/*
 * \brief  Manager of all VM requested console functionality
 * \author Markus Partheymueller
 * \author Norman Feske
 * \date   2012-07-31
 */

/*
 * Copyright (C) 2011-2013 Genode Labs GmbH
 * Copyright (C) 2012 Intel Corporation
 *
 * This file is distributed under the terms of the GNU General Public License
 * version 2.
 *
 * The code is partially based on the Vancouver VMM, which is distributed
 * under the terms of the GNU General Public License version 2.
 *
 * Modifications by Intel Corporation are contributed under the terms and
 * conditions of the GNU General Public License version 2.
 */

/* Genode includes */
#include <base/snprintf.h>
#include <util/register.h>

/* nitpicker graphics backend */
#include <os/pixel_rgb565.h>
#include <nitpicker_gfx/text_painter.h>

#include <nul/motherboard.h>

/* local includes */
#include "console.h"
#include "keyboard.h"

using Genode::env;
using Genode::Dataspace_client;
using Genode::Surface;
using Genode::Pixel_rgb565;
typedef Text_painter::Font Font;

extern char _binary_mono_tff_start;
Font default_font(&_binary_mono_tff_start);

bool fb_active = true;


/**
 * Layout of PS/2 mouse packet
 */
struct Ps2_mouse_packet : Genode::Register<32>
{
	struct Packet_size   : Bitfield<0, 3> { };
	struct Left_button   : Bitfield<8, 1> { };
	struct Middle_button : Bitfield<9, 1> { };
	struct Right_button  : Bitfield<10, 1> { };
	struct Rx_high       : Bitfield<12, 1> { };
	struct Ry_high       : Bitfield<13, 1> { };
	struct Rx_low        : Bitfield<16, 8> { };
	struct Ry_low        : Bitfield<24, 8> { };
};


static bool is_mouse_event(Input::Event const *ev)
{
	using Input::Event;
	if (ev->type() == Event::PRESS || ev->type() == Event::RELEASE) {
		if (ev->code() == Input::BTN_LEFT)   return true;
		if (ev->code() == Input::BTN_MIDDLE) return true;
		if (ev->code() == Input::BTN_RIGHT)  return true;
	}

	if (ev->type() == Event::MOTION)
		return true;

	return false;
}


/**
 * Convert Genode::Input event to PS/2 packet
 *
 * This function updates _left, _middle, and _right as a side effect.
 */
unsigned Vancouver_console::_input_to_ps2mouse(Input::Event const *ev)
{
	/* track state of mouse buttons */
	using Input::Event;
	if (ev->type() == Event::PRESS || ev->type() == Event::RELEASE) {
		bool const pressed = ev->type() == Event::PRESS;
		if (ev->code() == Input::BTN_LEFT)   _left   = pressed;
		if (ev->code() == Input::BTN_MIDDLE) _middle = pressed;
		if (ev->code() == Input::BTN_RIGHT)  _right  = pressed;
	}

	int rx;
	int ry;

	if (ev->is_absolute_motion()) {
		static Input::Event last_event;
		rx = ev->ax() - last_event.ax();
		ry = ev->ay() - last_event.ay();
		last_event = *ev;
	} else {
		rx = ev->rx();
		ry = ev->ry();
	}

	/* clamp relative motion vector to bounds */
	int const boundary = 200;
	rx =  Genode::min(boundary, Genode::max(-boundary, rx));
	ry = -Genode::min(boundary, Genode::max(-boundary, ry));

	/* assemble PS/2 packet */
	Ps2_mouse_packet::access_t packet = 0;
	Ps2_mouse_packet::Packet_size::set  (packet, 3);
	Ps2_mouse_packet::Left_button::set  (packet, _left);
	Ps2_mouse_packet::Middle_button::set(packet, _middle);
	Ps2_mouse_packet::Right_button::set (packet, _right);
	Ps2_mouse_packet::Rx_high::set      (packet, (rx >> 8) & 1);
	Ps2_mouse_packet::Ry_high::set      (packet, (ry >> 8) & 1);
	Ps2_mouse_packet::Rx_low::set       (packet, rx & 0xff);
	Ps2_mouse_packet::Ry_low::set       (packet, ry & 0xff);

	return packet;
}


/* bus callbacks */

bool Vancouver_console::receive(MessageConsole &msg)
{
	if (msg.type == MessageConsole::TYPE_ALLOC_VIEW) {
		_guest_fb = msg.ptr;

		if (msg.size < _fb_size)
			_fb_size = msg.size;

		_regs = msg.regs;

		msg.view = 0;
	} else if (msg.type == MessageConsole::TYPE_SWITCH_VIEW) {
		/* XXX: For now, we only have one view. */
	} else if (msg.type == MessageConsole::TYPE_GET_MODEINFO) {

		enum {
			MEMORY_MODEL_TEXT = 0,
			MEMORY_MODEL_DIRECT_COLOR = 6,
		};

		/*
		 * We supply two modes to the guest, text mode and one
		 * configured graphics mode 16-bit.
		 */
		if (msg.index == 0) {
			msg.info->_vesa_mode = 3;
			msg.info->attr = 0x1;
			msg.info->resolution[0] = 80;
			msg.info->resolution[1] = 25;
			msg.info->bytes_per_scanline = 80*2;
			msg.info->bytes_scanline = 80*2;
			msg.info->bpp = 4;
			msg.info->memory_model = MEMORY_MODEL_TEXT;
			msg.info->phys_base = 0xb8000;
			msg.info->_phys_size = 0x8000;
			return true;

		} else if (msg.index == 1) {

			/*
			 * It's important to set the _vesa_mode field, otherwise the
			 * device model is going to ignore this mode.
			 */
			msg.info->_vesa_mode = 0x114;
			msg.info->attr = 0x39f;
			msg.info->resolution[0] = _fb_mode.width();
			msg.info->resolution[1] = _fb_mode.height();
			msg.info->bytes_per_scanline = _fb_mode.width()*2;
			msg.info->bytes_scanline = _fb_mode.width()*2;
			msg.info->bpp = 16;
			msg.info->memory_model = MEMORY_MODEL_DIRECT_COLOR;
			msg.info->vbe1[0] = 0x5; /* red mask size */
			msg.info->vbe1[1] = 0xb; /* red field position */
			msg.info->vbe1[2] = 0x6; /* green mask size */
			msg.info->vbe1[3] = 0x5; /* green field position */
			msg.info->vbe1[4] = 0x5; /* blue mask size */
			msg.info->vbe1[5] = 0x0; /* blue field position */
			msg.info->vbe1[6] = 0x0; /* reserved mask size */
			msg.info->vbe1[7] = 0x0; /* reserved field position */
			msg.info->colormode = 0x0; /* direct color mode info */
			msg.info->phys_base = 0xe0000000;
			msg.info->_phys_size = _fb_mode.width()*_fb_mode.height()*2;
			return true;
		} else return false;
	}
	return true;
}


bool Vancouver_console::receive(MessageMemRegion &msg)
{
	if (msg.page >= 0xb8 && msg.page <= 0xbf) {

		/* we had a fault in the text framebuffer */
		if (!fb_active) fb_active = true;
		Logging::printf("Reactivating text buffer loop.\n");
	}
	return false;
}


void Vancouver_console::entry()
{
	/*
	 * Init sessions to the required external services
	 */
	enum { CONFIG_ALPHA = false };

	static Input::Connection  input;
	static Timer::Connection  timer;
	Framebuffer::Connection  *framebuffer = 0;

	try {
		framebuffer = new (env()->heap()) Framebuffer::Connection();
	} catch (...) {
		PERR("Headless mode - no framebuffer session available");
		_startup_lock.unlock();
		return;
	}

	Genode::Dataspace_capability ev_ds_cap = input.dataspace();

	Input::Event *ev_buf = static_cast<Input::Event *>
	                       (env()->rm_session()->attach(ev_ds_cap));

	_fb_size = Dataspace_client(framebuffer->dataspace()).size();
	_fb_mode = framebuffer->mode();

	_pixels = env()->rm_session()->attach(framebuffer->dataspace());

	Surface<Pixel_rgb565> surface((Pixel_rgb565 *) _pixels,
	                              Genode::Surface_base::Area(_fb_mode.width(),
	                              _fb_mode.height()));

	/*
	 * Handle input events
	 */
	unsigned long count = 0;
	bool revoked = false;
	Vancouver_keyboard vkeyb(_motherboard);

	Genode::uint64_t checksum1 = 0;
	Genode::uint64_t checksum2 = 0;
	unsigned unchanged = 0;
	bool cmp_even = 1;

	_startup_lock.unlock();

	while (1) {
		while (!input.is_pending()) {

			/* transfer text buffer content into chunky canvas */
			if (_regs && ++count % 10 == 0 && _regs->mode == 0
			 && _guest_fb && !revoked && fb_active) {

				memset(_pixels, 0, _fb_size);
				if (cmp_even) checksum1 = 0;
				else checksum2 = 0;
				for (int j=0; j<25; j++) {
					for (int i=0; i<80; i++) {
						Genode::Surface_base::Point where(i*8, j*15);
						char character = *((char *) (_guest_fb +(_regs->offset << 1) +j*80*2+i*2));
						char colorvalue = *((char *) (_guest_fb+(_regs->offset << 1)+j*80*2+i*2+1));
						char buffer[2]; buffer[0] = character; buffer[1] = 0;
						char fg = colorvalue & 0xf;
						if (fg == 0x8) fg = 0x7;
						unsigned lum = ((fg & 0x8) >> 3)*127;
						Genode::Color color(((fg & 0x4) >> 2)*127+lum, /* R+luminosity */
						                    ((fg & 0x2) >> 1)*127+lum, /* G+luminosity */
						                     (fg & 0x1)*127+lum        /* B+luminosity */);

						Text_painter::paint(surface, where, default_font, color, buffer);

						/* Checksum for comparing */
						if (cmp_even) checksum1 += character;
						else checksum2 += character;
					}
				}
				/* compare checksums to detect idle buffer */
				if (checksum1 == checksum2) {
					unchanged++;

					/* if we copy the same data 10 times, unmap the text buffer from guest */
					if (unchanged == 10) {

						Genode::Lock::Guard guard(_console_lock);

						env()->rm_session()->detach((void *)_guest_fb);
						env()->rm_session()->attach_at(_fb_ds, (Genode::addr_t)_guest_fb);
						unchanged = 0;
						fb_active = false;

						Logging::printf("Deactivated text buffer loop.\n");
					}
				} else {
					unchanged = 0;
					framebuffer->refresh(0, 0, _fb_mode.width(), _fb_mode.height());
				}

				cmp_even = !cmp_even;
			} else if (_regs && _guest_fb && _regs->mode != 0) {

				if (!revoked) {

					Genode::Lock::Guard guard(_console_lock);

					env()->rm_session()->detach((void *)_guest_fb);
					env()->rm_session()->attach_at(framebuffer->dataspace(),
					                               (Genode::addr_t)_guest_fb);

					/* if the VGA model expects a larger FB, pad to that size. */
					if (_fb_size < _vm_fb_size) {
						Genode::Ram_dataspace_capability _backup =
						  Genode::env()->ram_session()->alloc(_vm_fb_size-_fb_size);

						env()->rm_session()->attach_at(_backup,
						                               (Genode::addr_t) (_guest_fb+_fb_size));
					}

					revoked = true;
				}
				framebuffer->refresh(0, 0, _fb_mode.width(), _fb_mode.height());
			}

			timer.msleep(10);
		}

		for (int i = 0, num_ev = input.flush(); i < num_ev; i++) {
			Input::Event *ev = &ev_buf[i];

			/* update mouse model (PS2) */
			if (is_mouse_event(ev)) {
				MessageInput msg(0x10001, _input_to_ps2mouse(ev));
				_motherboard()->bus_input.send(msg);
			}

			if (ev->type() == Input::Event::PRESS)   {
				if (ev->code() <= 0xee) {
					vkeyb.handle_keycode_press(ev->code());
				}
			}
			if (ev->type() == Input::Event::RELEASE) {
				if (ev->code() <= 0xee) { /* keyboard event */
					vkeyb.handle_keycode_release(ev->code());
				}
			}
		}
	}
}


void Vancouver_console::register_host_operations(Motherboard &motherboard)
{
	motherboard.bus_console.  add(this, receive_static<MessageConsole>);
	motherboard.bus_memregion.add(this, receive_static<MessageMemRegion>);
}


Vancouver_console::Vancouver_console(Synced_motherboard &mb,
                                     Genode::size_t vm_fb_size,
                                     Genode::Dataspace_capability fb_ds)
:
	Thread("vmm_console"),
	_startup_lock(Genode::Lock::LOCKED),
	_motherboard(mb), _pixels(0), _guest_fb(0), _fb_size(0),
	_fb_ds(fb_ds), _vm_fb_size(vm_fb_size), _regs(0),
	_left(false), _middle(false), _right(false)
{
	start();

	/* shake hands with console thread */
	_startup_lock.lock();
}