package merkle

import (
    "fmt"
)

type Binary interface {
    ByteSize()      int
    SaveTo([]byte)  int
    Equals(Binary)  bool
}

type Value interface {
    Binary
}

type Key interface {
    Binary

    Less(b Key)     bool
}

type Db interface {
    Get([]byte) []byte
    Put([]byte, []byte)
}

type Tree interface {
    Root()          Node

    Size()          uint64
    Height()        uint8
    Has(key Key)    bool
    Get(key Key)    Value

    Hash()          (ByteSlice, uint64)
    Save()

    Put(Key, Value) bool
    Remove(Key)     (Value, error)
}

type Node interface {
    Binary

    Key()           Key
    Value()         Value
    Left(Db)        Node
    Right(Db)       Node

    Size()          uint64
    Height()        uint8
    Has(Db, Key)    bool
    Get(Db, Key)    Value

    Hash()          (ByteSlice, uint64)
    Save(Db)

    Put(Db, Key, Value) (Node, bool)
    Remove(Db, Key) (Node, Value, error)
}

type NodeIterator func() Node

func NotFound(key Key) error {
    return fmt.Errorf("Key was not found.")
}