import { FastifyInstance, FastifyReply } from 'fastify';
import { createTask, recordExternalTask, dispatchTask, listTasks, getTask, claimTask, doneTask, reviewTask, cancelTask, reopenTask, assignTask, deleteTask } from '../core/services/taskService.js';
import { getTaskActivity } from '../core/services/activityService.js';
import { appendTaskLog, readTaskLog } from '../core/services/taskLogService.js';
import { createHandoff, listHandoffs, getHandoff } from '../core/services/handoffService.js';
import { createDecision, listDecisions } from '../core/services/decisionService.js';
import { createMessage, listMessages, listInbox, markMessageRead, ackMessage, getMessage } from '../core/services/messageService.js';
import { createAsk, listAsks, getAsk, answerAsk, escalateAsk } from '../core/services/askService.js';
import { addMemory, searchMemory, listMemory } from '../core/services/memoryService.js';
import { getStatus, updateStatus } from '../core/services/statusService.js';
import { autoDelegate, suggestDelegation } from '../core/services/delegateService.js';
import { computeBudget } from '../core/services/budgetService.js';
import { getRoster } from '../core/services/rosterService.js';
import { computeHealth, enterLoop, leaveLoop, stampSeen, DORMANT_AFTER_MS } from '../core/services/presenceService.js';
import { resolvePending, hasPending } from '../core/services/checkinService.js';
import { loadConfig, saveConfig } from '../core/config.js';
import { agentIdentity } from '../core/services/identityService.js';
import { renderActivityHtml } from './activity.js';
import { renderAgentHealthHtml } from './agentHealth.js';
import { renderBoardHtml } from './board/index.js';
import { renderTeamHtml } from './team.js';
import { renderArchiveHtml } from './archive.js';
import { renderDecisionsHtml } from './decisions.js';
import { renderMessagesHtml } from './messages.js';
import { renderTaskDetailHtml } from './taskDetail.js';
import { configureDurableEvents, eventBus, emitChange } from './events.js';
import type { AgentHubEvent } from './events.js';
import { countHubEventsAfter, latestHubEventSeq, listHubEventsAfter } from './eventLog.js';
import type { Task, Handoff, Decision, Memory, Message, Ask } from '../core/schema.js';
import { readFile } from 'node:fs/promises';
import { fileURLToPath } from 'node:url';
import { join, extname, normalize } from 'node:path';
import { getFsWatchErrors } from './fsWatch.js';

const SSE_KEEPALIVE_MS = 10_000;

// KPI-card animated icons + vendored lottie player live in the repo `assets/` dir
// (../../assets relative to the compiled dist/server/routes.js).
const CARD_ASSETS_DIR = fileURLToPath(new URL('../../assets/', import.meta.url));

function notFound(reply: FastifyReply, resource: string) {
  return reply.status(404).send({ error: `${resource} not found` });
}

function badRequest(reply: FastifyReply, message: string) {
  return reply.status(400).send({ error: message });
}

function wantsHtml(request: { headers: { accept?: string } }): boolean {
  const accept = request.headers.accept ?? '';
  return accept.includes('text/html') && !accept.includes('application/json');
}

export async function registerRoutes(app: FastifyInstance, cwd: string): Promise<void> {
  configureDurableEvents(cwd);
  // Uptime anchor for /health (buildApp ≈ server start).
  const startedAtMs = Date.now();

  // Default dynamic responses to no-store so board reloads/fetches never reuse
  // stale task JSON or HTML. Static asset routes override this with cacheable
  // headers, and the SSE route writes its own raw no-cache header.
  app.addHook('onRequest', async (_request, reply) => {
    reply.header('Cache-Control', 'no-store, must-revalidate');
  });

  // Hub health: status + version + uptime + compact counts + per-agent lights.
  app.get('/health', async () => ({
    ...computeHealth(cwd, startedAtMs),
    indexErrors: getFsWatchErrors(),
  }));
  app.get('/architect/pulse', async (request) => {
    const query = request.query as { sinceSeq?: string; since?: string };
    const rawSince = query.sinceSeq ?? query.since;
    const explicitSince = rawSince !== undefined;
    const sinceSeq = Math.max(0, Number.parseInt(rawSince ?? '0', 10) || 0);
    const config = loadConfig(cwd);
    const architect = config.roles.architect?.preferredAgent ?? 'claude';
    const health = computeHealth(cwd, startedAtMs);
    const eventLimit = 5;
    const eventBase = explicitSince ? sinceSeq : Math.max(0, latestHubEventSeq(cwd) - eventLimit);
    const rawEvents = listHubEventsAfter(cwd, eventBase, eventLimit);
    const events = rawEvents.map(({ seq, type, action, id, status, assignedTo }) => ({
      seq, type, action, id, status, assignedTo,
    }));
    const nextSeq = rawEvents.length ? rawEvents[rawEvents.length - 1].seq : latestHubEventSeq(cwd);
    const availableEvents = countHubEventsAfter(cwd, explicitSince ? sinceSeq : 0);
    const eventsOmitted = Math.max(0, availableEvents - rawEvents.length);
    const allMessages = listMessages(cwd)
      .filter((message) => message.to === architect && message.status === 'unread');
    const messageLimit = 5;
    return {
      at: new Date().toISOString(),
      nextSeq,
      reviews: listTasks(cwd, { status: 'review' }).map((task) => ({
        id: task.id,
        assignedTo: task.assignedTo,
        updatedAt: task.updatedAt,
      })),
      // Zwei verschiedene Zustände, die nicht gleich behandelt werden dürfen:
      //
      //  a) `loopExitReason` gesetzt → der Agent hat den Loop AUSDRÜCKLICH
      //     verlassen ("turn ended"). Er hört ab sofort nicht mehr zu; ein
      //     Reopen erreicht ihn nie. Sofort melden, ohne Wartezeit.
      //  b) kein Exit-Grund, aber ein Task in Arbeit → der Agent FÜHRT gerade
      //     aus. `inLoop` ist dabei immer false; ohne Zeitbedingung wäre jeder
      //     hart arbeitende Agent "dormant" und der Architekt würde Leute
      //     anstoßen, die einwandfrei laufen. Erst nach DORMANT_AFTER_MS ohne
      //     Check-in ist das ein Fall für mich.
      dormantAgents: health.agents
        .filter((agent) => {
          if (agent.inLoop) return false;
          if (agent.loopExitReason) return true;
          if (!agent.taskId) return false;
          return agent.lastSeenAgoSec === undefined || agent.lastSeenAgoSec * 1000 >= DORMANT_AFTER_MS;
        })
        .map((agent) => ({
          name: agent.name,
          taskId: agent.taskId,
          lastSeenAgoSec: agent.lastSeenAgoSec,
          loopExitAgoSec: agent.loopExitAgoSec,
          loopExitReason: agent.loopExitReason,
        })),
      messages: allMessages.slice(0, messageLimit).map(({ id, from, taskId, createdAt }) => ({
        id, from, taskId, createdAt,
      })),
      events,
      omitted: {
        messages: Math.max(0, allMessages.length - messageLimit),
        events: eventsOmitted,
      },
    };
  });
  app.get('/agents/:agent/identity', async (request, reply) => {
    try {
      const identity = agentIdentity(cwd, (request.params as { agent: string }).agent);
      return { canonical: identity.canonical, names: [...identity.names] };
    } catch (err) {
      return badRequest(reply, err instanceof Error ? err.message : String(err));
    }
  });

  // Agent health-check page (TSK-0230): reachability traffic light per agent
  // (same /health data), test-message send with live delivery tracking,
  // cross-messaging view, and the page's own transport mode (SSE vs polling).
  app.get('/agent-health', async (_request, reply) =>
    reply.type('text/html; charset=utf-8').send(renderAgentHealthHtml(cwd, startedAtMs)),
  );

  // Static, self-contained Trello-like board. Polls /tasks, /handoffs and
  // /decisions on the same origin; no build step, no deps. Cached once — the
  // markup is constant, only the data it fetches changes.
  const boardHtml = renderBoardHtml(loadConfig(cwd).projectName);
  app.get('/board', async (_request, reply) => reply.type('text/html; charset=utf-8').send(boardHtml));

  // AgentHub logo (header, splash, favicon). Read-only, cacheable.
  app.get('/logo.svg', async (_request, reply) => {
    try {
      const buf = await readFile(join(CARD_ASSETS_DIR, 'logo.svg'));
      return reply.type('image/svg+xml').header('Cache-Control', 'public, max-age=3600').send(buf);
    } catch {
      return reply.status(404).send('not found');
    }
  });

  // Serve the KPI-card Lottie animations + the vendored lottie-web player from the
  // repo `assets/` dir. Read-only, path-traversal-guarded, cacheable.
  app.get('/card-assets/*', async (request, reply) => {
    const rel = normalize((request.params as Record<string, string>)['*'] || '');
    if (!rel || rel.startsWith('..') || rel.includes('\0')) return reply.status(404).send('not found');
    const full = join(CARD_ASSETS_DIR, rel);
    if (!full.startsWith(CARD_ASSETS_DIR)) return reply.status(404).send('not found');
    try {
      const buf = await readFile(full);
      const ext = extname(full).toLowerCase();
      const type = ext === '.json' ? 'application/json; charset=utf-8'
        : ext === '.js' ? 'text/javascript; charset=utf-8'
        : 'application/octet-stream';
      return reply.type(type).header('Cache-Control', 'public, max-age=3600').send(buf);
    } catch {
      return reply.status(404).send('not found');
    }
  });

  // Team hierarchy page: roles tree with per-agent free/busy state.
  app.get('/team', async (_request, reply) => {
    const teamHtml = renderTeamHtml(cwd);
    return reply.type('text/html; charset=utf-8').send(teamHtml);
  });

  app.get('/archive', async (_request, reply) => {
    const archiveHtml = renderArchiveHtml(cwd);
    return reply.type('text/html; charset=utf-8').send(archiveHtml);
  });

  app.get('/activity', async (_request, reply) => {
    const activityHtml = renderActivityHtml(cwd);
    return reply.type('text/html; charset=utf-8').send(activityHtml);
  });

  // ─── Server-Sent Events ──────────────────────────────────────────────────
  // GET /events?role=<role>
  //
  // Keeps the connection open and streams JSON-encoded AgentHubEvent objects
  // as SSE data lines. Sends an immediate keepalive comment and then another
  // one every 10 s so proxies, fetch(), and MCP clients don't treat an idle
  // work-loop request as a dead connection.
  //
  // Optional ?role= filter: tasks whose role doesn't match are dropped
  // server-side. All handoff / decision / memory events are always forwarded.
  //
  // Both REST mutations and direct local-CLI writes emit events: REST routes
  // publish via emitChange(), and the filesystem watcher (fsWatch.ts) observes
  // the entity directories and emits for any other write. A shared dedup cache
  // (events.ts) ensures each change is delivered exactly once.
  app.get('/events', async (request, reply) => {
    const { role } = request.query as { role?: string };
    const lastEventIdHeader = request.headers['last-event-id'];
    const lastEventId =
      typeof lastEventIdHeader === 'string'
        ? Number.parseInt(lastEventIdHeader, 10)
        : Number.parseInt((request.query as { lastEventId?: string }).lastEventId ?? '', 10);
    const replayAfterSeq = Number.isFinite(lastEventId) && lastEventId >= 0 ? lastEventId : undefined;

    // Take full control of the raw response so Fastify doesn't interfere.
    reply.hijack();

    const raw = reply.raw;
    raw.writeHead(200, {
      'Content-Type': 'text/event-stream',
      'Cache-Control': 'no-cache',
      Connection: 'keep-alive',
    });
    raw.flushHeaders();
    raw.write(': connected\n\n');

    let closed = false;
    let keepAliveTimer: ReturnType<typeof setInterval> | undefined;
    const cleanup = () => {
      if (closed) return;
      closed = true;
      if (keepAliveTimer) clearInterval(keepAliveTimer);
      eventBus.off('change', listener);
      eventBus.off('log', logListener);
    };
    const writeSse = (chunk: string) => {
      if (closed || raw.destroyed || raw.writableEnded) return;
      try {
        raw.write(chunk);
      } catch {
        cleanup();
      }
    };

    const writeEvent = (event: AgentHubEvent) => {
      // Server-side role filter: skip tasks that belong to a different role.
      // Handoffs, decisions and memory always pass through.
      if (role && event.type === 'task' && event.role !== undefined && event.role !== role) {
        return;
      }
      const idLine = event.seq !== undefined ? `id: ${event.seq}\n` : '';
      writeSse(`${idLine}data: ${JSON.stringify(event)}\n\n`);
    };

    const listener = (event: AgentHubEvent) => writeEvent(event);

    eventBus.on('change', listener);

    if (replayAfterSeq !== undefined) {
      for (const event of listHubEventsAfter(cwd, replayAfterSeq)) {
        writeEvent(event);
      }
    }

    // Task-log lines ride a NAMED `task-log` SSE event so the board's generic
    // onmessage handler ignores them; only the task-detail live console listens.
    const logListener = (payload: unknown) => {
      writeSse(`event: task-log\ndata: ${JSON.stringify(payload)}\n\n`);
    };
    eventBus.on('log', logListener);

    keepAliveTimer = setInterval(() => {
      writeSse(': keepalive\n\n');
    }, SSE_KEEPALIVE_MS);

    // Clean up when the client disconnects (or the server closes).
    request.raw.once('close', cleanup);
    request.raw.once('error', cleanup);
    raw.once('close', cleanup);
    raw.once('error', cleanup);
    raw.once('finish', cleanup);
  });

  // ─── Presence ──────────────────────────────────────────────────────────────
  // POST /announce { agent, role?, action? } — an agent reports in on connect.
  // Ephemeral: broadcast to SSE subscribers only, nothing is written to disk.
  app.post('/announce', async (request, reply) => {
    const { agent, role, action } = request.body as { agent?: string; role?: string; action?: string };
    if (!agent) return badRequest(reply, 'agent is required');
    stampSeen(agent);
    const ev: AgentHubEvent = {
      type: 'agent',
      action: action === 'left' ? 'left' : 'joined',
      id: agent,
      role,
    };
    eventBus.publish(ev);
    return { ok: true, agent, action: ev.action };
  });
  app.post('/agents/:agent/loop', async (request, reply) => {
    const agent = (request.params as { agent: string }).agent;
    const { active, reason } = request.body as { active?: boolean; reason?: string };
    try {
      const canonical = agentIdentity(cwd, agent).canonical;
      if (active) enterLoop(canonical);
      else leaveLoop(canonical, reason ?? 'ended');
      eventBus.publish({
        type: 'agent',
        action: active ? 'joined' : 'left',
        id: canonical,
        status: active ? 'in_loop' : `out_of_loop:${reason ?? 'ended'}`,
      });
      return { ok: true, agent: canonical, active: !!active, reason };
    } catch (err) {
      return badRequest(reply, err instanceof Error ? err.message : String(err));
    }
  });

  // ─── Status ──────────────────────────────────────────────────────────────
  app.get('/status', async () => ({ body: getStatus(cwd) }));
  app.post('/status/update', async () => ({ body: updateStatus(cwd) }));

  // Team roster (JSON) — used by the board's agent rail / drop targets.
  app.get('/agents', async () => getRoster(cwd));

  // Rename an org-chart node's display label (inline edit on /team).
  app.patch('/org/:id', async (request, reply) => {
    const { id } = request.params as { id: string };
    const { label } = (request.body ?? {}) as { label?: string };
    if (!label || typeof label !== 'string' || !label.trim()) return badRequest(reply, 'label is required');
    const config = loadConfig(cwd);
    const node = config.org?.find((n) => n.id === id);
    if (!node) return notFound(reply, 'Org node');
    node.label = label.trim().slice(0, 60);
    saveConfig(cwd, config);
    return { ok: true, id, label: node.label };
  });

  // Token & cost rollup per agent (real recorded + time-estimated, clearly flagged).
  app.get('/budget', async () => computeBudget(cwd));

  // Auto-log a task status transition to its live console. Best-effort: the
  // .log write + task-log SSE fan-out must never fail the underlying mutation.
  // (No double-emission: publishLog rides the separate 'log' channel, and
  // fsWatch only watches .md files, so the .log append is not re-emitted.)
  const logTaskStatus = (id: string, text: string, agent?: string) => {
    try {
      const entry = appendTaskLog(cwd, id, { text, agent, level: 'status' });
      eventBus.publishLog({ taskId: id, ...entry });
    } catch {
      /* logging is best-effort */
    }
  };

  // ─── Tasks ───────────────────────────────────────────────────────────────
  app.get('/tasks', async (request) => {
    const { status, role } = request.query as { status?: string; role?: string };
    return listTasks(cwd, { status, role });
  });

  app.post('/tasks', async (request, reply) => {
    let task: Task;
    try {
      task = createTask(cwd, request.body as Partial<Task>);
    } catch (err) {
      return badRequest(reply, err instanceof Error ? err.message : 'Invalid task');
    }
    emitChange(
      {
        type: 'task',
        action: 'created',
        id: task.id,
        title: task.title,
        status: task.status,
        role: task.role,
        assignedTo: task.assignedTo,
        claimedBy: task.claimedBy,
        reviewer: task.reviewer,
      },
      task.updatedAt,
    );
    return task;
  });
  app.post('/tasks/record', async (request, reply) => {
    try {
      const task = recordExternalTask(cwd, request.body as Parameters<typeof recordExternalTask>[1]);
      logTaskStatus(task.id, `Nachgetragen: außerhalb von AgentHub erledigt durch ${task.doneBy}`, task.doneBy);
      emitChange({ type: 'task', action: 'created', id: task.id, title: task.title, status: task.status, role: task.role, assignedTo: task.assignedTo, claimedBy: task.claimedBy }, task.updatedAt);
      return task;
    } catch (err) {
      return badRequest(reply, err instanceof Error ? err.message : 'Could not record external work');
    }
  });

  app.delete('/tasks/:id', async (request, reply) => {
    const { id } = request.params as { id: string };
    try {
      const result = deleteTask(cwd, id);
      emitChange({ type: 'task', action: 'deleted', id }, new Date().toISOString());
      return result;
    } catch (err) {
      return badRequest(reply, err instanceof Error ? err.message : 'Delete failed');
    }
  });

  app.get('/tasks/:id', async (request, reply) => {
    const { id } = request.params as { id: string };
    try {
      if (wantsHtml(request)) {
        return reply.type('text/html; charset=utf-8').send(renderTaskDetailHtml(cwd, id));
      }
      const { task, body } = getTask(cwd, id);
      return { task, body };
    } catch {
      return notFound(reply, 'Task');
    }
  });

  app.get('/tasks/:id/activity', async (request, reply) => {
    const { id } = request.params as { id: string };
    try {
      return getTaskActivity(cwd, id);
    } catch {
      return notFound(reply, 'Task');
    }
  });

  // ─── Live agent console ────────────────────────────────────────────────────
  // GET returns the task's streamed progress log; POST appends one line and
  // fans it out over SSE so an open task-detail console tails it live.
  app.get('/tasks/:id/log', async (request) => {
    const { id } = request.params as { id: string };
    return { log: readTaskLog(cwd, id) };
  });

  app.post('/tasks/:id/log', async (request, reply) => {
    const { id } = request.params as { id: string };
    const { text, agent, level } = request.body as { text?: string; agent?: string; level?: string };
    let entry;
    try {
      entry = appendTaskLog(cwd, id, { text: text ?? '', agent, level });
    } catch (err) {
      return badRequest(reply, err instanceof Error ? err.message : 'Invalid log line');
    }
    if (agent) stampSeen(agent);
    eventBus.publishLog({ taskId: id, ...entry });
    // TSK-0274 Check-in-Kanal: ein arbeitender Agent ist zwischen zwei
    // work-Aufrufen taub. Dieser Log-Aufruf ist der einzige Moment, in dem er
    // von sich aus spricht — also geben wir ihm hier zurück, was auf ihn
    // wartet (Reopen/Cancel seines Tasks, Nachrichten, offene Zuweisungen).
    if (!agent) return entry;
    const pending = resolvePending(cwd, agent, id);
    return hasPending(pending) ? { ...entry, pending } : entry;
  });

  /**
   * Expliziter Check-in (TSK-0274) — für Agenten, die zwischendurch nachsehen
   * wollen, ohne eine Log-Zeile zu schreiben, und für die Health-Sichtbarkeit.
   * `taskId` optional: damit wird zusätzlich geprüft, ob der Task dem Agenten
   * überhaupt noch gehört.
   */
  app.get('/agents/:agent/pending', async (request) => {
    const { agent } = request.params as { agent: string };
    const { taskId } = request.query as { taskId?: string };
    stampSeen(agent);
    return resolvePending(cwd, agent, taskId);
  });
  app.post('/tasks/:id/dispatch', async (request, reply) => {
    const { id } = request.params as { id: string };
    const { agent } = request.body as { agent?: string };
    try {
      const task = dispatchTask(cwd, id, agent ?? '');
      logTaskStatus(id, `Architect started ${task.claimedBy}`, 'architect');
      emitChange({ type: 'task', action: 'updated', id, title: task.title, status: task.status, role: task.role, assignedTo: task.assignedTo, claimedBy: task.claimedBy }, task.updatedAt);
      return task;
    } catch (err) {
      return badRequest(reply, err instanceof Error ? err.message : 'Dispatch failed');
    }
  });

  app.patch('/tasks/:id', async (request, reply) => {
    const { id } = request.params as { id: string };
    const patch = request.body as Partial<Task>;

    // Assign without claiming: address an open task to an agent (no status
    // change). Fires task/updated so a waiting `agenthub work` auto-claims it.
    if (patch.assignedTo !== undefined && patch.status === undefined) {
      let assigned: Task;
      try {
        assigned = assignTask(cwd, id, patch.assignedTo);
      } catch (err) {
        return badRequest(reply, err instanceof Error ? err.message : 'Invalid assignee');
      }
      logTaskStatus(id, `Addressed to ${assigned.assignedTo}`, assigned.assignedTo);
      emitChange(
        {
          type: 'task',
          action: 'updated',
          id: assigned.id,
          title: assigned.title,
          status: assigned.status,
          role: assigned.role,
          assignedTo: assigned.assignedTo,
          claimedBy: assigned.claimedBy,
          reviewer: assigned.reviewer,
        },
        assigned.updatedAt,
      );
      return assigned;
    }

    let task: Task;
    try {
      switch (patch.status) {
      case 'in_progress':
        {
          const current = getTask(cwd, id).task;
          const agent = patch.assignedTo?.trim() || current.assignedTo || 'manual';
          // claimTask is race-guarded (open-only). Surface a lost race / non-open
          // claim as a clean 400 so the board drag reverts gracefully instead of
          // 500-ing, and a second agent can't clobber the first's claim.
          task = claimTask(cwd, id, agent);
          stampSeen(agent);
        }
        break;
      case 'done':
        task = doneTask(cwd, id, {
          doneBy: patch.doneBy as string | undefined,
          doneTokens: patch.doneTokens as number | undefined,
          doneDuration: patch.doneDuration as number | undefined,
        });
        if (task.doneBy) stampSeen(task.doneBy);
        break;
      case 'review':
        task = reviewTask(cwd, id, patch.reviewer);
        // The submitter (assignee) is the acting agent here.
        if (task.assignedTo) stampSeen(task.assignedTo);
        break;
      case 'cancelled':
        task = cancelTask(cwd, id);
        break;
      case 'open':
        task = reopenTask(cwd, id);
        break;
        default:
          return badRequest(reply, 'Unsupported patch: status must be one of open, in_progress, review, done, cancelled');
      }
    } catch (err) {
      const message = err instanceof Error ? err.message : 'Invalid task transition';
      logTaskStatus(id, `Rejected transition${patch.status ? ` → ${patch.status}` : ''}: ${message}`, patch.assignedTo);
      return badRequest(reply, message);
    }

    // Uniformly log the transition for every status-changing caller (claim /
    // review / done / cancel / reopen), so the live console tracks progress.
    const logText =
      task.status === 'in_progress' ? `Claimed by ${task.claimedBy ?? task.assignedTo ?? 'agent'}`
      : task.status === 'review' ? `Submitted for review${task.reviewer ? ` → ${task.reviewer}` : ''}`
      : task.status === 'done' ? `Approved — done${task.doneBy ? ` by ${task.doneBy}` : ''}`
      : task.status === 'cancelled' ? 'Cancelled'
      : task.status === 'open' ? 'Reopened'
      : `Status → ${task.status}`;
    logTaskStatus(id, logText, task.claimedBy ?? task.assignedTo ?? task.reviewer ?? task.doneBy);

    emitChange(
      {
        type: 'task',
        action: 'updated',
        id: task.id,
        title: task.title,
        status: task.status,
        role: task.role,
        assignedTo: task.assignedTo,
        claimedBy: task.claimedBy,
        reviewer: task.reviewer,
      },
      task.updatedAt,
    );
    return task;
  });

  // ─── Handoffs ────────────────────────────────────────────────────────────
  app.get('/handoffs', async () => listHandoffs(cwd));
  app.post('/handoffs', async (request, reply) => {
    let handoff: Handoff;
    try {
      handoff = createHandoff(cwd, request.body as Partial<Handoff>);
    } catch (err) {
      return badRequest(reply, err instanceof Error ? err.message : 'Invalid handoff');
    }
    emitChange(
      {
        type: 'handoff',
        action: 'created',
        id: handoff.id,
        title: handoff.summary,
        role: handoff.toRole,
        assignedTo: handoff.toAgent,
      },
      handoff.createdAt,
    );
    return handoff;
  });
  app.get('/handoffs/:id', async (request, reply) => {
    const { id } = request.params as { id: string };
    try {
      const { handoff, body } = getHandoff(cwd, id);
      return { handoff, body };
    } catch {
      return notFound(reply, 'Handoff');
    }
  });

  // ─── Decisions ───────────────────────────────────────────────────────────
  app.get('/decisions', async (request, reply) => {
    if (wantsHtml(request)) {
      return reply.type('text/html; charset=utf-8').send(renderDecisionsHtml(cwd));
    }
    return listDecisions(cwd);
  });
  app.post('/decisions', async (request, reply) => {
    let decision: Decision;
    try {
      decision = createDecision(cwd, request.body as Partial<Decision>);
    } catch (err) {
      return badRequest(reply, err instanceof Error ? err.message : 'Invalid decision');
    }
    emitChange(
      {
        type: 'decision',
        action: 'created',
        id: decision.id,
        title: decision.title,
      },
      decision.updatedAt,
    );
    return decision;
  });

  // ─── Messages ────────────────────────────────────────────────────────────
  // Direct agent-to-agent / architect-to-agent messages. GET /messages returns
  // all (architect view); GET /messages/inbox?agent=X&unread=1 returns one
  // agent's inbox.
  app.get('/messages', async (request, reply) => {
    const { agent, unread, as, c } = request.query as { agent?: string; unread?: string; as?: string; c?: string };
    // JSON inbox contract (remoteClient.getInbox / agenthub_inbox) — unchanged.
    if (agent) return listInbox(cwd, agent, { unreadOnly: unread === '1' || unread === 'true' });
    // Browser navigation → the /messages conversation view.
    if (wantsHtml(request)) {
      return reply.type('text/html; charset=utf-8').send(renderMessagesHtml(cwd, as, c));
    }
    return listMessages(cwd);
  });
  app.post('/messages', async (request, reply) => {
    let message: Message;
    try {
      message = createMessage(cwd, request.body as Partial<Message>);
    } catch (err) {
      return badRequest(reply, err instanceof Error ? err.message : 'Invalid message');
    }
    stampSeen(message.from);
    emitChange(
      {
        type: 'message',
        action: 'created',
        id: message.id,
        title: `${message.from} → ${message.to}`,
        assignedTo: message.to,
        from: message.from,
      },
      message.updatedAt,
    );
    return message;
  });
  // Single message (frontmatter + body) — used by `message reply` to load the
  // parent it answers. JSON only.
  app.get('/messages/:id', async (request, reply) => {
    const { id } = request.params as { id: string };
    try {
      const { message, body } = getMessage(cwd, id);
      return { message, body };
    } catch {
      return notFound(reply, 'Message');
    }
  });
  app.post('/messages/:id/read', async (request, reply) => {
    const { id } = request.params as { id: string };
    try {
      const message = markMessageRead(cwd, id);
      // Read receipt: carry the reader (to) so the sender's stream shows
      // "✓ MSG-xxxx read by <agent>".
      emitChange(
        { type: 'message', action: 'updated', id: message.id, status: 'read', title: `${message.from} → ${message.to}`, assignedTo: message.to },
        message.updatedAt,
      );
      return message;
    } catch (err) {
      return badRequest(reply, err instanceof Error ? err.message : 'Message not found');
    }
  });
  app.post('/messages/:id/ack', async (request, reply) => {
    const { id } = request.params as { id: string };
    const { by } = (request.body ?? {}) as { by?: string };
    try {
      const message = ackMessage(cwd, id, by);
      // Ack receipt: mirror of /read so the sender's stream shows the strongest state.
      emitChange(
        { type: 'message', action: 'updated', id: message.id, status: 'acked', title: `${message.from} → ${message.to}`, assignedTo: message.to },
        message.updatedAt,
      );
      return message;
    } catch (err) {
      return badRequest(reply, err instanceof Error ? err.message : 'Message not found');
    }
  });

  // ─── Asks ────────────────────────────────────────────────────────────────
  // Blocking decision-routing questions (TSK-0118). POST creates + routes to the
  // architect; answer/escalate close them. Each mutation fires an 'ask' event so
  // a waiting `ask --wait` / agenthub_ask wakes.
  app.get('/asks', async (request) => {
    const { to, status } = request.query as { to?: string; status?: string };
    return listAsks(cwd, { to, status });
  });
  app.post('/asks', async (request, reply) => {
    let ask: Ask;
    try {
      ask = createAsk(cwd, request.body as Partial<Ask>);
    } catch (err) {
      return badRequest(reply, err instanceof Error ? err.message : 'Invalid ask');
    }
    emitChange(
      { type: 'ask', action: 'created', id: ask.id, title: `${ask.from} → ${ask.to}`, status: ask.status, assignedTo: ask.to },
      ask.updatedAt,
    );
    return ask;
  });
  app.get('/asks/:id', async (request, reply) => {
    const { id } = request.params as { id: string };
    try {
      const { ask, body } = getAsk(cwd, id);
      return { ask, body };
    } catch {
      return notFound(reply, 'Ask');
    }
  });
  app.post('/asks/:id/answer', async (request, reply) => {
    const { id } = request.params as { id: string };
    const { text, by } = (request.body ?? {}) as { text?: string; by?: string };
    try {
      const ask = answerAsk(cwd, id, text ?? '', by);
      emitChange(
        { type: 'ask', action: 'updated', id: ask.id, title: `${ask.from} → ${ask.to}`, status: ask.status, assignedTo: ask.to },
        ask.updatedAt,
      );
      return ask;
    } catch (err) {
      return badRequest(reply, err instanceof Error ? err.message : 'Ask not found');
    }
  });
  app.post('/asks/:id/escalate', async (request, reply) => {
    const { id } = request.params as { id: string };
    const { note } = (request.body ?? {}) as { note?: string };
    try {
      const ask = escalateAsk(cwd, id, note);
      emitChange(
        { type: 'ask', action: 'updated', id: ask.id, title: `${ask.from} → ${ask.to}`, status: ask.status, assignedTo: ask.escalatedTo },
        ask.updatedAt,
      );
      return ask;
    } catch (err) {
      return badRequest(reply, err instanceof Error ? err.message : 'Ask not found');
    }
  });

  // ─── Memory ──────────────────────────────────────────────────────────────
  app.get('/memory', async () => listMemory(cwd));
  app.post('/memory', async (request, reply) => {
    let memory: Memory;
    try {
      memory = addMemory(cwd, request.body as Partial<Memory>);
    } catch (err) {
      return badRequest(reply, err instanceof Error ? err.message : 'Invalid memory');
    }
    emitChange(
      {
        type: 'memory',
        action: 'created',
        id: memory.id,
        title: memory.title,
      },
      memory.updatedAt,
    );
    return memory;
  });
  app.get('/memory/search', async (request) => {
    const { q } = request.query as { q: string };
    return searchMemory(cwd, q ?? '');
  });

  // ─── Delegate ────────────────────────────────────────────────────────────
  app.post('/delegate', async (request) => {
    const { auto } = request.query as { auto?: string };
    const config = loadConfig(cwd);
    const suggestion = suggestDelegation(cwd);
    if (!suggestion) return { suggestion: null };
    const shouldAuto = auto === 'true' || config.delegationMode === 'auto';
    if (shouldAuto) {
      const handoff = autoDelegate(cwd);
      return { suggestion, handoff };
    }
    return { suggestion };
  });
}