import { readdirSync, statSync } from "node:fs"
import { dirname, join, parse, resolve } from "node:path"

import type { ResolveFriendlyOptions } from "./resolve.ts"
import { resolveStartDirectory } from "./resolve.ts"

export interface FindClosestFilePathOptions extends ResolveFriendlyOptions {
  targetBase: string
}
/**
 * @description 从指定地址开始，逐级向上查找，直到找到指定的文件为止，并返回该文件的路径。
 * 若未找到指定的文件，则返回 undefined。
 */
export const findClosestFilePath = (options: FindClosestFilePathOptions): string | undefined => {
  const { targetBase } = options

  let currentDir = resolveStartDirectory(options)

  const { root } = parse(currentDir)

  while (true) {
    const filePath = resolve(join(currentDir, targetBase))

    try {
      const stat = statSync(filePath)
      if (stat.isFile()) {
        return filePath
      }
    } catch {
      //
    }

    if (currentDir === root) {
      break
    }

    currentDir = dirname(currentDir)
  }

  return undefined
}

export interface FindPathOptions extends ResolveFriendlyOptions {
  targetPath: string[]
}
/**
 * @description 从指定地址开始，逐个判断目标路径是否存在，直到找到一个存在的路径为止，并返回该路径。
 * - 若目标路径是相对路径，则相对于当前地址进行解析。
 * - 若目标路径是绝对路径，则直接进行判断。
 * 若未找到存在的路径，则返回 undefined。
 */
export const findPath = (options: FindPathOptions): string | undefined => {
  const { targetPath } = options

  const currentDir = resolveStartDirectory(options)

  for (const currentPath of targetPath) {
    const filePath = resolve(currentDir, currentPath)

    try {
      statSync(filePath)
      return filePath
    } catch {
      //
    }
  }

  return undefined
}

export interface FindFilesOptions extends ResolveFriendlyOptions {
  basePattern: RegExp
}
/**
 * @description 在指定目录下查找所有符合指定模式的文件，并返回其路径列表。
 * - 仅查找指定目录本身，不递归查找子目录。
 */
export const findFiles = (options: FindFilesOptions): string[] => {
  const { startPath, basePattern } = options

  const startDirectory = resolveStartDirectory({ startPath })
  const filePathList: string[] = []

  for (const entry of readdirSync(startDirectory, { withFileTypes: true })) {
    if (entry.isFile()) {
      const currentPath = resolve(join(startDirectory, entry.name))
      basePattern.lastIndex = 0

      if (basePattern.test(entry.name)) {
        filePathList.push(currentPath)
      }
    }
  }

  return filePathList
}