From 36ba69be1fc04e5df9757c5d933a52e71a39c561 Mon Sep 17 00:00:00 2001
From: Omar Roth <omarroth@hotmail.com>
Date: Sat, 2 Jun 2018 19:52:58 -0500
Subject: [PATCH] Add channel page

---
 src/helpers.cr        | 79 +++++++++++++++++++++++++++++++++++++++++++
 src/invidious.cr      | 35 +++++++++++++++++++
 src/views/channel.ecr | 26 ++++++++++++++
 3 files changed, 140 insertions(+)
 create mode 100644 src/views/channel.ecr

diff --git a/src/helpers.cr b/src/helpers.cr
index e7a1e688..040f09fe 100644
--- a/src/helpers.cr
+++ b/src/helpers.cr
@@ -670,3 +670,82 @@ def decode_time(string)
 
   return time
 end
+
+def produce_playlist_url(ucid, index)
+  ucid = ucid.lstrip("UC")
+  ucid = "VLUU" + ucid
+
+  continuation = write_var_int(index)
+  continuation.unshift(0x08_u8)
+  slice = continuation.to_unsafe.to_slice(continuation.size)
+
+  continuation = Base64.urlsafe_encode(slice, false)
+  continuation = "PT:" + continuation
+  continuation = continuation.bytes
+  continuation.unshift(0x7a_u8, continuation.size.to_u8)
+
+  slice = continuation.to_unsafe.to_slice(continuation.size)
+  continuation = Base64.urlsafe_encode(slice)
+  continuation = URI.escape(continuation)
+  continuation = continuation.bytes
+  continuation.unshift(continuation.size.to_u8)
+
+  continuation.unshift(ucid.size.to_u8)
+  continuation = ucid.bytes + continuation
+  continuation.unshift(0x12.to_u8, ucid.size.to_u8)
+  continuation.unshift(0xe2_u8, 0xa9_u8, 0x85_u8, 0xb2_u8, 2_u8, continuation.size.to_u8)
+
+  slice = continuation.to_unsafe.to_slice(continuation.size)
+  continuation = Base64.urlsafe_encode(slice)
+  continuation = URI.escape(continuation)
+
+  url = "/browse_ajax?action_continuation=1&continuation=#{continuation}"
+
+  return url
+end
+
+def read_var_int(bytes)
+  numRead = 0
+  result = 0
+
+  read = bytes[numRead]
+
+  if bytes.size == 1
+    result = bytes[0].to_i32
+  else
+    while ((read & 0b10000000) != 0)
+      read = bytes[numRead].to_u64
+      value = (read & 0b01111111)
+      result |= (value << (7 * numRead))
+
+      numRead += 1
+      if numRead > 5
+        raise "VarInt is too big"
+      end
+    end
+  end
+
+  return result
+end
+
+def write_var_int(value : Int)
+  bytes = [] of UInt8
+  value = value.to_u32
+
+  if value == 0
+    bytes = [0_u8]
+  else
+    while value != 0
+      temp = (value & 0b01111111).to_u8
+      value = value >> 7
+
+      if value != 0
+        temp |= 0b10000000
+      end
+
+      bytes << temp
+    end
+  end
+
+  return bytes
+end
diff --git a/src/invidious.cr b/src/invidious.cr
index f86d9331..679fd748 100644
--- a/src/invidious.cr
+++ b/src/invidious.cr
@@ -908,6 +908,41 @@ get "/videoplayback" do |env|
   end
 end
 
+get "/channel/:ucid" do |env|
+  ucid = env.params.url["ucid"]
+
+  page = env.params.query["page"]?.try &.to_i
+  page ||= 1
+
+  client = make_client(YT_URL)
+
+  if !ucid.starts_with? "UC"
+    rss = client.get("/feeds/videos.xml?user=#{ucid}").body
+    rss = XML.parse_html(rss)
+
+    ucid = rss.xpath_node("//feed/channelid").not_nil!.content
+    env.redirect "/channel/#{ucid}"
+  end
+
+  url = produce_playlist_url(ucid, (page - 1) * 100)
+  response = client.get(url)
+
+  json = JSON.parse(response.body)
+  document = XML.parse_html(json["content_html"].as_s)
+  author = document.xpath_node(%q(//div[@class="pl-video-owner"]/a)).not_nil!.content
+
+  videos = [] of ChannelVideo
+  document.xpath_nodes(%q(//a[contains(@class,"pl-video-title-link")])).each do |item|
+    href = URI.parse(item["href"])
+    id = HTTP::Params.parse(href.query.not_nil!)["v"]
+    title = item.content
+
+    videos << ChannelVideo.new(id, title, Time.now, Time.now, ucid, author)
+  end
+
+  templated "channel"
+end
+
 options "/videoplayback" do |env|
   env.response.headers["Access-Control-Allow-Origin"] = "*"
   env.response.headers["Access-Control-Allow-Methods"] = "GET"
diff --git a/src/views/channel.ecr b/src/views/channel.ecr
new file mode 100644
index 00000000..857ad57a
--- /dev/null
+++ b/src/views/channel.ecr
@@ -0,0 +1,26 @@
+<% content_for "header" do %>
+<title><%= author %> - Invidious</title>
+<% end %>
+
+<h1><%= author %></h1>
+<% videos.each_slice(4) do |slice| %>
+<div class="pure-g">
+    <% slice.each do |video| %>
+        <%= rendered "components/video" %>
+    <% end %>
+</div> 
+<% end %>
+
+<div class="pure-g">
+    <div class="pure-u-1 pure-u-md-1-5">
+    <% if page > 2 %>
+        <a href="/channel/<%= ucid %>?page=<%= page - 1 %>">Previous page</a>
+    <% else %>
+        <a href="/channel/<%= ucid %>">Previous page</a>
+    <% end %>
+    </div>
+    <div class="pure-u-1 pure-u-md-3-5"></div>
+    <div style="text-align:right;" class="pure-u-1 pure-u-md-1-5">
+        <a href="/channel/<%= ucid %>?page=<%= page + 1 %>">Next page</a>
+    </div>
+</div>
\ No newline at end of file