package common

import (
	"bufio"
	"strconv"
	"strings"
)

type FileBase interface {
  GetSize() int
  GetName() string
}

type File struct {
  name string
  size int
}

func (file *File) GetSize() int {
  return file.size
}

func (file *File) GetName() string {
  return file.name
}

type Folder struct {
  name string
  content []FileBase
  parent *Folder
}

func (folder *Folder) GetSize() int {
  sum := 0
  for _, file := range folder.content {
    sum += file.GetSize()
  }
  return sum
}

func (folder *Folder) GetName() string {
  return folder.name
}

func (folder Folder) GetSubfoldersUnderSize(size int) []*Folder {
  folders := []*Folder{}
  for _, subfolder := range folder.GetSubfolders() {
    if subfolder.GetSize() <= size {
      folders = append(folders, subfolder)
    }
    folders = append(folders, subfolder.GetSubfoldersUnderSize(size)...)
  }
  return folders
}

func (folder Folder) GetSubfoldersOverSize(size int) []*Folder {
  folders := []*Folder{}
  for _, subfolder := range folder.GetSubfolders() {
    if subfolder.GetSize() >= size {
      folders = append(folders, subfolder)
    }
    folders = append(folders, subfolder.GetSubfoldersOverSize(size)...)
  }
  return folders
}

func (folder *Folder) GetSubfolders() []*Folder {
  subfolders := []*Folder{}
  for _, file := range folder.content {
    if folder, ok := file.(*Folder); ok {
      subfolders = append(subfolders, folder)
    }
  }
  return subfolders
}

func (folder *Folder) GetFiles() []*File {
  files := []*File{}
  for _, file := range folder.content {
    if file, ok := file.(*File); ok {
      files = append(files, file)
    }
  }
  return files
}

func (folder *Folder) GetOrCreateFolder(name string) *Folder {
  for _, subfolder := range folder.GetSubfolders() {
    if subfolder.GetName() == name {
      return subfolder
    }
  }
  newFolder := Folder{name, []FileBase{}, folder}
  folder.content = append(folder.content, &newFolder)
  return &newFolder
}

func (folder *Folder) GetOrCreateFile(name string, size int) *File {
  for _, file := range folder.GetFiles() {
    if file.GetName() == name {
      return file
    }
  }
  newFile := File{name, size}
  folder.content = append(folder.content, &newFile)
  return &newFile
}

func Parse(scanner bufio.Scanner) Folder {
  rootFolder := Folder{"/", []FileBase{}, nil}
  var currentFolder *Folder

  for scanner.Scan() {
    line := scanner.Text()
    switch line[0:4] {
      case "$ cd":
        if line[5:] == "/" {
          currentFolder = &rootFolder
        } else if line[5:] == ".." {
          currentFolder = currentFolder.parent
        } else {
          currentFolder = currentFolder.GetOrCreateFolder(line[5:])
        }

      case "$ ls":

      case "dir ":
        currentFolder.GetOrCreateFolder(line[4:])

      default:
        splittedLine := strings.Split(line, " ")
        size, _ := strconv.Atoi(splittedLine[0])
        currentFolder.GetOrCreateFile(splittedLine[1], size)
    }
  }

  return rootFolder
}