import { applyDecorators, NotFoundException, Type } from '@nestjs/common'
import { QueryPaginationDto } from '../dto/pagination-query.dto'
import { ApiExtraModels, ApiOkResponse, ApiResponseNoStatusOptions, getSchemaPath } from '@nestjs/swagger'
import { DEFAULT_PAGE_NUMBER, DEFAULT_PAGE_SIZE, PaginateOutputDto } from '../dto/pagination-output.dto'

export interface PrismaPaginationParams {
  skip: number
  take: number
}

export const paginate = (
  query: QueryPaginationDto,
): PrismaPaginationParams => {
  const size = query.size || DEFAULT_PAGE_SIZE
  const page = query.page || DEFAULT_PAGE_NUMBER
  return {
    skip: size * (page - 1),
    take: size,
  }
}

export const paginateOutput = <T>(
  data: T[],
  total: number,
  query: QueryPaginationDto,
): PaginateOutputDto<T> => {
  const page = query.page || DEFAULT_PAGE_NUMBER
  const size = query.size || DEFAULT_PAGE_SIZE

  const lastPage = Math.ceil(total / size)

  // if data is empty, return empty array
  if (!data.length) {
    return {
      data,
      meta: {
        total,
        lastPage,
        currentPage: page,
        totalPerPage: size,
        prevPage: null,
        nextPage: null,
      },
    }
  }

  // if page is greater than last page, throw an error
  if (page > lastPage) {
    throw new NotFoundException(
      `Page ${page} not found. Last page is ${lastPage}`,
    )
  }

  return {
    data,
    meta: {
      total,
      lastPage,
      currentPage: page,
      totalPerPage: size,
      prevPage: page > 1 ? page - 1 : null,
      nextPage: page < lastPage ? page + 1 : null,
    },
  }
}

export const ApiOkResponsePaginated = <DataDto extends Type<unknown>>(dataDto: DataDto, options?: ApiResponseNoStatusOptions) =>
  applyDecorators(
    ApiExtraModels(PaginateOutputDto, dataDto),
    ApiOkResponse({
      ...options,
      schema: {
        allOf: [
          { $ref: getSchemaPath(PaginateOutputDto) },
          {
            properties: {
              data: {
                type: 'array',
                items: { $ref: getSchemaPath(dataDto) },
              },
            },
          },
        ],
      },
    }),
  )