2 files changed, 88 insertions, 0 deletions
diff --git a/packages/pipeline/src/data-sources/etherscan/events.ts b/packages/pipeline/src/data-sources/etherscan/events.ts
new file mode 100644
index 000000000..50962a266
--- /dev/null
+++ b/packages/pipeline/src/data-sources/etherscan/events.ts
@@ -0,0 +1,54 @@
+import { AbiDecoder } from '@0xproject/utils';
+import { DecodedLogArgs, LogEntry, LogWithDecodedArgs } from 'ethereum-types';
+import * as R from 'ramda';
+
+import { artifacts } from '../../artifacts';
+
+// 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;
+}
+
+function convertResponseToLogEntry(result: EventsResponseResult): LogEntry {
+    const radix = 10;
+    return {
+        logIndex: parseInt(result.logIndex, radix),
+        transactionIndex: parseInt(result.logIndex, radix),
+        transactionHash: result.transactionHash,
+        blockHash: '',
+        blockNumber: parseInt(result.blockNumber, radix),
+        address: result.address,
+        data: result.data,
+        topics: result.topics,
+    };
+}
+
+function tryToDecodeLogOrNoop(log: LogEntry): LogWithDecodedArgs<DecodedLogArgs> {
+    const abiDecoder = new AbiDecoder([artifacts.Exchange.compilerOutput.abi]);
+    const logWithDecodedArgs = abiDecoder.tryToDecodeLogOrNoop(log);
+    // tslint:disable-next-line:no-unnecessary-type-assertion
+    return logWithDecodedArgs as LogWithDecodedArgs<DecodedLogArgs>;
+}
+
+/**
+ * Parses and abi-decodes the raw events response from etherscan.io.
+ * @param rawEventsResponse The raw events response from etherescan.io.
+ * @returns Parsed and decoded events.
+ */
+export const parseRawEventsResponse = R.pipe(R.map(convertResponseToLogEntry), R.map(tryToDecodeLogOrNoop));
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..0891d351a
--- /dev/null
+++ b/packages/pipeline/src/data-sources/etherscan/index.ts
@@ -0,0 +1,34 @@
+import { default as axios } from 'axios';
+import { BlockParam, BlockParamLiteral, DecodedLogArgs, LogWithDecodedArgs } from 'ethereum-types';
+
+import { EventsResponse, parseRawEventsResponse } from './events';
+
+const ETHERSCAN_URL = 'https://api.etherscan.io/api';
+
+export class Etherscan {
+    private readonly _apiKey: string;
+    constructor(apiKey: string) {
+        this._apiKey = apiKey;
+    }
+
+    /**
+     * Gets the decoded 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<Array<LogWithDecodedArgs<DecodedLogArgs>>> {
+        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.
+        const decodedEvents = parseRawEventsResponse(resp.data.result);
+        return decodedEvents;
+    }
+}