//
// Copyright (c) 2009-2010 Mikko Mononen memon@inside.org
//
// This software is provided 'as-is', without any express or implied
// warranty.  In no event will the authors be held liable for any damages
// arising from the use of this software.
// Permission is granted to anyone to use this software for any purpose,
// including commercial applications, and to alter it and redistribute it
// freely, subject to the following restrictions:
// 1. The origin of this software must not be misrepresented; you must not
//    claim that you wrote the original software. If you use this software
//    in a product, an acknowledgment in the product documentation would be
//    appreciated but is not required.
// 2. Altered source versions must be plainly marked as such, and must not be
//    misrepresented as being the original software.
// 3. This notice may not be removed or altered from any source distribution.
//

#include "TestCase.h"

#include "DetourCommon.h"
#include "DetourNavMesh.h"
#include "DetourNavMeshQuery.h"
#include "SDL_opengl.h"
#include "SampleInterfaces.h"
#include "imguiHelpers.h"

#include <ctype.h>
#include <math.h>
#include <stdio.h>
#include <string.h>
#ifdef __APPLE__
#	include <OpenGL/glu.h>
#else
#	include <GL/glu.h>
#endif
#include "PerfTimer.h"

#include <imgui.h>

#ifdef WIN32
#	define snprintf _snprintf
#endif

static char* parseRow(char* buf, char* bufEnd, char* row, int len)
{
	bool start = true;
	bool done = false;
	int n = 0;
	while (!done && buf < bufEnd)
	{
		char c = *buf;
		buf++;
		// multirow
		switch (c)
		{
		case '\n':
			if (start)
			{
				break;
			}
			done = true;
			break;
		case '\r':
			break;
		case '\t':
		case ' ':
			if (start)
			{
				break;
			}
			// else falls through
		default:
			start = false;
			row[n++] = c;
			if (n >= len - 1)
			{
				done = true;
			}
			break;
		}
	}
	row[n] = '\0';
	return buf;
}

static void copyName(std::string& dst, const char* src)
{
	// Skip white spaces
	while (*src && isspace(*src))
	{
		src++;
	}
	dst = src;
}

bool TestCase::load(const std::string& filePath)
{
	FileIO file;
	if (!file.openForRead(filePath.c_str()))
	{
		// ctx->log(RC_LOG_ERROR, "buildTiledNavigation: Could not load '%s'", filePath.c_str());
		return false;
	}

	size_t bufferLen = file.getFileSize();
	char* buffer = new char[bufferLen];

	if (!file.read(buffer, bufferLen))
	{
		// ctx->log(RC_LOG_ERROR, "buildTiledNavigation: Could not load '%s'", filePath.c_str());
		return false;
	}

	char* src = buffer;
	char* srcEnd = buffer + bufferLen;
	char row[512];
	while (src < srcEnd)
	{
		// Parse one row
		row[0] = '\0';
		src = parseRow(src, srcEnd, row, sizeof(row) / sizeof(char));
		if (row[0] == 's')
		{
			// Sample name.
			copyName(sampleName, row + 1);
		}
		else if (row[0] == 'f')
		{
			// File name.
			copyName(geomFileName, row + 1);
		}
		else if (row[0] == 'p' && row[1] == 'f')
		{
			// Pathfind test.
			auto test = std::make_unique<Test>();
			test->type = TestCase::TestType::PATHFIND;
			test->expand = false;
			sscanf(
				row + 2,
				"%f %f %f %f %f %f %hx %hx",
				&test->spos[0],
				&test->spos[1],
				&test->spos[2],
				&test->epos[0],
				&test->epos[1],
				&test->epos[2],
				&test->includeFlags,
				&test->excludeFlags);
			tests.emplace_back(std::move(test));
		}
		else if (row[0] == 'r' && row[1] == 'c')
		{
			// Pathfind test.
			auto test = std::make_unique<Test>();
			test->type = TestCase::TestType::RAYCAST;
			test->expand = false;
			sscanf(
				row + 2,
				"%f %f %f %f %f %f %hx %hx",
				&test->spos[0],
				&test->spos[1],
				&test->spos[2],
				&test->epos[0],
				&test->epos[1],
				&test->epos[2],
				&test->includeFlags,
				&test->excludeFlags);
			tests.emplace_back(std::move(test));
		}
	}

	delete[] buffer;
	return true;
}

void TestCase::resetTimes()
{
	for (auto& test : tests)
	{
		test->findNearestPolyTime = 0;
		test->findPathTime = 0;
		test->findStraightPathTime = 0;
	}
}

void TestCase::doTests(dtNavMesh* navmesh, dtNavMeshQuery* navquery)
{
	if (!navmesh || !navquery)
	{
		return;
	}

	resetTimes();

	static const int MAX_POLYS = 256;
	dtPolyRef polys[MAX_POLYS];
	float straight[MAX_POLYS * 3];
	const float polyPickExt[3] = {2, 4, 2};

	for (auto& test : tests)
	{
		delete[] test->polys;
		test->polys = 0;
		test->npolys = 0;
		delete[] test->straight;
		test->straight = 0;
		test->nstraight = 0;

		dtQueryFilter filter;
		filter.setIncludeFlags(test->includeFlags);
		filter.setExcludeFlags(test->excludeFlags);

		// Find start points
		TimeVal findNearestPolyStart = getPerfTime();

		dtPolyRef startRef, endRef;
		navquery->findNearestPoly(test->spos, polyPickExt, &filter, &startRef, test->nspos);
		navquery->findNearestPoly(test->epos, polyPickExt, &filter, &endRef, test->nepos);

		TimeVal findNearestPolyEnd = getPerfTime();
		test->findNearestPolyTime += getPerfTimeUsec(findNearestPolyEnd - findNearestPolyStart);

		if (!startRef || !endRef)
		{
			continue;
		}

		if (test->type == TestCase::TestType::PATHFIND)
		{
			// Find path
			TimeVal findPathStart = getPerfTime();

			navquery->findPath(startRef, endRef, test->spos, test->epos, &filter, polys, &test->npolys, MAX_POLYS);

			TimeVal findPathEnd = getPerfTime();
			test->findPathTime += getPerfTimeUsec(findPathEnd - findPathStart);

			// Find straight path
			if (test->npolys)
			{
				TimeVal findStraightPathStart = getPerfTime();

				navquery->findStraightPath(
					test->spos,
					test->epos,
					polys,
					test->npolys,
					straight,
					0,
					0,
					&test->nstraight,
					MAX_POLYS);
				TimeVal findStraightPathEnd = getPerfTime();
				test->findStraightPathTime += getPerfTimeUsec(findStraightPathEnd - findStraightPathStart);
			}

			// Copy results
			if (test->npolys)
			{
				test->polys = new dtPolyRef[test->npolys];
				memcpy(test->polys, polys, sizeof(dtPolyRef) * test->npolys);
			}
			if (test->nstraight)
			{
				test->straight = new float[test->nstraight * 3];
				memcpy(test->straight, straight, sizeof(float) * 3 * test->nstraight);
			}
		}
		else if (test->type == TestCase::TestType::RAYCAST)
		{
			float t = 0;
			float hitNormal[3], hitPos[3];

			test->straight = new float[2 * 3];
			test->nstraight = 2;

			test->straight[0] = test->spos[0];
			test->straight[1] = test->spos[1];
			test->straight[2] = test->spos[2];

			TimeVal findPathStart = getPerfTime();

			navquery->raycast(startRef, test->spos, test->epos, &filter, &t, hitNormal, polys, &test->npolys, MAX_POLYS);

			TimeVal findPathEnd = getPerfTime();
			test->findPathTime += getPerfTimeUsec(findPathEnd - findPathStart);

			if (t > 1)
			{
				// No hit
				dtVcopy(hitPos, test->epos);
			}
			else
			{
				// Hit
				dtVlerp(hitPos, test->spos, test->epos, t);
			}
			// Adjust height.
			if (test->npolys > 0)
			{
				float h = 0;
				navquery->getPolyHeight(polys[test->npolys - 1], hitPos, &h);
				hitPos[1] = h;
			}
			dtVcopy(&test->straight[3], hitPos);

			if (test->npolys)
			{
				test->polys = new dtPolyRef[test->npolys];
				memcpy(test->polys, polys, sizeof(dtPolyRef) * test->npolys);
			}
		}
	}

	printf("Test Results:\n");
	int n = 0;
	for (auto& test : tests)
	{
		const int total = test->findNearestPolyTime + test->findPathTime + test->findStraightPathTime;
		printf(" - Path %02d:     %.4f ms\n", n, (float)total / 1000.0f);
		printf("    - poly:     %.4f ms\n", (float)test->findNearestPolyTime / 1000.0f);
		printf("    - path:     %.4f ms\n", (float)test->findPathTime / 1000.0f);
		printf("    - straight: %.4f ms\n", (float)test->findStraightPathTime / 1000.0f);
		n++;
	}
}

void TestCase::handleRender()
{
	glLineWidth(2.0f);
	glBegin(GL_LINES);
	for (auto& test : tests)
	{
		float dir[3];
		dtVsub(dir, test->epos, test->spos);
		dtVnormalize(dir);
		glColor4ub(128, 25, 0, 192);
		glVertex3f(test->spos[0], test->spos[1] - 0.3f, test->spos[2]);
		glVertex3f(test->spos[0], test->spos[1] + 0.3f, test->spos[2]);
		glVertex3f(test->spos[0], test->spos[1] + 0.3f, test->spos[2]);
		glVertex3f(test->spos[0] + dir[0] * 0.3f, test->spos[1] + 0.3f + dir[1] * 0.3f, test->spos[2] + dir[2] * 0.3f);
		glColor4ub(51, 102, 0, 129);
		glVertex3f(test->epos[0], test->epos[1] - 0.3f, test->epos[2]);
		glVertex3f(test->epos[0], test->epos[1] + 0.3f, test->epos[2]);

		if (test->expand)
		{
			const float s = 0.1f;
			glColor4ub(255, 32, 0, 128);
			glVertex3f(test->spos[0] - s, test->spos[1], test->spos[2]);
			glVertex3f(test->spos[0] + s, test->spos[1], test->spos[2]);
			glVertex3f(test->spos[0], test->spos[1], test->spos[2] - s);
			glVertex3f(test->spos[0], test->spos[1], test->spos[2] + s);
			glColor4ub(255, 192, 0, 255);
			glVertex3f(test->nspos[0] - s, test->nspos[1], test->nspos[2]);
			glVertex3f(test->nspos[0] + s, test->nspos[1], test->nspos[2]);
			glVertex3f(test->nspos[0], test->nspos[1], test->nspos[2] - s);
			glVertex3f(test->nspos[0], test->nspos[1], test->nspos[2] + s);

			glColor4ub(255, 32, 0, 128);
			glVertex3f(test->epos[0] - s, test->epos[1], test->epos[2]);
			glVertex3f(test->epos[0] + s, test->epos[1], test->epos[2]);
			glVertex3f(test->epos[0], test->epos[1], test->epos[2] - s);
			glVertex3f(test->epos[0], test->epos[1], test->epos[2] + s);
			glColor4ub(255, 192, 0, 255);
			glVertex3f(test->nepos[0] - s, test->nepos[1], test->nepos[2]);
			glVertex3f(test->nepos[0] + s, test->nepos[1], test->nepos[2]);
			glVertex3f(test->nepos[0], test->nepos[1], test->nepos[2] - s);
			glVertex3f(test->nepos[0], test->nepos[1], test->nepos[2] + s);
		}

		if (test->expand)
		{
			glColor4ub(255, 192, 0, 255);
		}
		else
		{
			glColor4ub(0, 0, 0, 64);
		}

		for (int i = 0; i < test->nstraight - 1; ++i)
		{
			glVertex3f(test->straight[i * 3 + 0], test->straight[i * 3 + 1] + 0.3f, test->straight[i * 3 + 2]);
			glVertex3f(
				test->straight[(i + 1) * 3 + 0],
				test->straight[(i + 1) * 3 + 1] + 0.3f,
				test->straight[(i + 1) * 3 + 2]);
		}
	}
	glEnd();
	glLineWidth(1.0f);
}

bool TestCase::handleRenderOverlay(double* proj, double* model, int* view)
{
	GLdouble x, y, z;
	char text[64];
	int n = 0;

	static constexpr float LABEL_DIST = 1.0f;

	for (auto& test : tests)
	{
		float pt[3];
		float dir[3];
		if (test->nstraight)
		{
			dtVcopy(pt, &test->straight[3]);
			if (dtVdist(pt, test->spos) > LABEL_DIST)
			{
				dtVsub(dir, pt, test->spos);
				dtVnormalize(dir);
				dtVmad(pt, test->spos, dir, LABEL_DIST);
			}
			pt[1] += 0.5f;
		}
		else
		{
			dtVsub(dir, test->epos, test->spos);
			dtVnormalize(dir);
			dtVmad(pt, test->spos, dir, LABEL_DIST);
			pt[1] += 0.5f;
		}

		if (gluProject(pt[0], pt[1], pt[2], model, proj, view, &x, &y, &z))
		{
			snprintf(text, 64, "Path %d\n", n);
			unsigned int col = IM_COL32(0, 0, 0, 128);
			if (test->expand)
			{
				col = IM_COL32(255, 192, 0, 220);
			}
			DrawScreenspaceText(static_cast<float>(x), static_cast<float>(y) - 25, col, text, true);
		}

		n++;
	}

	ImGui::SetNextWindowPos(ImVec2(10, static_cast<float>(view[3]) - 10 - 350), ImGuiCond_Always);  // Position in screen space
	ImGui::SetNextWindowSize(ImVec2(200, 350), ImGuiCond_Always);                                   // Size of the window
	ImGui::Begin("Test Results");

	n = 0;
	for (auto& test : tests)
	{
		const int total = test->findNearestPolyTime + test->findPathTime + test->findStraightPathTime;
		snprintf(text, 64, "Path %d", n);

		if (ImGui::CollapsingHeader(text, ImGuiTreeNodeFlags_DefaultOpen))
		{
			ImGui::Text("Total: %.4f ms", static_cast<float>(total) / 1000.0f);
			ImGui::Text("Poly: %.4f ms", static_cast<float>(test->findNearestPolyTime) / 1000.0f);
			ImGui::Text("Path: %.4f ms", static_cast<float>(test->findPathTime) / 1000.0f);
			ImGui::Text("Straight: %.4f ms", static_cast<float>(test->findStraightPathTime) / 1000.0f);

			ImGui::Separator();
		}
	}

	ImGui::End();

	return false;
}