// Copyright (c) 2015, Emir Pasic. All rights reserved.
// Use of this source code is governed by a BSD-style
// license that can be found in the LICENSE file.

// Package treemap implements a map backed by red-black tree.
//
// Elements are ordered by key in the map.
//
// Structure is not thread safe.
//
// Reference: http://en.wikipedia.org/wiki/Associative_array
package treemap

import (
	"fmt"
	"github.com/emirpasic/gods/maps"
	rbt "github.com/emirpasic/gods/trees/redblacktree"
	"github.com/emirpasic/gods/utils"
	"strings"
)

func assertMapImplementation() {
	var _ maps.Map = (*Map)(nil)
}

// Map holds the elements in a red-black tree
type Map struct {
	tree *rbt.Tree
}

// NewWith instantiates a tree map with the custom comparator.
func NewWith(comparator utils.Comparator) *Map {
	return &Map{tree: rbt.NewWith(comparator)}
}

// NewWithIntComparator instantiates a tree map with the IntComparator, i.e. keys are of type int.
func NewWithIntComparator() *Map {
	return &Map{tree: rbt.NewWithIntComparator()}
}

// NewWithStringComparator instantiates a tree map with the StringComparator, i.e. keys are of type string.
func NewWithStringComparator() *Map {
	return &Map{tree: rbt.NewWithStringComparator()}
}

// Put inserts key-value pair into the map.
// Key should adhere to the comparator's type assertion, otherwise method panics.
func (m *Map) Put(key interface{}, value interface{}) {
	m.tree.Put(key, value)
}

// Get searches the element in the map by key and returns its value or nil if key is not found in tree.
// Second return parameter is true if key was found, otherwise false.
// Key should adhere to the comparator's type assertion, otherwise method panics.
func (m *Map) Get(key interface{}) (value interface{}, found bool) {
	return m.tree.Get(key)
}

// Remove removes the element from the map by key.
// Key should adhere to the comparator's type assertion, otherwise method panics.
func (m *Map) Remove(key interface{}) {
	m.tree.Remove(key)
}

// Empty returns true if map does not contain any elements
func (m *Map) Empty() bool {
	return m.tree.Empty()
}

// Size returns number of elements in the map.
func (m *Map) Size() int {
	return m.tree.Size()
}

// Keys returns all keys in-order
func (m *Map) Keys() []interface{} {
	return m.tree.Keys()
}

// Values returns all values in-order based on the key.
func (m *Map) Values() []interface{} {
	return m.tree.Values()
}

// Clear removes all elements from the map.
func (m *Map) Clear() {
	m.tree.Clear()
}

// Min returns the minimum key and its value from the tree map.
// Returns nil, nil if map is empty.
func (m *Map) Min() (key interface{}, value interface{}) {
	if node := m.tree.Left(); node != nil {
		return node.Key, node.Value
	}
	return nil, nil
}

// Max returns the maximum key and its value from the tree map.
// Returns nil, nil if map is empty.
func (m *Map) Max() (key interface{}, value interface{}) {
	if node := m.tree.Right(); node != nil {
		return node.Key, node.Value
	}
	return nil, nil
}

// String returns a string representation of container
func (m *Map) String() string {
	str := "TreeMap\nmap["
	it := m.Iterator()
	for it.Next() {
		str += fmt.Sprintf("%v:%v ", it.Key(), it.Value())
	}
	return strings.TrimRight(str, " ") + "]"

}