package std.util

import java.util.Map as JMap
import java.util.HashMap
import java.util.Collections

// Temporary workaround: commenting out
//import java.util.Map.Entry as JEntry

// Map APIs

/** Returns the size of the map */
val JMap<*,*>.size : Int
    get() = size()

/** Returns true if this map is empty */
val JMap<*,*>.empty : Boolean
    get() = isEmpty()

/** Provides [] access to maps */
fun <K, V> JMap<K, V>.set(key : K, value : V) = this.put(key, value)

/** Converts the nullable Map into an empty Map if its null */
inline fun <K,V> java.util.Map<K,V>?.notNull() : java.util.Map<K,V>
    = if (this != null) this else Collections.EMPTY_MAP as java.util.Map<K,V>


/** Returns the key of the entry */
// Temporary workaround: commenting out
//val <K,V> JEntry<K,V>.key : K
//    get() = getKey().sure()

/** Returns the value of the entry */
// Temporary workaround: commenting out
//val <K,V> JEntry<K,V>.value : V
//    get() = getValue().sure()

/** Returns the value for the given key or returns the result of the defaultValue function if there was no entry for the given key */
inline fun <K,V> java.util.Map<K,V>.getOrElse(key: K, defaultValue: ()-> V) : V {
  val current = this.get(key)
  if (current != null) {
    return current
  } else {
    return defaultValue()
  }
}

/** Returns the value for the given key or the result of the defaultValue function is put into the map for the given value and returned */
inline fun <K,V> java.util.Map<K,V>.getOrPut(key: K, defaultValue: ()-> V) : V {
  val current = this.get(key)
  if (current != null) {
    return current
  } else {
    val answer = defaultValue()
    this.put(key, answer)
    return answer
  }
}