From de9e4124512ca7dafef90b83387efade0a17bf18 Mon Sep 17 00:00:00 2001
From: Daniel Flanagan <daniel@lyte.dev>
Date: Mon, 26 Sep 2022 23:53:34 -0500
Subject: [PATCH] Means to an End done!

---
 main.ts | 52 ++++++++++++++++++++++++++++++++++++++--------------
 1 file changed, 38 insertions(+), 14 deletions(-)

diff --git a/main.ts b/main.ts
index a4d29b7..f3eb57b 100644
--- a/main.ts
+++ b/main.ts
@@ -1,5 +1,4 @@
-import { copy } from "https://deno.land/std@0.157.0/streams/conversion.ts?s=copy";
-import { Buffer } from "https://deno.land/std@0.157.0/io/buffer.ts";
+import { BufReader } from "https://deno.land/std@0.157.0/io/buffer.ts";
 import { ByteSet } from "https://deno.land/x/bytes@1.0.3/mod.ts";
 
 const QUERY_SIZE = 9;
@@ -22,29 +21,54 @@ for await (const conn of listener) {
 // problem 2
 async function meansToAnEnd(conn: Deno.Conn) {
   try {
+    const prices = [];
     for await (const query of queries(conn)) {
-      console.log("Query:", query);
-      conn.write(ByteSet.from(Uint8Array.from([0]), "big").buffer);
+      if (query == null) break;
+      const bs = ByteSet.from(query, "big");
+      const queryChar = String.fromCharCode(bs.read.uint8());
+      const a1 = bs.read.int32();
+      const a2 = bs.read.int32();
+      if (queryChar == "I") {
+        console.log(conn.remoteAddr, "Pushing I:", [a1, a2]);
+        prices.push([a1, a2]);
+      } else if (queryChar == "Q") {
+        console.log(conn.remoteAddr, "Querying:", a1, a2);
+        let numMatches = 0;
+        let sum = 0;
+        for (const [ts, price] of prices) {
+          if (ts < a1 || ts > a2) continue;
+          numMatches++;
+          sum += price;
+        }
+        let result = Math.floor(sum / numMatches);
+        if (isNaN(result)) result = 0;
+        console.log(
+          conn.remoteAddr,
+          `Result for ${prices.length} prices: ${sum} / ${numMatches} = ${result}`,
+        );
+        const response = new ByteSet(4, "big");
+        response.write.int32(result);
+        conn.write(response.buffer);
+      }
     }
     console.log("Done!");
   } catch (err) {
-    console.error(err);
+    console.error("Error processing query:", err);
   }
 }
 
 function queries(conn: Deno.Conn) {
   return {
     async *[Symbol.asyncIterator]() {
-      const b = new Uint8Array(1024);
-      const q = new Uint8Array();
-      let bytesRead = 0;
-      console.debug(b.length);
-      while (bytesRead < QUERY_SIZE) {
-        const n = await conn.read(b);
-        bytesRead += n;
-        console.debug(n, b.length);
+      const b = new Uint8Array(9);
+      const reader = new BufReader(conn, QUERY_SIZE);
+      try {
+        while (await reader.readFull(b) != null) {
+          yield b;
+        }
+      } catch (err) {
+        console.error("Error receiving query:", err);
       }
-      yield q;
     },
   };
 }