#!/bin/sh

if ! [ -f "$1" ]; then
    exit 1
fi

cache="$XDG_CACHE_HOME/lf"
index="$cache/index.json"
file="$(realpath "$1")"

mkdir -p "$cache"

if [ -f "$index" ]; then
    thumbnail="$(jq -r ". \"$file\"" <"$index")"
    if [ "$thumbnail" != "null" ]; then
        if [ ! -f "$cache/$thumbnail" ]; then
            exit 1
        fi
        echo "$cache/$thumbnail"
        exit 0
    fi
fi

thumbnail="$(uuidgen).jpg"

if ! ffmpegthumbnailer -i "$file" -o "$cache/$thumbnail" -s 0 2>/dev/null; then
    exit 1
fi

if [ ! -f "$index" ]; then
    echo "{\"$file\": \"$thumbnail\"}" >"$index"
fi
json="$(jq -r --arg "$file" "$thumbnail" ". + {\"$file\": \"$thumbnail\"}" <"$index")"
echo "$json" >"$index"

echo "$cache/$thumbnail"