1 files changed, 100 insertions, 0 deletions
diff --git a/Homework/cs5260/consumer/dao/DynamoWidgetDAO.ts b/Homework/cs5260/consumer/dao/DynamoWidgetDAO.ts
new file mode 100644
index 0000000..a90788f
--- /dev/null
+++ b/Homework/cs5260/consumer/dao/DynamoWidgetDAO.ts
@@ -0,0 +1,100 @@
+import { Widget, WidgetT } from "@/shared/schema";
+import { WidgetDAO } from ".";
+import { TracingLogger } from "@/consumer/log";
+import {
+  AttributeValue,
+  DeleteItemCommand,
+  DynamoDBClient,
+  GetItemCommand,
+  PutItemCommand,
+} from "@aws-sdk/client-dynamodb";
+
+export class DynamoWidgetDAO implements WidgetDAO {
+  private table: string;
+  private ddbClient: DynamoDBClient;
+  private logger: TracingLogger;
+
+  constructor(table: string, ddbClient: DynamoDBClient, logger: TracingLogger) {
+    this.table = table;
+    this.ddbClient = ddbClient;
+    this.logger = logger;
+  }
+
+  public async retrieve(widget: WidgetT) {
+    const getReq = new GetItemCommand({
+      TableName: this.table,
+      Key: {
+        id: {
+          S: widget.id,
+        },
+      },
+    });
+
+    const response = await this.ddbClient.send(getReq);
+    if (response.Item) {
+      this.logger.info(`sucessfully retrieved Widget=(${widget.id})`);
+      return this.deflate(response.Item);
+    }
+  }
+
+  public async save(widget: WidgetT) {
+    const putReq = new PutItemCommand({
+      TableName: this.table,
+      Item: this.inflate(widget),
+    });
+
+    await this.ddbClient.send(putReq);
+
+    this.logger.info(`sucessfully saved Widget=(${widget.id})`);
+    return widget;
+  }
+
+  public async delete(widget: WidgetT) {
+    const deleteReq = new DeleteItemCommand({
+      TableName: this.table,
+      Key: {
+        id: { S: widget.id },
+      },
+    });
+
+    await this.ddbClient.send(deleteReq);
+
+    this.logger.info(`sucessfully deleted Widget=(${widget.id})`);
+    return widget;
+  }
+
+  private inflate(widget: WidgetT): Record<string, AttributeValue> {
+    const additionalAttributes =
+      widget.otherAttributes?.reduce((acc, { name, value }) => {
+        acc[name] = { S: value };
+        return acc;
+      }, {} as Record<string, { S: string }>) ?? {};
+    if (widget.label) additionalAttributes["label"] = { S: widget.label };
+    if (widget.description)
+      additionalAttributes["description"] = { S: widget.description };
+
+    return {
+      id: { S: widget.id },
+      owner: { S: widget.owner },
+      ...additionalAttributes,
+    };
+  }
+
+  private deflate(item: Record<string, AttributeValue>): WidgetT {
+    const respWidget = Object.keys(item).reduce((widge, key: string) => {
+      const attributeValue = item![key];
+      if (["id", "owner", "label", "description"].includes(key)) {
+        widge[key] = attributeValue.S;
+        return widge;
+      }
+
+      const attribute = { name: key, value: attributeValue.S! };
+      widge["otherAttributes"] = widge["otherAttributes"]?.concat([
+        attribute,
+      ]) ?? [attribute];
+
+      return widge;
+    }, {} as Record<string, any>);
+    return Widget.parse(respWidget);
+  }
+}