import type { ApolloServerPlugin } from '@apollo/server';
import { logger, logQuery, logError } from '../monitoring/logger.js';
import {
  queryCounter,
  queryDuration,
  errorCounter,
  queryComplexityGauge,
} from '../monitoring/metrics.js';
import { createTrace, endTrace } from '../monitoring/tracing.js';

/**
 * Monitoring Plugin für Apollo Server
 * Sammelt Logs, Metrics und Traces für jeden Request
 */
export const monitoringPlugin = (): ApolloServerPlugin => {
  return {
    async requestDidStart() {
      return {
        async didResolveOperation({ request, operationName }) {
          // Erstelle Trace für Request
          const traceId = createTrace().traceId;
          (request as any).traceId = traceId;

          logger.info('GraphQL operation started', {
            operationName: operationName || 'unknown',
            query: request.query,
            variables: request.variables,
            traceId,
          });
        },

        async willSendResponse({ request, response }) {
          const traceId = (request as any).traceId;
          const operationName = request.operationName || 'unknown';
          const duration = traceId ? endTrace(traceId) : 0;

          // Log Query
          logQuery(operationName, request.variables, duration);

          // Metrics
          const status = response.errors && response.errors.length > 0 ? 'error' : 'success';
          queryCounter.inc({ operation: operationName, status });
          queryDuration.observe({ operation: operationName }, duration / 1000);

          // Log Errors
          if (response.errors && response.errors.length > 0) {
            response.errors.forEach((error) => {
              logError(error as Error, {
                operationName,
                traceId,
              });
              errorCounter.inc({
                type: error.extensions?.code as string || 'UNKNOWN',
                operation: operationName,
              });
            });
          }
        },

        async didEncounterErrors({ request, errors }) {
          const traceId = (request as any).traceId;
          const operationName = request.operationName || 'unknown';

          errors.forEach((error) => {
            logError(error as Error, {
              operationName,
              traceId,
            });
            errorCounter.inc({
              type: error.extensions?.code as string || 'UNKNOWN',
              operation: operationName,
            });
          });
        },
      };
    },
  };
};

/**
 * Plugin für Query Complexity Tracking
 */
export const queryComplexityMonitoringPlugin = (): ApolloServerPlugin => {
  return {
    async requestDidStart() {
      return {
        async didResolveOperation({ request, operationName }) {
          // Wird vom queryComplexityPlugin gesetzt
          const complexity = (request as any).complexity;
          if (complexity) {
            queryComplexityGauge.set(
              { operation: operationName || 'unknown' },
              complexity
            );
          }
        },
      };
    },
  };
};