import {
  ProgressReportSemester,
  ProgressReportStatus,
} from '@/generated/prisma/client';
import { Transform } from 'class-transformer';
import { IsEnum, IsInt, IsOptional, IsString, Max, Min } from 'class-validator';

// Empty query values should work like missing values.
// Example: ?year= becomes undefined instead of the number 0.
function emptyToUndefined(value: unknown): unknown {
  if (value === '' || value === null || value === undefined) {
    return undefined;
  }

  return value;
}

// Query parameters arrive as strings, so convert valid number values here.
function toOptionalNumber(value: unknown): unknown {
  const result = emptyToUndefined(value);

  return result === undefined ? undefined : Number(result);
}

// Remove extra spaces from optional text filters.
function trimOptionalString(value: unknown): unknown {
  const result = emptyToUndefined(value);

  if (typeof result !== 'string') {
    return result;
  }

  return result.trim() || undefined;
}

export class QueryProgressReportsDto {
  // Page and limit control pagination for the report list.
  @Transform(({ value }) => toOptionalNumber(value))
  @IsOptional()
  @IsInt()
  @Min(1)
  page?: number = 1;

  @Transform(({ value }) => toOptionalNumber(value))
  @IsOptional()
  @IsInt()
  @Min(1)
  @Max(100)
  limit?: number = 10;

  // Search currently matches the progress report title.
  @Transform(({ value }) => trimOptionalString(value))
  @IsOptional()
  @IsString()
  search?: string;

  @Transform(({ value }) => toOptionalNumber(value))
  @IsOptional()
  @IsInt()
  @Min(2000)
  @Max(2100)
  year?: number;

  @Transform(({ value }) => emptyToUndefined(value))
  @IsOptional()
  @IsEnum(ProgressReportSemester)
  semester?: ProgressReportSemester;

  @Transform(({ value }) => emptyToUndefined(value))
  @IsOptional()
  @IsEnum(ProgressReportStatus)
  status?: ProgressReportStatus;
}