/*
 * SPEC: PJ2026-0104010803 Workbench唯一投影 draft-2026-06-20-p2-terminal-outbox-recovery; draft-2026-06-27-p0-read-model-timeline-contract; draft-2026-06-28-p0-d518-session-timeline-consistency; PJ2026-010403 API契约 draft-2026-06-20-p2-terminal-outbox-recovery; draft-2026-06-27-p0-workbench-read-api-contract; PJ2026-010401 Web工作台 draft-2026-06-20-p2-terminal-outbox-recovery; draft-2026-06-27-p0-workbench-read-model-contract; PJ2026-01060505 Workbench Performance draft-2026-06-17-p0
 * 职责: Workbench durable fact normalization and DTO projection helpers; no HTTP or realtime transport ownership.
 */
import { createHash } from "node:crypto";

import { defaultCodeAgentTraceStore } from "./code-agent-trace-store.ts";
import {
  parsePositiveInteger,
  safeConversationId,
  safeOpaqueId,
  safeSessionId,
  safeTraceId,
  sendJson
} from "./server-http-utils.ts";
import { createWorkbenchReadModel } from "./workbench-read-model.ts";
import { createWorkbenchRuntimeClient } from "./workbench-runtime-client.ts";
import { buildWorkbenchSessionDetail, compactLaunchContext, includeMessagesForSessionDetail } from "./workbench-session-detail-response.ts";
import { durableTraceStatus, RUNNING_STATUSES, terminalFinalResponse, TERMINAL_STATUSES } from "./workbench-turn-projection.ts";
import { emitCodeAgentOtelSpan, emitHttpServerRequestSpan } from "./otel-trace.ts";

function projectionText(...values) {
  for (const value of values) {
    if (value && typeof value === "object") {
      const nested = messageAuthorityTextValue(value.text ?? value.content ?? value.message ?? value.summary ?? value.preview ?? value.title);
      if (nested) return nested;
      continue;
    }
    const text = messageAuthorityTextValue(value);
    if (text) return text;
  }
  return null;
}

function workbenchError(code, message, extra = {}) {
  return {
    ok: false,
    status: "failed",
    error: { code, message, ...extra },
    valuesRedacted: true,
    secretMaterialStored: false
  };
}

function normalizeRole(role) {
  const value = textValue(role).toLowerCase();
  return value === "agent" ? "assistant" : value;
}

function partFact(part, index, messageId, traceId) {
  const type = textValue(part?.type) || "text";
  const text = messageAuthorityTextValue(part?.text ?? part?.content ?? part?.message);
  return {
    partId: safePartId(part?.partId ?? part?.id) || `prt_${hash(`${messageId}:${index}:${type}`).slice(0, 24)}`,
    messageId,
    traceId,
    type,
    text: text || null,
    status: normalizeStatus(part?.status ?? "completed"),
    toolName: textValue(part?.toolName ?? part?.name) || null,
    createdAt: textValue(part?.createdAt ?? part?.timestamp) || null,
    valuesRedacted: part?.valuesRedacted !== false
  };
}

export function factSessionSummary(session, facts = {}) {
  const sessionId = factSessionId(session);
  if (!sessionId) return null;
  const currentTrace = factCurrentTraceForSession(facts, sessionId, session);
  const traceId = currentTrace?.traceId ?? factLastTraceId(session) ?? factLatestTraceIdForSession(facts, sessionId);
  const projection = traceId ? factProjectionForTrace(facts, traceId) : null;
  const turn = traceId ? factTurnForTrace(facts, traceId) : null;
  const checkpoint = traceId ? factCheckpointForTrace(facts, traceId) : null;
  const trace = traceId ? factTraceSnapshot(facts, traceId) : null;
  const messages = factMessagesForSession(session, facts);
  const terminalMessage = traceId ? factTerminalMessageForTrace(messages, traceId) : null;
  const traceStatus = normalizeTerminalStatus(trace?.status);
  const checkpointStatus = normalizeTerminalStatus(checkpoint?.status);
  const messageTerminalStatus = factTerminalStatusFromMessageProjection(terminalMessage);
  const turnStatus = normalizeStatus(turn?.status);
  const launchContext = compactLaunchContext(session?.sessionJson?.launchContext);
  const status = normalizeStatus(checkpointStatus ?? traceStatus ?? messageTerminalStatus ?? nonUnknownStatus(turnStatus) ?? nonUnknownStatus(currentTrace?.status) ?? session?.status);
  const timing = traceId
    ? factCombinedTimingProjection(status, checkpoint, messageTerminalStatus ? terminalMessage : null, turn, trace)
    : factTimingProjection(session, status);
  const title = sessionTitleFromMessages(messages);
  const preview = sessionPreviewFromMessages(messages);
  return {
    sessionId,
    threadId: safeOpaqueId(session?.threadId) ?? (textValue(session?.threadId) || null),
    agentId: session?.agentId ?? "hwlab-code-agent",
    title,
    preview,
    titleSource: title ? "message-projection" : null,
    previewSource: preview ? "message-projection" : null,
    status,
    running: RUNNING_STATUSES.has(status),
    terminal: TERMINAL_STATUSES.has(status) && !RUNNING_STATUSES.has(status),
    lastTraceId: traceId,
    projection,
    projectionStatus: projection?.projectionStatus ?? null,
    projectionHealth: projection?.projectionHealth ?? null,
    staleMs: projection?.staleMs ?? null,
    blocker: projection?.blocker ?? null,
    providerProfile: textValue(session?.providerProfile ?? session?.sessionJson?.providerProfile) || null,
    launchContext,
    messageCount: messages.length,
    firstUserMessagePreview: firstUserPreview(messages),
    updatedAt: factUpdatedAt(session),
    turnSummary: turn ? {
      turnId: factTurnId(turn, traceId),
      traceId,
      status,
      running: RUNNING_STATUSES.has(status),
      terminal: TERMINAL_STATUSES.has(status) && !RUNNING_STATUSES.has(status),
      eventCount: projection?.lastProjectedSeq ?? trace?.eventCount,
      projection,
      projectionStatus: projection?.projectionStatus ?? null,
      projectionHealth: projection?.projectionHealth ?? null,
      staleMs: projection?.staleMs ?? null,
      blocker: projection?.blocker ?? null,
      timing,
      startedAt: timing.startedAt,
      lastEventAt: timing.lastEventAt,
      finishedAt: timing.finishedAt,
      durationMs: timing.durationMs,
      updatedAt: factUpdatedAt(turn)
    } : null,
    valuesRedacted: true
  };
}

export function factSessionDetail(session, facts = {}, options = {}) {
  const sessionId = factSessionId(session);
  return buildWorkbenchSessionDetail({
    summary: factSessionSummary(session, facts),
    session,
    sessionId,
    includeMessages: options.includeMessages === true,
    messages: factMessagesForSession(session, facts)
  });
}

export function factMessagesForSession(session, facts = {}) {
  const sessionId = factSessionId(session);
  if (!sessionId) return [];
  const partsByMessageId = new Map();
  for (const part of factArray(facts.parts)) {
    if (part.sessionId !== sessionId) continue;
    const messageId = textValue(part.messageId);
    if (!messageId) continue;
    const existing = partsByMessageId.get(messageId) ?? [];
    existing.push(part);
    partsByMessageId.set(messageId, existing);
  }
  const messageGroups = canonicalFactMessageGroupsForSession(
    factArray(facts.messages)
      .filter((message) => message.sessionId === sessionId)
      .sort((left, right) => compareFactMessagesForSessionAsc(left, right, facts)),
    partsByMessageId,
    facts
  );
  return messageGroups
    .sort((left, right) => compareFactMessagesForSessionAsc(left.message, right.message, facts))
    .map((group) => factMessageDto(group.message, group.parts, facts))
    .filter(Boolean);
}

export function canonicalFactMessageGroupsForSession(messages = [], partsByMessageId = new Map(), facts = {}) {
  const groups = new Map();
  for (const message of messages) {
    const key = factMessageCanonicalGroupKey(message);
    const existing = groups.get(key) ?? [];
    existing.push(message);
    groups.set(key, existing);
  }
  return [...groups.values()].map((groupMessages) => {
    const message = selectCanonicalFactMessage(groupMessages, partsByMessageId, facts);
    const aliasIds = uniqueText(groupMessages.map((item) => item?.messageId));
    const parts = aliasIds.flatMap((messageId) => partsByMessageId.get(messageId) ?? []);
    return { message, parts };
  });
}

export function factMessageCanonicalGroupKey(message) {
  const messageId = textValue(message?.messageId) || textValue(message?.id);
  const role = textValue(message?.role) || "agent";
  const traceId = safeTraceId(message?.traceId);
  const sessionId = factSessionId(message) ?? textValue(message?.sessionId) ?? "session";
  if (traceId && isAssistantLikeRole(role)) return `assistant:${sessionId}:${traceId}`;
  return `message:${messageId || sessionId}:${role}:${traceId || "none"}`;
}

export function selectCanonicalFactMessage(messages = [], partsByMessageId = new Map(), facts = {}) {
  if (messages.length <= 1) return messages[0] ?? null;
  const traceId = safeTraceId(messages[0]?.traceId);
  const preferredMessageId = traceId ? workbenchLifecycleMessageId(traceId, "agent") : null;
  const turnMessageId = traceId ? textValue(factTurnForTrace(facts, traceId)?.messageId) || null : null;
  return [...messages].sort((left, right) => {
    const score = factMessageCanonicalScore(right, partsByMessageId, preferredMessageId, turnMessageId) - factMessageCanonicalScore(left, partsByMessageId, preferredMessageId, turnMessageId);
    return score || compareFactRecordsDesc(left, right);
  })[0] ?? messages[0] ?? null;
}

export function factMessageCanonicalScore(message, partsByMessageId = new Map(), preferredMessageId = null, turnMessageId = null) {
  const messageId = textValue(message?.messageId) || textValue(message?.id);
  let score = 0;
  if (preferredMessageId && messageId === preferredMessageId) score += 10000;
  if (turnMessageId && messageId === turnMessageId) score += 1000;
  if (factMessageHasFinalResponsePart(message, partsByMessageId)) score += 100;
  if (message?.sealed === true || message?.terminal === true) score += 50;
  if (isTerminalProjectionStatus(normalizeStatus(message?.status))) score += 25;
  score += Math.min(10, factSeq(message) ?? 0);
  return score;
}

export function factMessageHasFinalResponsePart(message, partsByMessageId = new Map()) {
  const messageId = textValue(message?.messageId) || textValue(message?.id);
  if (!messageId) return false;
  return (partsByMessageId.get(messageId) ?? []).some((part) => (textValue(part?.partType ?? part?.type) === "final_response") && Boolean(projectionText(part?.text, part?.content, part?.message)));
}

export function workbenchLifecycleMessageId(traceId, role = "agent") {
  const traceSuffix = (safeTraceId(traceId) || String(traceId || "trace"))
    .replace(/^trc_/u, "")
    .replace(/[^A-Za-z0-9_.:-]/gu, "_")
    .slice(0, 48) || "trace";
  return `msg_${traceSuffix}_${role === "user" ? "user" : "agent"}`;
}

export function factMessageDto(message, parts = [], facts = {}) {
  const messageId = safeMessageId(message?.messageId) || textValue(message?.messageId);
  if (!messageId) return null;
  const traceId = safeTraceId(message?.traceId) ?? null;
  const role = textValue(message?.role) || "agent";
  const turn = traceId ? factTurnForTrace(facts, traceId) : null;
  const checkpoint = traceId ? factCheckpointForTrace(facts, traceId) : null;
  const messageStatus = normalizeStatus(message?.status);
  const assistantLike = isAssistantLikeRole(role);
  const legacyText = projectionText(message?.text, message?.content, message?.message, message?.finalResponse);
  const baseParts = parts.length > 0
    ? [...parts].sort(compareFactPartsAsc).map((part) => factPartDto(part, messageId, traceId)).filter(Boolean)
    : !assistantLike && legacyText ? [partFact({ type: "text", text: legacyText, status: message?.status }, 0, messageId, traceId)] : [];
  const checkpointStatus = assistantLike ? normalizeTerminalStatus(checkpoint?.status) : null;
  const preliminaryStatus = normalizeStatus(checkpointStatus ?? (assistantLike ? turn?.status : null) ?? messageStatus);
  const syntheticTerminalFinalResponse = assistantLike && !factPartsHaveFinalResponse(baseParts)
    ? factSyntheticTerminalFinalResponse(preliminaryStatus, traceId, message, checkpoint, turn)
    : null;
  const normalizedParts = syntheticTerminalFinalResponse
    ? [...baseParts, partFact({ type: "final_response", text: syntheticTerminalFinalResponse.text, status: syntheticTerminalFinalResponse.status }, baseParts.length, messageId, traceId)]
    : baseParts;
  const messageTerminalStatus = assistantLike ? factTerminalStatusFromMessageProjection(message, normalizedParts) : null;
  const status = normalizeStatus(checkpointStatus ?? messageTerminalStatus ?? (assistantLike ? turn?.status : null) ?? messageStatus);
  const timing = assistantLike
    ? factCombinedTimingProjection(status, checkpoint, messageTerminalStatus ? { ...message, parts: normalizedParts } : null, turn, message)
    : factTimingProjection(message, status);
  const text = factMessageAuthorityText({ role, status, parts: normalizedParts, legacyText });
  return {
    messageId,
    role,
    sessionId: (safeSessionId(message?.sessionId) ?? textValue(message?.sessionId)) || null,
    traceId,
    turnId: safeTurnId(message?.turnId) || traceId,
    status,
    parts: normalizedParts,
    text: text || "",
    textPreview: text ? text.slice(0, 240) : null,
    createdAt: textValue(message?.createdAt) || null,
    updatedAt: factUpdatedAt(message),
    timing,
    startedAt: timing.startedAt,
    lastEventAt: timing.lastEventAt,
    finishedAt: timing.finishedAt,
    durationMs: timing.durationMs,
    projectionStatus: null,
    projectionHealth: null,
    valuesRedacted: message?.valuesRedacted !== false
  };
}

export function factMessageAuthorityText({ role, status, parts = [], legacyText = null } = {}) {
  if (!isAssistantLikeRole(role)) return firstFactPartText(parts) ?? legacyText ?? "";
  if (!isTerminalProjectionStatus(status)) return "";
  return firstFactPartText(parts, "final_response") ?? "";
}

export function factPartsHaveFinalResponse(parts = []) {
  return parts.some((part) => part?.type === "final_response" && Boolean(projectionText(part?.text)));
}

export function factSyntheticTerminalFinalResponse(status, traceId = null, ...records) {
  const terminalStatus = normalizeTerminalStatus(status);
  if (!terminalStatus || terminalStatus === "completed") return null;
  return terminalFinalResponse(terminalStatus, { traceId, status: terminalStatus, records }, { evidence: records });
}

export function isTerminalProjectionStatus(status) {
  return TERMINAL_STATUSES.has(status) && !RUNNING_STATUSES.has(status);
}

export function firstFactPartText(parts = [], type = null) {
  for (const part of parts) {
    if (type && part?.type !== type) continue;
    const text = projectionText(part?.text);
    if (text) return text;
  }
  return null;
}

export function factMessageFinalResponseText(message) {
  if (!message || !isAssistantLikeRole(message.role) || !isTerminalProjectionStatus(message.status)) return null;
  return firstFactPartText(message.parts, "final_response");
}

export function factTerminalMessageForTrace(messages = [], traceId = null) {
  const safeTrace = safeTraceId(traceId);
  return [...factArray(messages)].reverse().find((message) => {
    if (!message || !isAssistantLikeRole(message.role)) return false;
    if (safeTrace && message.traceId !== safeTrace) return false;
    return Boolean(factTerminalStatusFromMessageProjection(message));
  }) ?? null;
}

export function factTerminalStatusFromMessageProjection(message = null, parts = null) {
  if (!message || !isAssistantLikeRole(message.role)) return null;
  const sourceParts = Array.isArray(parts) ? parts : factArray(message.parts);
  if (!firstFactPartText(sourceParts, "final_response")) return null;
  const messageStatus = normalizeTerminalStatus(message.status);
  if (messageStatus) return messageStatus;
  for (const part of sourceParts) {
    if (textValue(part?.partType ?? part?.type) !== "final_response") continue;
    if (!projectionText(part?.text, part?.content, part?.message)) continue;
    const partStatus = normalizeTerminalStatus(part?.status);
    if (partStatus) return partStatus;
    if (part?.terminal === true || part?.sealed === true) return "completed";
  }
  return message.terminal === true || message.sealed === true ? "completed" : null;
}

export function factPartDto(part, messageId, traceId) {
  const partId = safePartId(part?.partId) || textValue(part?.partId) || `prt_${hash(`${messageId}:${part?.partIndex ?? 0}:${part?.partType ?? part?.type ?? "text"}`).slice(0, 24)}`;
  const text = projectionText(part?.text, part?.content, part?.message);
  return {
    partId,
    messageId,
    traceId: safeTraceId(part?.traceId) ?? traceId,
    type: textValue(part?.partType ?? part?.type) || "text",
    text: text || null,
    status: normalizeStatus(part?.status),
    toolName: textValue(part?.toolName ?? part?.name) || null,
    createdAt: textValue(part?.createdAt ?? part?.occurredAt) || null,
    valuesRedacted: part?.valuesRedacted !== false
  };
}

export function factTurnForTrace(facts = {}, traceId, turnId = null) {
  const safeTrace = safeTraceId(traceId);
  if (!safeTrace) return null;
  const requestedTurn = safeTurnId(turnId);
  const matches = factArray(facts.turns)
    .filter((turn) => turn.traceId === safeTrace && (!requestedTurn || turn.turnId === requestedTurn || turn.turnId === safeTrace))
    .sort(compareFactRecordsDesc);
  return matches[0] ?? null;
}

export function factTurnSnapshot({ turn = null, session = null, facts = {}, traceId, turnId = null } = {}) {
  const safeTrace = safeTraceId(traceId);
  const resolvedTurnId = factTurnId(turn, safeTrace) ?? safeTurnId(turnId) ?? safeTrace;
  const messages = session ? factMessagesForSession(session, facts) : [];
  const userMessage = messages.find((message) => message.role === "user") ?? null;
  const assistantMessage = [...messages].reverse().find((message) => isAssistantLikeRole(message.role)) ?? null;
  const terminalMessage = safeTrace ? factTerminalMessageForTrace(messages, safeTrace) : null;
  const checkpoint = safeTrace ? factCheckpointForTrace(facts, safeTrace) : null;
  const trace = factTraceSnapshot(facts, safeTrace);
  const checkpointStatus = normalizeTerminalStatus(checkpoint?.status);
  const traceStatus = normalizeTerminalStatus(trace.status);
  const messageTerminalStatus = factTerminalStatusFromMessageProjection(terminalMessage);
  const status = normalizeStatus(checkpointStatus ?? traceStatus ?? messageTerminalStatus ?? turn?.status ?? session?.status);
  const terminal = isTerminalProjectionStatus(status);
  const assistantText = terminal ? factMessageFinalResponseText(assistantMessage) : null;
  const timing = factCombinedTimingProjection(status, checkpoint, messageTerminalStatus ? terminalMessage : null, turn, trace);
  return {
    turnId: resolvedTurnId,
    traceId: safeTrace,
    status,
    running: RUNNING_STATUSES.has(status),
    terminal,
    sessionId: factSessionId(session) ?? turn?.sessionId ?? checkpoint?.sessionId ?? null,
    threadId: safeOpaqueId(session?.threadId) ?? (textValue(session?.threadId) || null),
    userMessageId: userMessage?.messageId ?? null,
    assistantMessageId: assistantMessage?.messageId ?? turn?.messageId ?? null,
    assistantText: assistantText ?? null,
    finalResponse: assistantText ? { text: assistantText, sealed: true, source: "message-part" } : null,
    timing,
    startedAt: timing.startedAt,
    lastEventAt: timing.lastEventAt,
    finishedAt: timing.finishedAt,
    durationMs: timing.durationMs,
    agentRun: checkpoint ? {
      runId: textValue(checkpoint.runId) || null,
      commandId: textValue(checkpoint.commandId) || null,
      status,
      lastSeq: factSeq(checkpoint),
      valuesRedacted: true
    } : null,
    trace: {
      traceId: safeTrace,
      status: trace.status,
      eventCount: trace.eventCount,
      timing: trace.timing,
      startedAt: trace.startedAt,
      lastEventAt: trace.lastEventAt,
      finishedAt: trace.finishedAt,
      durationMs: trace.durationMs,
      updatedAt: trace.updatedAt
    },
    urls: {
      self: resolvedTurnId ? `/v1/workbench/turns/${encodeURIComponent(resolvedTurnId)}` : null,
      traceEvents: safeTrace ? `/v1/workbench/traces/${encodeURIComponent(safeTrace)}/events` : null
    }
  };
}

export function factTraceSnapshot(facts = {}, traceId) {
  const safeTrace = safeTraceId(traceId);
  const events = factArray(facts.traceEvents)
    .filter((event) => !safeTrace || event.traceId === safeTrace)
    .sort(compareFactTraceEventsAsc)
    .map(factTraceEventDto)
    .filter(Boolean);
  const status = durableTraceStatus(events);
  const lastEvent = events.at(-1) ?? null;
  const checkpoint = factCheckpointForTrace(facts, safeTrace);
  const timing = factTraceTimingProjection(events, checkpoint, status);
  return {
    traceId: safeTrace,
    status,
    eventCount: events.length,
    events,
    lastEvent,
    timing,
    startedAt: timing.startedAt,
    lastEventAt: timing.lastEventAt,
    finishedAt: timing.finishedAt,
    durationMs: timing.durationMs,
    updatedAt: lastEvent?.updatedAt ?? lastEvent?.createdAt ?? checkpoint?.updatedAt ?? null,
    valuesRedacted: true,
    secretMaterialStored: false
  };
}

export function factTraceTimingProjection(events = [], checkpoint = null, status = null) {
  const checkpointTiming = factTimingProjection(checkpoint, status);
  const normalizedStatus = normalizeStatus(status ?? checkpoint?.status);
  const terminal = TERMINAL_STATUSES.has(normalizedStatus) && !RUNNING_STATUSES.has(normalizedStatus);
  const observedAt = new Date().toISOString();
  const eventStartTimes = factArray(events).flatMap((event) => [event?.createdAt, event?.occurredAt]);
  const eventActivityTimes = factArray(events).flatMap((event) => [event?.createdAt, event?.occurredAt, event?.updatedAt]);
  const terminalEventTimes = factArray(events)
    .filter(factTraceEventIsTerminalAuthority)
    .flatMap(factTraceEventTerminalTimes);
  const startedAt = firstTimestampIso(checkpointTiming.startedAt, ...eventStartTimes);
  const finishedAt = terminal ? latestTimestampIso(checkpointTiming.finishedAt, ...terminalEventTimes) : null;
  const lastEventAt = terminal && finishedAt ? finishedAt : latestTimestampIso(checkpointTiming.lastEventAt, ...eventActivityTimes);
  const durationMs = elapsedFactMs(startedAt, terminal ? finishedAt : observedAt);
  const lastEventAgeMs = terminal ? null : elapsedFactMs(lastEventAt, observedAt);
  return {
    ...checkpointTiming,
    startedAt,
    lastEventAt,
    finishedAt,
    durationMs,
    observedAt: terminal ? null : observedAt,
    lastEventAgeMs,
    valuesRedacted: true
  };
}

export function factTraceEventIsTerminalAuthority(event = null) {
  const eventType = textValue(event?.eventType ?? event?.type);
  return event?.terminal === true || event?.sealed === true || eventType === "terminal";
}

export function factTraceEventTerminalTimes(event = null) {
  const source = objectValue(event?.timing);
  return [source?.finishedAt, event?.finishedAt, source?.lastEventAt, event?.lastEventAt, event?.occurredAt, event?.createdAt];
}

export function factTraceEventDto(event, index) {
  const seq = factProjectedSeq(event);
  if (!seq) return null;
  const sourceSeq = Number.isFinite(Number(event?.sourceSeq)) && Number(event.sourceSeq) >= 0 ? Math.trunc(Number(event.sourceSeq)) : null;
  return {
    ...event,
    id: textValue(event?.id) || textValue(event?.sourceEventId) || null,
    seq,
    projectedSeq: seq,
    sourceSeq,
    type: textValue(event?.type ?? event?.eventType) || "event",
    label: textValue(event?.label ?? event?.eventType ?? event?.type) || null,
    status: normalizeStatus(event?.status),
    createdAt: textValue(event?.createdAt ?? event?.occurredAt) || null,
    updatedAt: factUpdatedAt(event),
    valuesRedacted: event?.valuesRedacted !== false
  };
}

export function factProjectionForTrace(facts = {}, traceId) {
  const checkpoint = factCheckpointForTrace(facts, traceId);
  if (!checkpoint) {
    return {
      projectionStatus: "unknown",
      projectionHealth: "unknown",
      lastProjectedSeq: null,
      sourceRunId: null,
      sourceCommandId: null,
      staleMs: null,
      blocker: null,
      updatedAt: null,
      valuesRedacted: true
    };
  }
  const projectionStatus = normalizeProjectionStatus(checkpoint.projectionStatus);
  const projectionHealth = normalizeProjectionHealth(checkpoint.projectionHealth, projectionStatus);
  const diagnostic = objectValue(checkpoint.diagnostic);
  const timing = factTimingProjection(checkpoint, normalizeStatus(checkpoint.status));
  return {
    projectionStatus,
    projectionHealth,
    lastProjectedSeq: factSeq(checkpoint),
    sourceRunId: textValue(checkpoint.runId ?? checkpoint.sourceRunId) || null,
    sourceCommandId: textValue(checkpoint.commandId ?? checkpoint.sourceCommandId) || null,
    staleMs: null,
    blocker: diagnostic.blocker ?? checkpoint.blocker ?? null,
    timing,
    startedAt: timing.startedAt,
    lastEventAt: timing.lastEventAt,
    finishedAt: timing.finishedAt,
    durationMs: timing.durationMs,
    updatedAt: factUpdatedAt(checkpoint),
    valuesRedacted: true
  };
}

export function factTimingProjection(record = null, status = null) {
  const source = objectValue(record?.timing);
  const observedAt = new Date().toISOString();
  const startedAt = timestampIso(source?.startedAt ?? record?.startedAt ?? record?.createdAt);
  const lastEventAt = timestampIso(source?.lastEventAt ?? record?.lastEventAt ?? record?.updatedAt ?? record?.createdAt);
  const normalizedStatus = normalizeStatus(status ?? record?.status);
  const terminal = record?.terminal === true || TERMINAL_STATUSES.has(normalizedStatus) && !RUNNING_STATUSES.has(normalizedStatus);
  const finishedAt = terminal ? timestampIso(source?.finishedAt ?? record?.finishedAt ?? record?.completedAt) : null;
  const durationMs = elapsedFactMs(startedAt, terminal ? finishedAt : observedAt);
  const lastEventAgeMs = terminal ? null : elapsedFactMs(lastEventAt, observedAt);
  return { startedAt, lastEventAt, finishedAt, durationMs, observedAt: terminal ? null : observedAt, lastEventAgeMs, valuesRedacted: source?.valuesRedacted !== false };
}

export function factCombinedTimingProjection(status = null, ...records) {
  const normalizedStatus = normalizeStatus(status ?? records.find((record) => record?.status)?.status);
  const terminal = TERMINAL_STATUSES.has(normalizedStatus) && !RUNNING_STATUSES.has(normalizedStatus);
  const observedAt = new Date().toISOString();
  const timings = records.map((record) => factTimingSource(record)).filter(Boolean);
  const startedAt = firstTimestampIso(...timings.map((timing) => timing.startedAt));
  const finishedAt = terminal ? latestTimestampIso(...timings.map((timing) => timing.finishedAt)) : null;
  const lastEventAt = terminal && finishedAt ? finishedAt : latestTimestampIso(...timings.map((timing) => timing.lastEventAt));
  const durationMs = elapsedFactMs(startedAt, terminal ? finishedAt : observedAt);
  const lastEventAgeMs = terminal ? null : elapsedFactMs(lastEventAt, observedAt);
  return { startedAt, lastEventAt, finishedAt, durationMs, observedAt: terminal ? null : observedAt, lastEventAgeMs, valuesRedacted: true };
}

export function factTimingSource(record = null) {
  if (!record) return null;
  const source = objectValue(record?.timing);
  return {
    startedAt: timestampIso(source?.startedAt ?? record?.startedAt ?? record?.createdAt),
    lastEventAt: timestampIso(source?.lastEventAt ?? record?.lastEventAt ?? record?.updatedAt ?? record?.createdAt),
    finishedAt: timestampIso(source?.finishedAt ?? record?.finishedAt ?? record?.completedAt)
  };
}

export function firstTimestampIso(...values) {
  for (const value of values) {
    const timestamp = timestampIso(value);
    if (timestamp) return timestamp;
  }
  return null;
}

export function latestTimestampIso(...values) {
  let latest = null;
  let latestMs = Number.NEGATIVE_INFINITY;
  for (const value of values) {
    const timestamp = timestampIso(value);
    if (!timestamp) continue;
    const ms = Date.parse(timestamp);
    if (!Number.isFinite(ms) || ms < latestMs) continue;
    latest = timestamp;
    latestMs = ms;
  }
  return latest;
}

export function elapsedFactMs(startedAt, endedAt) {
  const start = Date.parse(String(startedAt ?? ""));
  const end = Date.parse(String(endedAt ?? ""));
  if (!Number.isFinite(start) || !Number.isFinite(end) || end < start) return null;
  return Math.trunc(end - start);
}

export function timestampIso(value) {
  const ms = Date.parse(String(value ?? ""));
  return Number.isFinite(ms) ? new Date(ms).toISOString() : null;
}

export function factCheckpointForTrace(facts = {}, traceId) {
  const safeTrace = safeTraceId(traceId);
  if (!safeTrace) return null;
  return factArray(facts.checkpoints)
    .filter((checkpoint) => checkpoint.traceId === safeTrace)
    .sort(compareFactRecordsDesc)[0] ?? null;
}

export function workbenchProjectionStoreError(error) {
  const data = objectValue(error?.data) ?? {};
  const retryAfterNumber = Number(data.retryAfterMs);
  const retryAfterMs = Number.isFinite(retryAfterNumber) && retryAfterNumber >= 0 ? Math.trunc(retryAfterNumber) : null;
  const retryAttempt = nonNegativeIntegerOrNull(data.retryAttempt ?? data.retryAttempts);
  const retryMax = nonNegativeIntegerOrNull(data.retryMax);
  const retryDelaysMs = Array.isArray(data.retryDelaysMs)
    ? data.retryDelaysMs.map(nonNegativeIntegerOrNull).filter((value) => value !== null)
    : [];
  return workbenchError("projection_store_unavailable", "Workbench durable projection store is unavailable.", {
    causeCode: error?.code ?? null,
    queryResult: textValue(data.queryResult) || null,
    blockedLayer: textValue(data.blockedLayer) || null,
    retryable: data.retryable !== false,
    transient: data.transient === true || data.retryable === true,
    retryAfterMs: retryAfterMs ?? null,
    retryAttempt,
    retryMax,
    retryAttempts: retryAttempt,
    retryExhausted: data.retryExhausted === true,
    retryDelaysMs: retryDelaysMs.length > 0 ? retryDelaysMs : null
  });
}

export function nonNegativeIntegerOrNull(value) {
  const parsed = Number(value);
  return Number.isFinite(parsed) && parsed >= 0 ? Math.trunc(parsed) : null;
}

export function factSessionId(session) {
  return safeSessionId(session?.sessionId ?? session?.id) ?? null;
}

export function factLastTraceId(session) {
  return safeTraceId(session?.lastTraceId ?? session?.traceId) ?? null;
}

export function factLatestTraceIdForSession(facts = {}, sessionId) {
  const turn = factArray(facts.turns).filter((item) => item.sessionId === sessionId).sort(compareFactRecordsDesc)[0] ?? null;
  return safeTraceId(turn?.traceId) ?? null;
}

export function factCurrentTraceForSession(facts = {}, sessionId, session = null) {
  const candidates = [];
  const sessionTraceId = factLastTraceId(session);
  if (sessionTraceId) candidates.push(factTraceCandidate(session, sessionTraceId, normalizeStatus(session?.status), 0));
  for (const message of factArray(facts.messages)) {
    if (message?.sessionId !== sessionId || !safeTraceId(message?.traceId)) continue;
    candidates.push(factMessageTraceCandidate(message));
  }
  for (const turn of factArray(facts.turns)) {
    if (turn?.sessionId !== sessionId || !safeTraceId(turn?.traceId)) continue;
    candidates.push(factTraceCandidate(turn, safeTraceId(turn.traceId), normalizeStatus(turn?.status), 3));
  }
  return candidates.sort(compareTraceCandidatesDesc)[0] ?? null;
}

export function factMessageTraceCandidate(message) {
  const role = textValue(message?.role);
  let status = normalizeStatus(message?.status);
  let priority = 1;
  if (isAssistantLikeRole(role)) {
    priority = 2;
    if (status === "unknown") status = "running";
  } else if (safeTraceId(message?.traceId)) {
    status = "running";
  }
  return factTraceCandidate(message, safeTraceId(message?.traceId), status, priority);
}

export function factTraceCandidate(record, traceId, status, priority) {
  return { traceId: safeTraceId(traceId) ?? null, status: normalizeStatus(status), seq: factSeq(record), updatedAt: factUpdatedAt(record), priority };
}

export function compareTraceCandidatesDesc(left, right) {
  return compareNumberDesc(left?.seq, right?.seq) || compareTimestampDesc(left?.updatedAt, right?.updatedAt) || compareNumberDesc(left?.priority, right?.priority);
}

export function nonUnknownStatus(status) {
  return normalizeStatus(status) === "unknown" ? null : status;
}

export function factTurnId(turn, fallbackTraceId = null) {
  return safeTurnId(turn?.turnId) ?? safeTraceId(turn?.turnId) ?? safeTraceId(fallbackTraceId) ?? null;
}

export function factUpdatedAt(record) {
  return textValue(record?.updatedAt ?? record?.occurredAt ?? record?.createdAt) || null;
}

export function factSeq(record) {
  for (const value of [record?.projectedSeq, record?.sourceSeq, record?.seq]) {
    const parsed = Number(value);
    if (Number.isFinite(parsed) && parsed >= 0) return Math.trunc(parsed);
  }
  return null;
}

export function factProjectedSeq(record) {
  const parsed = Number(record?.projectedSeq);
  return Number.isFinite(parsed) && parsed > 0 ? Math.trunc(parsed) : null;
}

export function normalizeProjectionStatus(value) {
  const status = normalizeStatus(value);
  if (status === "caught-up") return "caught-up";
  if (status === "caughtup") return "caught-up";
  return ["projecting", "blocked", "stalled", "unknown"].includes(status) ? status : "unknown";
}

export function normalizeProjectionHealth(value, projectionStatus = "unknown") {
  const health = normalizeStatus(value);
  if (health === "healthy" && projectionStatus === "caught-up") return "caught-up";
  if (health === "healthy" && projectionStatus === "projecting") return "projecting";
  if (["caught-up", "projecting", "degraded", "stalled", "unavailable", "unknown"].includes(health)) return health;
  return projectionStatus === "caught-up" || projectionStatus === "projecting" ? projectionStatus : "unknown";
}

export function compareFactSessionsDesc(left, right) {
  return compareTimestampDesc(factUpdatedAt(left), factUpdatedAt(right)) || compareText(factSessionId(left), factSessionId(right));
}

export function compareFactMessagesAsc(left, right) {
  return compareNumberAsc(factSeq(left), factSeq(right)) || compareTimestampAsc(left?.createdAt ?? left?.updatedAt, right?.createdAt ?? right?.updatedAt) || compareText(left?.messageId, right?.messageId);
}

export function compareFactMessagesForSessionAsc(left, right, facts = {}) {
  const leftKey = factMessageTimelineKey(left, facts);
  const rightKey = factMessageTimelineKey(right, facts);
  return compareOptionalTimestampAsc(leftKey.timelineAnchorAt, rightKey.timelineAnchorAt)
    || compareOptionalNumberAsc(leftKey.turnSeq, rightKey.turnSeq)
    || compareTimestampAsc(leftKey.turnStartedAt, rightKey.turnStartedAt)
    || compareText(leftKey.traceId, rightKey.traceId)
    || compareOptionalNumberAsc(leftKey.roleRank, rightKey.roleRank)
    || compareTimestampAsc(leftKey.messageCreatedAt, rightKey.messageCreatedAt)
    || compareOptionalNumberAsc(leftKey.messageSeq, rightKey.messageSeq)
    || compareText(left?.messageId, right?.messageId);
}

export function factMessageTimelineKey(message, facts = {}) {
  const traceId = safeTraceId(message?.traceId) ?? null;
  const turn = traceId ? factTurnForTrace(facts, traceId) : null;
  const checkpoint = traceId ? factCheckpointForTrace(facts, traceId) : null;
  const anchorMessage = traceId ? factTimelineAnchorMessageForTrace(facts, traceId) : null;
  return {
    traceId: traceId ?? "",
    timelineAnchorAt: firstTimestampIso(anchorMessage?.createdAt, anchorMessage?.updatedAt),
    turnSeq: firstFiniteNumber(factSeq(turn), factSeq(checkpoint)),
    turnStartedAt: firstTimestampIso(turn?.startedAt, checkpoint?.startedAt, message?.createdAt, message?.updatedAt),
    roleRank: factMessageTimelineRoleRank(message?.role),
    messageCreatedAt: timestampIso(message?.createdAt ?? message?.updatedAt),
    messageSeq: factSeq(message)
  };
}

export function factTimelineAnchorMessageForTrace(facts = {}, traceId) {
  const safeTrace = safeTraceId(traceId);
  if (!safeTrace) return null;
  const messages = factArray(facts.messages).filter((message) => message.traceId === safeTrace);
  const userMessages = messages.filter((message) => normalizeRole(message?.role) === "user");
  const candidates = userMessages.length > 0 ? userMessages : messages;
  return [...candidates].sort((left, right) => compareOptionalTimestampAsc(left?.createdAt ?? left?.updatedAt, right?.createdAt ?? right?.updatedAt) || compareOptionalNumberAsc(factSeq(left), factSeq(right)) || compareText(left?.messageId, right?.messageId))[0] ?? null;
}

export function factMessageTimelineRoleRank(role) {
  const normalized = normalizeRole(role);
  if (normalized === "user") return 0;
  if (isAssistantLikeRole(normalized)) return 1;
  return 2;
}

export function firstFiniteNumber(...values) {
  for (const value of values) {
    const parsed = Number(value);
    if (Number.isFinite(parsed)) return Math.trunc(parsed);
  }
  return null;
}

export function compareOptionalNumberAsc(left, right) {
  const leftNumber = Number(left);
  const rightNumber = Number(right);
  const leftComparable = Number.isFinite(leftNumber) ? leftNumber : Number.MAX_SAFE_INTEGER;
  const rightComparable = Number.isFinite(rightNumber) ? rightNumber : Number.MAX_SAFE_INTEGER;
  return leftComparable - rightComparable;
}

export function compareFactPartsAsc(left, right) {
  return compareNumberAsc(left?.partIndex, right?.partIndex) || compareNumberAsc(factSeq(left), factSeq(right)) || compareText(left?.partId, right?.partId);
}

export function compareFactTraceEventsAsc(left, right) {
  return compareNumberAsc(factProjectedSeq(left), factProjectedSeq(right));
}

export function compareFactRecordsDesc(left, right) {
  return compareNumberDesc(factSeq(left), factSeq(right)) || compareTimestampDesc(factUpdatedAt(left), factUpdatedAt(right));
}

export function compareTimestampAsc(left, right) {
  return timestampMs(left) - timestampMs(right);
}

export function compareTimestampDesc(left, right) {
  return timestampMs(right) - timestampMs(left);
}

export function compareOptionalTimestampAsc(left, right) {
  const leftMs = optionalTimestampMs(left);
  const rightMs = optionalTimestampMs(right);
  return (leftMs ?? Number.MAX_SAFE_INTEGER) - (rightMs ?? Number.MAX_SAFE_INTEGER);
}

export function compareNumberAsc(left, right) {
  return numericValue(left, Number.MAX_SAFE_INTEGER) - numericValue(right, Number.MAX_SAFE_INTEGER);
}

export function compareNumberDesc(left, right) {
  return numericValue(right, -1) - numericValue(left, -1);
}

export function compareText(left, right) {
  return textValue(left).localeCompare(textValue(right));
}

export function timestampMs(value) {
  const parsed = Date.parse(String(value ?? ""));
  return Number.isFinite(parsed) ? parsed : 0;
}

export function optionalTimestampMs(value) {
  const parsed = Date.parse(String(value ?? ""));
  return Number.isFinite(parsed) ? parsed : null;
}

export function numericValue(value, fallback) {
  const parsed = Number(value);
  return Number.isFinite(parsed) ? parsed : fallback;
}

export function mergeFactSets(...sets) {
  const merged = emptyFactSet();
  const keys = {
    sessions: "sessionId",
    messages: "messageId",
    parts: "partId",
    turns: "turnId",
    traceEvents: "id",
    checkpoints: "traceId"
  };
  for (const set of sets) {
    for (const [key, idKey] of Object.entries(keys)) {
      const seen = new Set(merged[key].map((item) => textValue(item?.[idKey])));
      for (const item of factArray(set?.[key])) {
        const id = textValue(item?.[idKey]);
        if (id && seen.has(id)) continue;
        merged[key].push(item);
        if (id) seen.add(id);
      }
    }
  }
  return merged;
}

export function emptyFactSet() {
  return {
    sessions: [],
    messages: [],
    parts: [],
    turns: [],
    traceEvents: [],
    checkpoints: []
  };
}

export function factArray(value) {
  return Array.isArray(value) ? value : [];
}

export function uniqueText(values = []) {
  return [...new Set(values.map((value) => textValue(value)).filter(Boolean))];
}


export function eventSeq(event, index) {
  const seq = Number(event?.seq);
  return Number.isFinite(seq) && seq > 0 ? Math.trunc(seq) : index + 1;
}

export function normalizeStatus(value) {
  const text = textValue(value).toLowerCase().replace(/_/gu, "-");
  if (text === "cancelled") return "canceled";
  return text || "unknown";
}

export function normalizeTerminalStatus(value) {
  const status = normalizeStatus(value);
  return TERMINAL_STATUSES.has(status) && !RUNNING_STATUSES.has(status) ? status : null;
}

export function firstUserPreview(messages) {
  return messages.find((message) => message.role === "user")?.textPreview ?? null;
}

export function latestUserPreview(messages) {
  return [...messages].reverse().find((message) => message.role === "user")?.textPreview ?? null;
}

export function latestValidMessagePreview(messages) {
  return [...messages].reverse().find((message) => message.role === "user" || isAssistantLikeRole(message.role))?.textPreview ?? null;
}

export function latestAssistantPreview(messages) {
  return [...messages].reverse().find((message) => isAssistantLikeRole(message.role))?.textPreview ?? null;
}

export function sessionTitleFromMessages(messages = []) {
  return boundedPreviewText(latestUserPreview(messages) ?? firstUserPreview(messages) ?? latestAssistantPreview(messages));
}

export function sessionPreviewFromMessages(messages = []) {
  return boundedPreviewText(latestValidMessagePreview(messages) ?? firstUserPreview(messages) ?? latestAssistantPreview(messages));
}

export function boundedPreviewText(value, maxLength = 160) {
  const text = textValue(value).replace(/\s+/gu, " ").trim();
  if (!text) return null;
  return text.length > maxLength ? `${text.slice(0, maxLength - 3)}...` : text;
}

export function isAssistantLikeRole(role) {
  return role === "assistant" || role === "agent";
}

export function objectValue(value) {
  return value && typeof value === "object" && !Array.isArray(value) ? value : {};
}

export function textValue(value) {
  return String(value ?? "").trim();
}

export function messageAuthorityTextValue(value) {
  const text = String(value ?? "").replace(/\r\n?/gu, "\n");
  if (!text.trim() || text.trim() === "[object Object]") return "";
  return text;
}

export function safeTurnId(value) {
  const text = textValue(value);
  return /^turn_[A-Za-z0-9_.:-]+$/u.test(text) ? text : null;
}

export function safeMessageId(value) {
  const text = textValue(value);
  return /^msg_[A-Za-z0-9_.:-]+$/u.test(text) ? text : null;
}

export function safePartId(value) {
  const text = textValue(value);
  return /^prt_[A-Za-z0-9_.:-]+$/u.test(text) ? text : null;
}

export function hash(value) {
  return createHash("sha256").update(String(value)).digest("hex");
}