import {
  isSilentReplyText,
  SILENT_REPLY_TOKEN,
  startsWithSilentToken,
  stripLeadingSilentToken,
  stripSilentToken,
} from "../auto-reply/tokens.js";
import { defaultRuntime } from "../runtime.js";
import { isCronSessionKey } from "../sessions/session-key-utils.js";
import { normalizeOptionalString } from "../shared/string-coerce.js";
import { type DeliveryContext, normalizeDeliveryContext } from "../utils/delivery-context.js";
import { INTERNAL_MESSAGE_CHANNEL } from "../utils/message-channel.js";
import {
  buildAnnounceIdFromChildRun,
  buildAnnounceIdempotencyKey,
} from "./announce-idempotency.js";
import { formatAgentInternalEventsForPrompt, type AgentInternalEvent } from "./internal-events.js";
import {
  deliverSubagentAnnouncement,
  loadRequesterSessionEntry,
  loadSessionEntryByKey,
  runAnnounceDeliveryWithRetry,
  resolveSubagentAnnounceTimeoutMs,
  resolveSubagentCompletionOrigin,
} from "./subagent-announce-delivery.js";
import { resolveAnnounceOrigin } from "./subagent-announce-origin.js";
import {
  applySubagentWaitOutcome,
  buildChildCompletionFindings,
  buildCompactAnnounceStatsLine,
  dedupeLatestChildCompletionRows,
  filterCurrentDirectChildCompletionRows,
  readLatestSubagentOutputWithRetry,
  readSubagentOutput,
  type SubagentRunOutcome,
  waitForSubagentRunOutcome,
} from "./subagent-announce-output.js";
import {
  callGateway,
  isEmbeddedPiRunActive,
  loadConfig,
  waitForEmbeddedPiRunEnd,
} from "./subagent-announce.runtime.js";
import { getSubagentDepthFromSessionStore } from "./subagent-depth.js";
import type { SpawnSubagentMode } from "./subagent-spawn.types.js";
import { isAnnounceSkip } from "./tools/sessions-send-tokens.js";

type SubagentAnnounceDeps = {
  callGateway: typeof callGateway;
  loadConfig: typeof loadConfig;
  loadSubagentRegistryRuntime: typeof loadSubagentRegistryRuntime;
};

const defaultSubagentAnnounceDeps: SubagentAnnounceDeps = {
  callGateway,
  loadConfig,
  loadSubagentRegistryRuntime,
};

let subagentAnnounceDeps: SubagentAnnounceDeps = defaultSubagentAnnounceDeps;

let subagentRegistryRuntimePromise: Promise<
  typeof import("./subagent-announce.registry.runtime.js")
> | null = null;

function loadSubagentRegistryRuntime() {
  subagentRegistryRuntimePromise ??= import("./subagent-announce.registry.runtime.js");
  return subagentRegistryRuntimePromise;
}

export { buildSubagentSystemPrompt } from "./subagent-system-prompt.js";
export { captureSubagentCompletionReply } from "./subagent-announce-output.js";
export type { SubagentRunOutcome } from "./subagent-announce-output.js";

export type SubagentAnnounceType = "subagent task" | "cron job";

function buildAnnounceReplyInstruction(params: {
  requesterIsSubagent: boolean;
  announceType: SubagentAnnounceType;
  expectsCompletionMessage?: boolean;
}): string {
  if (params.requesterIsSubagent) {
    return `Convert this completion into a concise internal orchestration update for your parent agent in your own words. Keep this internal context private (don't mention system/log/stats/session details or announce type). If this result is duplicate or no update is needed, reply ONLY: ${SILENT_REPLY_TOKEN}.`;
  }
  if (params.expectsCompletionMessage) {
    return `A completed ${params.announceType} is ready for user delivery. Convert the result above into your normal assistant voice and send that user-facing update now. Keep this internal context private (don't mention system/log/stats/session details or announce type).`;
  }
  return `A completed ${params.announceType} is ready for user delivery. Convert the result above into your normal assistant voice and send that user-facing update now. Keep this internal context private (don't mention system/log/stats/session details or announce type), and do not copy the internal event text verbatim. Reply ONLY: ${SILENT_REPLY_TOKEN} if this exact result was already delivered to the user in this same turn.`;
}

function buildAnnounceSteerMessage(events: AgentInternalEvent[]): string {
  return (
    formatAgentInternalEventsForPrompt(events) ||
    "A background task finished. Process the completion update now."
  );
}

function hasUsableSessionEntry(entry: unknown): boolean {
  if (!entry || typeof entry !== "object") {
    return false;
  }
  const sessionId = (entry as { sessionId?: unknown }).sessionId;
  return typeof sessionId !== "string" || sessionId.trim() !== "";
}

function buildDescendantWakeMessage(params: { findings: string; taskLabel: string }): string {
  return [
    "[Subagent Context] Your prior run ended while waiting for descendant subagent completions.",
    "[Subagent Context] All pending descendants for that run have now settled.",
    "[Subagent Context] Continue your workflow using these results. Spawn more subagents if needed, otherwise send your final answer.",
    "",
    `Task: ${params.taskLabel}`,
    "",
    params.findings,
  ].join("\n");
}

const WAKE_RUN_SUFFIX = ":wake";

function stripWakeRunSuffixes(runId: string): string {
  let next = runId.trim();
  while (next.endsWith(WAKE_RUN_SUFFIX)) {
    next = next.slice(0, -WAKE_RUN_SUFFIX.length);
  }
  return next || runId.trim();
}

function isWakeContinuationRun(runId: string): boolean {
  const trimmed = runId.trim();
  if (!trimmed) {
    return false;
  }
  return stripWakeRunSuffixes(trimmed) !== trimmed;
}

function stripAndClassifyReply(text: string): string | null {
  let result = text;
  let didStrip = false;
  const hasLeadingSilentToken = startsWithSilentToken(result, SILENT_REPLY_TOKEN);
  if (hasLeadingSilentToken) {
    result = stripLeadingSilentToken(result, SILENT_REPLY_TOKEN);
    didStrip = true;
  }
  if (hasLeadingSilentToken || result.toLowerCase().includes(SILENT_REPLY_TOKEN.toLowerCase())) {
    result = stripSilentToken(result, SILENT_REPLY_TOKEN);
    didStrip = true;
  }
  if (
    didStrip &&
    (!result.trim() || isSilentReplyText(result, SILENT_REPLY_TOKEN) || isAnnounceSkip(result))
  ) {
    return null;
  }
  return result;
}

async function wakeSubagentRunAfterDescendants(params: {
  runId: string;
  childSessionKey: string;
  taskLabel: string;
  findings: string;
  announceId: string;
  signal?: AbortSignal;
}): Promise<boolean> {
  if (params.signal?.aborted) {
    return false;
  }

  const childEntry = loadSessionEntryByKey(params.childSessionKey);
  if (!hasUsableSessionEntry(childEntry)) {
    return false;
  }

  const cfg = subagentAnnounceDeps.loadConfig();
  const announceTimeoutMs = resolveSubagentAnnounceTimeoutMs(cfg);
  const wakeMessage = buildDescendantWakeMessage({
    findings: params.findings,
    taskLabel: params.taskLabel,
  });

  let wakeRunId = "";
  try {
    const wakeResponse = await runAnnounceDeliveryWithRetry<{ runId?: string }>({
      operation: "descendant wake agent call",
      signal: params.signal,
      run: async () =>
        await subagentAnnounceDeps.callGateway({
          method: "agent",
          params: {
            sessionKey: params.childSessionKey,
            message: wakeMessage,
            deliver: false,
            inputProvenance: {
              kind: "inter_session",
              sourceSessionKey: params.childSessionKey,
              sourceChannel: INTERNAL_MESSAGE_CHANNEL,
              sourceTool: "subagent_announce",
            },
            idempotencyKey: buildAnnounceIdempotencyKey(`${params.announceId}:wake`),
          },
          timeoutMs: announceTimeoutMs,
        }),
    });
    wakeRunId = normalizeOptionalString(wakeResponse?.runId) ?? "";
  } catch {
    return false;
  }

  if (!wakeRunId) {
    return false;
  }

  const { replaceSubagentRunAfterSteer } = await loadSubagentRegistryRuntime();
  return replaceSubagentRunAfterSteer({
    previousRunId: params.runId,
    nextRunId: wakeRunId,
    preserveFrozenResultFallback: true,
  });
}

export async function runSubagentAnnounceFlow(params: {
  childSessionKey: string;
  childRunId: string;
  requesterSessionKey: string;
  requesterOrigin?: DeliveryContext;
  requesterDisplayKey: string;
  task: string;
  timeoutMs: number;
  cleanup: "delete" | "keep";
  roundOneReply?: string;
  /**
   * Fallback text preserved from the pre-wake run when a wake continuation
   * completes with NO_REPLY despite an earlier final summary already existing.
   */
  fallbackReply?: string;
  waitForCompletion?: boolean;
  startedAt?: number;
  endedAt?: number;
  label?: string;
  outcome?: SubagentRunOutcome;
  announceType?: SubagentAnnounceType;
  expectsCompletionMessage?: boolean;
  spawnMode?: SpawnSubagentMode;
  wakeOnDescendantSettle?: boolean;
  signal?: AbortSignal;
  bestEffortDeliver?: boolean;
}): Promise<boolean> {
  let didAnnounce = false;
  const expectsCompletionMessage = params.expectsCompletionMessage === true;
  const announceType = params.announceType ?? "subagent task";
  let shouldDeleteChildSession = params.cleanup === "delete";
  try {
    let targetRequesterSessionKey = params.requesterSessionKey;
    let targetRequesterOrigin = normalizeDeliveryContext(params.requesterOrigin);
    const childSessionId = (() => {
      const entry = loadSessionEntryByKey(params.childSessionKey);
      return typeof entry?.sessionId === "string" && entry.sessionId.trim()
        ? entry.sessionId.trim()
        : undefined;
    })();
    const settleTimeoutMs = Math.min(Math.max(params.timeoutMs, 1), 120_000);
    let reply = params.roundOneReply;
    let outcome: SubagentRunOutcome | undefined = params.outcome;
    if (childSessionId && isEmbeddedPiRunActive(childSessionId)) {
      const settled = await waitForEmbeddedPiRunEnd(childSessionId, settleTimeoutMs);
      if (!settled && isEmbeddedPiRunActive(childSessionId)) {
        shouldDeleteChildSession = false;
        return false;
      }
    }

    if (!reply && params.waitForCompletion !== false) {
      const wait = await waitForSubagentRunOutcome(params.childRunId, settleTimeoutMs);
      const applied = applySubagentWaitOutcome({
        wait,
        outcome,
        startedAt: params.startedAt,
        endedAt: params.endedAt,
      });
      outcome = applied.outcome;
      params.startedAt = applied.startedAt;
      params.endedAt = applied.endedAt;
    }

    if (!outcome) {
      outcome = { status: "unknown" };
    }

    let requesterDepth = getSubagentDepthFromSessionStore(targetRequesterSessionKey);
    const requesterIsInternalSession = () =>
      requesterDepth >= 1 || isCronSessionKey(targetRequesterSessionKey);

    let childCompletionFindings: string | undefined;
    let subagentRegistryRuntime:
      | Awaited<ReturnType<typeof loadSubagentRegistryRuntime>>
      | undefined;
    try {
      subagentRegistryRuntime = await subagentAnnounceDeps.loadSubagentRegistryRuntime();
      if (
        requesterDepth >= 1 &&
        subagentRegistryRuntime.shouldIgnorePostCompletionAnnounceForSession(
          targetRequesterSessionKey,
        )
      ) {
        return true;
      }

      const pendingChildDescendantRuns = Math.max(
        0,
        subagentRegistryRuntime.countPendingDescendantRuns(params.childSessionKey),
      );
      if (pendingChildDescendantRuns > 0 && announceType !== "cron job") {
        shouldDeleteChildSession = false;
        return false;
      }

      if (typeof subagentRegistryRuntime.listSubagentRunsForRequester === "function") {
        const directChildren = subagentRegistryRuntime.listSubagentRunsForRequester(
          params.childSessionKey,
          {
            requesterRunId: params.childRunId,
          },
        );
        if (Array.isArray(directChildren) && directChildren.length > 0) {
          childCompletionFindings = buildChildCompletionFindings(
            dedupeLatestChildCompletionRows(
              filterCurrentDirectChildCompletionRows(directChildren, {
                requesterSessionKey: params.childSessionKey,
                getLatestSubagentRunByChildSessionKey:
                  subagentRegistryRuntime.getLatestSubagentRunByChildSessionKey,
              }),
            ),
          );
        }
      }
    } catch {
      // Best-effort only.
    }

    const announceId = buildAnnounceIdFromChildRun({
      childSessionKey: params.childSessionKey,
      childRunId: params.childRunId,
    });

    const childRunAlreadyWoken = isWakeContinuationRun(params.childRunId);
    if (
      params.wakeOnDescendantSettle === true &&
      childCompletionFindings?.trim() &&
      !childRunAlreadyWoken
    ) {
      const wakeAnnounceId = buildAnnounceIdFromChildRun({
        childSessionKey: params.childSessionKey,
        childRunId: stripWakeRunSuffixes(params.childRunId),
      });
      const woke = await wakeSubagentRunAfterDescendants({
        runId: params.childRunId,
        childSessionKey: params.childSessionKey,
        taskLabel: params.label || params.task || "task",
        findings: childCompletionFindings,
        announceId: wakeAnnounceId,
        signal: params.signal,
      });
      if (woke) {
        shouldDeleteChildSession = false;
        return true;
      }
    }

    if (!childCompletionFindings) {
      const fallbackReply = normalizeOptionalString(params.fallbackReply);
      const fallbackIsSilent =
        Boolean(fallbackReply) &&
        (isAnnounceSkip(fallbackReply) || isSilentReplyText(fallbackReply, SILENT_REPLY_TOKEN));

      if (!reply) {
        reply = await readSubagentOutput(params.childSessionKey, outcome);
      }

      if (!reply?.trim()) {
        reply = await readLatestSubagentOutputWithRetry({
          sessionKey: params.childSessionKey,
          maxWaitMs: params.timeoutMs,
          outcome,
        });
      }

      if (!reply?.trim() && fallbackReply && !fallbackIsSilent) {
        reply = fallbackReply;
      }

      // A worker can finish just after the first wait request timed out.
      // If we already have real completion content, do one cached recheck so
      // the final completion event prefers the authoritative terminal state.
      // This is best-effort; if the recheck fails, keep the known timeout
      // outcome instead of dropping the announcement entirely.
      if (outcome?.status === "timeout" && reply?.trim() && params.waitForCompletion !== false) {
        try {
          const rechecked = await waitForSubagentRunOutcome(params.childRunId, 0);
          const applied = applySubagentWaitOutcome({
            wait: rechecked,
            outcome,
            startedAt: params.startedAt,
            endedAt: params.endedAt,
          });
          outcome = applied.outcome;
          params.startedAt = applied.startedAt;
          params.endedAt = applied.endedAt;
        } catch {
          // Best-effort recheck; keep the existing timeout outcome on failure.
        }
      }

      if (isAnnounceSkip(reply) || isSilentReplyText(reply, SILENT_REPLY_TOKEN)) {
        if (fallbackReply && !fallbackIsSilent) {
          const cleaned = stripAndClassifyReply(fallbackReply);
          if (cleaned === null) {
            return true;
          }
          reply = cleaned;
        } else {
          return true;
        }
      } else if (reply) {
        const cleaned = stripAndClassifyReply(reply);
        if (cleaned === null) {
          if (fallbackReply && !fallbackIsSilent) {
            const cleanedFallback = stripAndClassifyReply(fallbackReply);
            if (cleanedFallback === null) {
              return true;
            }
            reply = cleanedFallback;
          } else {
            return true;
          }
        } else {
          reply = cleaned;
        }
      }
    }

    if (!outcome) {
      outcome = { status: "unknown" };
    }

    // Build status label
    const statusLabel =
      outcome.status === "ok"
        ? "completed successfully"
        : outcome.status === "timeout"
          ? "timed out"
          : outcome.status === "error"
            ? `failed: ${outcome.error || "unknown error"}`
            : "finished with unknown status";

    const taskLabel = params.label || params.task || "task";
    const announceSessionId = childSessionId || "unknown";
    const findings = childCompletionFindings || reply || "(no output)";

    let requesterIsSubagent = requesterIsInternalSession();
    if (requesterIsSubagent) {
      const {
        isSubagentSessionRunActive,
        resolveRequesterForChildSession,
        shouldIgnorePostCompletionAnnounceForSession,
      } = subagentRegistryRuntime ?? (await loadSubagentRegistryRuntime());
      if (!isSubagentSessionRunActive(targetRequesterSessionKey)) {
        if (shouldIgnorePostCompletionAnnounceForSession(targetRequesterSessionKey)) {
          return true;
        }
        const parentSessionEntry = loadSessionEntryByKey(targetRequesterSessionKey);
        const parentSessionAlive = hasUsableSessionEntry(parentSessionEntry);

        if (!parentSessionAlive) {
          const fallback = resolveRequesterForChildSession(targetRequesterSessionKey);
          if (!fallback?.requesterSessionKey) {
            shouldDeleteChildSession = false;
            return false;
          }
          targetRequesterSessionKey = fallback.requesterSessionKey;
          targetRequesterOrigin =
            normalizeDeliveryContext(fallback.requesterOrigin) ?? targetRequesterOrigin;
          requesterDepth = getSubagentDepthFromSessionStore(targetRequesterSessionKey);
          requesterIsSubagent = requesterIsInternalSession();
        }
      }
    }

    const replyInstruction = buildAnnounceReplyInstruction({
      requesterIsSubagent,
      announceType,
      expectsCompletionMessage,
    });
    const statsLine = await buildCompactAnnounceStatsLine({
      sessionKey: params.childSessionKey,
      startedAt: params.startedAt,
      endedAt: params.endedAt,
    });
    const internalEvents: AgentInternalEvent[] = [
      {
        type: "task_completion",
        source: announceType === "cron job" ? "cron" : "subagent",
        childSessionKey: params.childSessionKey,
        childSessionId: announceSessionId,
        announceType,
        taskLabel,
        status: outcome.status,
        statusLabel,
        result: findings,
        statsLine,
        replyInstruction,
      },
    ];
    const triggerMessage = buildAnnounceSteerMessage(internalEvents);

    // Send to the requester session. For nested subagents this is an internal
    // follow-up injection (deliver=false) so the orchestrator receives it.
    let directOrigin = targetRequesterOrigin;
    if (!requesterIsSubagent) {
      const { entry } = loadRequesterSessionEntry(targetRequesterSessionKey);
      directOrigin = resolveAnnounceOrigin(entry, targetRequesterOrigin);
    }
    const completionDirectOrigin =
      expectsCompletionMessage && !requesterIsSubagent
        ? await resolveSubagentCompletionOrigin({
            childSessionKey: params.childSessionKey,
            requesterSessionKey: targetRequesterSessionKey,
            requesterOrigin: directOrigin,
            childRunId: params.childRunId,
            spawnMode: params.spawnMode,
            expectsCompletionMessage,
          })
        : targetRequesterOrigin;
    const directIdempotencyKey = buildAnnounceIdempotencyKey(announceId);
    const delivery = await deliverSubagentAnnouncement({
      requesterSessionKey: targetRequesterSessionKey,
      announceId,
      triggerMessage,
      steerMessage: triggerMessage,
      internalEvents,
      summaryLine: taskLabel,
      requesterSessionOrigin: targetRequesterOrigin,
      requesterOrigin:
        expectsCompletionMessage && !requesterIsSubagent
          ? completionDirectOrigin
          : targetRequesterOrigin,
      completionDirectOrigin,
      directOrigin,
      sourceSessionKey: params.childSessionKey,
      sourceChannel: INTERNAL_MESSAGE_CHANNEL,
      sourceTool: "subagent_announce",
      targetRequesterSessionKey,
      requesterIsSubagent,
      expectsCompletionMessage: expectsCompletionMessage,
      bestEffortDeliver: params.bestEffortDeliver,
      directIdempotencyKey,
      signal: params.signal,
    });
    didAnnounce = delivery.delivered;
    if (!delivery.delivered && delivery.path === "direct" && delivery.error) {
      defaultRuntime.error?.(
        `Subagent completion direct announce failed for run ${params.childRunId}: ${delivery.error}`,
      );
    }
  } catch (err) {
    defaultRuntime.error?.(`Subagent announce failed: ${String(err)}`);
    // Best-effort follow-ups; ignore failures to avoid breaking the caller response.
  } finally {
    // Patch label after all writes complete
    if (params.label) {
      try {
        await subagentAnnounceDeps.callGateway({
          method: "sessions.patch",
          params: { key: params.childSessionKey, label: params.label },
          timeoutMs: 10_000,
        });
      } catch {
        // Best-effort
      }
    }
    if (shouldDeleteChildSession) {
      try {
        await subagentAnnounceDeps.callGateway({
          method: "sessions.delete",
          params: {
            key: params.childSessionKey,
            deleteTranscript: true,
            emitLifecycleHooks: params.spawnMode === "session",
          },
          timeoutMs: 10_000,
        });
      } catch {
        // ignore
      }
    }
  }
  return didAnnounce;
}

export const __testing = {
  setDepsForTest(overrides?: Partial<SubagentAnnounceDeps>) {
    subagentAnnounceDeps = overrides
      ? {
          ...defaultSubagentAnnounceDeps,
          ...overrides,
        }
      : defaultSubagentAnnounceDeps;
  },
};