1 files changed, 66 insertions, 0 deletions
diff --git a/src/helpers.cr b/src/helpers.cr
new file mode 100644
index 00000000..d2186d6c
--- /dev/null
+++ b/src/helpers.cr
@@ -0,0 +1,66 @@
+# See http://www.evanmiller.org/how-not-to-sort-by-average-rating.html
+def ci_lower_bound(pos, n)
+  if n == 0
+    return 0
+  end
+
+  # z value here represents a confidence level of 0.95
+  z = 1.96
+  phat = 1.0*pos/n
+
+  return (phat + z*z/(2*n) - z * Math.sqrt((phat*(1 - phat) + z*z/(4*n))/n))/(1 + z*z/n)
+end
+
+def elapsed_text(elapsed)
+  millis = elapsed.total_milliseconds
+  return "#{millis.round(2)}ms" if millis >= 1
+
+  "#{(millis * 1000).round(2)}µs"
+end
+
+def get_client
+  while POOL.empty?
+    sleep rand(0..10).milliseconds
+  end
+
+  return POOL.shift
+end
+
+def fetch_video(id)
+  # Grab connection from pool
+  client = get_client
+
+  info = client.get("/get_video_info?video_id=#{id}&el=detailpage&ps=default&eurl=&gl=US&hl=en").body
+  info = HTTP::Params.parse(info)
+
+  html = client.get("/watch?v=#{id}").body
+  html = XML.parse_html(html)
+
+  if info["reason"]?
+    raise info["reason"]
+  end
+
+  # Return connection to pool
+  POOL << client
+
+  video = Video.new(id, info, html, Time.now)
+
+  return video
+end
+
+def get_video(id, refresh = true)
+  if PG_DB.query_one?("SELECT EXISTS (SELECT true FROM videos WHERE id = $1)", id, as: Bool)
+    video = PG_DB.query_one("SELECT * FROM videos WHERE id = $1", id, as: Video)
+
+    # If record was last updated more than 5 hours ago, refresh (expire param in response lasts for 6 hours)
+    if refresh && Time.now - video.updated > Time::Span.new(0, 5, 0, 0)
+      video = fetch_video(id)
+      PG_DB.exec("UPDATE videos SET info = $2, html = $3, updated = $4 WHERE id = $1", video.to_a)
+    end
+  else
+    video = fetch_video(id)
+    PG_DB.exec("INSERT INTO videos VALUES ($1, $2, $3, $4)", video.to_a)
+  end
+
+  return video
+end