#!/bin/bash

# rom_system_split: split your roms across your local and external storage

# prerequesites:
# - store local roms must be stored in "/storage/roms_local"
# - store external roms must be stored in "/storage/roms"
# - you cannot spread the same system files across multiple locations.
#   if duplicate systems are found, local folders will take preference

LOCAL_FOLDER_NAME="roms_local"
EXT_FOLDER_NAME="roms"

LOCAL_ROM_FOLDERS=$(
    ls -d ${LOCAL_FOLDER_NAME}/*/ |
    sed -e "s/${LOCAL_FOLDER_NAME}//g"
)
EXT_ROM_FOLDERS=$(
    ls -d ${EXT_FOLDER_NAME}/*/ |
    sed -e "s/${EXT_FOLDER_NAME}//g"
)

ES_SYSTEMS="/storage/.emulationstation/es_systems.cfg"

ES_LIST=$(
    cat ${ES_SYSTEMS} |
    grep "<path>" |
    sed -e "s/<path>//g" -e "s/<\/path>//g" -e "s/\/storage\///g"
)


echo "LOCAL_FOLDER_NAME: ${LOCAL_FOLDER_NAME}"
echo "EXT_FOLDER_NAME: ${EXT_FOLDER_NAME}"
echo "EXT_STORAGE: ${EXT_STORAGE}"
echo "EXTERNAL: ${EXTERNAL}"
echo "LOCAL_ROM_FOLDERS: $LOCAL_ROM_FOLDERS{}"
echo "EXT_ROM_FOLDERS: ${EXT_ROM_FOLDERS}"
echo "ES_SYSTEMS: ${ES_SYSTEMS}"
echo "ES_LIST: ${ES_LIST}"


# required paramaters: local/external, rom folder list, es folder list
update_es_folders() {
    folder_name=${LOCAL_FOLDER_NAME}
    orig_folder_name=${EXT_FOLDER_NAME}
    if [[ $1 == "external" ]]
    then
        folder_name=${EXT_FOLDER_NAME}
        orig_folder_name=${LOCAL_FOLDER_NAME}
    fi
    folder_array=( $2 )
    for folder in ${folder_array[@]}
    do
        system=${folder%?}
        # check that the system exists in ES
        if [[ $3 == *"${system}"* ]]
        then
            # skip if there are no files in the folder
            if [ -z "$(ls -A /storage/${folder_name}${system})" ]
            then
                continue
            fi
            # if the folder doesn't exist in ES, update the original
            if [[ $3 != *"${folder_name}${system}"* ]]
            then
                sed -i -e "s|<path>/storage/${orig_folder_name}${system}</path>|<path>/storage/${folder_name}${system}</path>|g" ${ES_SYSTEMS}
            fi
        fi
    done
}
systemctl stop emustation

# check the external folders first
update_es_folders "external" "${EXT_ROM_FOLDERS}" "${ES_LIST}"
# next check the local folders
# if there are duplicate folders in EXTERNAL, LOCAL ones will take preference
update_es_folders "local" "${LOCAL_ROM_FOLDERS}" "${ES_LIST}"

systemctl start emustation