import { EntityType } from '../../types.generated';
import { Entity, PreviewType } from './Entity';

function validatedGet<K, V>(key: K, map: Map<K, V>): V {
    if (map.has(key)) {
        return map.get(key) as V;
    }
    throw new Error(`Unrecognized key ${key} provided in map ${JSON.stringify(map)}`);
}

/**
 * Serves as a singleton registry for all DataHub entities to appear on the frontend.
 */
export default class EntityRegistry {
    entities: Array<Entity<any>> = new Array<Entity<any>>();

    entityTypeToEntity: Map<EntityType, Entity<any>> = new Map<EntityType, Entity<any>>();

    collectionNameToEntityType: Map<string, EntityType> = new Map<string, EntityType>();

    pathNameToEntityType: Map<string, EntityType> = new Map<string, EntityType>();

    register(entity: Entity<any>) {
        this.entities.push(entity);
        this.entityTypeToEntity.set(entity.type, entity);
        this.collectionNameToEntityType.set(entity.getCollectionName(), entity.type);
        this.pathNameToEntityType.set(entity.getPathName(), entity.type);
    }

    getEntities(): Array<Entity<any>> {
        return this.entities;
    }

    getSearchEntityTypes(): Array<EntityType> {
        return this.entities.filter((entity) => entity.isSearchEnabled()).map((entity) => entity.type);
    }

    getDefaultSearchEntityType(): EntityType {
        return this.entities[0].type;
    }

    getBrowseEntityTypes(): Array<EntityType> {
        return this.entities.filter((entity) => entity.isBrowseEnabled()).map((entity) => entity.type);
    }

    getCollectionName(type: EntityType): string {
        const entity = validatedGet(type, this.entityTypeToEntity);
        return entity.getCollectionName();
    }

    getTypeFromCollectionName(name: string): EntityType {
        return validatedGet(name, this.collectionNameToEntityType);
    }

    getPathName(type: EntityType): string {
        const entity = validatedGet(type, this.entityTypeToEntity);
        return entity.getPathName();
    }

    getTypeFromPathName(pathName: string): EntityType {
        return validatedGet(pathName, this.pathNameToEntityType);
    }

    getTypeOrDefaultFromPathName(pathName: string, def: EntityType): EntityType {
        try {
            return validatedGet(pathName, this.pathNameToEntityType);
        } catch (e) {
            return def;
        }
    }

    renderProfile(type: EntityType, urn: string): JSX.Element {
        const entity = validatedGet(type, this.entityTypeToEntity);
        return entity.renderProfile(urn);
    }

    renderPreview<T>(entityType: EntityType, type: PreviewType, data: T): JSX.Element {
        const entity = validatedGet(entityType, this.entityTypeToEntity);
        return entity.renderPreview(type, data);
    }

    renderSearchResult<T>(type: EntityType, data: T): JSX.Element {
        const entity = validatedGet(type, this.entityTypeToEntity);
        return entity.renderPreview(PreviewType.SEARCH, data);
    }

    renderBrowse(type: EntityType, { urn, name }: { urn: string; name: string }): JSX.Element {
        const entity = validatedGet(type, this.entityTypeToEntity);
        return entity.renderPreview(PreviewType.BROWSE, { urn, name });
    }
}