From a715becca38951452bd303da136510ef947d82a9 Mon Sep 17 00:00:00 2001
From: syeopite <syeopite@syeopite.dev>
Date: Sun, 14 Nov 2021 08:37:50 -0800
Subject: [PATCH] Add special error page for InitialInnerTubeParseException

---
 src/invidious/errors/errors.cr             |  3 ++
 src/invidious/errors/special_exceptions.cr | 45 ++++++++++++++++++++--
 src/invidious/yt_backend/youtube_api.cr    | 21 +++++++++-
 3 files changed, 65 insertions(+), 4 deletions(-)

diff --git a/src/invidious/errors/errors.cr b/src/invidious/errors/errors.cr
index 2a9cbefd..3f7bfe8e 100644
--- a/src/invidious/errors/errors.cr
+++ b/src/invidious/errors/errors.cr
@@ -15,8 +15,11 @@ def github_details_backtrace(summary : String, content : String)
 end
 
 def generic_error_template_helper(env : HTTP::Server::Context, locale : Hash(String, JSON::Any) | Nil, status_code : Int32, exception : Exception)
+  # Custom error routing
   if exception.is_a?(InfoException)
     return generic_error_template_helper(env, locale, status_code, exception.message || "")
+  elsif exception.is_a? InitialInnerTubeParseException
+    return exception.error_template_helper(env, locale)
   end
 
   env.response.content_type = "text/html"
diff --git a/src/invidious/errors/special_exceptions.cr b/src/invidious/errors/special_exceptions.cr
index 86ac679a..dac4ebc0 100644
--- a/src/invidious/errors/special_exceptions.cr
+++ b/src/invidious/errors/special_exceptions.cr
@@ -14,10 +14,49 @@ end
 # the error page for debugging/research purposes.
 #
 class InitialInnerTubeParseException < Exception
-  # temporally place holder
-  def self.new(parse_exception, **kwargs)
+  def initialize(@endpoint : String, @client_config : String, @data : String, @status_code : Int32, @mime_type : String, @cause : Exception)
+  end
+
+  def self.new(parse_exception : Exception,
+               endpoint : String,
+               client_config : String,
+               data : String,
+               status_code : Int32,
+               mime_type : String)
     instance = InitialInnerTubeParseException.allocate
-    instance.initialize(error_message, parse_exception)
+    instance.initialize(endpoint, client_config, data, status_code, mime_type, cause: parse_exception)
     return instance
   end
+
+  private def render_innertube_metadata_section(locale)
+    contents = %(\n\n<details>)
+    contents += %(\n<summary>InnerTube request metadata</summary>)
+    contents += %(\n<p>\n)
+    contents += %(\n   \n```\n)
+
+    contents += %(Endpoint: `#{@endpoint}`\n)
+    contents += %(\nClient config: ```json\n#{@client_config}\n```\n)
+    contents += %(\nData: ```json\n#{@data}\n```\n)
+    contents += %(\nStatus code: `#{@status_code}`\n)
+    contents += %(MIME type: `#{@mime_type}`)
+
+    contents += %(\n```)
+    contents += %(\n</p>)
+    contents += %(\n</details>)
+
+    return HTML.escape(contents)
+  end
+
+  def error_template_helper(env, locale)
+    env.response.content_type = "text/html"
+    env.response.status_code = 500
+
+    # HTML rendering.
+    exception = @cause.not_nil!
+    backtrace = github_details_backtrace("Backtrace", @cause.not_nil!.inspect_with_backtrace)
+    backtrace += render_innertube_metadata_section(locale)
+    error_message = rendered "error_pages/generic"
+
+    return templated "error_pages/generic_wrapper"
+  end
 end
diff --git a/src/invidious/yt_backend/youtube_api.cr b/src/invidious/yt_backend/youtube_api.cr
index 27f25036..0f94cda1 100644
--- a/src/invidious/yt_backend/youtube_api.cr
+++ b/src/invidious/yt_backend/youtube_api.cr
@@ -135,6 +135,15 @@ module YoutubeAPI
         proxy_region: @proxy_region,
       }.to_s
     end
+
+    # Converts to hash for displaying on error pages
+    def to_h
+      return {
+        client_type:  self.name,
+        region:       @region,
+        proxy_region: @proxy_region,
+      }
+    end
   end
 
   # Default client config, used if nothing is passed
@@ -435,7 +444,17 @@ module YoutubeAPI
     end
 
     # Convert result to Hash
-    initial_data = JSON.parse(response.body).as_h
+    begin
+      initial_data = JSON.parse(response.body).as_h
+    rescue ex
+      raise InitialInnerTubeParseException.new(ex,
+        endpoint: endpoint.to_s,
+        client_config: client_config.to_h.to_pretty_json,
+        data: data.to_pretty_json,
+        status_code: response.status_code,
+        mime_type: "#{response.mime_type.try &.media_type}"
+      )
+    end
 
     # Error handling
     if initial_data.has_key?("error")