import {
  IsNotEmpty,
  IsString,
  IsOptional,
  IsEnum,
  IsUUID,
  MaxLength,
  MinLength,
} from 'class-validator';
import { Transform } from 'class-transformer';
import { ApiProperty, ApiPropertyOptional } from '@nestjs/swagger';
import { MessagePriority } from '@prisma/client';

export class CreateMessageDto {
  @ApiPropertyOptional({
    description: 'Driver ID to send to (required for new threads, optional when replying)',
  })
  @IsOptional()
  @IsUUID()
  driverId?: string;

  @ApiPropertyOptional({
    description: 'Parent message ID — set this to reply to an existing message thread',
  })
  @IsOptional()
  @IsUUID()
  replyToId?: string;

  @ApiPropertyOptional({ description: 'Subject line — max 200 characters' })
  @IsOptional()
  @IsString()
  @MaxLength(200, { message: 'subject must be 200 characters or fewer' })
  @Transform(({ value }) => (typeof value === 'string' ? value.trim() : value))
  subject?: string;

  /**
   * Message body. Hard cap at 5000 characters — anything longer is
   * almost certainly a paste of an entire log file or accidental
   * upload, and would bloat the DB and slow every read of the
   * conversation. The frontend mirrors this with a counter.
   */
  @ApiProperty({ description: 'Message body — 1 to 5000 characters' })
  @IsString()
  @IsNotEmpty()
  @MinLength(1)
  @MaxLength(5000, { message: 'body must be 5000 characters or fewer' })
  @Transform(({ value }) => (typeof value === 'string' ? value.trim() : value))
  body: string;

  @ApiPropertyOptional({ enum: MessagePriority })
  @IsOptional()
  @IsEnum(MessagePriority)
  priority?: MessagePriority;
}