/*
 * Copyright (c) 2006 Ondrej Palkovsky
 * Copyright (c) 2008 Martin Decky
 * Copyright (c) 2008 Pavel Rimsky
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 *
 * - Redistributions of source code must retain the above copyright
 *   notice, this list of conditions and the following disclaimer.
 * - Redistributions in binary form must reproduce the above copyright
 *   notice, this list of conditions and the following disclaimer in the
 *   documentation and/or other materials provided with the distribution.
 * - The name of the author may not be used to endorse or promote products
 *   derived from this software without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 */

/** @defgroup sgcnfb SGCN
 * @brief	userland driver of the Serengeti console output
 * @{
 */ 
/** @file
 */

#include <async.h>
#include <ipc/ipc.h>
#include <ipc/fb.h>
#include <sysinfo.h>
#include <as.h>
#include <errno.h>
#include <stdio.h>
#include <ddi.h>

#include "sgcn.h"

#define WIDTH 80
#define HEIGHT 24

#define MAX_CONTROL 20

/**
 * Virtual address mapped to SRAM.
 */
static uintptr_t sram_virt_addr;

/**
 * SGCN buffer offset within SGCN.
 */
static uintptr_t sram_buffer_offset;

/* Allow only 1 connection */
static int client_connected = 0;

/**
 * SGCN buffer header. It is placed at the very beginning of the SGCN
 * buffer. 
 */
typedef struct {
	/** hard-wired to "CON" */
	char magic[4];
	
	/** we don't need this */
	char unused[8];
	
	/** offset within the SGCN buffer of the input buffer start */
	uint32_t in_begin;
	
	/** offset within the SGCN buffer of the input buffer end */
	uint32_t in_end;
	
	/** offset within the SGCN buffer of the input buffer read pointer */
	uint32_t in_rdptr;
	
	/** offset within the SGCN buffer of the input buffer write pointer */
	uint32_t in_wrptr;

	/** offset within the SGCN buffer of the output buffer start */
	uint32_t out_begin;
	
	/** offset within the SGCN buffer of the output buffer end */
	uint32_t out_end;
	
	/** offset within the SGCN buffer of the output buffer read pointer */
	uint32_t out_rdptr;
	
	/** offset within the SGCN buffer of the output buffer write pointer */
	uint32_t out_wrptr;
} __attribute__ ((packed)) sgcn_buffer_header_t;

// TODO it is suggested to extract the common parts of this file and the msim.c file
// into a separate file and place that file to the genarch directory

/*
 * Returns a pointer to the object of a given type which is placed at the given
 * offset from the console buffer beginning.
 */
#define SGCN_BUFFER(type, offset) \
		((type *) (sram_virt_addr + sram_buffer_offset + (offset)))

/** Returns a pointer to the console buffer header. */
#define SGCN_BUFFER_HEADER	(SGCN_BUFFER(sgcn_buffer_header_t, 0))

static void sgcn_putc(char c)
{
	uint32_t begin = SGCN_BUFFER_HEADER->out_begin;
	uint32_t end = SGCN_BUFFER_HEADER->out_end;
	uint32_t size = end - begin;
	
	/* we need pointers to volatile variables */
	volatile char *buf_ptr = (volatile char *)
		SGCN_BUFFER(char, SGCN_BUFFER_HEADER->out_wrptr);
	volatile uint32_t *out_wrptr_ptr = &(SGCN_BUFFER_HEADER->out_wrptr);
	volatile uint32_t *out_rdptr_ptr = &(SGCN_BUFFER_HEADER->out_rdptr);

	uint32_t new_wrptr = (((*out_wrptr_ptr) - begin + 1) % size) + begin;
	while (*out_rdptr_ptr == new_wrptr)
		;
	*buf_ptr = c;
	*out_wrptr_ptr = new_wrptr;
}

static void sgcn_puts(char *str)
{
	while (*str)
		sgcn_putc(*(str++));
}

static void sgcn_goto(const unsigned int row, const unsigned int col)
{
	if ((row > HEIGHT) || (col > WIDTH))
		return;
	
	char control[20];
	snprintf(control, 20, "\033[%u;%uf", row + 1, col + 1);
	sgcn_puts(control);
}

static void sgcn_clrscr(void)
{
	sgcn_puts("\033[2J");
}

static void sgcn_scroll(int i)
{
	if (i > 0) {
		sgcn_goto(HEIGHT - 1, 0);
		while (i--)
			sgcn_puts("\033D");
	} else if (i < 0) {
		sgcn_goto(0, 0);
		while (i++)
			sgcn_puts("\033M");
	}
}

static void sgcn_set_style(const unsigned int mode)
{
	char control[MAX_CONTROL];
	snprintf(control, MAX_CONTROL, "\033[%um", mode);
	sgcn_puts(control);
}

static void sgcn_cursor_disable(void)
{
	sgcn_puts("\033[?25l");
}

static void sgcn_cursor_enable(void)
{
	sgcn_puts("\033[?25h");
}

static void sgcn_client_connection(ipc_callid_t iid, ipc_call_t *icall)
{
	int retval;
	ipc_callid_t callid;
	ipc_call_t call;
	char c;
	int lastcol = 0;
	int lastrow = 0;
	int newcol;
	int newrow;
	int fgcolor;
	int bgcolor;
	int i;
	
	if (client_connected) {
		ipc_answer_0(iid, ELIMIT);
		return;
	}
	
	client_connected = 1;
	ipc_answer_0(iid, EOK);
	
	/* Clear the terminal, set scrolling region
	   to 0 - 24 lines */
	sgcn_clrscr();
	sgcn_goto(0, 0);
	sgcn_puts("\033[0;24r");
	
	while (true) {
		callid = async_get_call(&call);
		switch (IPC_GET_METHOD(call)) {
		case IPC_M_PHONE_HUNGUP:
			client_connected = 0;
			ipc_answer_0(callid, EOK);
			return;
		case FB_PUTCHAR:
			c = IPC_GET_ARG1(call);
			newrow = IPC_GET_ARG2(call);
			newcol = IPC_GET_ARG3(call);
			if ((lastcol != newcol) || (lastrow != newrow))
				sgcn_goto(newrow, newcol);
			lastcol = newcol + 1;
			lastrow = newrow;
			sgcn_putc(c);
			retval = 0;
			break;
		case FB_CURSOR_GOTO:
			newrow = IPC_GET_ARG1(call);
			newcol = IPC_GET_ARG2(call);
			sgcn_goto(newrow, newcol);
			lastrow = newrow;
			lastcol = newcol;
			retval = 0;
			break;
		case FB_GET_CSIZE:
			ipc_answer_2(callid, EOK, HEIGHT, WIDTH);
			continue;
		case FB_CLEAR:
			sgcn_clrscr();
			retval = 0;
			break;
		case FB_SET_STYLE:
			fgcolor = IPC_GET_ARG1(call);
			bgcolor = IPC_GET_ARG2(call);
			if (fgcolor < bgcolor)
				sgcn_set_style(0);
			else
				sgcn_set_style(7);
			retval = 0;
			break;
		case FB_SCROLL:
			i = IPC_GET_ARG1(call);
			if ((i > HEIGHT) || (i < -HEIGHT)) {
				retval = EINVAL;
				break;
			}
			sgcn_scroll(i);
			sgcn_goto(lastrow, lastcol);
			retval = 0;
			break;
		case FB_CURSOR_VISIBILITY:
			if(IPC_GET_ARG1(call))
				sgcn_cursor_enable();
			else
				sgcn_cursor_disable();
			retval = 0;
			break;
		default:
			retval = ENOENT;
		}
		ipc_answer_0(callid, retval);
	}
}

int sgcn_init(void)
{
	sram_virt_addr = (uintptr_t) as_get_mappable_page(sysinfo_value("sram.area.size"));
	int result = physmem_map(
		(void *) sysinfo_value("sram.address.physical"),
		(void *) sram_virt_addr,
		sysinfo_value("sram.area.size") / PAGE_SIZE,
		AS_AREA_READ | AS_AREA_WRITE
		);
	if (result != 0) {
		printf("SGCN: uspace driver couldn't map physical memory: %d\n",
			result);
	}
	
	sram_buffer_offset = sysinfo_value("sram.buffer.offset");
	
	async_set_client_connection(sgcn_client_connection);
	return 0;
}

/** 
 * @}
 */