </header>
    <main>
      {{main}}
    </main>
    <footer>
      {{footer}}
    </footer>
  </body>
</html>
EOF

    [ ! -f "$footer_file" ] && cat << 'EOF' > "$footer_file"
<hr>
<p>All rights reserved.</p>
EOF

    [ ! -f "$head_file" ] && cat << 'EOF' > "$head_file"
<meta charset="UTF-8">
<meta name="color-scheme" content="light dark">
<meta name="viewport" content="width=device-width, initial-scale=1.0">
<meta name="description" content="{{description}}">
<meta name="keywords" content="{{keywords}}">
<meta name="author" content="{{author}}">
<meta name="robots" content="noindex,nofollow">
<title>{{title}}</title>
EOF

    [ ! -f "$header_file" ] && cat << 'EOF' > "$header_file"
<h1>{{title}}</h1>
<nav>
  <a href="/">home</a> | 
  <a href="/blogs">blogs</a> | 
  <a href="/index.xml">rss</a>
</nav>
<hr>
EOF
}

# Main execution
while [ "$#" -gt 0 ]; do
    case $1 in
        -h|--help) show_help; exit 0 ;;
        -i|--init) init; exit 0 ;;
        *) echo "Unknown flag '$1'"; show_help; exit 1 ;;
    esac
done

# Check dirs
for dir in $base_dirs; do
    if [ ! -d "$dir" ]; then
        echo "Run $0 --init first!"
        exit 1
    fi
done

rm -r public/
mkdir -p public/
cp -r static/. public/

compile_content
compile_index
compile_rss