Add Messages, Drafts, and Smart Compose APIs support (#166)

# Description
This PR adds support for messages, drafts, and smart compose APIs.

# License
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CHANGELOG.md

@@ -4,6 +4,7 @@
 
 ### Added
 * Added support for the free-busy endpoint
+* Added Messages, Drafts, and Smart Compose APIs support
 * Added support for custom authentication, connectors, and credentials APIs
 
 ### Changed

src/main/kotlin/com/nylas/NylasClient.kt

@@ -103,6 +103,14 @@ class NylasClient(
     return Connectors(this)
   }
 
+  /**
+   * Access the Drafts API
+   * @return The Drafts API
+   */
+  fun drafts(): Drafts {
+    return Drafts(this)
+  }
+
   /**
    * Access the Events API
    * @return The Events API
@@ -111,6 +119,22 @@ class NylasClient(
     return Events(this)
   }
 
+  /**
+   * Access the Messages API
+   * @return The Messages API
+   */
+  fun messages(): Messages {
+    return Messages(this)
+  }
+
+  /**
+   * Access the Threads API
+   * @return The Threads API
+   */
+  fun threads(): Threads {
+    return Threads(this)
+  }
+
   /**
    * Access the Webhooks API
    * @return The Webhooks API
@@ -223,6 +247,27 @@ class NylasClient(
     return executeRequest(url, HttpMethod.DELETE, null, resultType)
   }
 
+  /**
+   * Execute a request with a form-body payload to the Nylas API.
+   * @param path The path to request.
+   * @param method The HTTP method to use.
+   * @param requestBody The form-data request body.
+   * @param resultType The type of the response body.
+   * @param queryParams The query parameters.
+   * @suppress Not for public use.
+   */
+  @Throws(AbstractNylasApiError::class, NylasSdkTimeoutError::class)
+  fun <T> executeFormRequest(
+    path: String,
+    method: HttpMethod,
+    requestBody: RequestBody,
+    resultType: Type? = null,
+    queryParams: IQueryParams? = null,
+  ): T {
+    val url = buildUrl(path, queryParams)
+    return executeRequest(url, method, requestBody, resultType)
+  }
+
   private fun buildRequest(
     url: HttpUrl.Builder,
     method: HttpMethod,

src/main/kotlin/com/nylas/models/Attachment.kt

@@ -0,0 +1,49 @@
+package com.nylas.models
+
+import com.squareup.moshi.Json
+
+/**
+ * Class representation of a Nylas attachment object
+ */
+data class Attachment(
+  /**
+   * Globally unique object identifier.
+   */
+  @Json(name = "id")
+  val id: String? = null,
+  /**
+   * Nylas grant ID that is now successfully created.
+   */
+  @Json(name = "grant_id")
+  val grantId: String? = null,
+  /**
+   * The size of the attachment in bytes.
+   */
+  @Json(name = "size")
+  val size: Int? = null,
+  /**
+   * The filename of the attachment.
+   */
+  @Json(name = "filename")
+  val filename: String? = null,
+  /**
+   * The content type of the attachment.
+   */
+  @Json(name = "content_type")
+  val contentType: String? = null,
+  /**
+   * If it's an inline attachment.
+   */
+  @Json(name = "is_inline")
+  val isInline: Boolean? = null,
+  /**
+   * The content ID of the attachment.
+   */
+  @Json(name = "content_id")
+  val contentId: String? = null,
+  /**
+   * The content disposition if the attachment is located inline.
+   */
+  @Json(name = "content_disposition")
+  val contentDisposition: String? = null,
+)

src/main/kotlin/com/nylas/models/ComposeMessageRequest.kt

@@ -0,0 +1,11 @@
+package com.nylas.models
+
+/**
+ * Class representing a request to compose a message.
+ */
+data class ComposeMessageRequest(
+  /**
+   * The prompt that smart compose will use to generate a message suggestion.
+   */
+  val prompt: String,
+)

src/main/kotlin/com/nylas/models/ComposeMessageResponse.kt

@@ -0,0 +1,11 @@
+package com.nylas.models
+
+/**
+ * Class representing a response to a message composition request.
+ */
+data class ComposeMessageResponse(
+  /**
+   * The message suggestion generated by smart compose.
+   */
+  val suggestion: String,
+)

src/main/kotlin/com/nylas/models/CreateAttachmentRequest.kt

@@ -0,0 +1,97 @@
+package com.nylas.models
+
+import com.squareup.moshi.Json
+import java.io.InputStream
+
+/**
+ * Class representing a Nylas attachment object.
+ */
+class CreateAttachmentRequest(
+  /**
+   * The filename of the attachment.
+   */
+  @Json(name = "filename")
+  val filename: String,
+  /**
+   * The content type of the attachment.
+   */
+  @Json(name = "content_type")
+  val contentType: String,
+  /**
+   * The content of the attachment.
+   */
+  @Transient
+  val content: InputStream,
+  /**
+   * The size of the attachment in bytes.
+   */
+  @Json(name = "size")
+  val size: Int,
+  /**
+   * If it's an inline attachment.
+   */
+  @Json(name = "is_inline")
+  val isInline: Boolean? = null,
+  /**
+   * The content ID of the attachment.
+   */
+  @Json(name = "content_id")
+  val contentId: String? = null,
+  /**
+   * The content disposition if the attachment is located inline.
+   */
+  @Json(name = "content_disposition")
+  val contentDisposition: String? = null,
+) {
+  /**
+   * Builder for [CreateAttachmentRequest].
+   * @property filename The filename of the attachment.
+   * @property contentType The content type of the attachment.
+   * @property size The size of the attachment in bytes.
+   */
+  data class Builder(
+    private val filename: String,
+    private val contentType: String,
+    private val content: InputStream,
+    private val size: Int,
+  ) {
+    private var isInline: Boolean? = null
+    private var contentId: String? = null
+    private var contentDisposition: String? = null
+
+    /**
+     * Set if the attachment is inline.
+     * @param isInline If the attachment is inline.
+     * @return The builder.
+     */
+    fun isInline(isInline: Boolean) = apply { this.isInline = isInline }
+
+    /**
+     * Set the content ID of the attachment.
+     * @param contentId The content ID of the attachment.
+     * @return The builder.
+     */
+    fun contentId(contentId: String) = apply { this.contentId = contentId }
+
+    /**
+     * Set the content disposition of the attachment.
+     * @param contentDisposition The content disposition of the attachment.
+     * @return The builder.
+     */
+    fun contentDisposition(contentDisposition: String) = apply { this.contentDisposition = contentDisposition }
+
+    /**
+     * Build the [CreateAttachmentRequest].
+     * @return The [CreateAttachmentRequest].
+     */
+    fun build() = CreateAttachmentRequest(
+      filename = filename,
+      contentType = contentType,
+      content = content,
+      size = size,
+      isInline = isInline,
+      contentId = contentId,
+      contentDisposition = contentDisposition,
+    )
+  }
+}

src/main/kotlin/com/nylas/models/CreateCredentialRequest.kt

@@ -35,7 +35,7 @@ sealed class CreateCredentialRequest(
      * Data that specifies some special data required for a Microsoft credential
      */
     @Json(name = "credential_data")
-    override val credentialData: MicrosoftAdminConsentCredentialData,
+    override val credentialData: CredentialData.MicrosoftAdminConsent,
   ) : CreateCredentialRequest(name, credentialData, CredentialType.ADMINCONSENT)
 
   /**
@@ -51,7 +51,7 @@ sealed class CreateCredentialRequest(
      * Data that specifies some special data required for a Google credential
      */
     @Json(name = "credential_data")
-    override val credentialData: GoogleServiceAccountCredentialData,
+    override val credentialData: CredentialData.GoogleServiceAccount,
   ) : CreateCredentialRequest(name, credentialData, CredentialType.SERVICEACCOUNT)
 
   /**
@@ -67,6 +67,6 @@ sealed class CreateCredentialRequest(
      * Data that specifies some special data required for an override credential
      */
     @Json(name = "credential_data")
-    override val credentialData: ConnectorOverrideCredentialData,
+    override val credentialData: CredentialData.ConnectorOverride,
   ) : CreateCredentialRequest(name, credentialData, CredentialType.CONNECTOR)
 }