import { existsSync } from "node:fs";
import { readFile } from "node:fs/promises";
import { join } from "node:path";
import type {
  DuplicatedPackage,
  DuplicatedPackageInstance,
  NodeModulePaths,
} from "./utils";

export async function getPackageVersion(packagePath: string) {
  const packageJsonPath = join(packagePath, "package.json");
  console.log("packageJsonPath", packageJsonPath);
  if (!existsSync(packageJsonPath)) {
    console.warn(
      `Package.json not found at ${packageJsonPath}. This may not be a node module.`,
    );
    return "unknown";
  }
  const jsonString = await readFile(packageJsonPath, "utf-8");
  const jsonObj = JSON.parse(jsonString);
  return jsonObj.version;
}

export const getDuplicateNodeModules = async (
  nodeModulePaths: NodeModulePaths,
) => {
  const duplicates: DuplicatedPackage[] = [];
  for (const [packageName, packagePaths] of Object.entries(nodeModulePaths)) {
    if (packagePaths.length < 2) {
      continue;
    }
    const instances: DuplicatedPackageInstance[] = [];
    for (const packagePath of packagePaths) {
      instances.push({
        path: packagePath,
        version: await getPackageVersion(packagePath),
      });
    }
    duplicates.push({
      name: packageName,
      instances,
    });
  }

  return duplicates;
};