#ifndef _VBUFSTORAGE_H
#define _VBUFSTORAGE_H

#include <wchar.h>
#include <string>
#include <map>
#include <set>
#include "virtualBuffer.h"

#define DLLEXPORT extern "C" __declspec(dllexport)

//Buffers and nodes share some commen members
//The following dataType constants help to distinguish the difference between buffers and nodes at runtime
#define VBUFINTERNAL_NODETYPE_BUFFER 1
#define VBUFINTERNAL_NODETYPE_TAG 2
#define VBUFINTERNAL_NODETYPE_TEXT 3

//A class that can hold values to uniquely identify a node
typedef struct _VBufStorage_nodeIdentifier_struct {
	bool operator<(const _VBufStorage_nodeIdentifier_struct&) const;
	int docHandle;
	int ID;
} VBufStorage_nodeIdentifier_t;

//buffer and node types, struct definitions are further down
typedef struct _VBufStorage_bufferNode_struct VBufStorage_bufferNode_t;
typedef struct _VBufStorage_node_struct VBufStorage_node_t;
typedef struct _VBufStorage_tagNode_struct VBufStorage_tagNode_t;
typedef struct _VBufStorage_textNode_struct VBufStorage_textNode_t;

//A struct for the node type
struct _VBufStorage_node_struct {
	int dataType;
	VBufStorage_nodeIdentifier_t identifier; 
	VBufStorage_bufferNode_t* buffer;
	VBufStorage_node_t* firstChild;
	VBufStorage_node_t* lastChild;
	VBufStorage_node_t* previous;
	VBufStorage_node_t* next;
	VBufStorage_node_t* parent;
	int startOffset;
	int endOffset;
};

//A struct for the buffer type
struct _VBufStorage_bufferNode_struct : _VBufStorage_node_struct {
	std::map<_VBufStorage_nodeIdentifier_struct,VBufStorage_node_t*>* nodesByIdentifier;
	std::wstring* bufferText;
	int selectionStart;
	int selectionEnd;
};

//A struct for the tag node type
struct _VBufStorage_tagNode_struct : _VBufStorage_node_struct {
	VBuf_attribute_t* attribs;
	int numAttribs;
	int isBlock;
};

//A struct for the text node type
struct _VBufStorage_textNode_struct : _VBufStorage_node_struct {
};

//All the following functions return error codes less than 0 if there is an error

//Creates a new buffer and returns a pointer to it.
//If successfull it returns a pointer to the buffer
DLLEXPORT VBufStorage_bufferNode_t* VBufStorage_createBuffer();

//Gets the node in given buffer that has a given docHandle and ID
DLLEXPORT VBufStorage_node_t* VBufStorage_getBufferNodeWithIdentifier(VBufStorage_bufferNode_t* buf, int docHandle, int ID);

//Merges a buffer's contents in to another buffer
DLLEXPORT int VBufStorage_mergeBuffer(VBufStorage_node_t* parent, VBufStorage_node_t* previous, VBufStorage_bufferNode_t* node);
 
//Destroies the buffer pointed to by buf. It also firstly clears the buffer, removing any nodes it has
//If successfull it returns 0
DLLEXPORT int VBufStorage_destroyBuffer(VBufStorage_bufferNode_t* buf);

//Clears the buffer pointed to by buf (removing all nodes associated with it) 
//Returns 0 on success
DLLEXPORT int VBufStorage_clearBuffer(VBufStorage_bufferNode_t* buf);

//Splits a text node in to two adjacent text nodes
DLLEXPORT int VBufStorage_splitTextNodeAtOffset(VBufStorage_textNode_t* node, int offset);

//Creates a new tag node, setting its docHandle to given docHandle, ID to given ID and attribs to given attribs 
//It links it to given parent and previous nodes
DLLEXPORT VBufStorage_tagNode_t* VBufStorage_addTagNodeToBuffer(VBufStorage_node_t* parent, VBufStorage_node_t* previous, int docHandle, int ID, VBuf_attribute_t* attribs, int numAttribs, int isBlock);

//Creates a new text node, setting its docHandle to given docHandle and ID to given ID, and inserts the given text. 
//It links it to given parent and previous nodes
DLLEXPORT VBufStorage_textNode_t* VBufStorage_addTextNodeToBuffer(VBufStorage_node_t* parent, VBufStorage_node_t* previous, int docHandle, int ID, wchar_t* text);

//Removes the node , 
//It also removes any nodes that are descendants of the node being removed.
//Returns 0 on success
DLLEXPORT int VBufStorage_removeNodeFromBuffer(VBufStorage_node_t* node);

//Removes the descendants of the node
//Returns 0 on success
DLLEXPORT int VBufStorage_removeDescendantsFromBufferNode(VBufStorage_node_t* node);

//Finds the node who owns the range of text in the buffer that includes the given offset.
//Places the docHandle and ID in given by ref arguments
//Returns 0 on success
DLLEXPORT int VBufStorage_getFieldIdentifierFromBufferOffset(VBufStorage_bufferNode_t* buf, int offset, int* foundDocHandle, int* foundID);

//Gets the offsets of the node identified by the given docHandle and ID.
//The offsets are placed in memory pointed to by the given startOffset and endOffset pointers.
//Returns 0 on success
DLLEXPORT int VBufStorage_getBufferOffsetsFromFieldIdentifier(VBufStorage_bufferNode_t* buf, int docHandle, int ID, int* startOffset, int* endOffset);

//Finds the next or previous node of the buffer pointed to by buf, that matches the given attribs. 
//any attrib can be listed more than once to match on more than one possibility
//It starts from the given startOffset, and searches in the direction given by direction.
//It places the found node's docHandle and ID in given by ref arguments
//It returns 0 on success
DLLEXPORT int VBufStorage_findBufferFieldIdentifierByProperties(VBufStorage_bufferNode_t* buf, int direction, int startOffset, VBuf_multyValueAttribute_t* attribs, int numAttribs, int* foundDocHandle, int* foundID);

//Returns the length of the text in the buffer pointed to by buf.
DLLEXPORT int VBufStorage_getBufferTextLength(VBufStorage_bufferNode_t* buf); 

//Returns the number of nodes in the buffer pointed to by buf.
DLLEXPORT int VBufStorage_getBufferFieldCount(VBufStorage_bufferNode_t* buf);

//Searches the buffer pointed to by buf, for the given text, in the direction given by direction.
//Currently ignores flags, is always case sensitive.
//Returns the offset of the text if its found
DLLEXPORT int VBufStorage_findBufferText(VBufStorage_bufferNode_t* buf, wchar_t* text, int startOffset, int direction, int flags);

//Copies the text between the given start and end offsets, in to the memory pointed to by text
DLLEXPORT int VBufStorage_getBufferTextByOffsets(VBufStorage_bufferNode_t* buf, int startOffset, int endOffset, wchar_t* text);

//Gets a string of XML open tags that represents the field ancestry from the root node to the given offset.
//Call it once with textBuf as NULL and it will cache the xml and return the length so you can allocate appropriate memory and call it again.
DLLEXPORT int VBufStorage_getXMLContextAtBufferOffset(VBufStorage_bufferNode_t* buf, int offset, wchar_t* textBuf);

//Builds a string of xml, which describes the text and fields between the given startOffset and endOffset, of the buffer pointed to by buf.
//This XML is relative to the start offset.
//To find out the length of the xml (for purposes of allocating enough memory), call this function 
//With text as NULL, and it will generate the xml, cache it, and return the length in wchars.
//Then call it again with an appropriately sized block of memory, pointed to by text, to copy the xml in to the memory block.
//Once copied, it again returns the length of the xml.
DLLEXPORT int VBufStorage_getXMLBufferTextByOffsets(VBufStorage_bufferNode_t* buf, int startOffset, int endOffset, wchar_t* text);

//Gets the start and end offsets for the line at given offset, and places them in startOffset and endOffset. 
//Takes maxLineLength in to account when calculating offsets
//If useScreenLayout is True then lines will not be broken at all tags, but only ones that are block tags. Of course lines will also be broken at \n.
//Returns 0 on success
DLLEXPORT int VBufStorage_getBufferLineOffsets(VBufStorage_bufferNode_t* buf, int offset, int maxLineLength, int useScreenLayout, int* startOffset, int* endOffset);

//Gets the current selection offsets, putting them in given startOffset and endOffset parameters.
//Returns 0 on success
DLLEXPORT int VBufStorage_getBufferSelectionOffsets(VBufStorage_bufferNode_t* buf, int* startOffset, int* endOffset);

//Sets the selection to the given startOffset and endOffset parameters.
//Returns 0 on success
DLLEXPORT int VBufStorage_setBufferSelectionOffsets(VBufStorage_bufferNode_t* buf, int startOffset, int endOffset);

#endif