/* ScummVM - Graphic Adventure Engine
 *
 * ScummVM is the legal property of its developers, whose names
 * are too numerous to list here. Please refer to the COPYRIGHT
 * file distributed with this source distribution.
 *
 * This program is free software; you can redistribute it and/or
 * modify it under the terms of the GNU General Public License
 * as published by the Free Software Foundation; either version 2
 * of the License, or (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write to the Free Software
 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
 *
 */

#include "common/scummsys.h"

#if defined(PSP2)

#include <psp2/kernel/processmgr.h>
#include <psp2/touch.h>
#include "backends/platform/sdl/psp2/psp2.h"
#include "backends/events/psp2sdl/psp2sdl-events.h"
#include "backends/platform/sdl/sdl.h"
#include "engines/engine.h"

#include "common/util.h"
#include "common/events.h"
#include "common/config-manager.h"

#include "math.h"

PSP2EventSource::PSP2EventSource() {
	for (int port = 0; port < SCE_TOUCH_PORT_MAX_NUM; port++) {
		for (int i = 0; i < MAX_NUM_FINGERS; i++) {
			_finger[port][i].id = -1;
		}
		_multiFingerDragging[port] = false;
	}
}

void PSP2EventSource::preprocessEvents(SDL_Event *event) {

	// prevent suspend (scummvm games contain a lot of cutscenes..)
	sceKernelPowerTick(SCE_KERNEL_POWER_TICK_DISABLE_AUTO_SUSPEND);
	sceKernelPowerTick(SCE_KERNEL_POWER_TICK_DISABLE_OLED_OFF);

	// Supported touch gestures:
	// left mouse click: single finger short tap
	// right mouse click: second finger short tap while first finger is still down
	// pointer motion: single finger drag
	if (event->type == SDL_FINGERDOWN || event->type == SDL_FINGERUP || event->type == SDL_FINGERMOTION) {
		// front (0) or back (1) panel
		SDL_TouchID port = event->tfinger.touchId;
		if (port < SCE_TOUCH_PORT_MAX_NUM && port >= 0) {
			// touchpad_mouse_mode off: use only front panel for direct touch control of pointer
			// touchpad_mouse_mode on: also enable rear touch with indirect touch control
			// where the finger can be somewhere else than the pointer and still move it
			if (port == 0 || ConfMan.getBool("touchpad_mouse_mode")) {
				switch (event->type) {
				case SDL_FINGERDOWN:
					preprocessFingerDown(event);
					break;
				case SDL_FINGERUP:
					preprocessFingerUp(event);
					break;
				case SDL_FINGERMOTION:
					preprocessFingerMotion(event);
					break;
				}
			}
		}
	}
}

void PSP2EventSource::preprocessFingerDown(SDL_Event *event) {
	// front (0) or back (1) panel
	SDL_TouchID port = event->tfinger.touchId;
	// id (for multitouch)
	SDL_FingerID id = event->tfinger.fingerId;

	int x = _km.x / MULTIPLIER;
	int y = _km.y / MULTIPLIER;

	if (port == 0) {
		convertTouchXYToGameXY(event->tfinger.x, event->tfinger.y, &x, &y);
	}

	// we need the timestamps to decide later if the user performed a short tap (click)
	// or a long tap (drag)
	// we also need the last coordinates for each finger to keep track of dragging
	for (int i = 0; i < MAX_NUM_FINGERS; i++) {
		if (_finger[port][i].id == -1) {
			_finger[port][i].id = id;
			_finger[port][i].timeLastDown = event->tfinger.timestamp;
			_finger[port][i].lastX = x;
			_finger[port][i].lastY = y;
			break;
		}
	}
}

void PSP2EventSource::preprocessFingerUp(SDL_Event *event) {
	// front (0) or back (1) panel
	SDL_TouchID port = event->tfinger.touchId;
	// id (for multitouch)
	SDL_FingerID id = event->tfinger.fingerId;

	// find out how many fingers were down before this event
	int numFingersDown = 0;
	for (int i = 0; i < MAX_NUM_FINGERS; i++) {
		if (_finger[port][i].id >= 0) {
			numFingersDown++;
		}
	}

	int x = _km.x / MULTIPLIER;
	int y = _km.y / MULTIPLIER;

	for (int i = 0; i < MAX_NUM_FINGERS; i++) {
		if (_finger[port][i].id == id) {
			_finger[port][i].id = -1;
			if (!_multiFingerDragging[port]) {
				if ((event->tfinger.timestamp - _finger[port][i].timeLastDown) <= MAX_TAP_TIME) {
					// short (<MAX_TAP_TIME ms) tap is interpreted as right/left mouse click depending on # fingers already down
					if (numFingersDown == 2 || numFingersDown == 1) {
						Uint8 simulatedButton = 0;
						if (numFingersDown == 2) {
							simulatedButton = SDL_BUTTON_RIGHT;
						} else if (numFingersDown == 1) {
							simulatedButton = SDL_BUTTON_LEFT;
							if (port == 0) {
								convertTouchXYToGameXY(event->tfinger.x, event->tfinger.y, &x, &y);
							}
						}

						event->type = SDL_MOUSEBUTTONDOWN;
						event->button.button = simulatedButton;
						event->button.x = x;
						event->button.y = y;

						SDL_Event ev;
						ev.type = SDL_MOUSEBUTTONUP;
						ev.button.button = simulatedButton;
						ev.button.x = x;
						ev.button.y = y;
						SDL_PushEvent(&ev);
					}
				}
			} else if (numFingersDown == 1) {
				// when dragging, and the last finger is lifted, the drag is over
				if (port == 0) {
					convertTouchXYToGameXY(event->tfinger.x, event->tfinger.y, &x, &y);
				}
				event->type = SDL_MOUSEBUTTONUP;
				event->button.button = SDL_BUTTON_LEFT;
				event->button.x = x;
				event->button.y = y;
				_multiFingerDragging[port] = false;
			}
		}
	}
}

void PSP2EventSource::preprocessFingerMotion(SDL_Event *event) {
	// front (0) or back (1) panel
	SDL_TouchID port = event->tfinger.touchId;
	// id (for multitouch)
	SDL_FingerID id = event->tfinger.fingerId;

	// find out how many fingers were down before this event
	int numFingersDown = 0;
	for (int i = 0; i < MAX_NUM_FINGERS; i++) {
		if (_finger[port][i].id >= 0) {
			numFingersDown++;
		}
	}

	if (numFingersDown >= 1) {
		int x = _km.x / MULTIPLIER;
		int y = _km.y / MULTIPLIER;

		if (port == 0) {
			convertTouchXYToGameXY(event->tfinger.x, event->tfinger.y, &x, &y);
		}	else {
			// for relative mode, use the pointer speed setting
			float speedFactor = 1.0;

			switch (ConfMan.getInt("kbdmouse_speed")) {
			// 0.25 keyboard pointer speed
			case 0:
				speedFactor = 0.25;
				break;
			// 0.5 speed
			case 1:
				speedFactor = 0.5;
				break;
			// 0.75 speed
			case 2:
				speedFactor = 0.75;
				break;
			// 1.0 speed
			case 3:
				speedFactor = 1.0;
				break;
			// 1.25 speed
			case 4:
				speedFactor = 1.25;
				break;
			// 1.5 speed
			case 5:
				speedFactor = 1.5;
				break;
			// 1.75 speed
			case 6:
				speedFactor = 1.75;
				break;
			// 2.0 speed
			case 7:
				speedFactor = 2.0;
				break;
			default:
				speedFactor = 1.0;
			}

			// convert touch events to relative mouse pointer events
			// Whenever an SDL_event involving the mouse is processed,
			// _km.x/y are truncated from subpixel precision to regular pixel precision.
			// Therefore, there's no need here to deal with subpixel precision in _km.x/y.
			x = (_km.x / MULTIPLIER + (event->tfinger.dx * 1.25 * speedFactor * _km.x_max));
			y = (_km.y / MULTIPLIER + (event->tfinger.dy * 1.25 * speedFactor * _km.y_max));
		}

		if (x > _km.x_max) {
			x = _km.x_max;
		} else if (x < 0) {
			x = 0;
		}
		if (y > _km.y_max) {
			y = _km.y_max;
		} else if (y < 0) {
			y = 0;
		}

		// update the current finger's coordinates so we can track it later
		for (int i = 0; i < MAX_NUM_FINGERS; i++) {
			if (_finger[port][i].id == id) {
				_finger[port][i].lastX = x;
				_finger[port][i].lastY = y;
			}
		}

		// If we are starting a multi-finger drag, start holding down the mouse button
		if (numFingersDown >= 2) {
			if (!_multiFingerDragging[port]) {
				// only start a multi-finger drag if at least two fingers have been down long enough
				int numFingersDownLong = 0;
				for (int i = 0; i < MAX_NUM_FINGERS; i++) {
					if (_finger[port][i].id >= 0) {
						if (event->tfinger.timestamp - _finger[port][i].timeLastDown > MAX_TAP_TIME) {
							numFingersDownLong++;
						}
					}
				}
				if (numFingersDownLong >= 2) {
					// starting drag, so push mouse down at current location (back) 
					// or location of "oldest" finger (front)
					int mouseDownX = x;
					int mouseDownY = y;
					if (port == 0) {
						for (int i = 0; i < MAX_NUM_FINGERS; i++) {
							if (_finger[port][i].id == id) {
								for (int j = 0; j < MAX_NUM_FINGERS; j++) {
									if (_finger[port][j].id >= 0 && (i != j) ) {
										if (_finger[port][j].timeLastDown < _finger[port][i].timeLastDown) {
											mouseDownX = _finger[port][j].lastX;
											mouseDownY = _finger[port][j].lastY;
										}
									}
								}
							}
						}
					}
					SDL_Event ev;
					ev.type = SDL_MOUSEBUTTONDOWN;
					ev.button.button = SDL_BUTTON_LEFT;
					ev.button.x = mouseDownX;
					ev.button.y = mouseDownY;
					SDL_PushEvent(&ev);
					_multiFingerDragging[port] = true;
				}
			}
		}

		//check if this is the "oldest" finger down (or the only finger down), otherwise it will not affect mouse motion
		bool updatePointer = true;
		if (numFingersDown > 1) {
			for (int i = 0; i < MAX_NUM_FINGERS; i++) {
				if (_finger[port][i].id == id) {
					for (int j = 0; j < MAX_NUM_FINGERS; j++) {
						if (_finger[port][j].id >= 0 && (i != j) ) {
							if (_finger[port][j].timeLastDown < _finger[port][i].timeLastDown) {
								updatePointer = false;
							}
						}
					}
				}
			}
		}
		if (updatePointer) {
			event->type = SDL_MOUSEMOTION;
			event->motion.x = x;
			event->motion.y = y;
		}
	}
}

void PSP2EventSource::convertTouchXYToGameXY(float touchX, float touchY, int *gameX, int *gameY) {
	int screenH = _km.y_max;
	int screenW = _km.x_max;

	bool fullscreen = ConfMan.getBool("fullscreen");
	bool aspectRatioCorrection = ConfMan.getBool("aspect_ratio");

	const int dispW = 960;
	const int dispH = 544;

	int x, y, w, h;
	float sx, sy;
	float ratio = (float)screenW / (float)screenH;

	if (aspectRatioCorrection) {
		ratio = 4.0 / 3.0;
	}

	if (fullscreen || screenH >= dispH) {
		h = dispH;
		if (aspectRatioCorrection) {
			ratio = ratio * 1.1;
		}
		w = h * ratio;
	} else {
		if (screenH <= dispH / 2 && screenW <= dispW / 2) {
			// Use Vita hardware 2x scaling if the picture is really small
			// this uses the current shader and filtering mode
			h = screenH * 2;
			w = screenW * 2;
		} else {
			h = screenH;
			w = screenW;
		}
		if (aspectRatioCorrection) {
			// stretch the height only if it fits, otherwise make the width smaller
			if (((float)w * (1.0 / ratio)) <= (float)dispH) {
				h = w * (1.0 / ratio);
			} else {
				w = h * ratio;
			}
		}
	}

	x = (dispW - w) / 2;
	y = (dispH - h) / 2;

	sy = (float)h / (float)screenH;
	sx = (float)w / (float)screenW;

	// Find touch coordinates in terms of Vita screen pixels
	float dispTouchX = (touchX * (float)dispW);
	float dispTouchY = (touchY * (float)dispH);

	*gameX = (dispTouchX - x) / sx;
	*gameY = (dispTouchY - y) / sy;

	if (*gameX < 0) {
		*gameX = 0;
	} else if (*gameX > _km.x_max) {
		*gameX = _km.x_max;
	}
	if (*gameY < 0) {
		*gameY = 0;
	} else if (*gameY > _km.y_max) {
		*gameY = _km.y_max;
	}
}
#endif