Add metadata field for threads

Useful for e.g. storing plugin-specific data about a thread.

src/data/Thread.js

@@ -28,6 +28,7 @@ const {THREAD_MESSAGE_TYPE, THREAD_STATUS, DISCORD_MESSAGE_ACTIVITY_TYPES} = req
  * @property {String} log_storage_type
  * @property {Object} log_storage_data
  * @property {String} created_at
+ * @property {String} metadata
  */
 class Thread {
   constructor(props) {
@@ -38,6 +39,12 @@ class Thread {
         this.log_storage_data = JSON.parse(props.log_storage_data);
       }
     }
+
+    if (props.metadata) {
+      if (typeof props.metadata === "string") {
+        this.metadata = JSON.parse(props.metadata);
+      }
+    }
   }
 
   getSQLProps() {
@@ -767,6 +774,30 @@ class Thread {
         log_storage_data,
       });
   }
+
+  /**
+   * @param {string} key
+   * @param {*} value
+   * @return {Promise<void>}
+   */
+  async setMetadataValue(key, value) {
+    this.metadata = this.metadata || {};
+    this.metadata[key] = value;
+
+    await knex("threads")
+      .where("id", this.id)
+      .update({
+        metadata: this.getSQLProps().metadata,
+      });
+  }
+
+  /**
+   * @param {string} key
+   * @returns {*}
+   */
+  getMetadataValue(key) {
+    return this.metadata ? this.metadata[key] : null;
+  }
 }
 
 module.exports = Thread;

src/data/migrations/20201012183935_add_metadata_field_to_threads.js

@@ -0,0 +1,11 @@
+exports.up = async function(knex) {
+  await knex.schema.table("threads", table => {
+    table.text("metadata").nullable().defaultTo(null);
+  });
+};
+
+exports.down = async function(knex) {
+  await knex.schema.table("threads", table => {
+    table.dropColumn("metadata");
+  });
+};