[grilo-plugins] grl-acoustid: Add query operation to return multiple results

[Victor Toso <victortoso src gnome org>]

commit 14c5801b3bdc195c4de3320bd22214e8344c11f1
Author: Sumaid Syed <sumaidsyed gmail com>
Date:   Fri Aug 2 22:50:50 2019 +0530

    grl-acoustid: Add query operation to return multiple results
    
    Before the logic was to return the recording with most sources.
    Now, we need to return multiple results.
    We need to retrieve first release belonging to each release
    group of each recording which matched with the given chromaprint.
    
    https://gitlab.gnome.org/GNOME/grilo-plugins/issues/51

 src/lua-factory/sources/grl-acoustid.lua | 72 +++++++++++++++++++++++++++++++-
 1 file changed, 70 insertions(+), 2 deletions(-)
---
diff --git a/src/lua-factory/sources/grl-acoustid.lua b/src/lua-factory/sources/grl-acoustid.lua
index 0acc4c26..71149417 100644
--- a/src/lua-factory/sources/grl-acoustid.lua
+++ b/src/lua-factory/sources/grl-acoustid.lua
@@ -50,7 +50,8 @@ netopts = {
 acoustid = {}
 
 -- https://acoustid.org/webservice#lookup
-ACOUSTID_LOOKUP = 
"https://api.acoustid.org/v2/lookup?client=%s&meta=compress+recordings+releasegroups+releases+sources+tracks&duration=%d&fingerprint=%s";
+ACOUSTID_ROOT_URL = 
"https://api.acoustid.org/v2/lookup?client=%s&meta=compress+recordings+releasegroups+releases+sources+tracks";
+ACOUSTID_LOOKUP_FINGERPRINT = ACOUSTID_ROOT_URL .. "&duration=%d&fingerprint=%s"
 
 ---------------------------------
 -- Handlers of Grilo functions --
@@ -72,15 +73,46 @@ function grl_source_resolve ()
     return
   end
 
-  url = string.format (ACOUSTID_LOOKUP, acoustid.api_key, media.duration,
+  url = string.format (ACOUSTID_LOOKUP_FINGERPRINT, acoustid.api_key, media.duration,
                        media.chromaprint)
   grl.fetch (url, netopts, lookup_cb_resolve)
 end
 
+-- Query is a Method of acoustid's webservice to perform a lookup operation
+-- See: https://acoustid.org/webservice
+-- by fingerprint: duration=duration&fingerprint=fingerprint
+function grl_source_query (query)
+  local url
+  duration, fingerprint = query:match("duration=(%d+)&fingerprint=(%w+)")
+  if duration and fingerprint then
+    url = string.format(ACOUSTID_ROOT_URL .. "&" .. query, acoustid.api_key)
+    grl.fetch (url, netopts, lookup_cb_query)
+  else
+    grl.callback ()
+    return
+  end
+end
+
 ---------------
 -- Utilities --
 ---------------
 
+function get_count(results)
+  local count = 0
+
+  if results and #results > 0 then
+    for _,result in ipairs(results) do
+      if result.recordings and #result.recordings > 0 then
+        for _,recording in ipairs(result.recordings) do
+          count = count + #recording.releasegroups
+        end
+      end
+    end
+  end
+
+  return count
+end
+
 function lookup_cb_resolve (feed)
   local sources = 0
   local record, releasegroup
@@ -114,6 +146,42 @@ function lookup_cb_resolve (feed)
   end
 end
 
+function lookup_cb_query (feed)
+  local count
+  if not feed then
+    grl.callback()
+    return
+  end
+
+  local json = grl.lua.json.string_to_table (feed)
+  if not json or json.status ~= "ok" or
+     not json.results or #json.results <= 0 then
+    grl.callback()
+  end
+
+  count = grl.get_options("count")
+  if not count or count <= 0 then
+    count = get_count(json.results)
+  end
+  for _,result in ipairs(json.results) do
+    if result.recordings and
+      #result.recordings > 0 then
+      for _, recording in ipairs(result.recordings) do
+        if recording.releasegroups and
+          #recording.releasegroups > 0 then
+          for _, releasegroup in ipairs(recording.releasegroups) do
+            count = count - 1
+            media = build_media (recording, releasegroup)
+            grl.callback (media, count)
+            if count == 0 then
+              return
+            end
+          end
+        end
+      end
+    end
+  end
+end
 
 function build_media(record, releasegroup)
   local media = {}