emots.gbs.io.downloader.bash

#!/bin/bash

INDEX_URL="http://emotes.gbs.io/"
ZIP_URL="https://s3.amazonaws.com/emotes.gbs.io/pidgin.zip"
ZIP_OUT="pidgin.zip"

ERROR_UNSPECIFIED=1
ERROR_NO_ETAG=2
ERROR_DOWNLOAD_FAIL=3
ERROR_UNZIP_FAIL=4

headers=`curl -sIX HEAD "$ZIP_URL"`
new_etag=""
if [[ $headers =~ [Ee][Tt][Aa][Gg]:\ \"(.*)\" ]]; then
    new_etag="${BASH_REMATCH[1]}";
else
    exit $ERROR_NO_ETAG;
fi

if [ -f "${ZIP_OUT}.etag" ]; then
    old_etag=`cat "${ZIP_OUT}.etag"`

    if [[ "$old_etag" == "$new_etag" ]]; then
        # no changes, exit with success
        exit 0
    fi
fi

if curl -s "$ZIP_URL" > "$ZIP_OUT"; then
    if unzip -uq "$ZIP_OUT"; then
        echo $new_etag > "${ZIP_OUT}.etag"
        # woo! success
        exit 0
    else
        exit $ERROR_UNZIP_FAIL
    fi
else
    exit $ERROR_DOWNLOAD_FAIL
fi

exit $ERROR_UNSPECIFIED;