/**
 * Build the Hono app. Exported separately from index.ts so tests can
 * import it without binding a port.
 */
import { Hono } from 'hono';
import { cors } from 'hono/cors';
import { logger } from 'hono/logger';
import { UniverseSnapshotSchema } from '@kerbal-rt/shared-types';
import { z } from 'zod';
import type { StateStore } from '@kerbal-rt/db';

export interface AppDeps {
  store: StateStore;
  /** The expected ingest API key, or null to disable auth (dev only). */
  ingestApiKey: string | null;
}

export function buildApp(deps: AppDeps) {
  const app = new Hono();
  const { store, ingestApiKey } = deps;

  app.use('*', logger());
  app.use('*', cors({ origin: process.env.CORS_ORIGIN?.split(',') ?? '*' }));

  // ─── health ─────────────────────────────────────────────────────────────
  app.get('/health', (c) =>
    c.json({
      ok: true,
      service: 'kerbal-rt-api',
      version: '0.1.0',
      store: store.constructor.name,
      ts: new Date().toISOString(),
    }),
  );

  // ─── ingest (called by the KSP telemetry bridge) ───────────────────────
  const IngestAuth = z.object({ 'x-api-key': z.string() });

  app.post('/api/v1/ingest', async (c) => {
    if (ingestApiKey) {
      const headerParse = IngestAuth.safeParse(
        Object.fromEntries(Array.from(c.req.raw.headers.entries())),
      );
      if (!headerParse.success) {
        return c.json({ error: true, code: 'UNAUTHORIZED', message: 'Missing API key' }, 401);
      }
      if (headerParse.data['x-api-key'] !== ingestApiKey) {
        return c.json({ error: true, code: 'FORBIDDEN', message: 'Bad API key' }, 403);
      }
    } else if (process.env.NODE_ENV === 'production') {
      // Belt and suspenders: never allow unauthenticated ingest in prod
      // even if the env var is missing.
      return c.json({ error: true, code: 'UNAUTHORIZED', message: 'Ingest disabled' }, 401);
    }

    const body = await c.req.json();
    const parsed = UniverseSnapshotSchema.safeParse(body);
    if (!parsed.success) {
      return c.json(
        {
          error: true,
          code: 'BAD_PAYLOAD',
          message: 'Invalid snapshot',
          details: parsed.error.format(),
        },
        400,
      );
    }
    const result = await store.applySnapshot(parsed.data);
    return c.json({
      error: false,
      data: { ok: true, rowsInserted: result.rowsInserted, ts: new Date().toISOString() },
    });
  });

  // ─── read-only endpoints ───────────────────────────────────────────────
  app.get('/api/v1/state', async (c) => {
    const snap = await store.latestSnapshot();
    if (!snap) return c.json({ error: true, code: 'NO_DATA', message: 'No snapshot yet' }, 503);
    return c.json({ error: false, data: snap });
  });

  app.get('/api/v1/bodies', async (c) => c.json({ error: false, data: await store.listBodies() }));

  app.get('/api/v1/vessels', async (c) =>
    c.json({ error: false, data: await store.listVessels() }),
  );

  app.get('/api/v1/vessels/:id', async (c) => {
    const v = await store.getVessel(c.req.param('id'));
    if (!v) return c.json({ error: true, code: 'NOT_FOUND', message: 'Vessel not found' }, 404);
    return c.json({ error: false, data: v });
  });

  return app;
}

export type AppType = ReturnType<typeof buildApp>;