fix: refactor minecraft waypoints message

src/minecraft_coords_table.js

@@ -0,0 +1,91 @@
+const DISCORD_MESSAGE_LIMIT = 2000;
+const CODEBLOCK_FENCE_LENGTH = '```\n'.length + '\n```'.length;
+const MAX_TABLE_LENGTH = DISCORD_MESSAGE_LIMIT - CODEBLOCK_FENCE_LENGTH;
+
+const NO_WAYPOINTS_MESSAGE = 'No publicly shared waypoints available.';
+
+const COLUMNS = ['owner', 'name', 'world', 'coords'];
+const HEADERS = ['Owner', 'Name', 'World', '(x, y, z)'];
+
+function getDateString() {
+  const date = new Date();
+  const pad = (n) => String(n).padStart(2, '0');
+  return `${pad(date.getDate())}/${pad(date.getMonth() + 1)}/${date.getFullYear()}`;
+}
+
+function parseWaypointsCsv(csv) {
+  const [, ...rows] = csv.split('\n').filter((line) => line.length > 0);
+  return rows
+    .filter((row) => row.split(',').length >= 6)
+    .map((row) => {
+      const [owner, name, world, x, y, z] = row.split(',');
+      return { owner, name, world, x, y, z };
+    });
+}
+
+// Mirrors the table's previous merged-cell look: blank out an Owner/World
+// cell when it repeats the value directly above it.
+function collapseRepeatedColumns(waypoints) {
+  let lastOwner = '';
+  let lastWorld = '';
+  return waypoints.map((waypoint) => {
+    const row = {
+      owner: waypoint.owner === lastOwner ? '' : waypoint.owner,
+      name: waypoint.name,
+      world: waypoint.world === lastWorld ? '' : waypoint.world,
+      coords: `(${waypoint.x}, ${waypoint.y}, ${waypoint.z})`,
+    };
+    lastOwner = waypoint.owner;
+    lastWorld = waypoint.world;
+    return row;
+  });
+}
+
+function buildTableLines(rows) {
+  const widths = COLUMNS.map((column, i) => Math.max(HEADERS[i].length, ...rows.map((row) => row[column].length)));
+  const buildSeparator = () => `+${widths.map((width) => '-'.repeat(width + 2)).join('+')}+`;
+  const buildRow = (cells) => `| ${cells.map((cell, i) => cell.padEnd(widths[i])).join(' | ')} |`;
+
+  const separator = buildSeparator();
+  const headerLines = [separator, buildRow(HEADERS), separator];
+  const dataLines = rows.map((row) => buildRow(COLUMNS.map((column) => row[column])));
+
+  return { headerLines, dataLines, separator };
+}
+
+// Packs the table into as few codeblocks as fit Discord's message length
+// limit, repeating the header in every continuation block.
+function packIntoCodeblocks(headerLines, dataLines, separator, titleLine) {
+  const chunks = [];
+  let current = [titleLine, ...headerLines];
+  let hasRows = false;
+
+  dataLines.forEach((dataLine) => {
+    const candidateLength = [...current, dataLine, separator].join('\n').length;
+    if (hasRows && candidateLength > MAX_TABLE_LENGTH) {
+      chunks.push([...current, separator].join('\n'));
+      current = [...headerLines];
+      hasRows = false;
+    }
+    current.push(dataLine);
+    hasRows = true;
+  });
+
+  chunks.push([...current, separator].join('\n'));
+  return chunks.map((chunk) => `\`\`\`\n${chunk}\n\`\`\``);
+}
+
+function buildCoordsMessages(csv) {
+  const waypoints = parseWaypointsCsv(csv);
+  if (waypoints.length === 0) {
+    return [`\`\`\`\n${NO_WAYPOINTS_MESSAGE}\n\`\`\``];
+  }
+
+  const rows = collapseRepeatedColumns(waypoints);
+  const { headerLines, dataLines, separator } = buildTableLines(rows);
+  const titleLine = `Publicly shared waypoints (updated: ${getDateString()})`;
+
+  return packIntoCodeblocks(headerLines, dataLines, separator, titleLine);
+}
+
+module.exports = { buildCoordsMessages };

src/robo_scorp.js

@@ -1,6 +1,7 @@
 const { Client, GatewayIntentBits, Events } = require('discord.js');
 const { MessageGenerator } = require('./message_generation/message_generator');
 const { TcpServer } = require('./tcp_server');
+const { buildCoordsMessages } = require('./minecraft_coords_table');
 const logger = require('./logger');
 
 class RoboScorp {
@@ -89,21 +90,27 @@ class RoboScorp {
   }
 
   #createTcpServer() {
-    this.#tcpServer = new TcpServer(process.env.TCP_CONNECTION_PORT, (tcpMessage) => {
-      this.#discordClient.channels
-        .fetch(process.env.MINECRAFT_COORDS_CHANNEL_ID)
-        .then((channel) => {
-          channel.messages
-            .fetch(process.env.MINECRAFT_COORDS_MESSAGE_ID)
-            .then((discordMessage) => {
-              const codeblock = '```\n';
-              discordMessage.edit(codeblock + tcpMessage + codeblock);
-            })
-            .catch(logger.error, RoboScorp.LogLabel.Discord);
-        })
-        .catch(logger.error, RoboScorp.LogLabel.Discord);
+    this.#tcpServer = new TcpServer(process.env.TCP_CONNECTION_PORT, (csvMessage) => {
+      this.#updateCoordsChannel(csvMessage).catch((err) => logger.error(err, RoboScorp.LogLabel.Discord));
     });
   }
+
+  async #updateCoordsChannel(csvMessage) {
+    logger.info(csvMessage);
+    const channel = await this.#discordClient.channels.fetch(process.env.MINECRAFT_COORDS_CHANNEL_ID);
+
+    const previousMessages = await channel.messages.fetch({ limit: 100 });
+    const ownMessages = previousMessages.filter((message) => message.author.id === this.#discordClient.user.id);
+    await Promise.allSettled(ownMessages.map((message) => message.delete()));
+
+    const coordsMessages = buildCoordsMessages(csvMessage);
+    logger.info(coordsMessages);
+    for (const messageContent of coordsMessages) {
+      await channel.send(messageContent).catch((err) => {
+        logger.error(`Failed to send coords message (${messageContent.length} chars): ${err}`, RoboScorp.LogLabel.Discord);
+      });
+    }
+  }
 }
 
 module.exports = { RoboScorp };

src/tcp_server.js

@@ -18,8 +18,14 @@ class TcpServer {
   }
 
   #onClientConnection = (sock) => {
+    const chunks = [];
+
     sock.on('data', (data) => {
-      const dataString = data.toString('utf8');
+      chunks.push(data);
+    });
+
+    sock.on('end', () => {
+      const dataString = Buffer.concat(chunks).toString('utf8');
       if (dataString.length > 0) {
         logger.debug(`Received message: ${dataString}`, TcpServer.LogLabel);
         this.#onMessageFunction(dataString);