import { config, isUnitTest } from "../../utils/config";
import { EndFunction, BucketSet } from "../metric.service";
import AbstractScoreHashMap, { NormStats } from "./abstractScoreHashMap.service";
import { ChoiceRequest } from "../../models";
import constants from "../../utils/constants";
import logger from "../../utils/logger";

const LOG_ID = "[CONTEXTHASHMAP_SERVICE]";
const RELOAD_SECTION_NAME: string = "context_hashmap_reload";
const GET_SCORE_SECTION_NAME: string = "context_hashmap_get_score";
const HB_DISPLAY_DEFAULT_SCORE_USAGE = "context_hashmap_hb_display_default_score_usage";
const CONTEXT_HASHMAP_FALLBACK_LEVEL = "context_hashmap_fallback_level";

interface DefaultAccScore {
  fromFallbacklevel: number;
  scoreValue: number;
}

export interface ContextFeatures {
  economicType?: string | null;
  format?: string | null;
  ssp?: string | null;
  campaignId: string;
  assetId?: string | null;
  assetUnit?: string | null;
  defaultAccScore?: DefaultAccScore;

  // new features for price model
  environmentType: string;
  priceModel: string;
  adUnitType?: string | null;
  // advertType: string; temporary remove since the value in not sync with stats
  apiKey?: string | null;
}

export class ContextHashMap extends AbstractScoreHashMap {
  private static instance: ContextHashMap;
  protected logId: string = LOG_ID;
  protected s3Bucket: string = `${config.S3_CONTEXT_BUCKET}`;
  protected s3Prefix: string = `${config.S3_CONTEXT_ACC_RATE_PREFIX}/${config.INVENTORY}`;
  protected maxRetries: number = parseInt(config.ACC_RATE_MAP_MAX_RETRIES);
  protected retryDelay: number = parseInt(config.ACC_RATE_MAP_RETRY_DELAY);
  protected refreshInterval: number = parseInt(config.ACC_RATE_MAP_REFRESH_INTERVAL);
  protected refreshMetricLabel: string = RELOAD_SECTION_NAME;

  private constructor() {
    super();
    this.metricService.addSection(RELOAD_SECTION_NAME);
    this.metricService.addSection(GET_SCORE_SECTION_NAME, [], BucketSet.zeroTo5ms);
    this.metricService.addCounter(
      HB_DISPLAY_DEFAULT_SCORE_USAGE,
      "number of time default score for display campaign in header-bidding is used"
    );
    this.metricService.addCounter(
      CONTEXT_HASHMAP_FALLBACK_LEVEL,
      "accomplish fallback level when get context score is used",
      ["level"]
    );
    this.scheduleRefresh();
  }

  public static getInstance(): ContextHashMap {
    if (!this.instance || isUnitTest()) {
      this.instance = new ContextHashMap();
    }

    return this.instance;
  }

  private static buildLevelKey(features: ContextFeatures, level: number): string {
    if (config.INVENTORY === "internal") {
      const keyCommonPart = `${features.economicType}|${features.environmentType}|${features.priceModel}|${features.adUnitType}`;
      switch (level) {
        case 1:
          return `${keyCommonPart}|${features.campaignId}|${features.apiKey}|${features.assetUnit}`;
        case 2:
          return `${keyCommonPart}|${features.campaignId}|${features.apiKey}|${constants.FALLBACK_STR}`;
        case 3:
          return `${keyCommonPart}|${features.campaignId}|${constants.FALLBACK_STR}|${constants.FALLBACK_STR}`;
        case 4:
          return `${keyCommonPart}|${constants.FALLBACK_STR}|${constants.FALLBACK_STR}|${constants.FALLBACK_STR}`;
        default:
          throw new Error("Error level key should be between 1 and 4 (included)");
      }
    } else {
      switch (level) {
        case 1:
          return `${features.economicType}|${features.format}|${features.ssp}|${features.campaignId}|${features.assetId}|${features.assetUnit}`;
        case 2:
          return `${features.economicType}|${features.format}|${features.ssp}|${features.campaignId}|${features.assetId}|${constants.FALLBACK_STR}`;
        case 3:
          return `${features.economicType}|${features.format}|${features.ssp}|${features.campaignId}|${constants.FALLBACK_STR}|${constants.FALLBACK_STR}`;
        case 4:
          return `${features.economicType}|${features.format}|${constants.FALLBACK_STR}|${constants.FALLBACK_STR}|${constants.FALLBACK_STR}|${constants.FALLBACK_STR}`;
        default:
          throw new Error("Error level key should be between 1 and 4 (included)");
      }
    }
  }

  /**
   * Get statistics by campaign. Fallback on economic type & format average if campaign entry do not exist
   * @param economicType
   * @param format
   * @param campaignId
   */
  public getStatistics(
    economicType: string | null | undefined,
    format: string | null | undefined,
    campaignId: string
  ): NormStats {
    const statistics: NormStats | undefined = this.normMap.get(
      `${economicType}|${format}|${campaignId}`
    );
    const fallbackStatistics: NormStats | undefined = this.normMap.get(
      `${economicType}|${format}|${constants.FALLBACK_STR}`
    );

    return this.formatStatistics(statistics, fallbackStatistics);
  }

  /**
   * get score from hashMap using economicType, format, ssp, campaignId, appBundleId|domain and adUnitId|webPage with a fallback mechanism.
   * Lookup score using ssp, campaignId and app.
   * If no match lookup on using ssp and campaignId.
   * If no match lookup on using economicType and format.
   * @param {ContextFeatures} features
   * @param {ChoiceRequest} request
   * @return {number} score retrieved from the map. No score is retrieved return undefined value
   * @memberof ContextHashMap
   */
  public getScore(features: ContextFeatures, request: ChoiceRequest): number | undefined {
    const end: EndFunction = this.metricService.startSection(GET_SCORE_SECTION_NAME);
    let score;
    let level = features.assetUnit ? 1 : 2;
    request.metadata.context_level = level;
    while (score === undefined && level < 5) {
      const key = ContextHashMap.buildLevelKey(features, level);
      logger.debug(() => `${LOG_ID} key level ${level}: ${key}`);
      score = this.scoresMap.get(key);
      request.metadata.context_level = level;
      level++;
    }

    this.metricService.incCounterWithReq(request, CONTEXT_HASHMAP_FALLBACK_LEVEL, 1, {
      level: request.metadata.context_level,
    });

    end(true);
    return score;
  }
}