/*
   Copyright 2014 CoreOS, Inc.

   Licensed under the Apache License, Version 2.0 (the "License");
   you may not use this file except in compliance with the License.
   You may obtain a copy of the License at

       http://www.apache.org/licenses/LICENSE-2.0

   Unless required by applicable law or agreed to in writing, software
   distributed under the License is distributed on an "AS IS" BASIS,
   WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
   See the License for the specific language governing permissions and
   limitations under the License.
*/

package store

import (
	"sort"
	"time"

	"github.com/coreos/etcd/Godeps/_workspace/src/github.com/jonboulle/clockwork"
)

// NodeExtern is the external representation of the
// internal node with additional fields
// PrevValue is the previous value of the node
// TTL is time to live in second
type NodeExtern struct {
	Key           string      `json:"key,omitempty"`
	Value         *string     `json:"value,omitempty"`
	Dir           bool        `json:"dir,omitempty"`
	Expiration    *time.Time  `json:"expiration,omitempty"`
	TTL           int64       `json:"ttl,omitempty"`
	Nodes         NodeExterns `json:"nodes,omitempty"`
	ModifiedIndex uint64      `json:"modifiedIndex,omitempty"`
	CreatedIndex  uint64      `json:"createdIndex,omitempty"`
}

func (eNode *NodeExtern) loadInternalNode(n *node, recursive, sorted bool, clock clockwork.Clock) {
	if n.IsDir() { // node is a directory
		eNode.Dir = true

		children, _ := n.List()
		eNode.Nodes = make(NodeExterns, len(children))

		// we do not use the index in the children slice directly
		// we need to skip the hidden one
		i := 0

		for _, child := range children {
			if child.IsHidden() { // get will not return hidden nodes
				continue
			}

			eNode.Nodes[i] = child.Repr(recursive, sorted, clock)
			i++
		}

		// eliminate hidden nodes
		eNode.Nodes = eNode.Nodes[:i]

		if sorted {
			sort.Sort(eNode.Nodes)
		}

	} else { // node is a file
		value, _ := n.Read()
		eNode.Value = &value
	}

	eNode.Expiration, eNode.TTL = n.expirationAndTTL(clock)
}

func (eNode *NodeExtern) Clone() *NodeExtern {
	if eNode == nil {
		return nil
	}
	nn := &NodeExtern{
		Key:           eNode.Key,
		Dir:           eNode.Dir,
		TTL:           eNode.TTL,
		ModifiedIndex: eNode.ModifiedIndex,
		CreatedIndex:  eNode.CreatedIndex,
	}
	if eNode.Value != nil {
		s := *eNode.Value
		nn.Value = &s
	}
	if eNode.Expiration != nil {
		t := *eNode.Expiration
		nn.Expiration = &t
	}
	if eNode.Nodes != nil {
		nn.Nodes = make(NodeExterns, len(eNode.Nodes))
		for i, n := range eNode.Nodes {
			nn.Nodes[i] = n.Clone()
		}
	}
	return nn
}

type NodeExterns []*NodeExtern

// interfaces for sorting
func (ns NodeExterns) Len() int {
	return len(ns)
}

func (ns NodeExterns) Less(i, j int) bool {
	return ns[i].Key < ns[j].Key
}

func (ns NodeExterns) Swap(i, j int) {
	ns[i], ns[j] = ns[j], ns[i]
}