Re-organize event parsing and decoding

1 files changed, 52 insertions, 0 deletions

diff --git a/packages/pipeline/src/data_sources/etherscan/index.ts b/packages/pipeline/src/data_sources/etherscan/index.ts
new file mode 100644
index 000000000..044fff02e
--- /dev/null
+++ b/packages/pipeline/src/data_sources/etherscan/index.ts
@@ -0,0 +1,52 @@
+import { default as axios } from 'axios';
+import { BlockParam, BlockParamLiteral } from 'ethereum-types';
+
+const ETHERSCAN_URL = 'https://api.etherscan.io/api';
+
+export class Etherscan {
+    private readonly _apiKey: string;
+    constructor(apiKey: string) {
+        this._apiKey = apiKey;
+    }
+
+    /**
+     * Gets the raw events for a specific contract and block range.
+     * @param contractAddress  The address of the contract to get the events for.
+     * @param fromBlock The start of the block range to get events for (inclusive).
+     * @param toBlock The end of the block range to get events for (inclusive).
+     * @returns A list of decoded events.
+     */
+    public async getContractEventsAsync(
+        contractAddress: string,
+        fromBlock: BlockParam = BlockParamLiteral.Earliest,
+        toBlock: BlockParam = BlockParamLiteral.Latest,
+    ): Promise<EventsResponse> {
+        const fullURL = `${ETHERSCAN_URL}?module=logs&action=getLogs&address=${contractAddress}&fromBlock=${fromBlock}&toBlock=${toBlock}&apikey=${
+            this._apiKey
+        }`;
+        const resp = await axios.get<EventsResponse>(fullURL);
+        // TODO(albrow): Check response code.
+        return resp.data;
+    }
+}
+
+// Raw events response from etherescan.io
+export interface EventsResponse {
+    status: string;
+    message: string;
+    result: EventsResponseResult[];
+}
+
+// Events as represented in the response from etherscan.io
+export interface EventsResponseResult {
+    address: string;
+    topics: string[];
+    data: string;
+    blockNumber: string;
+    timeStamp: string;
+    gasPrice: string;
+    gasUsed: string;
+    logIndex: string;
+    transactionHash: string;
+    transactionIndex: string;
+}