import {
  BannerBlockConfiguration,
  BuildingBlockConfiguration,
  PageConfigurationWithTransformedDynamicForms,
  OverarchingDetailsBlockConfiguration,
  PageConfiguration
} from '@allianz/taly-core/schemas';
import { transformJourneyToInternalJourney } from '../journey/transform/transform';
import { Journey } from '../model/journey';

type PageWithBlocks = PageConfigurationWithTransformedDynamicForms &
  Required<Pick<PageConfigurationWithTransformedDynamicForms, 'blocks'>>;

interface BuildingBlockWithJourneyMetadata {
  block: BuildingBlockConfiguration;
  meta: {
    onPages: { pageId: string; count: number }[];
    count: number;
  };
}

/**
 * @param journey Journey configuration
 * @returns An array of the unique Building Block selectors that are used in the given journey configuration
 */
export function getUniqueBuildingBlocks(journey: Journey): string[] {
  const uniqueBuildingBlocks = new Set<string>();

  getBuildingBlockConfigurations(journey).forEach((block) =>
    uniqueBuildingBlocks.add(block.selector)
  );

  return Array.from(uniqueBuildingBlocks);
}

/**
 * @param journey Journey configuration
 * @returns An array of all building block configurations across all pages
 */
export function getBuildingBlockConfigurations(
  journey: Journey
): (
  | BuildingBlockConfiguration
  | OverarchingDetailsBlockConfiguration
  | BannerBlockConfiguration
)[] {
  const transformedPagesConfiguration =
    transformJourneyToInternalJourney(journey).pagesConfiguration;
  const buildingBlocks = transformedPagesConfiguration.pages
    .filter((page: PageConfiguration) => isPageWithBlocks(page))
    .flatMap((page) => getAllBuildingBlocksInPage(page));

  if (journey.pagesConfiguration.frame?.header?.actions?.length) {
    buildingBlocks.push(...journey.pagesConfiguration.frame.header.actions);
  }

  return buildingBlocks;
}

/**
 * @param page Page configuration
 * @returns An array of all building block configurations in a page
 */
export function getAllBuildingBlocksInPage(
  page: PageConfigurationWithTransformedDynamicForms
): (
  | BuildingBlockConfiguration
  | OverarchingDetailsBlockConfiguration
  | BannerBlockConfiguration
)[] {
  const result: (
    | BuildingBlockConfiguration
    | OverarchingDetailsBlockConfiguration
    | BannerBlockConfiguration
  )[] = [];

  result.push(...(page.blocks ?? []));

  if (page.overarchingDetailsBlock) {
    result.push(page.overarchingDetailsBlock);
  }

  if (page.bannerBlock) {
    result.push(page.bannerBlock);
  }

  return result;
}
/**
 * @param journey Journey configuration
 * @returns A map with building block selectors as keys and the count how often they are used in the journey as values
 */
export function getBuildingBlockUsageCounts(journey: Journey): Map<string, number> {
  const usageCounts = new Map<string, number>();

  getBuildingBlockConfigurations(journey).forEach((block) =>
    usageCounts.set(block.selector, (usageCounts.get(block.selector) ?? 0) + 1)
  );

  return usageCounts;
}

/**
 * @param journey Journey configuration
 * @returns An Array with the Building Block libraries used within the journey.
 */
export function getBuildingBlockLibraries(journey: Journey): string[] {
  const journeyPackages = new Set<string>();

  getBuildingBlockConfigurations(journey).forEach((block) => journeyPackages.add(block.package));

  return Array.from(journeyPackages);
}

/**
 * @param journey Journey configuration
 * @returns An Array with the libraries listed within the journey configuration.
 */
export function getJourneyPackages(journey: Journey): string[] {
  const set = new Set(journey.pagesConfiguration.libraries.map((library) => library.package));
  return [...set];
}

/**
 * @param journey Journey configuration
 * @returns An Array with {@link BuildingBlockWithJourneyMetadata} objects.
 *          Each object contains the building block configuration in the `block`
 *          property, and meta data on the building block inside the journey
 *          context (i.e. which pages the block is used on, and if it is global
 *          or local).
 */
export function getBuildingBlocksWithJourneyMetadata(
  journey: Journey
): BuildingBlockWithJourneyMetadata[] {
  const blocks: BuildingBlockWithJourneyMetadata[] = [];
  const transformedPagesConfiguration =
    transformJourneyToInternalJourney(journey).pagesConfiguration;

  for (const page of transformedPagesConfiguration.pages) {
    const allBlocks = getAllBuildingBlocksInPage(page) ?? [];
    for (const block of allBlocks) {
      let entryForBlock = blocks.find((entry) => entry.block.selector === block.selector);

      if (!entryForBlock) {
        entryForBlock = {
          block,
          meta: {
            onPages: [],
            count: 0
          }
        };

        blocks.push(entryForBlock);
      }

      entryForBlock.meta.count++;

      let onPagesEntry = entryForBlock?.meta.onPages.find((onPage) => onPage.pageId === page.id);

      if (!onPagesEntry) {
        onPagesEntry = {
          pageId: page.id,
          count: 0
        };

        entryForBlock?.meta.onPages.push(onPagesEntry);
      }

      onPagesEntry.count++;
    }
  }

  return blocks;
}

function isPageWithBlocks(page: PageConfiguration): page is PageWithBlocks {
  return Boolean(page.blocks) || Boolean(page.overarchingDetailsBlock) || Boolean(page.bannerBlock);
}