#!/bin/bash

SITE="https://volpeon.ink/"

CONTENT_DIR="content/"
FILTERS_DIR="filters/"
METADATA_DIR="metadata/"
TEMPLATES_DIR="templates/"
OUTPUT_DIR="output/"

get_filters() {
    filters_args=""

    mapfile -d $'\0' filters < <(find $FILTERS_DIR \
        -type f \
        -name "*.lua" ! -name ".*" \
        -print0)

    for file in "${filters[@]}"; do
        filters_args="$filters_args --lua-filter $file"
    done

    echo $filters_args
}

FILTERS=$(get_filters)

target_filename() {
    filename=$1
    filename=${filename#"$CONTENT_DIR"}
    if [ "${filename##*.}" = "md" ]; then
        filename="${filename%.md}.html"
    fi
    echo "$OUTPUT_DIR$filename"
}

target_url_rel() {
    basedir=$1
    filename=$2
    ext=$3
    filename=$(realpath --relative-to="$basedir" "$filename")
    filename="${filename%.md}.$ext"
    filename=${filename%index.html}
    echo "$filename"
}

target_url_abs() {
    echo "/$(target_url_rel "$CONTENT_DIR" "$1" "$2")"
}

metadata() {
    pandoc "$1" \
        -f markdown \
        -t plain \
        --template scripts/metadata_tpl.json
}

get_section() {
    filename=$1
    filename=${filename#"$CONTENT_DIR"}
    filename=${filename%.md}
    filename=$(echo "$filename" | cut -f1 -d /)
    echo "$filename"
}

get_subpages_basedir() {
    filename=$1
    if [ "${filename##*/}" = "index.md" ]; then
        filename=$(dirname "$filename")
    fi
    echo "$filename"
}

get_subpages_meta() {
    basedir=$(get_subpages_basedir "$1")
    child_pages=()

    if [ -d "$basedir" ]; then
        mapfile -d $'\0' child_pages_1 < <(find $basedir/ \
            -type f \
            -name "*.md" ! -name "index.md" \
            -maxdepth 1 \
            -print0)

        mapfile -d $'\0' child_pages_2 < <(find $basedir/ \
            -type f \
            -name "index.md" \
            -mindepth 2 \
            -maxdepth 2 \
            -print0)

        child_pages=("${child_pages_1[@]}" "${child_pages_2[@]}")
    fi

    pages=$(echo "{}" | jq ". + { \
        all: [], \
        by_year: {}, \
        not_empty: false \
    }")

    if [ ${#child_pages[@]} -ne 0 ]; then
        #echo -e "\033[0;90m[////////]\033[0m Child pages:"

        pages=$(echo "$pages" | jq ".not_empty = true")

        for file in "${child_pages[@]}"; do
            #echo -e "\033[0;90m[////////]\033[0m   -  $file"

            metadata=$(metadata "$file")

            url_rel=$(target_url_rel "$basedir" "$file" "html")
            url_abs=$(target_url_abs "$file" "html")
            url_full="${SITE%/}$url_abs"

            date=$(echo "$metadata" | jq -r .date)
            date_rfc3339=""

            if [ "$date" != "" ]; then
                date_rfc3339=$(date -d "$date" --rfc-3339=seconds | sed 's/ /T/')
            fi

            metadata=$(echo "$metadata" | jq ". * { \
                date: { \
                    yyyy_mm_dd: \"$date\", \
                    rfc3339: \"$date_rfc3339\" \
                }, \
                url: { \
                    rel: \"$url_rel\", \
                    abs: \"$url_abs\", \
                    full: \"$url_full\" \
                } \
            }")

            pages=$(echo "$pages" | jq ".all += [ $metadata ]")

            if [ "$date" != "" ]; then
                date_year=$(date -d "$date" +%Y)
                #date_month=$(date -d "$date" +%m)
                #date_day=$(date -d "$date" +%d)

                pages=$(echo "$pages" | jq ".by_year.\"$date_year\" += [ $metadata ]")
            fi
        done

        pages=$(echo "$pages" \
            | jq ".all |= (sort_by(.date) | reverse) \
                | .by_year |= (to_entries | sort_by(.key) | reverse \
                    | .[].value |= (sort_by(.date) | reverse))")
    fi

    echo "{}" | jq ". + { \
        pages: $pages \
    }"
}

handle () {
    target_file=$(target_filename "$1")

    mkdir -p $(dirname "$target_file")

    if [ "${1#*.}" = "md" ]; then
        echo -e "\033[0;32m[COMPILE ]\033[0m $1 -> $target_file"

        meta_file=$(mktemp)

        metadata=$(metadata "$file")
        metadata=$(echo "[ \
            $metadata, \
            $(get_subpages_meta "$1") \
        ]" | jq ".[0] * .[1]")

        url_abs=$(target_url_abs "$1" "html")
        url_full="${SITE%/}$url_abs"

        section=$(get_section "$1")

        is_home=false
        if [ "$target_file" = "${OUTPUT_DIR}index.html" ]; then
            is_home=true
        fi

        metadata=$(echo "$metadata" | jq ". * { \
            url: { \
                abs: \"$url_abs\", \
                full: \"$url_full\" \
            }, \
            section: { \
                id: \"$section\", \
                is_$section: true \
            }, \
            is_home: $is_home \
        }")

        create_feed=$(echo "$metadata" | jq -r ".create_feed")

        if [ "$create_feed" = "true" ]; then
            feed_target_file="${target_file%.html}.xml"
            feed_url_abs="$(target_url_abs "$1" "xml")"
            feed_url_full="${SITE%/}$feed_url_abs"
            last_update=$(echo "$metadata" | jq -r ".pages.all[0].date")

            metadata=$(echo "$metadata" | jq ". * { \
                feed: { \
                    last_update: $last_update, \
                    url: { \
                        abs: \"$feed_url_abs\", \
                        full: \"$feed_url_full\" \
                    } \
                } \
            }")

            echo "$metadata" > "$meta_file"
            
            pandoc "$1" \
                -f markdown \
                -t html5 \
                --template "${TEMPLATES_DIR}feed.xml" \
                -o "$feed_target_file" \
                --metadata-file metadata/metadata.yaml \
                --metadata-file "$meta_file" \
                $FILTERS
        fi

        echo "$metadata" > "$meta_file"

        pandoc "$1" \
            -f markdown \
            -t html5 \
            --template "${TEMPLATES_DIR}base.html" \
            -o "$target_file" \
            --metadata-file metadata/metadata.yaml \
            --metadata-file "$meta_file" \
            $FILTERS

        rm "$meta_file"

        # echo $(pandoc "$1" \
        #     -f markdown \
        #     -t json)
    else
        echo -e "\033[0;32m[COPY    ]\033[0m $1 -> $target_file"

        cp "$1" "$target_file"
    fi
}

if [ -z "$1" ]; then
    find "$CONTENT_DIR" \
        -type f \
        | while read file
            do
                handle "$file"
            done
elif [ "$1" = "all_md" ]; then
    find "$CONTENT_DIR" \
        -type f \
        -name "*.md" \
        | while read file
            do
                handle "$file"
            done
elif [ "$1" = "single" ]; then
    if [ -z "$2" ]; then
        echo -e "\033[0;31m[ERROR   ]\033[0m \"single\" operation requires file argument"
    else
        handle "$2"
    fi
elif [ "$1" = "delete" ]; then
    if [ -z "$2" ]; then
        echo -e "\033[0;31m[ERROR   ]\033[0m \"delete\" operation requires file argument"
    else
        target_file=$(target_filename "$2")
        echo -e "\033[0;32m[DELETE  ]\033[0m $2 -> $target_file"
        rm -rf $target_file
    fi
else
    echo -e "\033[0;31m[ERROR   ]\033[0m Unknown operation: \"$1\""
fi