import {
  Body,
  Controller,
  HttpCode,
  Post,
  Request,
  UploadedFile,
  UseGuards,
  UseInterceptors,
  BadRequestException,
  UnauthorizedException,
} from '@nestjs/common';
import { Throttle } from '@nestjs/throttler';
import { FileInterceptor } from '@nestjs/platform-express';
import { memoryStorage } from 'multer';
import { ReceiptImportService } from './receipt-import.service';
import { ParsedReceiptItem } from './dto/parsed-receipt-item.dto';
import { SaveReceiptDto } from './dto/save-receipt.dto';
import { SaveReceiptResponse } from './dto/save-receipt.response';
import { CreateUnitMappingDto } from './dto/create-unit-mapping.dto';
import { AuthGuard } from '@nestjs/passport';

const ALLOWED_MIMES = [
  'image/jpeg',
  'image/png',
  'image/webp',
  'image/heic',
  'image/heif',
  'application/pdf',
  'application/octet-stream', // Flutter Web skickar detta för PDF-filer
];

@Controller('receipt-import')
export class ReceiptImportController {
  constructor(private readonly receiptImportService: ReceiptImportService) {}

  @HttpCode(200)
  @Post()
  @Throttle({ default: { ttl: 60_000, limit: 20 } })
  @UseInterceptors(
    FileInterceptor('file', {
      storage: memoryStorage(),
      limits: { fileSize: 15 * 1024 * 1024 }, // 15 MB
    }),
  )
  async parseReceipt(
    @UploadedFile() file?: Express.Multer.File,
    @Request() req?: any,
  ): Promise<ParsedReceiptItem[]> {
    if (!file?.buffer) {
      throw new BadRequestException('Ingen fil skickades med.');
    }
    if (!ALLOWED_MIMES.includes(file.mimetype)) {
      throw new BadRequestException(
        'Otillåten filtyp. Använd JPEG, PNG, WebP eller PDF.',
      );
    }
    const isPremium = req?.user?.isPremium === true || req?.user?.role === 'admin';
    const userId = typeof req?.user?.id === 'number' ? req.user.id : undefined;
    return this.receiptImportService.parseReceipt(file, isPremium, userId);
  }

  @Post('unit-mappings')
  @UseGuards(AuthGuard('jwt'))
  async upsertUnitMapping(
    @Body() dto: CreateUnitMappingDto,
    @Request() req?: any,
  ) {
    const userId =
      typeof req?.user?.id === 'number'
        ? req.user.id
        : typeof req?.user?.userId === 'number'
          ? req.user.userId
          : undefined;
    if (!userId) {
      throw new UnauthorizedException('Kunde inte identifiera användaren.');
    }

    return this.receiptImportService.upsertUnitMapping(
      userId,
      dto.productId,
      dto.originalUnit,
      dto.preferredUnit,
    );
  }

  @HttpCode(200)
  @Post('save')
  @UseGuards(AuthGuard('jwt'))
  @Throttle({ default: { ttl: 60_000, limit: 10 } })
  async saveReceipt(
    @Body() dto: SaveReceiptDto,
    @Request() req?: any,
  ): Promise<SaveReceiptResponse> {
    const userId =
      typeof req?.user?.id === 'number'
        ? req.user.id
        : typeof req?.user?.userId === 'number'
          ? req.user.userId
          : undefined;
    if (!userId) {
      throw new UnauthorizedException('Kunde inte identifiera användaren.');
    }

    const isAdmin = req?.user?.role === 'admin';
    if (dto.items.some((item) => item.learnAliasGlobally === true) && !isAdmin) {
      throw new BadRequestException('Endast administratörer kan spara globala aliaser.');
    }

    return this.receiptImportService.saveReceipt(userId, dto);
  }
}