import fs from 'fs';
import path from 'path';

export default function resolveFilePath(
  urlPath: string[] | undefined,
  basePath: string,
  missingExtname: string[] = [],
  missingFilename: string[] = []
): string | null {
  // If urlPath is undefined, set it to an empty array
  const segments = urlPath || []

  // Construct the base file path
  let filePath: string = path.join(basePath, ...segments)
  let find:boolean = false

  do {
    if (fs.existsSync(filePath) && fs.statSync(filePath).isFile()) {
      break
    }
  
    for (const extend of missingExtname) {
      const newPath = filePath + extend;
      if (fs.existsSync(newPath) && fs.statSync(newPath).isFile()) {
        filePath = newPath
        find = true
        break
      }
    }
    if (find) break

    if (fs.existsSync(filePath) && fs.statSync(filePath).isDirectory()) {
      for (const extend of missingFilename) {
        const newPath = path.join(filePath, extend);
        if (fs.existsSync(newPath) && fs.statSync(newPath).isFile()) {
          filePath = newPath
          find = true
          break
        }
      }
    }
    if (find) break

    return null
  } while(0)

  if (!filePath.startsWith(basePath)) {
    return null
  }

  return filePath
}