Add endpoint for file downloads

packages/nylas-api/routes/files.js

@@ -73,4 +73,40 @@ module.exports = (server) => {
       })
     },
   })
+
+  server.route({
+    method: 'GET',
+    path: '/files/{id}/download',
+    config: {
+      description: 'Returns binary data for file with specified id.',
+      notes: 'Notes go here',
+      tags: ['files'],
+      validate: {
+        params: {
+          id: Joi.string(),
+        },
+      },
+    },
+    handler: (request, reply) => {
+      request.getAccountDatabase()
+      .then((db) => {
+        const {headers: {accept}} = request
+        const {params: {id}} = request
+        const account = request.auth.credentials
+
+        db.File.findOne({where: {id}})
+        .then((file) => {
+          if (!file) {
+            return reply.notFound(`File ${id} not found`)
+          }
+          return file.fetch({account, db})
+          .then((stream) => reply(stream))
+        })
+        .catch((error) => {
+          console.log('Error fetching file: ', error)
+          reply(error)
+        })
+      })
+    },
+  })
 };

packages/nylas-core/imap-connection.js

@@ -73,6 +73,24 @@ class IMAPBox {
     })
   }
 
+  fetchStream({messageId, options}) {
+    if (!messageId) {
+      throw new Error("IMAPConnection.fetchStream requires a message identifier.")
+    }
+    if (!options) {
+      throw new Error("IMAPConnection.fetchStream requires an options object.")
+    }
+    return new Promise((resolve, reject) => {
+      const f = this._imap.fetch(messageId, options);
+      f.on('message', (imapMessage) => {
+        imapMessage.on('body', (stream) => {
+          resolve(stream)
+        })
+      })
+      f.once('error', (error) => reject)
+    })
+  }
+
   /**
    * @return {Promise} that resolves to requested message
    */

packages/nylas-core/models/account/file.js

@@ -1,9 +1,12 @@
+const IMAPConnection = require('../../imap-connection')
+const NylasError = require('../../nylas-error')
+
 module.exports = (sequelize, Sequelize) => {
   const File = sequelize.define('file', {
     accountId: { type: Sequelize.STRING, allowNull: false },
     version: Sequelize.INTEGER,
     filename: Sequelize.STRING,
-    contentId: Sequelize.STRING,
+    partId: Sequelize.STRING,
     contentType: Sequelize.STRING,
     size: Sequelize.INTEGER,
   }, {
@@ -13,6 +16,31 @@ module.exports = (sequelize, Sequelize) => {
       },
     },
     instanceMethods: {
+      fetch: function fetch({account, db}) {
+        const settings = Object.assign({}, account.connectionSettings, account.decryptedCredentials())
+        return Promise.props({
+          message: this.getMessage(),
+          connection: IMAPConnection.connect(db, settings),
+        })
+        .then(({message, connection}) => {
+          return message.getCategory()
+          .then((category) => connection.openBox(category.name))
+          .then((imapBox) => imapBox.fetchStream({
+            messageId: message.categoryUID,
+            options: {
+              bodies: [this.partId],
+              struct: true,
+            }
+          }))
+          .then((stream) => {
+            if (stream) {
+              return Promise.resolve(stream)
+            }
+            return Promise.reject(new NylasError(`Unable to fetch binary data for File ${this.id}`))
+          })
+          .finally(() => connection.end())
+        })
+      },
       toJSON: function toJSON() {
         return {
           id: this.id,
@@ -20,7 +48,7 @@ module.exports = (sequelize, Sequelize) => {
           account_id: this.accountId,
           message_id: this.messageId,
           filename: this.filename,
-          content_id: this.contentId,
+          part_id: this.partId,
           content_type: this.contentType,
           size: this.size,
         };

packages/nylas-sync/imap/fetch-messages-in-category.js

@@ -181,14 +181,19 @@ class FetchMessagesInCategory {
     for (const part of struct) {
       if (part.constructor === Array) {
         this._createFilesFromStruct({message, struct: part})
-      } else if (part.disposition) {
+      } else if (part.type !== 'text' && part.disposition) {
         let filename = null
         if (part.disposition.params) {
           filename = part.disposition.params.filename
         }
+        // Only exposes partId for inline attachments
+        let partId = null
+        if (part.disposition.type === 'inline') {
+          partId = part.partID
+        }
         File.create({
           filename: filename,
-          contentId: part.partID,
+          partId: partId,
           contentType: `${part.type}/${part.subtype}`,
           accountId: this._db.accountId,
           size: part.size,