import { randomUUID } from "node:crypto";

const DEFAULT_MAX_TRACES = 256;
const DEFAULT_MAX_EVENTS = 600;
const TEXT_LIMIT = 1200;
const SECRET_PATTERN = /\b(?:sk-[A-Za-z0-9_-]+|OPENAI_API_KEY|DATABASE_URL|secretRef:[^\s,;]+|secret|token|password|passwd|credential|private[_ -]?key|kubeconfig|BEGIN [A-Z ]*PRIVATE KEY)\b/giu;

export function createCodeAgentTraceStore(options = {}) {
  const maxTraces = positiveInteger(options.maxTraces, DEFAULT_MAX_TRACES);
  const maxEvents = positiveInteger(options.maxEvents, DEFAULT_MAX_EVENTS);
  const traces = new Map();

  function ensure(traceId, meta = {}) {
    const id = cleanTraceId(traceId) || `trc_${randomUUID()}`;
    let trace = traces.get(id);
    if (!trace) {
      const timestamp = timestampFor(meta.now);
      trace = {
        traceId: id,
        status: "running",
        createdAt: timestamp,
        updatedAt: timestamp,
        startedAt: timestamp,
        finishedAt: null,
        nextSeq: 1,
        events: [],
        listeners: new Set(),
        meta: {
          runnerKind: meta.runnerKind ?? null,
          workspace: meta.workspace ?? null,
          sandbox: meta.sandbox ?? null,
          sessionMode: meta.sessionMode ?? null,
          implementationType: meta.implementationType ?? null
        }
      };
      traces.set(id, trace);
      prune();
    } else {
      trace.meta = {
        ...trace.meta,
        ...dropEmpty({
          runnerKind: meta.runnerKind,
          workspace: meta.workspace,
          sandbox: meta.sandbox,
          sessionMode: meta.sessionMode,
          implementationType: meta.implementationType
        })
      };
    }
    return trace;
  }

  function append(traceId, event = {}, meta = {}) {
    const trace = ensure(traceId, meta);
    const normalized = normalizeTraceEvent(event, {
      traceId: trace.traceId,
      seq: trace.nextSeq,
      now: meta.now,
      fallbackRunnerKind: trace.meta.runnerKind
    });
    trace.nextSeq += 1;
    trace.events.push(normalized);
    if (trace.events.length > maxEvents) {
      trace.events.splice(0, trace.events.length - maxEvents);
    }
    trace.updatedAt = normalized.createdAt;
    if (normalized.terminal === true) {
      trace.status = normalized.status === "completed"
        ? "completed"
        : normalized.status === "canceled"
          ? "canceled"
          : normalized.type;
      trace.finishedAt = normalized.createdAt;
    } else if (normalized.status === "failed" || normalized.type === "error" || normalized.type === "timeout") {
      trace.status = normalized.type;
      trace.finishedAt = normalized.createdAt;
    }
    notify(trace, normalized);
    return normalized;
  }

  function snapshot(traceId, extra = {}) {
    const trace = traces.get(cleanTraceId(traceId));
    if (!trace) return emptySnapshot(traceId, extra);
    const events = trace.events.map((event) => ({ ...event }));
    const lastEvent = events.at(-1) ?? null;
    return {
      traceId: trace.traceId,
      status: trace.status,
      createdAt: trace.createdAt,
      updatedAt: trace.updatedAt,
      startedAt: trace.startedAt,
      finishedAt: trace.finishedAt,
      eventCount: events.length,
      events,
      eventLabels: events.map((event) => event.label).filter(Boolean),
      lastEvent,
      elapsedMs: elapsedMs(trace.startedAt, trace.finishedAt ?? trace.updatedAt),
      waitingFor: lastWaitingFor(events),
      runnerKind: extra.runnerKind ?? trace.meta.runnerKind ?? null,
      workspace: extra.workspace ?? trace.meta.workspace ?? null,
      sandbox: extra.sandbox ?? trace.meta.sandbox ?? null,
      sessionMode: extra.sessionMode ?? trace.meta.sessionMode ?? null,
      implementationType: extra.implementationType ?? trace.meta.implementationType ?? null,
      sessionId: extra.sessionId ?? lastEvent?.sessionId ?? null,
      sessionStatus: extra.sessionStatus ?? lastEvent?.sessionStatus ?? null,
      turn: extra.turn ?? lastEvent?.turn ?? null,
      outputTruncated: events.some((event) => event.outputTruncated === true),
      valuesPrinted: false
    };
  }

  function subscribe(traceId, listener, meta = {}) {
    const trace = ensure(traceId, meta);
    trace.listeners.add(listener);
    return () => {
      trace.listeners.delete(listener);
    };
  }

  function clear() {
    traces.clear();
  }

  function prune() {
    if (traces.size <= maxTraces) return;
    const stale = [...traces.values()]
      .sort((left, right) => String(left.updatedAt).localeCompare(String(right.updatedAt)))
      .slice(0, traces.size - maxTraces);
    for (const trace of stale) {
      traces.delete(trace.traceId);
    }
  }

  return {
    ensure,
    append,
    snapshot,
    subscribe,
    clear
  };
}

export const defaultCodeAgentTraceStore = createCodeAgentTraceStore();

export function createCodeAgentTraceRecorder({
  traceStore = defaultCodeAgentTraceStore,
  traceId,
  now,
  runnerKind = null,
  workspace = null,
  sandbox = null,
  sessionMode = null,
  implementationType = null
} = {}) {
  const startedAt = timestampFor(now);
  const startedEpochMs = Date.now();
  const baseMeta = { now, runnerKind, workspace, sandbox, sessionMode, implementationType };
  traceStore.ensure(traceId, baseMeta);

  function append(event = {}) {
    return traceStore.append(traceId, {
      elapsedMs: Date.now() - startedEpochMs,
      ...event
    }, baseMeta);
  }

  function snapshot(extra = {}) {
    return traceStore.snapshot(traceId, { runnerKind, workspace, sandbox, sessionMode, implementationType, ...extra });
  }

  function runnerTrace(extra = {}) {
    const current = snapshot(extra);
    return {
      traceId: current.traceId,
      runnerKind: extra.runnerKind ?? current.runnerKind,
      workspace: extra.workspace ?? current.workspace,
      sandbox: extra.sandbox ?? current.sandbox,
      sessionMode: extra.sessionMode ?? current.sessionMode,
      sessionId: extra.sessionId ?? current.sessionId,
      sessionStatus: extra.sessionStatus ?? current.sessionStatus,
      idleTimeoutMs: extra.idleTimeoutMs ?? null,
      lastTraceId: extra.lastTraceId ?? current.traceId,
      turn: extra.turn ?? current.turn,
      sessionReused: extra.sessionReused ?? false,
      implementationType: extra.implementationType ?? current.implementationType,
      limitations: Array.isArray(extra.limitations) ? extra.limitations : [],
      startedAt: extra.startedAt ?? startedAt,
      finishedAt: extra.finishedAt ?? current.finishedAt ?? timestampFor(now),
      updatedAt: current.updatedAt,
      events: current.events,
      eventLabels: current.eventLabels,
      lastEvent: current.lastEvent,
      elapsedMs: current.elapsedMs,
      waitingFor: current.waitingFor,
      outputTruncated: current.outputTruncated || extra.outputTruncated === true,
      valuesPrinted: false,
      note: extra.note ?? "Real-time runnerTrace is appended as Codex stdio/session events are captured."
    };
  }

  return {
    traceId,
    append,
    snapshot,
    runnerTrace
  };
}

export function runnerTraceFromSnapshot(snapshot = {}, extra = {}) {
  return {
    traceId: snapshot.traceId ?? extra.traceId ?? null,
    runnerKind: extra.runnerKind ?? snapshot.runnerKind ?? null,
    workspace: extra.workspace ?? snapshot.workspace ?? null,
    sandbox: extra.sandbox ?? snapshot.sandbox ?? null,
    sessionMode: extra.sessionMode ?? snapshot.sessionMode ?? null,
    sessionId: extra.sessionId ?? snapshot.sessionId ?? null,
    sessionStatus: extra.sessionStatus ?? snapshot.sessionStatus ?? null,
    idleTimeoutMs: extra.idleTimeoutMs ?? null,
    lastTraceId: extra.lastTraceId ?? snapshot.traceId ?? null,
    turn: extra.turn ?? snapshot.turn ?? null,
    sessionReused: extra.sessionReused ?? false,
    implementationType: extra.implementationType ?? snapshot.implementationType ?? null,
    limitations: Array.isArray(extra.limitations) ? extra.limitations : [],
    startedAt: extra.startedAt ?? snapshot.startedAt ?? null,
    finishedAt: extra.finishedAt ?? snapshot.finishedAt ?? snapshot.updatedAt ?? null,
    updatedAt: snapshot.updatedAt ?? null,
    events: Array.isArray(snapshot.events) ? snapshot.events : [],
    eventLabels: Array.isArray(snapshot.eventLabels) ? snapshot.eventLabels : [],
    lastEvent: snapshot.lastEvent ?? null,
    elapsedMs: snapshot.elapsedMs ?? null,
    waitingFor: snapshot.waitingFor ?? null,
    outputTruncated: snapshot.outputTruncated === true || extra.outputTruncated === true,
    valuesPrinted: false,
    note: extra.note ?? "runnerTrace snapshot"
  };
}

function normalizeTraceEvent(event, { traceId, seq, now, fallbackRunnerKind } = {}) {
  const type = safeToken(event.type ?? event.kind ?? "event");
  const status = safeToken(event.status ?? "observed");
  const toolName = safeText(event.toolName ?? event.name, 120);
  const label = safeText(event.label, 180) || labelFor({ type, status, toolName });
  return dropUndefined({
    seq,
    traceId,
    type,
    stage: safeToken(event.stage ?? type),
    status,
    label,
    createdAt: timestampFor(now),
    elapsedMs: typeof event.elapsedMs === "number" ? Math.max(0, Math.trunc(event.elapsedMs)) : null,
    runnerKind: safeText(event.runnerKind ?? fallbackRunnerKind, 140),
    sessionId: safeText(event.sessionId, 180),
    sessionStatus: safeText(event.sessionStatus, 80),
    sessionReused: typeof event.sessionReused === "boolean" ? event.sessionReused : undefined,
    turn: typeof event.turn === "number" ? event.turn : undefined,
    toolName,
    promptSummary: safeText(event.promptSummary, 240),
    outputSummary: safeText(event.outputSummary, 400),
    chunk: safeText(event.chunk, 400),
    message: safeText(event.message, 500),
    errorCode: safeText(event.errorCode, 120),
    waitingFor: safeText(event.waitingFor, 220),
    timeoutMs: typeof event.timeoutMs === "number" ? Math.trunc(event.timeoutMs) : undefined,
    hardTimeoutMs: typeof event.hardTimeoutMs === "number" ? Math.trunc(event.hardTimeoutMs) : undefined,
    lastActivityAt: safeText(event.lastActivityAt, 80),
    idleMs: typeof event.idleMs === "number" ? Math.max(0, Math.trunc(event.idleMs)) : undefined,
    outputTruncated: event.outputTruncated === true,
    terminal: event.terminal === true,
    valuesPrinted: false
  });
}

function labelFor({ type, status, toolName }) {
  if (type === "session") return `session:${status}`;
  if (type === "prompt") return `prompt:${status}`;
  if (type === "tool_call") return `tool:${toolName || "codex"}:${status}`;
  if (type === "assistant_message") return `assistant:${status}`;
  if (["timeout", "cancel", "error"].includes(type)) return type;
  if (type === "request") return `request:${status}`;
  if (type === "stdio") return `stdio:${status}`;
  return `${type}:${status}`;
}

function notify(trace, event) {
  const snapshot = {
    ...emptySnapshot(trace.traceId),
    ...{
      traceId: trace.traceId,
      status: trace.status,
      createdAt: trace.createdAt,
      updatedAt: trace.updatedAt,
      startedAt: trace.startedAt,
      finishedAt: trace.finishedAt,
      eventCount: trace.events.length,
      events: trace.events.map((item) => ({ ...item })),
      eventLabels: trace.events.map((item) => item.label).filter(Boolean),
      lastEvent: event,
      elapsedMs: elapsedMs(trace.startedAt, trace.finishedAt ?? trace.updatedAt),
      waitingFor: lastWaitingFor(trace.events),
      runnerKind: trace.meta.runnerKind,
      workspace: trace.meta.workspace,
      sandbox: trace.meta.sandbox,
      sessionMode: trace.meta.sessionMode,
      implementationType: trace.meta.implementationType,
      outputTruncated: trace.events.some((item) => item.outputTruncated === true),
      valuesPrinted: false
    }
  };
  for (const listener of trace.listeners) {
    try {
      listener(event, snapshot);
    } catch {
      trace.listeners.delete(listener);
    }
  }
}

function emptySnapshot(traceId, extra = {}) {
  const id = cleanTraceId(traceId);
  return {
    traceId: id,
    status: "missing",
    createdAt: null,
    updatedAt: null,
    startedAt: null,
    finishedAt: null,
    eventCount: 0,
    events: [],
    eventLabels: [],
    lastEvent: null,
    elapsedMs: null,
    waitingFor: null,
    runnerKind: extra.runnerKind ?? null,
    workspace: extra.workspace ?? null,
    sandbox: extra.sandbox ?? null,
    sessionMode: extra.sessionMode ?? null,
    implementationType: extra.implementationType ?? null,
    sessionId: null,
    sessionStatus: null,
    turn: null,
    outputTruncated: false,
    valuesPrinted: false
  };
}

function lastWaitingFor(events) {
  for (const event of [...events].reverse()) {
    if (event.waitingFor) return event.waitingFor;
    if (event.type === "tool_call" && ["started", "output_chunk"].includes(event.status)) {
      return `tool:${event.toolName ?? "codex"}`;
    }
    if (event.type === "prompt" && event.status === "sent") return "assistant-message";
  }
  return null;
}

function elapsedMs(start, end) {
  const startMs = Date.parse(start ?? "");
  const endMs = Date.parse(end ?? "");
  if (!Number.isFinite(startMs) || !Number.isFinite(endMs)) return null;
  return Math.max(0, endMs - startMs);
}

function safeText(value, limit = TEXT_LIMIT) {
  if (value === undefined || value === null || value === "") return undefined;
  const redacted = String(value).replace(SECRET_PATTERN, "[redacted]").replace(/\s+/gu, " ").trim();
  if (!redacted) return undefined;
  return redacted.length > limit ? `${redacted.slice(0, limit - 3)}...` : redacted;
}

function safeToken(value) {
  return String(value ?? "")
    .trim()
    .replace(/[^A-Za-z0-9_.:-]/gu, "_")
    .slice(0, 80) || "event";
}

function cleanTraceId(value) {
  const id = String(value ?? "").trim();
  return /^trc_[A-Za-z0-9_.:-]+$/u.test(id) ? id : null;
}

function timestampFor(now) {
  const value = typeof now === "function" ? now() : now;
  const date = value ? new Date(value) : new Date();
  return Number.isNaN(date.getTime()) ? new Date().toISOString() : date.toISOString();
}

function positiveInteger(value, fallback) {
  const parsed = Number.parseInt(value ?? "", 10);
  return Number.isInteger(parsed) && parsed > 0 ? parsed : fallback;
}

function dropEmpty(value) {
  return Object.fromEntries(Object.entries(value).filter(([, item]) => item !== undefined && item !== null && item !== ""));
}

function dropUndefined(value) {
  return Object.fromEntries(Object.entries(value).filter(([, item]) => item !== undefined));
}