[grilo-plugins] Add grl-steam-store plugin

[Victor Toso <victortoso src gnome org>]

commit 6ffe48330ff652a347cd98c4926d04b43e191e86
Author: Tony Crisci <tony dubstepdish com>
Date:   Sun Sep 30 13:57:10 2018 -0400

    Add grl-steam-store plugin
    
    The Steam Store API plugin fetches Steam metadata from a Steam app id.
    
    From discussion in grilo-plugins!33
     > In gnome-games, we get the ids from the file system. Steam has
     > registry files at ~/.steam/registry.vdf and
     > ~/.local/share/Steam/steamapps/*.acf which contain the application ids
     > of the installed games.
    
    Fixes #29

 src/lua-factory/sources/grl-steam-store.lua | 152 ++++++++++++++++++++++++++++
 src/lua-factory/sources/meson.build         |   1 +
 2 files changed, 153 insertions(+)
---
diff --git a/src/lua-factory/sources/grl-steam-store.lua b/src/lua-factory/sources/grl-steam-store.lua
new file mode 100644
index 0000000..2bab40f
--- /dev/null
+++ b/src/lua-factory/sources/grl-steam-store.lua
@@ -0,0 +1,152 @@
+--[[
+* Copyright (C) 2018 Grilo Project
+*
+* This library is free software; you can redistribute it and/or
+* modify it under the terms of the GNU Lesser General Public License
+* as published by the Free Software Foundation; version 2.1 of
+* the License, or (at your option) any later version.
+*
+* This library is distributed in the hope that it will be useful, but
+* WITHOUT ANY WARRANTY; without even the implied warranty of
+* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
+* Lesser General Public License for more details.
+*
+* You should have received a copy of the GNU Lesser General Public
+* License along with this library; if not, write to the Free Software
+* Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA
+* 02110-1301 USA
+*
+--]]
+
+---------------------------
+-- Source initialization --
+---------------------------
+
+source = {
+  id = "grl-steam-store",
+  name = "Steam Store",
+  description = "a source for game information from the Steam store api",
+  supported_keys = { "title", "description", "thumbnail", "external-url", "rating", "publication-date", 
"genre", "developer", "publisher"},
+  resolve_keys = {
+    ["type"] = "none",
+    required = { "id" },
+  },
+  tags = { 'games', 'net:internet' },
+}
+
+netopts = {
+  user_agent = "Grilo Source SteamStore/0.3.0",
+}
+
+------------------
+-- Source utils --
+------------------
+
+BASE_API_URL = "https://store.steampowered.com/api/appdetails?appids=";
+
+---------------------------------
+-- Handlers of Grilo functions --
+---------------------------------
+
+function grl_source_resolve()
+  local url, req
+
+  req = grl.get_media_keys()
+  if not req or not req.id
+    or #req.id == 0 then
+    grl.callback()
+    return
+  end
+
+  url = BASE_API_URL .. req.id
+  grl.debug('Fetching URL ' .. url .. ' for appid ' .. req.id)
+  grl.fetch(url, netopts, fetch_game_cb, req.id)
+end
+
+---------------
+-- Utilities --
+---------------
+
+function format_date(date)
+  local month_map = {
+    Jan = 1,
+    Feb = 2,
+    Mar = 3,
+    Apr = 4,
+    May = 5,
+    Jun = 6,
+    Jul = 7,
+    Aug = 8,
+    Sep = 9,
+    Oct = 10,
+    Nov = 11,
+    Dec = 12,
+  }
+  month, day, year = string.match(date, '^(%w+) (%d+), (%d+)')
+  day = tonumber(day)
+  year = tonumber(year)
+
+  if not month or not month_map[month] or not day or not year then
+    grl.warning('could not parse date: ' .. date)
+    return nil
+  end
+
+  return string.format("%d-%d-%d", year, month_map[month], day)
+end
+
+function fetch_game_cb(results, appid)
+  local results_table, data, media
+
+  results_table = grl.lua.json.string_to_table(results)
+
+  if not results_table[appid] or not results_table[appid].data then
+    grl.warning('Got a result without data')
+    grl.callback()
+    return
+  end
+
+  data = results_table[appid].data
+
+  media = {}
+
+  -- simple properties
+  local propmap = {
+    title = 'name',
+    description = 'about_the_game',
+    thumbnail = 'header_image',
+    external_url = 'website',
+    developer = 'developers',
+    publisher = 'publishers',
+  }
+
+  for media_key, data_key in pairs(propmap) do
+    if data[data_key] then
+      media[media_key] = data[data_key]
+    end
+  end
+
+  -- genre
+  if data.genres and #data.genres > 0 then
+    media.genre = {}
+    for i, genre_info in ipairs(data.genres) do
+      if genre_info.description then
+        table.insert(media.genre, genre_info.description)
+      end
+    end
+  end
+
+  -- rating
+  if type(data.metacritic) == 'table' and data.metacritic.score then
+    media.rating = data.metacritic.score
+  end
+
+  -- publication-date
+  if type(data.release_date) == 'table' and data.release_date.date then
+    local date = format_date(data.release_date.date)
+    if date then
+      media.publication_date = date
+    end
+  end
+
+  grl.callback(media, 0)
+end
diff --git a/src/lua-factory/sources/meson.build b/src/lua-factory/sources/meson.build
index adddf0f..37aba5a 100644
--- a/src/lua-factory/sources/meson.build
+++ b/src/lua-factory/sources/meson.build
@@ -15,6 +15,7 @@ sources = [
     'grl-musicbrainz',
     'grl-radiofrance',
     'grl-spotify-cover',
+    'grl-steam-store',
     'grl-theaudiodb-cover',
     'grl-thegamesdb',
     'grl-video-title-parsing',