Donki API - CME Updated

Author: Jeffrey Brown

.gitignore

@@ -45,4 +45,4 @@ Thumbs.db
 
 # misc
 .env
-./testing
+apiTesting.js

README.md

@@ -146,6 +146,31 @@
   });
   ```
 
+  #### DONKI
+  The `donki()` function provides access to the Space Weather Database of Notifications, Knowledge, and Information (DONKI). This API is particularly useful for space weather forecasters, scientists, and the general space science community.
+
+  The API consists of a variety of components, each providing access to different data.
+
+  ##### Coronal Mass Ejection (CME)
+
+  Coronal Mass Ejections (CMEs) are large expulsions of plasma and magnetic field from the Sun's corona. This API provides data for specific CME events in a specified time period.
+
+  The `start_date` and `end_date` parameters are optional, and if omitted from the payload the request will default to pulling the last 30 days worth of data.
+
+
+    ```js
+  const payload = {
+    start_date: '2021-01-01', // optional //
+    end_date: '2021-01-02', // optional //
+    key: 'DEMO_KEY',
+    type: 'cme'
+  };
+
+  celestial.donki(payload, cmeResponse => {
+    return cmeResponse;
+  });
+  ```
+
 
   ## Contributing
 

lib/donki.js

@@ -0,0 +1,58 @@
+// import libraries //
+const axios = require('axios')
+const Joi = require('joi')
+
+// import utilities //
+const dateUtils = require('../utils/dates.js')
+
+// neows (near earth object web service) //
+function donki (payload, callback) {
+  let request, start, end, key
+  const type = payload.type
+
+  // donki request type is coronal mass ejection (cme) //
+  if (type === 'cme') {
+
+    // define validation schema //
+    const validationSchema = Joi.object({
+      end_date: Joi.string().regex(/\d{4}-\d{2}-\d{2}/, { name: 'endDate' }).optional(),
+      key: Joi.string().required(),
+      start_date: Joi.string().regex(/\d{4}-\d{2}-\d{2}/, { name: 'startDate' }).optional(),
+      type: Joi.string().regex(/\w{3,6}/, { name: 'requestType' }).required()
+    })
+
+    key = payload.key
+    end = payload.end_date
+    start = payload.start_date
+
+    // validate the payload input //
+    const { error } = validationSchema.validate(payload)
+    if (error) throw error
+
+    // payload logic validation //
+    if (payload.end_date && (payload.start_date > payload.end_date)) throw new Error('Start date cannot come after the end date provided')
+    if (payload.end_date && !payload.start_date) throw new Error('Start Date must be included if using End Date')
+
+    // define url request parameters //
+    let requestURLParameters = `api_key=${key}`
+    if (start) requestURLParameters = requestURLParameters.concat(`&start_date=${payload.start_date}`)
+    if (end) requestURLParameters = requestURLParameters.concat(`&end_date=${payload.end_date}`)
+
+    // define request url //
+    request = `https://api.nasa.gov/DONKI/CME?${requestURLParameters}`
+  }
+
+  // api request //
+  return axios(request)
+    .then((response) => {
+      try {
+        callback(response.data)
+        return response.data
+      } catch (error) {
+        callback(response.data)
+        return response.data
+      }
+    })
+}
+
+module.exports.donki = donki