import { createHash } from "node:crypto";
import type { User as DomainUser } from "@cv/auth";
import { JwtAuthGuard, VerifiedScopeGuard } from "@cv/auth";
import { validateFile } from "@cv/file-upload";
import { BadRequestException, UseGuards } from "@nestjs/common";
import { Args, Mutation, Resolver } from "@nestjs/graphql";
import { CurrentUser } from "@/modules/current-user/current-user.decorator";
import { UserFileType } from "@/modules/data-import/graphql/user-file.type";
import { ImportService } from "@/modules/data-import/import.service";
import { FileImportSource } from "@/modules/data-import/sources/file-import-source";
import { ProfileService } from "@/modules/profile/profile.service";
import { UploadFileInput } from "./upload-file.input";

const MAX_DECODED_SIZE = 10 * 1024 * 1024; // 10MB

@Resolver()
@UseGuards(JwtAuthGuard, VerifiedScopeGuard)
export class UploadFileResolver {
  constructor(
    private readonly importService: ImportService,
    private readonly fileImportSource: FileImportSource,
    private readonly profileService: ProfileService,
  ) {}

  @Mutation(() => UserFileType)
  async uploadFile(
    @CurrentUser() user: DomainUser,
    @Args("input") input: UploadFileInput,
  ): Promise<UserFileType> {
    const buffer = Buffer.from(input.content, "base64");

    if (buffer.byteLength > MAX_DECODED_SIZE) {
      throw new BadRequestException(
        `File exceeds maximum size of ${MAX_DECODED_SIZE / (1024 * 1024)}MB`,
      );
    }

    const validation = validateFile({
      buffer,
      mimeType: input.mimeType,
      originalName: input.fileName,
      sizeBytes: buffer.byteLength,
    });

    if (!validation.valid) {
      throw new BadRequestException(validation.error);
    }

    const fingerprint = createHash("sha256").update(buffer).digest("hex");

    const duplicate = await this.importService.findDuplicateForUser(
      user.id,
      fingerprint,
    );

    if (duplicate) {
      return UserFileType.fromDomain(duplicate, { isDuplicate: true });
    }

    const profile = input.profileId
      ? await this.profileService.findByIdAndUserOrFail(input.profileId, user.id)
      : await this.profileService.getOrCreateDefaultProfile(user.id);

    const userFile = await this.importService.createImport(
      user,
      profile.id,
      this.fileImportSource,
      {
        fileName: input.fileName,
        mimeType: input.mimeType,
        sizeBytes: buffer.byteLength,
        fingerprint,
      },
      { buffer, mimeType: input.mimeType },
    );

    return UserFileType.fromDomain(userFile);
  }
}