From e2d01f7eb9e4af2cb6a75c07abb810aae1e1bad3 Mon Sep 17 00:00:00 2001
From: Alex Ling <hkalexling@gmail.com>
Date: Tue, 3 Mar 2020 02:33:32 +0000
Subject: [PATCH] Remove error handling in the `parse_query_result` method of
 MangaDex::Job, and pass the possible exceptions to the frontend and handle
 them there.

---
 public/js/download-manager.js |  4 ++++
 src/mangadex/downloader.cr    | 35 +++++++++++++++--------------------
 src/routes/api.cr             | 18 +++++++++++++-----
 3 files changed, 32 insertions(+), 25 deletions(-)

diff --git a/public/js/download-manager.js b/public/js/download-manager.js
index 7488ee0..d302aa5 100644
--- a/public/js/download-manager.js
+++ b/public/js/download-manager.js
@@ -91,6 +91,10 @@ const load = () => {
 		dataType: 'json'
 	})
 	.done(data => {
+		if (!data.success && data.error) {
+			alert('danger', `Failed to fetch download queue. Error: ${data.error}`);
+			return;
+		}
 		console.log(data);
 		const btnText = data.paused ? "Resume download" : "Pause download";
 		$('#pause-resume-btn').text(btnText);
diff --git a/src/mangadex/downloader.cr b/src/mangadex/downloader.cr
index a061ed2..d773c23 100644
--- a/src/mangadex/downloader.cr
+++ b/src/mangadex/downloader.cr
@@ -33,30 +33,25 @@ module MangaDex
 		property time : Time
 
 		def parse_query_result(res : DB::ResultSet)
-			begin
-				@id = res.read String
-				@manga_id = res.read String
-				@title = res.read String
-				@manga_title = res.read String
-				status = res.read Int32
-				@status_message = res.read String
-				@pages = res.read Int32
-				@success_count = res.read Int32
-				@fail_count = res.read Int32
-				time = res.read Int64
-				@status = JobStatus.new status
-				@time = Time.unix_ms time
-				return true
-			rescue e
-				puts e
-				return false
-			end
+			@id = res.read String
+			@manga_id = res.read String
+			@title = res.read String
+			@manga_title = res.read String
+			status = res.read Int32
+			@status_message = res.read String
+			@pages = res.read Int32
+			@success_count = res.read Int32
+			@fail_count = res.read Int32
+			time = res.read Int64
+			@status = JobStatus.new status
+			@time = Time.unix_ms time
 		end
 
+		# Raises if the result set does not contain the correct set of columns
 		def self.from_query_result(res : DB::ResultSet)
 			job = Job.allocate
-			success = job.parse_query_result res
-			return success ? job : nil
+			job.parse_query_result res
+			return job
 		end
 
 		def initialize(@id, @manga_id, @title, @manga_title, @status, @time)
diff --git a/src/routes/api.cr b/src/routes/api.cr
index 1b9cf9e..5b78ba8 100644
--- a/src/routes/api.cr
+++ b/src/routes/api.cr
@@ -128,11 +128,19 @@ class APIRouter < Router
 		end
 
 		get "/api/admin/mangadex/queue" do |env|
-			jobs = @context.queue.get_all
-			send_json env, {
-				"jobs" => jobs,
-				"paused" => @context.queue.paused?
-			}.to_json
+			begin
+				jobs = @context.queue.get_all
+				send_json env, {
+					"jobs" => jobs,
+					"paused" => @context.queue.paused?,
+					"success" => true
+				}.to_json
+			rescue e
+				send_json env, {
+					"success" => false,
+					"error" => e.message
+				}.to_json
+			end
 		end
 
 		post "/api/admin/mangadex/queue/delete/:id" do |env|