/*
 * This file is subject to the terms of the GFX License. If a copy of
 * the license was not distributed with this file, you can obtain one at:
 *
 *              http://ugfx.org/license.html
 */

/**
 * @file    src/gwin/console.c
 * @brief   GWIN sub-system console code.
 */

#include "gfx.h"

#if GFX_USE_GWIN && GWIN_NEED_CONSOLE

#include <string.h>

#include "gwin/class_gwin.h"

#define GWIN_CONSOLE_USE_CLEAR_LINES			TRUE			// Clear each line before using it
#define GWIN_CONSOLE_USE_FILLED_CHARS			FALSE			// Use filled characters instead of drawn characters
#define GWIN_CONSOLE_BUFFER_SCROLLING			TRUE			// Use the history buffer to scroll when it is available

// Our control flags
#define GCONSOLE_FLG_NOSTORE					(GWIN_FIRST_CONTROL_FLAG<<0)
#define GCONSOLE_FLG_OVERRUN					(GWIN_FIRST_CONTROL_FLAG<<1)

/*
 * Stream interface implementation. The interface is write only
 */

#if GFX_USE_OS_CHIBIOS && GWIN_CONSOLE_USE_BASESTREAM
	#define Stream2GWindow(ip)		((GHandle)(((char *)(ip)) - (size_t)(&(((GConsoleObject *)0)->stream))))

	static size_t GWinStreamWrite(void *ip, const uint8_t *bp, size_t n) { gwinPutCharArray(Stream2GWindow(ip), (const char *)bp, n); return RDY_OK; }
	static size_t GWinStreamRead(void *ip, uint8_t *bp, size_t n) {	(void)ip; (void)bp; (void)n; return 0; }
	static msg_t GWinStreamPut(void *ip, uint8_t b) { gwinPutChar(Stream2GWindow(ip), (char)b); return RDY_OK; }
	static msg_t GWinStreamGet(void *ip) {(void)ip; return RDY_OK; }
	static msg_t GWinStreamPutTimed(void *ip, uint8_t b, systime_t time) { (void)time; gwinPutChar(Stream2GWindow(ip), (char)b); return RDY_OK; }
	static msg_t GWinStreamGetTimed(void *ip, systime_t timeout) { (void)ip; (void)timeout; return RDY_OK; }
	static size_t GWinStreamWriteTimed(void *ip, const uint8_t *bp, size_t n, systime_t time) { (void)time; gwinPutCharArray(Stream2GWindow(ip), (const char *)bp, n); return RDY_OK; }
	static size_t GWinStreamReadTimed(void *ip, uint8_t *bp, size_t n, systime_t time) { (void)ip; (void)bp; (void)n; (void)time; return 0; }

	struct GConsoleWindowVMT_t {
		_base_asynchronous_channel_methods
	};

	static const struct GConsoleWindowVMT_t GWindowConsoleVMT = {
		GWinStreamWrite,
		GWinStreamRead,
		GWinStreamPut,
		GWinStreamGet,
		GWinStreamPutTimed,
		GWinStreamGetTimed,
		GWinStreamWriteTimed,
		GWinStreamReadTimed
	};
#endif

#if GWIN_CONSOLE_USE_HISTORY
	static void HistoryDestroy(GWindowObject *gh) {
		#define gcw		((GConsoleObject *)gh)

		// Deallocate the history buffer if required.
		if (gcw->buffer) {
			gfxFree(gcw->buffer);
			gcw->buffer = 0;
		}

		#undef gcw
	}

	static void HistoryRedraw(GWindowObject *gh) {
		#define gcw		((GConsoleObject *)gh)

		// No redrawing if there is no history
		if (!gcw->buffer)
			return;

		// We are printing the buffer - don't store it again
		gh->flags |= GCONSOLE_FLG_NOSTORE;

		#if !GWIN_CONSOLE_USE_CLEAR_LINES
			// Clear the screen
			gdispGFillArea(gh->display, gh->x, gh->y, gh->width, gh->height, gh->bgcolor);
		#endif

		// Reset the cursor
		gcw->cx = 0;
		gcw->cy = 0;

		// Print the buffer
		gwinPutCharArray(gh, gcw->buffer, gcw->bufpos);

		#if !GWIN_CONSOLE_USE_CLEAR_LINES
			// Clear the remaining space
			if (gcw->cy + fy < gh->height)
				gdispGFillArea(gh->display, gh->x, gh->y+gcw->cy+fy, gh->width, gh->height-(gcw->cy+fy), gh->bgcolor);
		#endif

		// Turn back on storing of buffer contents
		gh->flags &= ~GCONSOLE_FLG_NOSTORE;

		#undef gcw
	}

	/**
	 * Put a character into our history buffer
	 */
	static void putCharInBuffer(GConsoleObject *gcw, char c) {
		// Only store if we need to
		if (!gcw->buffer || (gcw->g.flags & GCONSOLE_FLG_NOSTORE))
			return;

		// Do we have enough space in the buffer
		if (gcw->bufpos >= gcw->bufsize) {
			char *	p;
			size_t	dp;

			/**
			 * This should never really happen except if the user has changed the window
			 * size without turning off and then on the buffer. Even then it is unlikely
			 * because of our conservative allocation strategy.
			 * If it really is needed we scroll one line to make some space. We also mark
			 * it is an overrun so that if asked to really scroll later we know we already have.
			 * Note we only use one bit to indicate an overrun, so an overrun of more
			 * than one line will lead to some interesting scrolling and refreshing
			 * effects.
			 */

			// Remove one line from the start
			for(p = gcw->buffer; *p && *p != '\n'; p++);

			// Was there a newline?
			if (*p != '\n')
				p = gcw->buffer;						// Oops - no newline, just delete one char
			else
				gcw->g.flags |= GCONSOLE_FLG_OVERRUN;	// Mark the overrun

			// Delete the data
			dp = ++p - gcw->buffer;						// Calculate the amount to to be removed
			gcw->bufpos -= dp;							// Calculate the new size
			if (gcw->bufpos)
				memcpy(gcw->buffer, p, gcw->bufpos);	// Move the rest of the data
		}

		// Save the character
		gcw->buffer[gcw->bufpos++] = c;
	}

	/**
	 * Scroll the history buffer by one line
	 */
	static void scrollBuffer(GConsoleObject *gcw) {
		char *	p;
		size_t	dp;

		// Only scroll if we need to
		if (!gcw->buffer || (gcw->g.flags & GCONSOLE_FLG_NOSTORE))
			return;

		// If a buffer overrun has been marked don't scroll as we have already
		if ((gcw->g.flags & GCONSOLE_FLG_OVERRUN)) {
			gcw->g.flags &= ~GCONSOLE_FLG_OVERRUN;
			return;
		}

		// Remove one line from the start
		for(p = gcw->buffer; *p && *p != '\n'; p++);

		// Was there a newline, if not delete everything.
		if (*p != '\n') {
			gcw->bufpos = 0;
			return;
		}

		// Delete the data
		dp = ++p - gcw->buffer;						// Calculate the amount to to be removed
		gcw->bufpos -= dp;							// Calculate the new size
		if (gcw->bufpos)
			memcpy(gcw->buffer, p, gcw->bufpos);	// Move the rest of the data
	}

	/**
	 * Clear the history buffer
	 */
	static void clearBuffer(GConsoleObject *gcw) {

		// Only clear if we need to
		if (!gcw->buffer || (gcw->g.flags & GCONSOLE_FLG_NOSTORE))
			return;

		gcw->bufpos = 0;
	}

#else
	#define putCharInBuffer(gcw, c)
	#define scrollBuffer(gcw)
	#define clearBuffer(gcw)
#endif

static void AfterClear(GWindowObject *gh) {
	#define gcw		((GConsoleObject *)gh)
	gcw->cx = 0;
	gcw->cy = 0;
	clearBuffer(gcw);
	#undef gcw		
}

static const gwinVMT consoleVMT = {
	"Console",				// The classname
	sizeof(GConsoleObject),	// The object size
	#if GWIN_CONSOLE_USE_HISTORY
		HistoryDestroy,		// The destroy routine (custom)
		HistoryRedraw,		// The redraw routine (custom)
	#else
		0,					// The destroy routine
		0,					// The redraw routine (default)
	#endif
	AfterClear,				// The after-clear routine
};

GHandle gwinGConsoleCreate(GDisplay *g, GConsoleObject *gc, const GWindowInit *pInit) {
	if (!(gc = (GConsoleObject *)_gwindowCreate(g, &gc->g, pInit, &consoleVMT, 0)))
		return 0;

	#if GFX_USE_OS_CHIBIOS && GWIN_CONSOLE_USE_BASESTREAM
		gc->stream.vmt = &GWindowConsoleVMT;
	#endif

	#if GWIN_CONSOLE_USE_HISTORY
		gc->buffer = 0;
		#if GWIN_CONSOLE_HISTORY_ATCREATE
			gwinConsoleSetBuffer(&gc->g, TRUE);
		#endif
	#endif

	gc->cx = 0;
	gc->cy = 0;

	gwinSetVisible((GHandle)gc, pInit->show);

	return (GHandle)gc;
}

#if GFX_USE_OS_CHIBIOS && GWIN_CONSOLE_USE_BASESTREAM
	BaseSequentialStream *gwinConsoleGetStream(GHandle gh) {
		if (gh->vmt != &consoleVMT)
			return 0;

		return (BaseSequentialStream *)&(((GConsoleObject *)(gh))->stream);
	}
#endif

#if GWIN_CONSOLE_USE_HISTORY
	bool_t gwinConsoleSetBuffer(GHandle gh, bool_t onoff) {
		#define gcw		((GConsoleObject *)gh)

		if (gh->vmt != &consoleVMT)
			return FALSE;

		// Do we want the buffer turned off?
		if (!onoff) {
			if (gcw->buffer) {
				gfxFree(gcw->buffer);
				gcw->buffer = 0;
			}
			return FALSE;
		}

		// Is the buffer already on?
		if (gcw->buffer)
			return TRUE;

		// Get the number of characters that fit in the x direction
		#if GWIN_CONSOLE_HISTORY_AVERAGING
			gcw->bufsize = gh->width / ((2*gdispGetFontMetric(gh->font, fontMinWidth)+gdispGetFontMetric(gh->font, fontMaxWidth))/3);
		#else
			gcw->bufsize = gh->width / gdispGetFontMetric(gh->font, fontMinWidth);
		#endif
		gcw->bufsize++;				// Allow space for a newline on each line.

		// Multiply by the number of lines
		gcw->bufsize *= gh->height / gdispGetFontMetric(gh->font, fontHeight);

		// Allocate the buffer
		if (!(gcw->buffer = gfxAlloc(gcw->bufsize)))
			return FALSE;

		// All good!
		gh->flags &= ~GCONSOLE_FLG_OVERRUN;
		gcw->bufpos = 0;
		return TRUE;
		
		#undef gcw
	}
#endif

void gwinPutChar(GHandle gh, char c) {
	#define gcw		((GConsoleObject *)gh)
	uint8_t			width, fy;

	if (gh->vmt != &consoleVMT || !gh->font)
		return;

	// only render new character if the console is visible
	if (!gwinGetVisible(gh))
		return;

	fy = gdispGetFontMetric(gh->font, fontHeight);

	#if GDISP_NEED_CLIP
		gdispGSetClip(gh->display, gh->x, gh->y, gh->width, gh->height);
	#endif
	
	/**
	 * Special Characters:
	 *
	 * Carriage returns and line feeds (\r & \n) are handled in unix terminal cooked mode; that is,
	 * line feeds perform both actions and carriage-returns are ignored.
	 *
	 * All other characters are treated as printable.
	 */
	switch (c) {
	case '\n':
		// clear to the end of the line
		#if GWIN_CONSOLE_USE_CLEAR_LINES
			if (gcw->cx == 0 && gcw->cy+fy < gh->height)
				gdispGFillArea(gh->display, gh->x, gh->y + gcw->cy, gh->width, fy, gh->bgcolor);
		#endif
		// update the cursor
		gcw->cx = 0;
		gcw->cy += fy;
		putCharInBuffer(gcw, '\n');
		// We use lazy scrolling here and only scroll when the next char arrives
		return;

	case '\r':
		// gcw->cx = 0;
		return;
	}

	// Characters with no width are ignored
	if (!(width = gdispGetCharWidth(c, gh->font)))
		return;

	// Do we need to go to the next line to fit this character?
	if (gcw->cx + width >= gh->width) {
		gcw->cx = 0;
		gcw->cy += fy;
		putCharInBuffer(gcw, '\n');
	}

	// Do we need to scroll to fit this character?
	if (gcw->cy + fy > gh->height) {
		#if GWIN_CONSOLE_USE_HISTORY && GWIN_CONSOLE_BUFFER_SCROLLING
			if (gcw->buffer) {
				// Scroll the buffer and then redraw using the buffer
				scrollBuffer(gcw);
				HistoryRedraw(gh);
			} else
		#endif
		#if GDISP_NEED_SCROLL
			{
				// Scroll the console using hardware
				scrollBuffer(gcw);
				gdispGVerticalScroll(gh->display, gh->x, gh->y, gh->width, gh->height, fy, gh->bgcolor);

				// Set the cursor to the start of the last line
				gcw->cx = 0;
				gcw->cy = (((coord_t)(gh->height/fy))-1)*fy;
			}
		#else
			{
				// Clear the console and reset the cursor
				clearBuffer(gcw);
				gdispGFillArea(gh->display, gh->x, gh->y, gh->width, gh->height, gh->bgcolor);
				gcw->cx = 0;
				gcw->cy = 0;
			}
		#endif
	}

	// If we are at the beginning of a new line clear the line
	#if GWIN_CONSOLE_USE_CLEAR_LINES
		if (gcw->cx == 0)
			gdispGFillArea(gh->display, gh->x, gh->y + gcw->cy, gh->width, fy, gh->bgcolor);
	#endif

	// Draw the character
	#if GWIN_CONSOLE_USE_FILLED_CHARS
		gdispGFillChar(gh->display, gh->x + gcw->cx, gh->y + gcw->cy, c, gh->font, gh->color, gh->bgcolor);
	#else
		gdispGDrawChar(gh->display, gh->x + gcw->cx, gh->y + gcw->cy, c, gh->font, gh->color);
	#endif
	putCharInBuffer(gcw, c);

	// Update the cursor
	gcw->cx += width + gdispGetFontMetric(gh->font, fontCharPadding);

	#undef gcw
}

void gwinPutString(GHandle gh, const char *str) {
	while(*str)
		gwinPutChar(gh, *str++);
}

void gwinPutCharArray(GHandle gh, const char *str, size_t n) {
	while(n--)
		gwinPutChar(gh, *str++);
}

#include <stdarg.h>

#define MAX_FILLER 11
#define FLOAT_PRECISION 100000

static char *ltoa_wd(char *p, long num, unsigned radix, long divisor) {
	int i;
	char *q;

	if (!divisor) divisor = num;

	q = p + MAX_FILLER;
	do {
		i = (int)(num % radix);
		i += '0';
		if (i > '9')
		  i += 'A' - '0' - 10;
		*--q = i;
		num /= radix;
	} while ((divisor /= radix) != 0);

	i = (int)(p + MAX_FILLER - q);
	do {
		*p++ = *q++;
	} while (--i);

	return p;
}

#if GWIN_CONSOLE_USE_FLOAT
	static char *ftoa(char *p, double num) {
		long l;
		unsigned long precision = FLOAT_PRECISION;

		l = num;
		p = ltoa_wd(p, l, 10, 0);
		*p++ = '.';
		l = (num - l) * precision;
		return ltoa_wd(p, l, 10, precision / 10);
	}
#endif

void gwinPrintf(GHandle gh, const char *fmt, ...) {
	va_list ap;
	char *p, *s, c, filler;
	int i, precision, width;
	bool_t is_long, left_align;
	long l;
	#if GWIN_CONSOLE_USE_FLOAT
		float f;
		char tmpbuf[2*MAX_FILLER + 1];
	#else
		char tmpbuf[MAX_FILLER + 1];
	#endif

	if (gh->vmt != &consoleVMT || !gh->font)
		return;

	va_start(ap, fmt);
	while (TRUE) {
		c = *fmt++;
		if (c == 0) {
			va_end(ap);
			return;
		}
		if (c != '%') {
			gwinPutChar(gh, c);
			continue;
		}

		p = tmpbuf;
		s = tmpbuf;
		left_align = FALSE;
		if (*fmt == '-') {
			fmt++;
			left_align = TRUE;
		}
		filler = ' ';
		if (*fmt == '.') {
			fmt++;
			filler = '0';
		}
		width = 0;

		while (TRUE) {
			c = *fmt++;
			if (c >= '0' && c <= '9')
				c -= '0';
			else if (c == '*')
				c = va_arg(ap, int);
			else
				break;
			width = width * 10 + c;
		}
		precision = 0;
		if (c == '.') {
			while (TRUE) {
				c = *fmt++;
				if (c >= '0' && c <= '9')
					c -= '0';
				else if (c == '*')
					c = va_arg(ap, int);
				else
					break;
				precision = precision * 10 + c;
			}
		}
		/* Long modifier.*/
		if (c == 'l' || c == 'L') {
			is_long = TRUE;
			if (*fmt)
				c = *fmt++;
		}
		else
			is_long = (c >= 'A') && (c <= 'Z');

		/* Command decoding.*/
		switch (c) {
		case 'c':
			filler = ' ';
			*p++ = va_arg(ap, int);
			break;
		case 's':
			filler = ' ';
			if ((s = va_arg(ap, char *)) == 0)
				s = "(null)";
			if (precision == 0)
				precision = 32767;
			for (p = s; *p && (--precision >= 0); p++);
			break;
		case 'D':
		case 'd':
			if (is_long)
				l = va_arg(ap, long);
			else
				l = va_arg(ap, int);
			if (l < 0) {
				*p++ = '-';
				l = -l;
			}
			p = ltoa_wd(p, l, 10, 0);
			break;
		#if GWIN_CONSOLE_USE_FLOAT
			case 'f':
				f = (float) va_arg(ap, double);
				if (f < 0) {
					*p++ = '-';
					f = -f;
				}
				p = ftoa(p, f);
				break;
		#endif
		case 'X':
		case 'x':
			c = 16;
			goto unsigned_common;
		case 'U':
		case 'u':
			c = 10;
			goto unsigned_common;
		case 'O':
		case 'o':
			c = 8;
		unsigned_common:
			if (is_long)
				l = va_arg(ap, long);
			else
				l = va_arg(ap, int);
			p = ltoa_wd(p, l, c, 0);
			break;
		default:
			*p++ = c;
			break;
		}

		i = (int)(p - s);
		if ((width -= i) < 0)
			width = 0;
		if (left_align == FALSE)
			width = -width;
		if (width < 0) {
			if (*s == '-' && filler == '0') {
				gwinPutChar(gh, *s++);
				i--;
			}
			do {
				gwinPutChar(gh, filler);
			} while (++width != 0);
		}
		while (--i >= 0)
			gwinPutChar(gh, *s++);
		while (width) {
			gwinPutChar(gh, filler);
			width--;
		}
	}
}

#endif /* GFX_USE_GWIN && GWIN_NEED_CONSOLE */