feat: add codex llm backend

packages/cli/src/context/llm/codex-exec-events.ts

@@ -0,0 +1,144 @@
+import type { LlmTokenUsage, RunLoopStopReason } from './runtime-port.js';
+
+export interface CodexExecEventSummary {
+  finalText: string;
+  stopReason: RunLoopStopReason;
+  usage: LlmTokenUsage;
+  stepCount: number;
+  stepBoundariesMs: number[];
+  toolCallCount: number;
+  toolFailures: string[];
+  error?: Error;
+}
+
+interface CodexEventParseOptions {
+  startedAt?: number;
+  now?: () => number;
+}
+
+function record(value: unknown): Record<string, unknown> | undefined {
+  return value && typeof value === 'object' ? (value as Record<string, unknown>) : undefined;
+}
+
+function text(value: unknown): string | undefined {
+  return typeof value === 'string' && value.trim().length > 0 ? value : undefined;
+}
+
+function numberValue(value: unknown): number | undefined {
+  return typeof value === 'number' && Number.isFinite(value) ? value : undefined;
+}
+
+function usageFrom(value: unknown): LlmTokenUsage {
+  const usage = record(value);
+  if (!usage) {
+    return {};
+  }
+  const inputTokens = numberValue(usage.input_tokens ?? usage.inputTokens);
+  const outputTokens = numberValue(usage.output_tokens ?? usage.outputTokens);
+  const totalTokens = numberValue(usage.total_tokens ?? usage.totalTokens);
+  return {
+    ...(inputTokens !== undefined ? { inputTokens } : {}),
+    ...(outputTokens !== undefined ? { outputTokens } : {}),
+    ...(totalTokens !== undefined ? { totalTokens } : {}),
+  };
+}
+
+function stopReasonFrom(value: unknown): RunLoopStopReason {
+  const reason = text(value)?.toLowerCase();
+  if (reason && /(budget|max_turn|max-turn|limit)/.test(reason)) {
+    return 'budget';
+  }
+  return 'natural';
+}
+
+function errorMessageFrom(value: unknown): string {
+  if (value instanceof Error) {
+    return value.message;
+  }
+  const asRecord = record(value);
+  const message = text(asRecord?.message);
+  return message ?? text(value) ?? 'Codex turn failed';
+}
+
+/** @internal */
+export function parseCodexExecEventLine(line: string): unknown {
+  try {
+    return JSON.parse(line) as unknown;
+  } catch (error) {
+    throw new Error(`Codex JSONL event stream was malformed: ${error instanceof Error ? error.message : String(error)}`);
+  }
+}
+
+export function summarizeCodexExecEvents(
+  events: Iterable<unknown>,
+  options: CodexEventParseOptions = {},
+): CodexExecEventSummary {
+  const startedAt = options.startedAt ?? Date.now();
+  const now = options.now ?? Date.now;
+  let finalText = '';
+  let stopReason: RunLoopStopReason = 'natural';
+  let usage: LlmTokenUsage = {};
+  let stepCount = 0;
+  const stepBoundariesMs: number[] = [];
+  let toolCallCount = 0;
+  const toolFailures: string[] = [];
+  let error: Error | undefined;
+
+  for (const event of events) {
+    const eventRecord = record(event);
+    const eventType = text(eventRecord?.type);
+    if (!eventRecord || !eventType) {
+      continue;
+    }
+
+    if (eventType === 'turn.started') {
+      stepCount += 1;
+      continue;
+    }
+
+    if (eventType === 'turn.completed') {
+      usage = usageFrom(eventRecord.usage);
+      stepBoundariesMs.push(now() - startedAt);
+      stopReason = stopReasonFrom(eventRecord.reason ?? eventRecord.stop_reason ?? eventRecord.terminal_reason);
+      continue;
+    }
+
+    if (eventType === 'turn.failed' || eventType === 'error') {
+      stopReason = 'error';
+      error = new Error(errorMessageFrom(eventRecord.error ?? eventRecord.message));
+      continue;
+    }
+
+    const item = record(eventRecord.item);
+    const itemType = text(item?.type);
+    if (!item || !itemType) {
+      continue;
+    }
+
+    if (eventType === 'item.completed' && itemType === 'agent_message') {
+      finalText = text(item.text) ?? finalText;
+      continue;
+    }
+
+    if (eventType === 'item.started' && itemType === 'mcp_tool_call') {
+      toolCallCount += 1;
+      continue;
+    }
+
+    if (eventType === 'item.completed' && itemType === 'mcp_tool_call' && item.error !== undefined) {
+      const name = text(item.name) ?? text(item.tool_name) ?? 'unknown';
+      toolFailures.push(`${name}: ${errorMessageFrom(item.error)}`);
+    }
+  }
+
+  return {
+    finalText,
+    stopReason,
+    usage,
+    stepCount,
+    stepBoundariesMs,
+    toolCallCount,
+    toolFailures,
+    ...(error ? { error } : {}),
+  };
+}