From 803cc34d47406a3fe62ae3db649dfcd3d3c2eb7d Mon Sep 17 00:00:00 2001
From: Patrik Oldsberg <poldsberg@gmail.com>
Date: Wed, 10 Mar 2021 21:46:47 +0100
Subject: [PATCH] todo-backend: add ordering support

Signed-off-by: Patrik Oldsberg <poldsberg@gmail.com>
---
 .../src/service/TodoReaderService.ts          | 22 ++++++++-
 plugins/todo-backend/src/service/router.ts    | 48 ++++++++++++++++++-
 plugins/todo-backend/src/service/types.ts     |  4 ++
 3 files changed, 72 insertions(+), 2 deletions(-)

diff --git a/plugins/todo-backend/src/service/TodoReaderService.ts b/plugins/todo-backend/src/service/TodoReaderService.ts
index 57010ee7e0..85949065e7 100644
--- a/plugins/todo-backend/src/service/TodoReaderService.ts
+++ b/plugins/todo-backend/src/service/TodoReaderService.ts
@@ -78,8 +78,28 @@ export class TodoReaderService implements TodoService {
       offset = totalCount - limit;
     }
 
+    let items = todos.items;
+    const { orderBy } = req;
+    if (orderBy) {
+      const dir = orderBy.direction === 'asc' ? 1 : -1;
+      const field = orderBy.field;
+      items = items.slice().sort((item1, item2) => {
+        const field1 = item1[field];
+        const field2 = item2[field];
+
+        if (field1 && field2) {
+          return dir * field1?.localeCompare(field2, 'en-US');
+        } else if (field1 && !field2) {
+          return -1;
+        } else if (!field1 && field2) {
+          return 1;
+        }
+        return 0;
+      });
+    }
+
     return {
-      items: todos.items.slice(offset, offset + limit),
+      items: items.slice(offset, offset + limit),
       totalCount,
       offset,
       limit,
diff --git a/plugins/todo-backend/src/service/router.ts b/plugins/todo-backend/src/service/router.ts
index 12655cb208..1132b879c4 100644
--- a/plugins/todo-backend/src/service/router.ts
+++ b/plugins/todo-backend/src/service/router.ts
@@ -20,6 +20,13 @@ import express from 'express';
 import Router from 'express-promise-router';
 import { TodoService } from './types';
 
+const ALLOWED_ORDER_BY_FIELDS = [
+  'text',
+  'author',
+  'viewUrl',
+  'repoFilePath',
+] as const;
+
 export interface RouterOptions {
   todoService: TodoService;
 }
@@ -35,6 +42,11 @@ export async function createRouter(
   router.get('/v1/todos', async (req, res) => {
     const offset = parseIntegerParam(req.query.offset, 'offset query');
     const limit = parseIntegerParam(req.query.limit, 'limit query');
+    const orderBy = parseOrderByParam(
+      req.query.orderBy,
+      'orderBy query',
+      ALLOWED_ORDER_BY_FIELDS,
+    );
 
     const entityRef = req.query.entity;
     if (entityRef && typeof entityRef !== 'string') {
@@ -49,7 +61,12 @@ export async function createRouter(
       }
     }
 
-    const todos = await todoService.listTodos({ entity, offset, limit });
+    const todos = await todoService.listTodos({
+      entity,
+      offset,
+      limit,
+      orderBy,
+    });
     res.json(todos);
   });
 
@@ -69,3 +86,32 @@ function parseIntegerParam(str: unknown, ctx: string): number | undefined {
   }
   return parsed;
 }
+
+function parseOrderByParam<T extends readonly string[]>(
+  str: unknown,
+  ctx: string,
+  allowedFields: T,
+): { field: T[number]; direction: 'asc' | 'desc' } | undefined {
+  if (str === undefined) {
+    return undefined;
+  }
+  if (typeof str !== 'string') {
+    throw new InputError(`invalid ${ctx}, must be a string`);
+  }
+  const [field, direction] = str.split('=');
+  if (!field) {
+    throw new InputError(`invalid ${ctx}, field name is empty`);
+  }
+  if (direction !== 'asc' && direction !== 'desc') {
+    throw new InputError(
+      `invalid ${ctx}, order direction must be 'asc' or 'desc'`,
+    );
+  }
+
+  if (field && !allowedFields.includes(field)) {
+    throw new InputError(
+      `invalid orderBy query, must be one of ${allowedFields.join(', ')}`,
+    );
+  }
+  return { field, direction };
+}
diff --git a/plugins/todo-backend/src/service/types.ts b/plugins/todo-backend/src/service/types.ts
index ac8ecc16b5..0f06951132 100644
--- a/plugins/todo-backend/src/service/types.ts
+++ b/plugins/todo-backend/src/service/types.ts
@@ -21,6 +21,10 @@ export type ListTodosRequest = {
   entity?: EntityName;
   offset?: number;
   limit?: number;
+  orderBy?: {
+    field: 'text' | 'author' | 'viewUrl' | 'repoFilePath';
+    direction: 'asc' | 'desc';
+  };
 };
 
 export type ListTodosResponse = {