import fs from "node:fs/promises"
import path from "path"
import os from "os"
import { glob } from "glob"

export async function fileExists(filePath) {
  try {
    await fs.stat(filePath)
    return true
  } catch (err) {
    if (err.code === "ENOENT") {
      return false
    }
    throw err // re-throw other errors
  }
}

export async function readDirectoryRecursively(dir, files = []) {
  const exists = await fileExists(dir)
  if (!exists) {
    return files
  }
  const contents = await fs.readdir(dir, { withFileTypes: true })
  for (const item of contents) {
    const itemPath = path.join(dir, item.name)
    if (item.isDirectory()) {
      readDirectoryRecursively(itemPath, files)
    } else {
      files.push(itemPath)
    }
  }
  return files
}

// type InputConfig
// {
//  pattern: String | String[];
//  ignore:  String | String[];
// }
export async function readFilesByGlob(globConfigs) {
  const matchPromises = globConfigs.reduce(
    async (existingMatches, globConfig) => {
      const { pattern, ignore, dot } = {
        dot: false,
        ignore: [],
        ...globConfig,
      }
      const matches = await glob(expandTilde(pattern), {
        ignore,
        dot,
      })
      return [...(await existingMatches), ...matches]
    },
    [],
  )
  const files = await matchPromises
  return [...new Set(files)]
}

export function expandTilde(path) {
  if (!path.startsWith("~")) return path
  return path.replace(/^~(?=$|\/|\\)/, os.homedir())
}

export async function checkFilesExist(files, baseDir) {
  const filesToCheck = Array.isArray(files) ? files : [files]
  const fileCheckResults = await Promise.all(
    filesToCheck.map(async file => {
      const filePath = path.join(baseDir, file)
      const exists = await fileExists(filePath)
      return { filePath, exists }
    }),
  )
  return fileCheckResults.reduce(
    (sorted, { filePath, exists }) => {
      return exists
        ? { ...sorted, present: [...sorted.present, filePath] }
        : { ...sorted, absent: [...sorted.absent, filePath] }
    },
    { present: [], absent: [] },
  )
}

export async function writeFile(filePath, content) {
  const fileDir = path.dirname(filePath)
  await fs.mkdir(fileDir, { recursive: true })
  return await fs.writeFile(filePath, content, {
    encoding: "utf8",
  })
}