#!/bin/bash

CONTENT_DIR="content/"
TEMPLATES_DIR="templates/"
OUTPUT_DIR="output/"

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=$2
    filename=$(realpath --relative-to="$basedir" "$filename")
    filename="${filename%.md}.html"
    if [ "${filename##*/}" = "index.html" ]; then
        filename=${filename%index.html}
    fi
    echo "$filename"
}

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

get_section() {
    filename=$1
    filename=${filename#"$CONTENT_DIR"}
    filename=${filename%.md}
    filename=$(echo "$filename" | cut -f1 -d /)
    if [ "$filename" = "index.md" ]; then
        filename="home"
    fi
    echo "$filename"
}

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

get_subpages() {
    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

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

        collected_metadata="[]"

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

            url_rel=$(target_url_rel "$basedir" "$file")
            url_abs=$(target_url_abs "$file")

            metadata=$(pandoc "$file" \
                -f markdown \
                -t plain \
                --template scripts/metadata_tpl.json)

            metadata=$(echo "$metadata" | jq ". + { url_rel: \"$url_rel\", url_abs: \"$url_abs\" }")

            collected_metadata=$(echo "$collected_metadata" | jq ". + [ $metadata ]")
        done

        collected_metadata=$(echo "$collected_metadata" | jq "sort_by(.date)")

        echo "$collected_metadata"
    fi
}

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

    mkdir -p $(dirname "$target")

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

        is_home=false
        section=$(get_section "$1")

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

        subpages_meta=$(mktemp)

        # $(get_subpages "$1") > "$subpages_meta"

        get_subpages "$1"

        pandoc "$1" \
            -f markdown \
            -t html5 \
            --template "${TEMPLATES_DIR}base.html" \
            -o "$target" \
            --metadata isHome=$is_home \
            --metadata section=$section \
            --metadata-file metadata/metadata.yaml \
            --metadata-file "$subpages_meta"

        rm "$subpages_meta"
    else
        echo -e "\033[0;32m[COPY    ]\033[0m $1 -> $target"

        cp "$1" "$target"
    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 "$2" ]; then
        echo -e "\033[0;31m[ERROR   ]\033[0m \"delete\" operation requires file argument"
    else
        TARGET=$(target_filename "$2")
        echo -e "\033[0;32m[DELETE  ]\033[0m $2 -> $TARGET"
        rm -rf $TARGET
    fi
else
    echo -e "\033[0;31m[ERROR   ]\033[0m Unknown operation: \"$1\""
fi