import { createHash } from "crypto";
import { promises as fs } from "fs";
import path from "path";

import { AppConfig } from "../../../../shared/infrastructure/config/app-config";
import { DocumentStoragePort, DownloadedBinary, StoredDocumentDescriptor, UploadedBinary } from "../../application/ports/document-storage.port";

export class LocalDocumentStorageService implements DocumentStoragePort {
  private readonly rootPath: string;

  constructor(private readonly basePath: string) {
    this.rootPath = path.resolve(process.cwd(), basePath);
  }

  public async upload(
    tenantId: string,
    documentId: string,
    file: UploadedBinary
  ): Promise<StoredDocumentDescriptor> {
    const sanitizedFileName = sanitizeFileName(file.originalFileName);
    const storageKey = path.posix.join(tenantId, documentId, sanitizedFileName);
    const fullPath = this.resolveAbsolutePath(storageKey);

    await fs.mkdir(path.dirname(fullPath), { recursive: true });
    await fs.writeFile(fullPath, file.buffer);

    return {
      storageProvider: "local",
      storageKey,
      checksumSha256: createHash("sha256").update(file.buffer).digest("hex")
    };
  }

  public async download(_tenantId: string, storageKey: string): Promise<DownloadedBinary> {
    const fullPath = this.resolveAbsolutePath(storageKey);
    const buffer = await fs.readFile(fullPath);

    return { buffer };
  }

  public async delete(_tenantId: string, storageKey: string): Promise<void> {
    const fullPath = this.resolveAbsolutePath(storageKey);
    await fs.rm(fullPath, { force: true });
  }

  private resolveAbsolutePath(storageKey: string): string {
    return path.resolve(this.rootPath, storageKey.split("/").join(path.sep));
  }
}

function sanitizeFileName(fileName: string): string {
  const normalized = fileName.trim().replace(/[^a-zA-Z0-9._-]+/g, "-");
  return normalized || "document.bin";
}