Support wallpaper from Unsplash

luasrc/view/themes/argon/sysauth.htm

@@ -72,10 +72,11 @@
 		local mimeType 			= ""
 
 		if fs.access("/etc/config/argon") then
-			if uci:get_first('argon', 'global', 'bing_background') == "1" then
-				local bing = sys.exec("/usr/libexec/argon/bing_wallpaper")
-				if (bing and bing ~= '') then
-					return bing, "Image", ""
+			local online_wallpaper = uci:get_first('argon', 'global', 'online_wallpaper')
+			if (online_wallpaper and online_wallpaper ~= "none") then
+				local picurl = sys.exec("/usr/libexec/argon/online_wallpaper")
+				if (picurl and picurl ~= '') then
+					return picurl, "Image", ""
 				end
 			end
 		end

root/usr/libexec/argon/online_wallpaper

@@ -0,0 +1,68 @@
+#!/bin/sh
+# author jjm2473
+
+WEB_PIC_SRC=$(uci -q get argon.@global[0].online_wallpaper)
+CACHE=/var/run/argon_${WEB_PIC_SRC}.url
+WRLOCK=/var/lock/argon_${WEB_PIC_SRC}.lock
+
+fetch_pic_url() {
+    case $WEB_PIC_SRC in
+    bing)
+        local picpath=$(curl --fail --show-error --max-time 1 \
+            "http://www.bing.com/HPImageArchive.aspx?format=js&n=1" 2>/dev/null |
+            jsonfilter -q -e '@.images[0].url')
+        echo "//www.bing.com${picpath}"
+        ;;
+    unsplash)
+        curl --fail --show-error --max-time 1 \
+            "https://source.unsplash.com/random/1920x1080" 2>/dev/null |
+            sed -E 's#^.*href="([^?]+)\?.*$#\1?fm=jpg\&w=1920\&h=1080#'
+        ;;
+    unsplash_*)
+        local collection_id=${WEB_PIC_SRC#unsplash_}
+        curl --fail --show-error --max-time 1 \
+            "https://source.unsplash.com/collection/${collection_id}/1920x1080" 2>/dev/null |
+            sed -E 's#^.*href="([^?]+)\?.*$#\1?fm=jpg\&w=1920\&h=1080#'
+        ;;
+    esac
+}
+
+try_update() {
+    local lock="$WRLOCK"
+    exec 200>$lock
+
+    if flock -n 200 >/dev/null 2>&1; then
+        local picurl=$(fetch_pic_url)
+        if [ -n "$picurl" ]; then
+            echo "${picurl}" >"$CACHE"
+        else
+            if [ -s "$CACHE" ]; then
+                cat "$CACHE"
+            else
+                touch "$CACHE"
+            fi
+        fi
+        flock -u 200 >/dev/null 2>&1
+    elif [ -s "$CACHE" ]; then
+        cat "$CACHE"
+    fi
+}
+
+get_url() {
+    if [ -f "$CACHE" ]; then
+        local idle_t=$(($(date '+%s') - $(date -r "$CACHE" '+%s' 2>/dev/null || echo '0')))
+        if [ -s "$CACHE" ]; then
+            if [ $idle_t -le 43200 ]; then
+                cat "$CACHE"
+                return
+            fi
+        else
+            if [ $idle_t -le 120 ]; then
+                return
+            fi
+        fi
+    fi
+    try_update
+}
+
+get_url