twitsplit.swift

//: Playground - noun: a place where people can play

import UIKit

let CHARACTER_LIMIT = 7
let text = "a b c d e f g h i j k"

class TweetComponent: CustomStringConvertible {
  var content: String
  let index: Int
  let maxPages: Int
  
  var prefix: String {
    return "\(index)/\(maxPages) "
  }
  var characterLimit: Int {
    return CHARACTER_LIMIT - prefix.characters.count
  }
  
  init(content: String, index: Int, maxPages: Int) {
    self.content = content
    self.index = index
    self.maxPages = maxPages
    if content.characters.count > characterLimit {
      print("ERROR \(content) too long, it needs to be \(characterLimit)")
    }
  }
  
  func append(str: String) -> Bool {
    let proposedSentence = "\(content) \(str)"
    if proposedSentence.characters.count <= characterLimit {
      content = proposedSentence
      return true
    }
    return false
  }
  
  public var description: String {
    return "\(prefix)\(content)"
  }

}

func split(inputStr: String, maxPages: Int=1) -> [TweetComponent] {
  var words = inputStr.components(separatedBy: .whitespacesAndNewlines)
  // Initialize the first component manually. We'll fix up maxPages later.
  var ret: [TweetComponent] = [TweetComponent.init(content: words.remove(at: 0), index: 1, maxPages: maxPages)]
  for word in words {
    let last = ret.last!
    // A try catch here would be nicer, perhaps.
    let success = last.append(str: word)
    if !success {
      ret.append(TweetComponent.init(content: word, index: ret.count + 1, maxPages: maxPages))
    }
  }
  if ret.count > maxPages {
    return split(inputStr: inputStr, maxPages: ret.count)
  }
  return ret
}



func prettyPrint(strArr: [TweetComponent]) {
  for tweet in strArr {
    print("\(tweet) (length: \(tweet.description.characters.count))")
  }
  print("total is \(strArr.count)")
}

prettyPrint(strArr: split(inputStr: text))