import { EventEmitter } from 'node:events';
import { fetch } from 'cross-fetch';

import { SPECIFY_DISABLE_ANALYTICS, SPECIFY_SDK_VERSION } from '../constants/index.js';
import { formatRequestHeaders } from '../httpApi/clients/internals/formatRequestHeaders.js';
import { makeSpecifyHttpApiRoute } from '../httpApi/clients/internals/makeSpecifyHttpApiRoute.js';
import { SDKTelemetryEvent, SDKTelemetryEventContext } from './events.js';

/* v8 ignore start */

const telemetryEvent = 'specifyTelemetryEvent';
const telemetryEmitter = new EventEmitter();
if (!SPECIFY_DISABLE_ANALYTICS) {
  telemetryEmitter.on(telemetryEvent, ({ name, payload, context, at }: SDKTelemetryEvent) => {
    fetch(makeSpecifyHttpApiRoute('/telemetry/sdk'), {
      method: 'POST',
      body: JSON.stringify({ name, payload, context, at }),
      headers: formatRequestHeaders(context.personalAccessToken),
    }).catch(error => {});
  });
}

const telemetryContext: SDKTelemetryEventContext = {};

export class SDKTelemetry {
  constructor(context?: SDKTelemetryEventContext) {
    if (context) {
      this.setContext({
        sdkVersion: SPECIFY_SDK_VERSION,
        ...context,
      });
    }
  }

  setContext(context: SDKTelemetryEventContext) {
    Object.assign(telemetryContext, context);
    return this;
  }

  track<
    Name extends SDKTelemetryEvent['name'],
    Computed extends Extract<SDKTelemetryEvent, { name: Name }>,
  >(name: Name, payload: Computed['payload'], context?: SDKTelemetryEventContext) {
    if (!SPECIFY_DISABLE_ANALYTICS) {
      const { personalAccessToken, ...sanitizedContext } = { ...telemetryContext, ...context };
      telemetryEmitter.emit(telemetryEvent, {
        name,
        payload,
        context: sanitizedContext,
        at: Date.now(),
      });
    }
    return this;
  }
}

/* v8 ignore stop */