// Read-only Ops Console API. Every handler returns the standard ok() envelope. No writes,
// no auth (loopback-bound, "Đọc ≠ Ghi"); management/RBAC is Plan-13 Track 2/3 (future).
import { Controller, Get, Inject, Param, Query, Req, Res } from '@nestjs/common';
import type { Request, Response } from 'express';
import { ok } from '../common/api-response.js';
import { TelemetryService } from './telemetry.service.js';

@Controller('api/v1')
export class TelemetryController {
  // Explicit @Inject token so DI works under BOTH tsc (emits decorator metadata) and the
  // tsx/esbuild dev runner (which does not emit design:paramtypes).
  constructor(@Inject(TelemetryService) private readonly svc: TelemetryService) {}

  @Get('overview')
  overview() {
    return ok(this.svc.overview());
  }

  @Get('runs')
  runs(@Query('limit') limit?: string) {
    const n = Math.min(Math.max(Number(limit) || 50, 1), 500);
    const r = this.svc.runs(n);
    return ok(r, { total: r.count });
  }

  @Get('runs/:traceId')
  run(@Param('traceId') traceId: string) {
    return ok(this.svc.run(traceId));
  }

  @Get('runs/:traceId/graph')
  traceGraph(@Param('traceId') traceId: string) {
    return ok(this.svc.traceGraph(traceId));
  }

  @Get('runs/:traceId/events')
  traceEvents(@Param('traceId') traceId: string, @Req() req: Request, @Res() res: Response) {
    res.setHeader('Content-Type', 'text/event-stream');
    res.setHeader('Cache-Control', 'no-cache, no-transform');
    res.setHeader('Connection', 'keep-alive');
    res.flushHeaders();

    let previous = '';
    const publish = () => {
      const graph = this.svc.traceGraph(traceId);
      const serialized = JSON.stringify(graph);
      if (serialized !== previous) {
        res.write(`event: trace\ndata: ${serialized}\n\n`);
        previous = serialized;
      } else {
        res.write(': heartbeat\n\n');
      }
    };
    const timer = setInterval(publish, 750);
    const close = () => {
      clearInterval(timer);
      if (!res.writableEnded) res.end();
    };
    req.on('close', close);
    publish();
  }

  @Get('governance')
  governance() {
    return ok(this.svc.governance());
  }

  @Get('security')
  security() {
    return ok(this.svc.security());
  }

  @Get('incidents')
  incidents() {
    return ok(this.svc.incidents());
  }

  @Get('tools')
  tools() {
    return ok(this.svc.tools());
  }

  @Get('traceability')
  traceability() {
    return ok(this.svc.traceability());
  }

  @Get('drift')
  drift() {
    return ok(this.svc.drift());
  }

  @Get('cost')
  cost() {
    return ok(this.svc.cost());
  }

  @Get('command')
  command() {
    return ok(this.svc.commandCenter());
  }
}