import type { Context } from 'hono';
import { randomUUID } from 'node:crypto';
import { createRouter } from '../../create-router';
import * as errors from '@@/custom-errors';
import { resolveHomeDir } from '@@/user-home';
import { getCommandersDir, toShellUsername } from '@@/data-path';
import { getChatEventsSince } from 'officerdb';
import type { ServerMessage } from '../chat/types';
import {
  listClaudeSessions,
  loadClaudeSessionById,
  renameClaudeSession,
  deleteClaudeSession,
  type ChatIdentity,
  type ClaudeSessionSummary,
} from '../chat/claude-sessions';
import { collectRunningTasks, startClaudeTurn, getUserDefaultModel, DEFAULT_MODEL } from '../chat/websocket';
import {
  listCommandHqCategories,
  createCommandHqCategory,
  renameCommandHqCategory,
  deleteCommandHqCategory,
  createCommandHqSession,
  listCommandHqSessions,
  getCommandHqSession,
  setCommandHqSessionCategory,
  purgeCommandHqSessions,
  deleteCommandHqSession,
  disarmCommandHqWatcher,
  getCommandHqCostSummary,
  listCommandHqTurns,
  listCommandHqWatcherFires,
  getLastFiredAtBySessionRowIds,
  listCommandHqSessionTags,
  listCommandHqTags,
  createCommandHqTag,
  deleteCommandHqTag,
  addCommandHqSessionTag,
  removeCommandHqSessionTag,
  type CommandHqCostSummary,
} from 'officerdb';

/**
 * Command HQ — commanders (long-running background jobs the owner starts, names and organises separately
 * from `/chat`). Design record: `docs/command-hq.md`. That file is the "why"; this file is the "what",
 * kept deliberately explicit in its doc comments because it is the contract a mobile client builds against.
 *
 * ── Identity ──
 *
 * Every route resolves `commandHqIdentity`, the same shape `/chat` resolves as `chatIdentity` (duplicated
 * rather than imported — that function is private to `chat.ts` and this is five lines, not worth coupling
 * two routers over). `core` permission, no grant to hold: every account reaches this router, and every
 * query is additionally scoped to the caller's own `user_id` regardless.
 *
 * ── Where commanders live ──
 *
 * Every commander shares ONE working directory per user — `getCommandersDir(email)` — never one per
 * commander. That means listing a user's commanders is exactly `listClaudeSessions` (the same function
 * `/chat` uses for its own per-directory list) pointed at that one directory, filtered to sessions with a
 * `command_hq_sessions` row. No new session-scanning code exists here; this router is a client of the same
 * transcript reader `/chat` already is.
 */

async function commandHqIdentity(user: { id: number; email: string }): Promise<ChatIdentity> {
  const resolved = await resolveHomeDir(user.id);
  if (!resolved.ok) throw errors.FORBIDDEN(resolved.reason);
  return { email: user.email, home: resolved.home, osUser: resolved.osUser, isOwner: resolved.isOwner };
}

export const commandHqRouter = createRouter();

// ── Categories ──

// GET /command-hq/categories
commandHqRouter.get('/categories', async (ctx) => {
  const user = ctx.get('user');
  return ctx.json({ categories: await listCommandHqCategories(user.id) });
});

// POST /command-hq/categories  { name: string }
commandHqRouter.post('/categories', async (ctx) => {
  const user = ctx.get('user');
  const body = await ctx.req.json<{ name?: string }>().catch(() => ({}) as { name?: string });
  const name = body.name?.trim();
  if (!name) throw errors.BAD_REQUEST('name is required');
  try {
    return ctx.json(await createCommandHqCategory(user.id, name));
  } catch {
    // The unique index (`uq_command_hq_categories_user_name`) is the real guard; a Postgres constraint
    // violation is the only way this throws, so it is read back as the one thing it can mean.
    throw errors.CONFLICT('a category with this name already exists');
  }
});

// PATCH /command-hq/categories/:id  { name: string }
commandHqRouter.patch('/categories/:id', async (ctx) => {
  const user = ctx.get('user');
  const id = Number(ctx.req.param('id'));
  const body = await ctx.req.json<{ name?: string }>().catch(() => ({}) as { name?: string });
  const name = body.name?.trim();
  if (!name) throw errors.BAD_REQUEST('name is required');
  const ok = await renameCommandHqCategory(user.id, id, name);
  if (!ok) throw errors.NOT_FOUND('no such category');
  return ctx.json({ ok: true });
});

// DELETE /command-hq/categories/:id — uncategorises its commanders (onDelete: 'set null'), does not delete them.
commandHqRouter.delete('/categories/:id', async (ctx) => {
  const user = ctx.get('user');
  const id = Number(ctx.req.param('id'));
  const ok = await deleteCommandHqCategory(user.id, id);
  if (!ok) throw errors.NOT_FOUND('no such category');
  return ctx.json({ ok: true });
});

// ── Tags (schema only — no UI planned yet, but the endpoints are real) ──

// GET /command-hq/tags
commandHqRouter.get('/tags', async (ctx) => {
  const user = ctx.get('user');
  return ctx.json({ tags: await listCommandHqTags(user.id) });
});

// POST /command-hq/tags  { name: string }
commandHqRouter.post('/tags', async (ctx) => {
  const user = ctx.get('user');
  const body = await ctx.req.json<{ name?: string }>().catch(() => ({}) as { name?: string });
  const name = body.name?.trim();
  if (!name) throw errors.BAD_REQUEST('name is required');
  try {
    return ctx.json(await createCommandHqTag(user.id, name));
  } catch {
    throw errors.CONFLICT('a tag with this name already exists');
  }
});

// DELETE /command-hq/tags/:id
commandHqRouter.delete('/tags/:id', async (ctx) => {
  const user = ctx.get('user');
  const id = Number(ctx.req.param('id'));
  const ok = await deleteCommandHqTag(user.id, id);
  if (!ok) throw errors.NOT_FOUND('no such tag');
  return ctx.json({ ok: true });
});

// ── Commanders ──

/** A grid card's worth of information — the transcript summary plus what Command HQ knows about it. */
type CommanderSummary = ClaudeSessionSummary & {
  categoryId: number | null;
  tagIds: number[];
  /**
   * Derived from `chat_session_events` at request time — `task:started` minus `task:notification` — the
   * same fold `/chat`'s own background-job tray uses (`collectRunningTasks`). NOT a stored value: see
   * `docs/command-hq.md` for why a status column would go stale exactly when this feature matters most.
   */
  running: boolean;
  /**
   * Whether the platform is keeping this commander's watcher re-armed — see `docs/command-hq.md` → "The
   * watcher loop". Unlike `running`, this IS stored: it is the owner's own intent, not a live-process fact
   * the platform is reporting on. `watcherTaskId` itself is not exposed — an internal correlation id with
   * no display meaning, the join key `armCommandHqWatcher` uses and nothing a card needs to show.
   */
  watcherArmed: boolean;
  /** Since when the CURRENT run has been going, or null if never armed. Untouched by every self-re-arm. */
  watcherArmedAt: Date | null;
  /** When the current run ended, or null while still armed (or never armed). Paired with `watcherArmedAt`. */
  watcherStoppedAt: Date | null;
  /** `MAX(firedAt)` for this commander — no column of its own, see `docs/command-hq.md` → "The watcher loop". */
  watcherLastFiredAt: Date | null;
  /** The running total — every turn this commander has ever cost, summed. See `GET .../turns` for the raw series. */
  cost: CommandHqCostSummary;
};

async function isRunning(sessionId: string): Promise<boolean> {
  const events = await getChatEventsSince(sessionId, 0);
  return collectRunningTasks(events.map((e) => e.event as ServerMessage)).length > 0;
}

/**
 * GET /command-hq/commanders[?category=<id>|none]
 *
 * `category` omitted → every commander, categorised or not. `category=none` → only the uncategorised
 * bucket. `category=<id>` → one category.
 *
 * A row whose transcript no longer resolves is silently dropped, never rendered as a tombstone — the
 * design's explicit stance (see "The /chat ↔ /command-hq relationship" in the design doc). Response order
 * is newest-updated first, matching `/chat`'s own list.
 */
commandHqRouter.get('/commanders', async (ctx) => {
  const user = ctx.get('user');
  const who = await commandHqIdentity(user);
  const categoryParam = ctx.req.query('category');
  const categoryId = categoryParam === undefined ? undefined : categoryParam === 'none' ? null : Number(categoryParam);

  const [rows, live] = await Promise.all([
    listCommandHqSessions(user.id, categoryId),
    listClaudeSessions(who, getCommandersDir(who.email)),
  ]);

  const liveById = new Map(live.map((s) => [s.id, s]));
  const filed = rows.filter((row) => liveById.has(row.sessionId));

  const [tagsByRow, lastFiredByRow, runningById, costByRow] = await Promise.all([
    listCommandHqSessionTags(filed.map((row) => row.id)),
    getLastFiredAtBySessionRowIds(filed.map((row) => row.id)),
    Promise.all(filed.map(async (row) => [row.sessionId, await isRunning(row.sessionId)] as const)).then(
      (pairs) => new Map(pairs),
    ),
    // One aggregate query per commander, the same cost class `isRunning` above already accepts for this
    // grid — not batched, because a running SUM/COUNT is not a lookup on a small shared table the way tags
    // and last-fired are.
    Promise.all(filed.map(async (row) => [row.id, await getCommandHqCostSummary(row.id)] as const)).then(
      (pairs) => new Map(pairs),
    ),
  ]);

  const commanders: CommanderSummary[] = filed
    .map((row) => ({
      ...liveById.get(row.sessionId)!,
      categoryId: row.categoryId,
      tagIds: tagsByRow.get(row.id) ?? [],
      running: runningById.get(row.sessionId) ?? false,
      watcherArmed: row.watcherArmed,
      watcherArmedAt: row.watcherArmedAt,
      watcherStoppedAt: row.watcherStoppedAt,
      watcherLastFiredAt: lastFiredByRow.get(row.id) ?? null,
      cost: costByRow.get(row.id) ?? { turnCount: 0, inputTokens: 0, outputTokens: 0, totalUsd: 0 },
    }))
    .sort((a, b) => b.updatedAt.localeCompare(a.updatedAt));

  return ctx.json({ commanders });
});

/**
 * POST /command-hq/commanders/new  { prompt: string, displayText?: string, categoryId?: number | null }
 *
 * Creates a commander for a client that cannot open a websocket with the right parameters — mobile,
 * notably. The web composer never calls this: it sends an ordinary `/chat` turn with `context:
 * 'command-hq'`, and the row is written the moment the harness reports a transcript id (see
 * `websocket.ts` → `fileAsCommander`). This route drives the SAME path — `startClaudeTurn`, the function
 * that logic was extracted into — with no live socket, and waits for that same id before answering.
 *
 * `prompt` is required, deliberately. A commander begins as an ordinary conversation — sometimes a real
 * back-and-forth before a background job is ever armed, sometimes just "you know what to do" once that
 * has already happened elsewhere — but it always begins with something, the same as any `/chat`
 * conversation does. There is no "empty commander" to create and later fill in.
 *
 * `displayText`, separately, is what TITLES the commander — found missing here by the mobile side after
 * this route first shipped without it. A commander created to become a background job sends the full
 * `buildBackgroundJobPrompt` mechanics as `prompt` (a page of preamble) with the owner's actual sentence
 * only at the end, and `command_hq_sessions` has no name column — the title comes from
 * `session.meta.title = (displayText ?? prompt).slice(0, 100)`, same precedence the websocket path
 * already uses. Without this field every commander created this way titles itself with the mechanics
 * text, and the grid becomes a column of identical, unreadable cards.
 *
 * The response's `sessionId` is Claude's own transcript id — not a placeholder, not Officer's — so the
 * client has something it can immediately resume, attach to, or list among its commanders. Getting it
 * costs actually starting the turn: Claude assigns no id until one has run at least far enough to report
 * `system.init`, which `startClaudeTurn` surfaces as `session:claude`. Waiting for that alone, not the
 * whole turn, is what keeps this endpoint fast — the conversation keeps streaming afterward exactly like
 * any other session, reachable the normal way from here on.
 */
commandHqRouter.post('/commanders/new', async (ctx) => {
  const user = ctx.get('user');
  const body = await ctx.req
    .json<{ prompt?: string; displayText?: string; categoryId?: number | null }>()
    .catch(() => ({}) as { prompt?: string; displayText?: string; categoryId?: number | null });
  const prompt = body.prompt?.trim();
  if (!prompt) throw errors.BAD_REQUEST('prompt is required');

  const sessionId = randomUUID();
  const model = (await getUserDefaultModel(user.id)) || DEFAULT_MODEL;

  const outcome = await new Promise<{ ok: true; transcriptId: string } | { ok: false; error: string }>((resolve) => {
    // 30s covers a slow spawn (member login checks, a cold sidecar) without holding an HTTP connection
    // open indefinitely if something upstream never reports back at all.
    const timeout = setTimeout(
      () => resolve({ ok: false, error: 'Timed out waiting for the harness to start' }),
      30_000,
    );
    const settle = (result: { ok: true; transcriptId: string } | { ok: false; error: string }) => {
      clearTimeout(timeout);
      resolve(result);
    };
    void startClaudeTurn({
      email: user.email,
      username: toShellUsername(user.username ?? '', user.email),
      userId: user.id,
      ws: null,
      sessionId,
      model,
      msg: { prompt, displayText: body.displayText?.trim() || undefined, context: 'command-hq' },
      effectivePrompt: prompt,
      onOutcome: settle,
    });
  });

  if (!outcome.ok) throw errors.INTERNAL_SERVER_ERROR(outcome.error);

  /*
    The row already exists — `fileAsCommander` wrote it, off the same `session:claude` event this promise
    resolved on. What might not have landed yet is the CATEGORY: that write is fire-and-forget and always
    files with none, so a race between it and this request is possible in either order. `createCommandHqSession`
    is an upsert-on-conflict-do-nothing (safe either way), and the `setCommandHqSessionCategory` UPDATE below
    is unconditional and runs after both, which is what makes the outcome deterministic regardless of which
    of the two insert attempts actually won: whichever category this request asked for is the one that is
    left standing.
  */
  await createCommandHqSession(user.id, outcome.transcriptId, body.categoryId ?? null);
  await setCommandHqSessionCategory(user.id, outcome.transcriptId, body.categoryId ?? null);

  return ctx.json({ sessionId: outcome.transcriptId, cwd: getCommandersDir(user.email) });
});

/**
 * GET /command-hq/commanders/:sessionId
 *
 * Command HQ's OWN metadata for one commander — category, tags, liveness. Deliberately does NOT return the
 * conversation itself: the transcript is `GET /chat/sessions/:id`, unchanged, and a client fetches both
 * rather than this route duplicating it. 404 both when the session was never filed and when its transcript
 * has since vanished — from the caller's side those are the same fact, "not a commander right now".
 */
commandHqRouter.get('/commanders/:sessionId', async (ctx) => {
  const user = ctx.get('user');
  const who = await commandHqIdentity(user);
  const sessionId = ctx.req.param('sessionId');

  const row = await getCommandHqSession(user.id, sessionId);
  if (!row) throw errors.NOT_FOUND('not a commander');
  if (!loadClaudeSessionById(who, sessionId)) throw errors.NOT_FOUND('not a commander');

  const [tagsByRow, running, lastFiredByRow, cost] = await Promise.all([
    listCommandHqSessionTags([row.id]),
    isRunning(sessionId),
    getLastFiredAtBySessionRowIds([row.id]),
    getCommandHqCostSummary(row.id),
  ]);
  return ctx.json({
    sessionId: row.sessionId,
    categoryId: row.categoryId,
    tagIds: tagsByRow.get(row.id) ?? [],
    running,
    watcherArmed: row.watcherArmed,
    watcherArmedAt: row.watcherArmedAt,
    watcherStoppedAt: row.watcherStoppedAt,
    watcherLastFiredAt: lastFiredByRow.get(row.id) ?? null,
    cost,
    createdAt: row.createdAt,
  });
});

/**
 * GET /command-hq/commanders/:sessionId/turns
 *
 * The raw per-turn cost ledger, oldest first — what a client plots "cost over time" from, and what
 * `cost` on the detail route above is the sum of. Not included inline on that route because it is
 * unbounded (a commander running for months accumulates one row per turn), so a client that only wants
 * the running total is not paying for the whole history on every open.
 */
commandHqRouter.get('/commanders/:sessionId/turns', async (ctx) => {
  const user = ctx.get('user');
  const sessionId = ctx.req.param('sessionId');
  const row = await getCommandHqSession(user.id, sessionId);
  if (!row) throw errors.NOT_FOUND('not a commander');
  return ctx.json({ turns: await listCommandHqTurns(row.id) });
});

/**
 * GET /command-hq/commanders/:sessionId/fires
 *
 * Every trigger this commander's watcher has ever fired, oldest first — the boundaries a client uses to
 * group `.../turns` by trigger, and the full history behind the single `watcherLastFiredAt` the other
 * routes report.
 */
commandHqRouter.get('/commanders/:sessionId/fires', async (ctx) => {
  const user = ctx.get('user');
  const sessionId = ctx.req.param('sessionId');
  const row = await getCommandHqSession(user.id, sessionId);
  if (!row) throw errors.NOT_FOUND('not a commander');
  return ctx.json({ fires: await listCommandHqWatcherFires(row.id) });
});

/**
 * POST /command-hq/commanders  { sessionId: string, categoryId?: number }
 *
 * Files an EXISTING session as a commander. Idempotent — filing an already-filed session is a no-op, and
 * does not move it to a different category (use PATCH for that).
 *
 * This is a low-level primitive, not the normal creation path. The normal path is starting a new commander
 * through Command HQ's own composer, which writes this row itself the moment the harness reports a real
 * transcript id — see `docs/command-hq.md` → "How a commander is created". This route exists for that
 * wiring to call, and for anything else (a purge-and-refile flow, a script) that needs to file a session
 * without going through a live chat turn.
 *
 * The session must actually exist in the commanders directory, or this refuses — filing a `/chat` session
 * makes no sense given commanders and `/chat` never share a working directory.
 */
commandHqRouter.post('/commanders', async (ctx) => {
  const user = ctx.get('user');
  const who = await commandHqIdentity(user);
  const body = await ctx.req
    .json<{ sessionId?: string; categoryId?: number }>()
    .catch(() => ({}) as { sessionId?: string; categoryId?: number });
  const sessionId = body.sessionId?.trim();
  if (!sessionId) throw errors.BAD_REQUEST('sessionId is required');

  const live = listClaudeSessions(who, getCommandersDir(who.email));
  if (!live.some((s) => s.id === sessionId)) throw errors.NOT_FOUND('no such session in the commanders directory');

  const row = await createCommandHqSession(user.id, sessionId, body.categoryId ?? null);
  return ctx.json(row);
});

/**
 * PATCH /command-hq/commanders/:sessionId
 *
 * Body may carry any of:
 *   `categoryId: number | null` — move to a category, or `null` to uncategorise
 *   `name: string` — rename. Proxies straight to `renameClaudeSession`, the SAME function `/chat`'s own
 *   rename action calls — there is no separate name field on this table to disagree with it.
 *   `watcherArmed: false` — disarm a watcher, so the harness stops re-arming it on its next fire. Only
 *   `false` is accepted here: arming requires a live task id (`armCommandHqWatcher`), which only the turn
 *   that starts the watcher has — there is no product path to arm one from outside a running turn, and
 *   this route is not it.
 */
commandHqRouter.patch('/commanders/:sessionId', async (ctx) => {
  const user = ctx.get('user');
  const who = await commandHqIdentity(user);
  const sessionId = ctx.req.param('sessionId');
  const body = await ctx.req
    .json<{ categoryId?: number | null; name?: string; watcherArmed?: false }>()
    .catch(() => ({}) as { categoryId?: number | null; name?: string; watcherArmed?: false });

  const row = await getCommandHqSession(user.id, sessionId);
  if (!row) throw errors.NOT_FOUND('not a commander');

  if (body.categoryId !== undefined) {
    await setCommandHqSessionCategory(user.id, sessionId, body.categoryId);
  }
  if (body.name !== undefined) {
    const ok = renameClaudeSession(who, getCommandersDir(who.email), sessionId, body.name.trim());
    if (!ok) throw errors.NOT_FOUND('transcript not found');
  }
  if (body.watcherArmed === false) {
    await disarmCommandHqWatcher(user.id, sessionId);
  }
  return ctx.json({ ok: true });
});

/**
 * DELETE /command-hq/commanders/:sessionId
 *
 * Deletes the commander outright: the transcript itself (via `deleteClaudeSession`, the same function
 * `DELETE /chat/sessions/:id` calls — a `/clear` chain goes with it, every part), then the
 * `command_hq_sessions` row. Unlike everywhere else in this file, this is NOT the "row disagrees with
 * disk, so hide it" pattern `purgeCommandHqSessions` exists for — it is the one place that makes the two
 * agree by deleting the thing itself, on purpose, because the owner asked to.
 *
 * A watcher still armed at the time of deletion is left as-is rather than disarmed first: the transcript
 * is gone either way, `armCommandHqWatcher`/`recordCommandHqWatcherFired` can no longer find a row to
 * update once this returns, and the running background process (if any) dies on its own the same way it
 * would if the harness process were killed out from under any other conversation — not a new failure
 * mode this route has to account for.
 */
commandHqRouter.delete('/commanders/:sessionId', async (ctx) => {
  const user = ctx.get('user');
  const who = await commandHqIdentity(user);
  const sessionId = ctx.req.param('sessionId');

  const row = await getCommandHqSession(user.id, sessionId);
  if (!row) throw errors.NOT_FOUND('not a commander');

  deleteClaudeSession(who, getCommandersDir(who.email), sessionId);
  await deleteCommandHqSession(user.id, sessionId);
  return ctx.json({ ok: true });
});

/**
 * POST /command-hq/purge
 *
 * Deletes every `command_hq_sessions` row whose transcript no longer resolves in the commanders directory.
 * Housekeeping only — nothing about correctness ever depended on this running, since a dangling row is
 * already invisible everywhere. Returns how many rows were removed.
 */
commandHqRouter.post('/purge', async (ctx) => {
  const user = ctx.get('user');
  const who = await commandHqIdentity(user);
  const live = listClaudeSessions(who, getCommandersDir(who.email));
  const removed = await purgeCommandHqSessions(user.id, new Set(live.map((s) => s.id)));
  return ctx.json({ removed });
});

// ── Tag assignment ──

// POST /command-hq/commanders/:sessionId/tags  { tagId: number }
commandHqRouter.post('/commanders/:sessionId/tags', async (ctx) => {
  const user = ctx.get('user');
  const sessionId = ctx.req.param('sessionId');
  const body = await ctx.req.json<{ tagId?: number }>().catch(() => ({}) as { tagId?: number });
  if (!body.tagId) throw errors.BAD_REQUEST('tagId is required');

  const row = await getCommandHqSession(user.id, sessionId);
  if (!row) throw errors.NOT_FOUND('not a commander');
  await addCommandHqSessionTag(row.id, body.tagId);
  return ctx.json({ ok: true });
});

// DELETE /command-hq/commanders/:sessionId/tags/:tagId
commandHqRouter.delete('/commanders/:sessionId/tags/:tagId', async (ctx: Context) => {
  const user = ctx.get('user');
  const sessionId = ctx.req.param('sessionId');
  const tagId = Number(ctx.req.param('tagId'));

  const row = await getCommandHqSession(user.id, sessionId);
  if (!row) throw errors.NOT_FOUND('not a commander');
  await removeCommandHqSessionTag(row.id, tagId);
  return ctx.json({ ok: true });
});