import { SpaceRepository } from '@app/common/modules/space/repositories';
import {
  BadRequestException,
  HttpException,
  HttpStatus,
  Injectable,
} from '@nestjs/common';
import { AddSpaceDto } from '../dtos';
import { SuccessResponseDto } from '@app/common/dto/success.response.dto';
import { BaseResponseDto } from '@app/common/dto/base.response.dto';
import { CommunityRepository } from '@app/common/modules/community/repositories';
import { SpaceEntity } from '@app/common/modules/space/entities';
import { generateRandomString } from '@app/common/helper/randomString';
import { SpaceLinkService } from './space-link';
import { SpaceProductService } from './space-products';

@Injectable()
export class SpaceService {
  constructor(
    private readonly spaceRepository: SpaceRepository,
    private readonly communityRepository: CommunityRepository,
    private readonly spaceLinkService: SpaceLinkService,
    private readonly spaceProductService: SpaceProductService,
  ) {}

  async createSpace(
    addSpaceDto: AddSpaceDto,
    communityId: string,
  ): Promise<BaseResponseDto> {
    const { parentUuid, direction, products } = addSpaceDto;

    const community = await this.validateCommunity(communityId);

    const parent = parentUuid ? await this.validateSpace(parentUuid) : null;
    try {
      const newSpace = this.spaceRepository.create({
        ...addSpaceDto,
        community,
        parent: parentUuid ? parent : null,
      });

      await this.spaceRepository.save(newSpace);

      if (direction && parent) {
        await this.spaceLinkService.saveSpaceLink(
          parent.uuid,
          newSpace.uuid,
          direction,
        );
      }

      if (products && products.length > 0) {
        await this.spaceProductService.assignProductsToSpace(
          newSpace,
          products,
        );
      }

      return new SuccessResponseDto({
        statusCode: HttpStatus.CREATED,
        data: newSpace,
        message: 'Space created successfully',
      });
    } catch (error) {
      throw new HttpException(error.message, HttpStatus.INTERNAL_SERVER_ERROR);
    }
  }

  async getSpacesHierarchyForCommunity(
    communityUuid: string,
  ): Promise<BaseResponseDto> {
    await this.validateCommunity(communityUuid);
    try {
      // Get all spaces related to the community, including the parent-child relations
      const spaces = await this.spaceRepository.find({
        where: { community: { uuid: communityUuid } },
        relations: [
          'parent',
          'children',
          'incomingConnections',
          'spaceProducts',
          'spaceProducts.product',
        ], // Include parent and children relations
      });

      // Organize spaces into a hierarchical structure
      const spaceHierarchy = this.buildSpaceHierarchy(spaces);

      return new SuccessResponseDto({
        message: `Spaces in community ${communityUuid} successfully fetched in hierarchy`,
        data: spaceHierarchy,
        statusCode: HttpStatus.OK,
      });
    } catch (error) {
      throw new HttpException(
        'An error occurred while fetching the spaces',
        HttpStatus.INTERNAL_SERVER_ERROR,
      );
    }
  }

  async findOne(spaceUuid: string): Promise<BaseResponseDto> {
    try {
      const space = await this.validateSpace(spaceUuid);

      return new SuccessResponseDto({
        message: `Space with ID ${spaceUuid} successfully fetched`,
        data: space,
      });
    } catch (error) {
      if (error instanceof HttpException) {
        throw error; // If it's an HttpException, rethrow it
      } else {
        throw new HttpException(
          'An error occurred while deleting the community',
          HttpStatus.INTERNAL_SERVER_ERROR,
        );
      }
    }
  }

  async delete(
    spaceUuid: string,
    communityUuid: string,
  ): Promise<BaseResponseDto> {
    try {
      // First, check if the community exists
      const space = await this.validateCommunityAndSpace(
        communityUuid,
        spaceUuid,
      );

      // Delete the space
      await this.spaceRepository.remove(space);

      return new SuccessResponseDto({
        message: `Space with ID ${spaceUuid} successfully deleted`,
        statusCode: HttpStatus.OK,
      });
    } catch (error) {
      if (error instanceof HttpException) {
        throw error;
      }
      throw new HttpException(
        'An error occurred while deleting the space',
        HttpStatus.INTERNAL_SERVER_ERROR,
      );
    }
  }

  async updateSpace(
    spaceUuid: string,
    communityId: string,
    updateSpaceDto: AddSpaceDto,
  ): Promise<BaseResponseDto> {
    try {
      const space = await this.validateCommunityAndSpace(
        communityId,
        spaceUuid,
      );

      // If a parentId is provided, check if the parent exists
      const { parentUuid, products } = updateSpaceDto;
      const parent = parentUuid ? await this.validateSpace(parentUuid) : null;

      // Update other space properties from updateSpaceDto
      Object.assign(space, updateSpaceDto, { parent });

      // Save the updated space
      const updatedSpace = await this.spaceRepository.save(space);

      if (products && products.length > 0) {
        await this.spaceProductService.assignProductsToSpace(
          updatedSpace,
          products,
        );
      }

      return new SuccessResponseDto({
        message: `Space with ID ${spaceUuid} successfully updated`,
        data: space,
        statusCode: HttpStatus.OK,
      });
    } catch (error) {
      if (error instanceof HttpException) {
        throw error;
      }
      throw new HttpException(
        'An error occurred while updating the space',
        HttpStatus.INTERNAL_SERVER_ERROR,
      );
    }
  }

  async getSpacesHierarchyForSpace(
    spaceUuid: string,
  ): Promise<BaseResponseDto> {
    await this.validateSpace(spaceUuid);

    try {
      // Get all spaces that are children of the provided space, including the parent-child relations
      const spaces = await this.spaceRepository.find({
        where: { parent: { uuid: spaceUuid } },
        relations: ['parent', 'children'], // Include parent and children relations
      });

      // Organize spaces into a hierarchical structure
      const spaceHierarchy = this.buildSpaceHierarchy(spaces);

      return new SuccessResponseDto({
        message: `Spaces under space ${spaceUuid} successfully fetched in hierarchy`,
        data: spaceHierarchy,
        statusCode: HttpStatus.OK,
      });
    } catch (error) {
      throw new HttpException(
        'An error occurred while fetching the spaces under the space',
        HttpStatus.INTERNAL_SERVER_ERROR,
      );
    }
  }

  async getSpaceInvitationCode(spaceUuid: string): Promise<any> {
    try {
      const invitationCode = generateRandomString(6);

      const space = await this.validateSpace(spaceUuid);

      space.invitationCode = invitationCode;
      await this.spaceRepository.save(space);

      return new SuccessResponseDto({
        message: `Invitation code has been successfuly added to the space`,
        data: space,
      });
    } catch (err) {
      if (err instanceof BadRequestException) {
        throw err;
      } else {
        throw new HttpException('Space not found', HttpStatus.NOT_FOUND);
      }
    }
  }

  private buildSpaceHierarchy(spaces: SpaceEntity[]): SpaceEntity[] {
    const map = new Map<string, SpaceEntity>();

    // Step 1: Create a map of spaces by UUID
    spaces.forEach((space) => {
      map.set(
        space.uuid,
        this.spaceRepository.create({
          ...space,
          children: [], // Add children if needed
        }),
      );
    });

    // Step 2: Organize the hierarchy
    const rootSpaces: SpaceEntity[] = [];
    spaces.forEach((space) => {
      if (space.parent && space.parent.uuid) {
        const parent = map.get(space.parent.uuid);
        parent?.children?.push(map.get(space.uuid));
      } else {
        rootSpaces.push(map.get(space.uuid));
      }
    });

    return rootSpaces;
  }

  private async validateCommunity(communityId: string) {
    const community = await this.communityRepository.findOne({
      where: { uuid: communityId },
    });
    if (!community) {
      throw new HttpException(
        `Community with ID ${communityId} not found`,
        HttpStatus.NOT_FOUND,
      );
    }
    return community;
  }

  async validateCommunityAndSpace(communityUuid: string, spaceUuid: string) {
    const community = await this.validateCommunity(communityUuid);
    if (!community) {
      this.throwNotFound('Community', communityUuid);
    }

    const space = await this.validateSpace(spaceUuid);
    return space;
  }

  private async validateSpace(spaceUuid: string) {
    const space = await this.spaceRepository.findOne({
      where: { uuid: spaceUuid },
    });
    if (!space) this.throwNotFound('Space', spaceUuid);
    return space;
  }

  private throwNotFound(entity: string, uuid: string) {
    throw new HttpException(
      `${entity} with ID ${uuid} not found`,
      HttpStatus.NOT_FOUND,
    );
  }
}