import type {
  MarketApiFailureReason,
  MarketApiResult,
  MarketRowSnapshot
} from "./types";
import type { AfterSearchRates } from "./types";

interface ResultStoreLike {
  setAuthorFailed(authorId: string, reason: MarketApiFailureReason): void;
  setAuthorLoading(authorId: string): void;
  setAuthorSuccess(authorId: string, rates: AfterSearchRates): void;
  upsertMarketRow(row: MarketRowSnapshot): void;
}

interface FullScanControllerOptions {
  goToNextPage(): Promise<boolean>;
  hasNextPage(): boolean;
  loadAuthorMetrics(authorId: string): Promise<MarketApiResult>;
  readCurrentPageRows(): MarketRowSnapshot[];
  resultStore: ResultStoreLike;
}

export function createFullScanController(options: FullScanControllerOptions) {
  let completedScan = false;
  let scanPromise: Promise<void> | null = null;

  return {
    ensureScanForExport() {
      return ensureScan();
    },
    ensureScanForFilter() {
      return ensureScan();
    },
    ensureScanForSort() {
      return ensureScan();
    }
  };

  function ensureScan(): Promise<void> {
    if (completedScan) {
      return Promise.resolve();
    }

    if (scanPromise) {
      return scanPromise;
    }

    scanPromise = runScan().finally(() => {
      scanPromise = null;
    });
    return scanPromise;
  }

  async function runScan(): Promise<void> {
    do {
      await scanCurrentPage();
      if (!options.hasNextPage()) {
        completedScan = true;
        return;
      }
    } while (await options.goToNextPage());

    completedScan = true;
  }

  async function scanCurrentPage(): Promise<void> {
    const rows = options.readCurrentPageRows();

    for (const row of rows) {
      options.resultStore.upsertMarketRow(row);
      if (row.hasDirectRatesSource) {
        const directRates = row.rates ?? {};
        const hasAllRates =
          Boolean(directRates.singleVideoAfterSearchRate) &&
          Boolean(directRates.personalVideoAfterSearchRate);

        options.resultStore.setAuthorSuccess(row.authorId, directRates);
        if (hasAllRates) {
          continue;
        }
      }

      options.resultStore.setAuthorLoading(row.authorId);

      const metricsResult = await options.loadAuthorMetrics(row.authorId);
      if (metricsResult.success) {
        options.resultStore.setAuthorSuccess(row.authorId, metricsResult.rates);
        continue;
      }

      options.resultStore.setAuthorFailed(row.authorId, metricsResult.reason);
    }
  }
}