//
//

#include "DebugWindow.h"

#include "globalincs/alphacolors.h"

namespace {
uint32_t get_debug_display() {
	// If there are two or more monitors then we would like to display the window on the second monitor but it shouldn't
	// be shown on the same monitor that the game is running on
	// If there is only then then we'll just display it on that one
	auto numDisplays = SDL_GetNumVideoDisplays();
	
	if (numDisplays < 1) {
		// Some kind of error
		return 0;
	}
	
	if (numDisplays == 1) {
		// We only have one display
		return 0;
	}
	auto mainDisplay = os_config_read_uint("Video", "Display", 0);
	if (mainDisplay == 1) {
		// Game is on the second monitor => use the primary screen
		return 0;
	} else {
		// Use the secondary screen
		return 1;
	}
}
}

namespace osapi {

DebugWindow::DebugWindow() {
	os::ViewPortProperties attrs;
	uint32_t display = get_debug_display();
	attrs.display = display;

	SDL_Rect size;
	SDL_GetDisplayBounds(display, &size);
	attrs.width = (uint32_t) size.w;
	attrs.height = (uint32_t) size.h - 40; // Reduce the height a bit to account for window decorations

	attrs.title = "FreeSpace Open - Debug Window";

	auto debugView = gr_create_viewport(attrs);
	if (debugView) {
		debug_view = os::addViewport(std::move(debugView));
	}
}

DebugWindow::~DebugWindow() {
}

void DebugWindow::doFrame(float) {
	if (!debug_view) {
		// Failed to create debug window, nothing to do here
		return;
	}

	gr_use_viewport(debug_view);

	gr_clear();
	font::set_font(font::FONT1);

	if (max_category_width != 0) {
		// Draw a line to separate the category from the text
		auto x_pos = max_category_width + 14;
		gr_set_color_fast(&Color_grey);
		gr_line(x_pos, 0, x_pos, gr_screen.max_h, GR_RESIZE_NONE);
	}

	// Print the saved debug log lines from the bottom up
	float current_y = i2fl(gr_screen.max_h - 10);
	if (!current_line.empty()) {
		LineInfo info;
		info.text = current_line;
		info.category = current_category;

		current_y = print_line(current_y, info);
	}
	// Now print all the stored lines
	// Backwards iteration of the vector comes from here: http://stackoverflow.com/a/4206815
	for (auto i = lines.size(); i-- > 0; ) {
		auto& line = lines[i];

		current_y = print_line(current_y, line);

		if (current_y < 0.f) {
			// End to iteration if the rendered string would be invisible
			break;
		}
	}

	// Don't run scripting here
	gr_flip(false);

	gr_use_viewport(os::getMainViewport());
}

float DebugWindow::print_line(float bottom_y, const LineInfo& line) {
	int width, height;
	gr_get_string_size(&width, &height, line.text.c_str());

	int category_width;
	gr_get_string_size(&category_width, nullptr, line.category.c_str());

	float y_pos = bottom_y - height;
	float cat_x_pos = max_category_width - category_width + 10.f;
	// Give each category a unique color. We do this by hashing the string and using that to construct the RGB values
	auto hash = std::hash<SCP_string>()(line.category);
	gr_set_color((int) (hash & 0xFF), (int) ((hash & 0xFF00) >> 8), (int) ((hash & 0xFF0000) >> 16));
	gr_string(cat_x_pos, y_pos, line.category.c_str(), GR_RESIZE_NONE);

	// We could use word wrapping here if the width if the string is too big but that's currently not a problem
	gr_set_color_fast(&Color_white);
	gr_string(max_category_width + 18.f, bottom_y - height, line.text.c_str(), GR_RESIZE_NONE);

	return bottom_y - height;
}

void DebugWindow::addDebugMessage(const char* category, const char* text) {
	if (!debug_view) {
		// Failed to create debug window, nothing to do here
		return;
	}

	if (category != current_category) {
		// There is a new category so we need to write the old string to our log

		// Find finished lines and add them to our vector
		split_current_and_add_to_log(category);

		if (!current_line.empty()) {
			// Write the last line to our log
			LineInfo info;
			info.text = current_line;
			info.category = category;
			addToLog(std::move(info));

			current_line.clear();
		}
	}

	current_category = category;
	current_line += text;

	split_current_and_add_to_log(category);
}
void DebugWindow::split_current_and_add_to_log(const SCP_string& category) {
	size_t pos;
	while((pos = current_line.find('\n')) != SCP_string::npos) {
		LineInfo info;
		info.text = current_line.substr(0, pos);
		info.category = category;
		addToLog(std::move(info));

		// Since pos refers to a valid position in the string, the expression pos + 1 is always valid since substr
		// allows values up to str.size()
		current_line = current_line.substr(pos + 1);
	}
}
void DebugWindow::addToLog(LineInfo&& line) {
	int cat_width;
	gr_get_string_size(&cat_width, nullptr, line.category.c_str());

	max_category_width = std::max(cat_width, max_category_width);

	lines.push_back(std::move(line));
}

}