20-nextcloud.hook

[Trigger]
Operation = Install
Operation = Upgrade
Type = Path
Target = etc/mime.types
Target = usr/share/webapps/nextcloud/resources/config/mimetypemapping.dist.json

[Action]
Description = Updating Nextcloud's mime type mapping...
When = PostTransaction
Exec = /usr/bin/sudo -u nextcloud /usr/local/bin/nextcloud-mimetypes.sh
Depends = bash
Depends = gawk
Depends = sed
Depends = sudo

nextcloud-mimetypes.sh

#! /usr/bin/env bash

if [[ $USER != nextcloud ]]; then
	echo "This script can only be ran by the nextcloud user."
	exit 1
fi

wantedMimeTypes=()
readarray -t systemMimeTypes <<< "$(cat "/etc/mime.types" | sed "/^#..*/d" | sed "/^$/d" | sed "/..*\t/"'!'"d" | sed "s/\s\s*/,/" | sed "s/\s/@/g")"

wantedMimeTypes+=("{")

for i in "${systemMimeTypes[@]}"; do
	numDups="$(awk -F"@" '{ print NF }' <<< "$i")"
	for (( j = 1; j <= $numDups; j++ )); do
		fileType="$(echo -n "$i" | awk 'BEGIN { FS=","; OFS=","; } { print $2 }' | awk 'BEGIN { FS="@"; OFS="@"; } { print $'"$j"' }')"
		if ! grep -Fq "$(echo -e '"'"$fileType"'":')" "/usr/share/webapps/nextcloud/resources/config/mimetypemapping.dist.json"; then
			wantedMimeTypes+=("$(echo -e '\t"'"$fileType"'": ["'"$(echo -n "$i" | awk 'BEGIN { FS=","; OFS=","; } { print $1 }')"'"]'"$([ "$i" != "${systemMimeTypes[-1]}" ] && echo -n ",")")")
		fi
	done
done

wantedMimeTypes+=("}")

echo -n "" > "/etc/webapps/nextcloud/config/mimetypemapping.json"
for i in "${wantedMimeTypes[@]}"; do
	echo "$i" >> "/etc/webapps/nextcloud/config/mimetypemapping.json"
done