#!/bin/sh

# constants
conf="${XDG_CONFIG_DIR:-$HOME/.config}/memeatlas-sync"
cache="${XDG_CACHE_DIR:-$HOME/.cache}/memeatlas-sync"
base_url="https://www.memeatlas.com/"
ex_base_url="https:\/\/www.memeatlas.com\/"
oldindex="none"

# check dependencies
for prog in jq wget; do
	! command -v "$prog" > /dev/null && 
        echo "Error: Program '$prog' not found." && exit 1
done

error() {
    echo "Error: $@" && exit 1
}


# make sure needed dirs exist
[ -d "$conf" ] || mkdir -p "$conf" || error "Could not create config directory"
[ -d "$cache" ] || mkdir -p "$cache" || error "Could not create cache directory"

# get dest dir
[ -f "$conf/config" ] || error "No config file found"
dest="$(cat "$conf/config")"
# TODO: check $dest and s/~/$HOME/


echo "Fetching Index ..."

[ -f "$cache/index" ] && mv "$cache/index" "$cache/index.old" && oldindex=
[ -f "$cache/index.html" ] && rm "$cache/index.html"
wget -q --show-progress -P "$cache" "$base_url"
categories="$(sed '0,/index.html/d; 0,/contact/!d' "$conf/index.html" | \
    head -n -1 | sed 's/^.*href="//; s/.html.*$//')"
for c in $categories; do
    [ -f "$cache/$c.html" ] && rm "$cache/$c.html"
done
echo "$categories" | sed "s/^/$ex_base_url/; s/$/.html/" | wget -q --show-progress -P "$cache" -i -

printf "\nGenerating Index ...\n"

# generate new index
for c in $categories; do
    sed '0,/id="list/d; /flexListItem/!d; s/^.*href="//; s/".*$//' \
        "$cache/$c.html" >> "$cache/index"
done

# check what files are new, create download list
if [ -z "$oldindex" ]; then
    [ -f "$cache/dl" ] && rm "$cache/dl"
    while IFS='' read -r line; do
        grep -q "$line" "$cache/index.old" || echo "$line" >> "$cache/dl"
    done < "$cache/index"
else
    cp "$cache/index" "$cache/dl"
fi

if [ ! -f "$cache/dl" ]; then
    printf "\nDownloading Skipped, already up-to-date...\n"
else
    printf "\nDownloading Images...\n"
        sed "s/^/$ex_base_url/;" "$cache/dl" | \
            wget -q --show-progress -P "$dest" -i -
fi