Simplify telemetry to three game events

src/lib/telemetry.ts

@@ -1,6 +1,49 @@
-export interface RoundTelemetry {
-    server: string;
-    round: number;
-    players: number;
-    receivedAt: string;
+export interface TelemetryPlayer {
+    name: string;
+    guid: string;
+}
+
+export interface TelemetryPlayerStats extends TelemetryPlayer {
+    kills: number;
+    headshots: number;
+    downs: number;
+    revives: number;
+    score: number;
+}
+
+export type GameEvent = { server: string; map: string } & (
+    | { event: 'game_start'; players: TelemetryPlayer[] }
+    | { event: 'round_change' | 'game_end'; round: number; players: TelemetryPlayerStats[] }
+);
+
+export type GameTelemetry = GameEvent & { receivedAt: string };
+
+/** Validate the three script payloads; beta state is never part of the protocol. */
+export function parseGameEvent(value: unknown): GameEvent {
+    if (!value || typeof value !== 'object' || Array.isArray(value)) throw new Error('Payload must be a JSON object');
+    const body = value as Record<string, unknown>;
+    if (!['game_start', 'round_change', 'game_end'].includes(String(body.event))) throw new Error('event must be game_start, round_change, or game_end');
+    for (const key of ['server', 'map'] as const) {
+        if (typeof body[key] !== 'string' || !body[key].trim() || body[key].length > 255) throw new Error(`${key} must be a nonempty string (up to 255 characters)`);
+    }
+    if (!Array.isArray(body.players)) throw new Error('players must be an array');
+    const players = body.players.map((value, index) => {
+        if (!value || typeof value !== 'object' || Array.isArray(value)) throw new Error(`players[${index}] must be an object`);
+        const player = value as Record<string, unknown>;
+        for (const key of ['name', 'guid'] as const) {
+            if (typeof player[key] !== 'string' || !player[key].trim()) throw new Error(`players[${index}].${key} must be a nonempty string`);
+        }
+        const identity = { name: player.name as string, guid: player.guid as string };
+        if (body.event === 'game_start') return identity;
+        const stats = {} as Omit<TelemetryPlayerStats, keyof TelemetryPlayer>;
+        for (const key of ['kills', 'headshots', 'downs', 'revives', 'score'] as const) {
+            if (!Number.isSafeInteger(player[key]) || (player[key] as number) < 0) throw new Error(`players[${index}].${key} must be a nonnegative integer`);
+            stats[key] = player[key] as number;
+        }
+        return { ...identity, ...stats };
+    });
+    const common = { server: body.server as string, map: body.map as string };
+    if (body.event === 'game_start') return { ...common, event: 'game_start', players };
+    if (!Number.isSafeInteger(body.round) || (body.round as number) < 0) throw new Error('round must be a nonnegative integer');
+    return { ...common, event: body.event as 'round_change' | 'game_end', round: body.round as number, players: players as TelemetryPlayerStats[] };
 }