import { Registry, Counter, Histogram, Gauge } from 'prom-client';

const registry = new Registry();

const requestCounter = new Counter({
  name: 'canva_api_requests_total',
  help: 'Total Canva Connect API requests',
  labelNames: ['method', 'endpoint', 'status'],
  registers: [registry],
});

const requestDuration = new Histogram({
  name: 'canva_api_duration_seconds',
  help: 'Canva API request duration',
  labelNames: ['method', 'endpoint'],
  buckets: [0.05, 0.1, 0.25, 0.5, 1, 2.5, 5, 10],
  registers: [registry],
});

const rateLimitGauge = new Gauge({
  name: 'canva_rate_limit_remaining',
  help: 'Remaining rate limit for endpoint',
  labelNames: ['endpoint'],
  registers: [registry],
});

const exportDuration = new Histogram({
  name: 'canva_export_duration_seconds',
  help: 'Time from export request to completion',
  labelNames: ['format'],
  buckets: [1, 2, 5, 10, 20, 30, 60],
  registers: [registry],
});

async function instrumentedCanvaRequest<T>(
  method: string,
  endpoint: string,
  fn: () => Promise<Response>
): Promise<T> {
  const timer = requestDuration.startTimer({ method, endpoint });

  try {
    const res = await fn();

    // Track rate limit headroom
    const remaining = res.headers.get('X-RateLimit-Remaining');
    if (remaining) {
      rateLimitGauge.set({ endpoint }, parseInt(remaining));
    }

    const status = res.ok ? 'success' : `error_${res.status}`;
    requestCounter.inc({ method, endpoint, status });

    if (!res.ok) {
      const body = await res.text();
      throw new CanvaAPIError(res.status, body, endpoint);
    }

    return res.json();
  } catch (error) {
    requestCounter.inc({ method, endpoint, status: 'exception' });
    throw error;
  } finally {
    timer();
  }
}

import { trace, SpanStatusCode } from '@opentelemetry/api';

const tracer = trace.getTracer('canva-connect-api');

async function tracedCanvaCall<T>(
  operationName: string,
  fn: () => Promise<T>
): Promise<T> {
  return tracer.startActiveSpan(`canva.${operationName}`, async (span) => {
    span.setAttribute('canva.base_url', 'api.canva.com/rest/v1');

    try {
      const result = await fn();
      span.setStatus({ code: SpanStatusCode.OK });
      return result;
    } catch (error: any) {
      span.setStatus({ code: SpanStatusCode.ERROR, message: error.message });
      span.setAttribute('canva.error_code', error.status || 'unknown');
      span.recordException(error);
      throw error;
    } finally {
      span.end();
    }
  });
}

import pino from 'pino';

const logger = pino({ name: 'canva', level: process.env.LOG_LEVEL || 'info' });

function logCanvaRequest(data: {
  method: string;
  endpoint: string;
  status: number;
  durationMs: number;
  rateLimitRemaining?: number;
}) {
  // NEVER log access tokens or refresh tokens
  logger.info({
    service: 'canva-connect-api',
    ...data,
  });
}

# prometheus/canva-alerts.yml
groups:
  - name: canva_connect_api
    rules:
      - alert: CanvaHighErrorRate
        expr: |
          rate(canva_api_errors_total[5m]) /
          rate(canva_api_requests_total[5m]) > 0.05
        for: 5m
        labels:
          severity: warning
        annotations:
          summary: "Canva API error rate > 5%"

      - alert: CanvaHighLatency
        expr: |
          histogram_quantile(0.95,
            rate(canva_api_duration_seconds_bucket[5m])
          ) > 3
        for: 5m
        labels:
          severity: warning
        annotations:
          summary: "Canva API P95 latency > 3s"

      - alert: CanvaRateLimitLow
        expr: canva_rate_limit_remaining < 5
        for: 1m
        labels:
          severity: warning
        annotations:
          summary: "Canva rate limit nearly exhausted"

      - alert: CanvaTokenRefreshFailing
        expr: increase(canva_token_refresh_total{status="error"}[15m]) > 0
        labels:
          severity: critical
        annotations:
          summary: "Canva token refresh failing — users may lose access"

      - alert: CanvaExportSlow
        expr: |
          histogram_quantile(0.95,
            rate(canva_export_duration_seconds_bucket[15m])
          ) > 30
        for: 10m
        labels:
          severity: warning
        annotations:
          summary: "Canva exports taking > 30s at P95"

# Request rate by endpoint
rate(canva_api_requests_total[5m])

# P95 latency
histogram_quantile(0.95, rate(canva_api_duration_seconds_bucket[5m]))

# Error rate percentage
100 * rate(canva_api_requests_total{status=~"error.*"}[5m]) / rate(canva_api_requests_total[5m])

# Rate limit headroom
canva_rate_limit_remaining

# Export completion time P50/P95
histogram_quantile(0.5, rate(canva_export_duration_seconds_bucket[5m]))
histogram_quantile(0.95, rate(canva_export_duration_seconds_bucket[5m]))