/*
 * Copyright (c) 2022 Snowplow Analytics Ltd, 2010 Anthon Pang
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions are met:
 *
 * 1. Redistributions of source code must retain the above copyright notice, this
 *    list of conditions and the following disclaimer.
 *
 * 2. Redistributions in binary form must reproduce the above copyright notice,
 *    this list of conditions and the following disclaimer in the documentation
 *    and/or other materials provided with the distribution.
 *
 * 3. Neither the name of the copyright holder nor the names of its
 *    contributors may be used to endorse or promote products derived from
 *    this software without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
 * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
 * DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE
 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
 * SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
 * CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
 * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
 * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 */

import { BrowserPlugin, parseAndValidateInt } from '@snowplow/browser-tracker-core';
import { OptimizelyxSummary } from './contexts';

declare global {
  interface Window {
    /*
    The following property is technically optional since the Optimizely SDK
    loads asynchronously; the inner `get` is also optional for the older SDK
    and during brief periods where the SDK is only partially loaded.
    As Window interface type conflicts can break builds, we leave them as
    non-optional for backwards compatibility, but changes to this plugin should
    be aware that this interface may not be fully available. See #1343
    */
    optimizely: {
      get: (property: string) => { [key: string]: any };
    };
  }
}

/**
 * Adds Optimizely X context to events
 */
export function OptimizelyXPlugin(): BrowserPlugin {
  /**
   * Check that *both* optimizely and optimizely.get exist
   *
   * @param property - optimizely data property
   */
  function getOptimizelyXData(property: string) {
    const windowOptimizelyAlias = window.optimizely;
    let data: Record<string, any> | undefined;
    if (windowOptimizelyAlias && typeof windowOptimizelyAlias.get === 'function') {
      data = windowOptimizelyAlias.get(property);
    }
    return data;
  }

  /**
   * Get data for OptimizelyX contexts - active campaigns on current page.
   * Uses getCampaignStates() instead of getActiveExperimentIds() to correctly
   * capture campaignId (layerId) for both Web Experimentation and Personalization
   * campaigns. For Personalization campaigns, experimentId will reflect the
   * experience ID (the sub-unit within the campaign).
   *
   * @returns Array content of optimizely summary context
   */
  function getOptimizelyXSummary(): OptimizelyxSummary[] {
    const state = getOptimizelyXData('state');
    if (state == null || typeof state.getCampaignStates !== 'function') return [];

    const campaignStates = state.getCampaignStates({ isActive: true }) || {};
    const visitor = getOptimizelyXData('visitor');
    const visitorId = (visitor && visitor.visitorId && visitor.visitorId.toString()) || null;

    return Object.keys(campaignStates).map((campaignId: string) => {
      const campaign = campaignStates[campaignId];
      const experimentId = campaign.experiment && campaign.experiment.id;
      const variationId = campaign.variation && campaign.variation.id;
      const variationName =
        (campaign.variation && campaign.variation.name && campaign.variation.name.toString()) || null;

      return {
        campaignId: parseAndValidateInt(campaignId) || null,
        experimentId: parseAndValidateInt(experimentId) || null,
        variationName: variationName,
        variation: parseAndValidateInt(variationId) || null,
        visitorId: visitorId,
      };
    });
  }

  /**
   * Creates an OptimizelyX context containing only data required to join
   * event to experiment data
   *
   * @returns Array of custom contexts
   */
  function getOptimizelyXSummaryContexts() {
    return getOptimizelyXSummary().map(function (experiment) {
      return {
        schema: 'iglu:com.optimizely.optimizelyx/summary/jsonschema/1-1-0',
        data: experiment,
      };
    });
  }

  return {
    contexts: () => {
      // Add Optimizely Contexts
      if (window.optimizely) {
        return getOptimizelyXSummaryContexts();
      }

      return [];
    },
  };
}