common handler

pages/api/account/private-tags/address/[id].ts

-import type { NextApiRequest, NextApiResponse } from 'next'
+import type { NextApiRequest } from 'next'
 
-import fetch from 'pages/api/utils/fetch';
+import handler from 'pages/api/utils/handler';
 
-export default async function handler(_req: NextApiRequest, res: NextApiResponse) {
-  const { id } = _req.query;
-  const url = `/account/v1/user/tags/address/${ id }`;
+const getUrl = (req: NextApiRequest) => `/account/v1/user/tags/address/${ req.query.id }`
 
-  switch (_req.method) {
-    case 'DELETE': {
-      const response = await fetch(url, { method: 'DELETE' });
-      // FIXME: add error handlers
-      if (response.status !== 200) {
-        // eslint-disable-next-line no-console
-        console.log(response.statusText);
-      }
-      res.status(200).end();
-      break;
-    }
+const addressDeleteHandler = handler(getUrl, [ 'DELETE' ]);
 
-    default: {
-      res.setHeader('Allow', [ 'DELETE' ])
-      res.status(405).end(`Method ${ _req.method } Not Allowed`)
-    }
-  }
-}
+export default addressDeleteHandler;

pages/api/account/private-tags/address/index.ts

-import type { NextApiRequest, NextApiResponse } from 'next'
+import handler from 'pages/api/utils/handler';
 
-import fetch from 'pages/api/utils/fetch';
+import type { AddressTags } from 'pages/api/types/account';
 
-export default async function handler(_req: NextApiRequest, res: NextApiResponse) {
-  const url = '/account/v1/user/tags/address';
+const addressHandler = handler<AddressTags>(() => '/account/v1/user/tags/address', [ 'GET', 'POST' ]);
 
-  switch (_req.method) {
-    case 'GET': {
-      const response = await fetch(url)
-      const data = await response.json();
-
-      res.status(200).json(data)
-      break;
-    }
-
-    case 'POST': {
-      const response = await fetch(url, {
-        method: 'POST',
-        body: _req.body,
-      })
-      const data = await response.json();
-
-      res.status(200).json(data)
-      break;
-    }
-
-    default: {
-      res.setHeader('Allow', [ 'GET', 'POST' ])
-      res.status(405).end(`Method ${ _req.method } Not Allowed`)
-    }
-  }
-}
+export default addressHandler;

pages/api/account/private-tags/transaction/[id].ts

-import type { NextApiRequest, NextApiResponse } from 'next'
+import type { NextApiRequest } from 'next'
 
-import fetch from 'pages/api/utils/fetch';
+import handler from 'pages/api/utils/handler';
 
-export default async function handler(_req: NextApiRequest, res: NextApiResponse) {
-  const { id } = _req.query;
-  const url = `/account/v1/user/tags/transaction/${ id }`;
+const getUrl = (req: NextApiRequest) => `/account/v1/user/tags/transaction/${ req.query.id }`
 
-  switch (_req.method) {
-    case 'DELETE': {
-      const response = await fetch(url, { method: 'DELETE' });
-      // FIXME: add error handlers
-      if (response.status !== 200) {
-        // eslint-disable-next-line no-console
-        console.log(response.statusText);
-      }
-      res.status(200).end();
-      break;
-    }
+const transactionDeleteHandler = handler(getUrl, [ 'DELETE' ]);
 
-    default: {
-      res.setHeader('Allow', [ 'DELETE' ])
-      res.status(405).end(`Method ${ _req.method } Not Allowed`)
-    }
-  }
-}
+export default transactionDeleteHandler;

pages/api/account/private-tags/transaction/index.ts

-import type { NextApiRequest, NextApiResponse } from 'next'
+import handler from 'pages/api/utils/handler';
 
-import fetch from 'pages/api/utils/fetch';
+import type { TransactionTags } from 'pages/api/types/account';
 
-export default async function handler(_req: NextApiRequest, res: NextApiResponse) {
-  const url = '/account/v1/user/tags/transaction';
+const transactionHandler = handler<TransactionTags>(() => '/account/v1/user/tags/transaction', [ 'GET', 'POST' ]);
 
-  switch (_req.method) {
-    case 'GET': {
-      const response = await fetch(url)
-      const data = await response.json();
-
-      res.status(200).json(data)
-      break;
-    }
-
-    case 'POST': {
-      const response = await fetch(url, {
-        method: 'POST',
-        body: _req.body,
-      })
-      const data = await response.json();
-
-      res.status(200).json(data)
-      break;
-    }
-
-    default: {
-      res.setHeader('Allow', [ 'GET', 'POST' ])
-      res.status(405).end(`Method ${ _req.method } Not Allowed`)
-    }
-  }
-}
+export default transactionHandler;

pages/api/types/account.ts

+// FIXME: here are types of the elixir api's responses
+// and in types/api/ folder we have types of the node api's responses
+// maybe they are always the same and there is no need to keep two separate files with types
+export interface AddressTag {
+  address_hash: string;
+  name: string;
+  id: string;
+}
+
+export type AddressTags = Array<AddressTag>
+
+export interface ApiKey {
+  apiKey: string;
+  apiKeyName: string;
+}
+
+export type ApiKeys = Array<ApiKey>
+
+export interface ModelError {
+  message: string;
+}
+
+export interface NotificationDirection {
+  incoming: boolean;
+  outcoming: boolean;
+}
+
+export interface NotificationSettings {
+  _native?: NotificationDirection;
+  erc20?: NotificationDirection;
+  erc7211155?: NotificationDirection;
+}
+
+export interface Transaction {
+  fromAddressHash?: string;
+  toAddressHash?: string;
+  createdContractAddressHash?: string;
+}
+
+export interface TransactionTag {
+  transaction_hash: string;
+  name: string;
+  id: string;
+}
+
+export type TransactionTags = Array<TransactionTag>
+
+export type Transactions = Array<Transaction>
+
+export interface UserInfo {
+  name?: string;
+  nickname?: string;
+  email?: string;
+}
+
+export interface WatchlistAddress {
+  addressHash: string;
+  addressName: string;
+  addressBalance: number;
+  coinName: string;
+  exchangeRate?: number;
+  notificationSettings: NotificationSettings;
+}
+
+export interface WatchlistAddressNew {
+  addressName: string;
+  notificationSettings: NotificationSettings;
+}
+
+export type WatchlistAddresses = Array<WatchlistAddress>

pages/api/utils/handler.ts

+import type { NextApiRequest, NextApiResponse } from 'next'
+
+import fetch from './fetch';
+
+type Methods = 'GET' | 'POST' | 'DELETE';
+
+export default function handler<TRes>(getUrl: (_req: NextApiRequest) => string, allowedMethods: Array<Methods>) {
+  return async(_req: NextApiRequest, res: NextApiResponse<TRes>) => {
+    if (_req.method === 'GET' && allowedMethods.includes('GET')) {
+      const response = await fetch(getUrl(_req))
+      const data = await response.json() as TRes;
+
+      res.status(200).json(data);
+    } else if (allowedMethods.includes('POST') && _req.method === 'POST') {
+      const response = await fetch(getUrl(_req), {
+        method: 'POST',
+        body: _req.body,
+      })
+      const data = await response.json() as TRes;
+
+      res.status(200).json(data)
+    } else if (allowedMethods.includes('DELETE') && _req.method === 'DELETE') {
+      const response = await fetch(getUrl(_req), { method: 'DELETE' });
+      // FIXME: add error handlers
+      if (response.status !== 200) {
+        // eslint-disable-next-line no-console
+        console.log(response.statusText);
+      }
+      res.status(200).end();
+    } else {
+      res.setHeader('Allow', allowedMethods)
+      res.status(405).end(`Method ${ _req.method } Not Allowed`)
+    }
+  }
+}