#include <string>
#include <cstring>
#include <stdlib.h>
#include <stdio.h>
#include "Recast.h"
#include "DetourCommon.h"
#include "DetourNavMesh.h"
#include "DetourNavMeshBuilder.h"
#include "DetourNavMeshQuery.h"

#include "mesh_loader.h"


void save_navmesh(const char* path, const dtNavMesh* mesh) {
	if (!mesh) return;

	FILE* fp = fopen(path, "wb");
	if (!fp)
		return;

	// Store header.
	NavMeshSetHeader header;
	header.magic = NAVMESHSET_MAGIC;
	header.version = NAVMESHSET_VERSION;
	header.numTiles = 0;
	for (int i = 0; i < mesh->getMaxTiles(); ++i)
	{
		const dtMeshTile* tile = mesh->getTile(i);
		if (!tile || !tile->header || !tile->dataSize) continue;
		header.numTiles++;
	}
	memcpy(&header.params, mesh->getParams(), sizeof(dtNavMeshParams));
	fwrite(&header, sizeof(NavMeshSetHeader), 1, fp);

	// Store tiles.
	for (int i = 0; i < mesh->getMaxTiles(); ++i)
	{
		const dtMeshTile* tile = mesh->getTile(i);
		if (!tile || !tile->header || !tile->dataSize) continue;

		NavMeshTileHeader tileHeader;
		tileHeader.tileRef = mesh->getTileRef(tile);
		tileHeader.dataSize = tile->dataSize;
		fwrite(&tileHeader, sizeof(tileHeader), 1, fp);

		fwrite(tile->data, tile->dataSize, 1, fp);
	}

	fclose(fp);
}

dtNavMesh* load_navmesh(const char* path)
{
	FILE* fp = fopen(path, "rb");
	if (!fp) return 0;

	// Read header.
	NavMeshSetHeader header;
	fread(&header, sizeof(NavMeshSetHeader), 1, fp);
	if (header.magic != NAVMESHSET_MAGIC)
	{
		fclose(fp);
   fprintf (stderr, "Bad magic %d\n", header.magic);
		return 0;
	}

	if (header.version != NAVMESHSET_VERSION)
	{
		fclose(fp);
   fprintf (stderr, "Bad version %d\n", header.version);
		return 0;
	}

	dtNavMesh* mesh = dtAllocNavMesh();
	if (!mesh)
	{
		fclose(fp);
		return 0;
	}
	dtStatus status = mesh->init(&header.params);
	if (dtStatusFailed(status))
	{
		fclose(fp);
		return 0;
	}

	// Read tiles.
	for (int i = 0; i < header.numTiles; ++i)
	{
		NavMeshTileHeader tileHeader;
		fread(&tileHeader, sizeof(tileHeader), 1, fp);
		if (!tileHeader.tileRef || !tileHeader.dataSize)
			break;

		unsigned char* data = (unsigned char*)dtAlloc(tileHeader.dataSize, DT_ALLOC_PERM);
		if (!data) break;
		memset(data, 0, tileHeader.dataSize);
		fread(data, tileHeader.dataSize, 1, fp);

   //fprintf (stderr, "Adding tile %s\n", data);
		mesh->addTile(data, tileHeader.dataSize, DT_TILE_FREE_DATA, tileHeader.tileRef, 0);
	}

	fclose(fp);

	return mesh;
}