/*********************************************************/

/*  ptycon: a pty-console bridge                         */

/*  Copyright (C) 2016--2017  SysDeer Technologies, LLC  */

/*  Released under GPLv2 and GPLv3; see COPYING.PTYCON.  */

/*********************************************************/

#include <psxtypes/psxtypes.h>

#include <ntcon/ntcon.h>

#include <ntapi/ntapi.h>

#include <gdi/gdi.h>

#include <ptycon/ptycon.h>

#include "ptycon_driver_impl.h"

#include "ptycon_status_impl.h"

static ptyc_term_handler	ptyc_screen_handler;

static ptyc_term_handler	ptyc_ctrl_handler;

static ptyc_term_handler	ptyc_flush_screen_buffer;

int __stdcall ptyc_console_writer(struct ptyc_driver_ctx_impl * ictx)

{

	int32_t						status;

	nt_iosb						iosb;

	size_t						nsteps;

	void *						hwait;

	unsigned char *					inbuf;

	struct ptyc_term_ctx *				tctx;

	nt_unicode_conversion_params_utf8_to_utf16	uc_params;

	if ((status = ntapi->tt_create_private_event(

			&hwait,

			NT_NOTIFICATION_EVENT,

			NT_EVENT_NOT_SIGNALED)))

		return status;

	tctx				= &ictx->tctx;

	inbuf				= (unsigned char *)&tctx->data.in[1];

	uc_params.dst_size_in_bytes	= sizeof(tctx->data.out);

	uc_params.leftover_count	= 0;

	uc_params.leftover_bytes	= 0;

	tctx->handler			= ptyc_screen_handler;

	tctx->char_handler		= ptyc_screen_handler;

	tctx->ctrl_handler		= ptyc_ctrl_handler;

	tctx->ctrl_handlers[0]		= ptyc_esi_handlers;

	tctx->wch_con			= tctx->data.screen;

	do {

		uc_params.code_points	= 0;

		uc_params.addr_failed	= 0;

		uc_params.bytes_written	= 0;

		status = ntapi->pty_read(

			ictx->cctx.hptm,

			hwait,0,0,

			&iosb,

			inbuf,

			sizeof(tctx->data.in) - sizeof(uintptr_t),

			0,0);

		if (status == NT_STATUS_PENDING)

			if (!(status = ntapi->zw_wait_for_single_object(

					hwait,NT_SYNC_ALERTABLE,0)))

				status = iosb.status;

		if (status)

			return ptyc_set_status(&ictx->ctx,status);

		/* account for leftover bytes from the previous conversion */

		tctx->data.in[0]		= uc_params.leftover_bytes;

		uc_params.src			= inbuf - uc_params.leftover_count;

		uc_params.src_size_in_bytes	= iosb.info + uc_params.leftover_count;

		uc_params.dst			= tctx->data.out;

		/* utf-8 --> utf-16 */

		status = ntapi->uc_convert_unicode_stream_utf8_to_utf16(

			&uc_params);

		/* process the converted (utf-16) stream */

		tctx->wch_pty = tctx->data.out;

		nsteps        = uc_params.bytes_written / sizeof(wchar16_t);

		for (; nsteps; nsteps--)

			tctx->handler = (ptyc_term_handler *)tctx->handler(tctx);

		/* output to console */

		ptyc_flush_screen_buffer(tctx);

	} while (1);

	return NT_STATUS_INTERNAL_ERROR;

}

static void * __fastcall ptyc_screen_handler(struct ptyc_term_ctx * tctx)

{

	if (*tctx->wch_pty == '\x1b') {

		/* output all pending characters */

		ptyc_flush_screen_buffer(tctx);

		/* advance stream pointer */

		tctx->wch_pty++;

		/* set initial control state */

		tctx->ctrl_state = PTYC_CTRL_STATE_ESI;

		tctx->ctrl_cap   = PTYC_ESI_ARRAY_SIZE;

		/* switch mode */

		return tctx->ctrl_handler;

	} else {

		/* filter out bell key? */

		if (*tctx->wch_pty == 0x7)

			if (!(tctx->drvflags & PTYC_DRIVER_BELL))

				return ptyc_screen_handler;

		/* copy character to the screen buffer */

		*tctx->wch_con = *tctx->wch_pty;

		/* advance the screen and stream pointers */

		tctx->wch_con++;

		tctx->wch_pty++;

		/* retain mode */

		return ptyc_screen_handler;

	}

}

static void * __fastcall ptyc_ctrl_handler(struct ptyc_term_ctx * tctx)

{

	ptyc_term_handler * const *	handlers;

	ptyc_term_handler *		handler;

	unsigned			idx;

	idx = (*tctx->wch_pty < tctx->ctrl_cap)

			? *tctx->wch_pty

			: tctx->ctrl_cap - 1;

	handlers = tctx->ctrl_handlers[tctx->ctrl_state];

	handler  = handlers[idx];

	return handler(tctx);

}

static void * __fastcall ptyc_flush_screen_buffer(struct ptyc_term_ctx * tctx)

{

	uint32_t ncunits;

	uint32_t nwritten;

	if (!(ncunits = (uint32_t)(tctx->wch_con - tctx->data.screen)))

		return tctx->wch_con;

	ntcon->write_console_utf16(

		tctx->hout,

		tctx->data.screen,

		ncunits,

		&nwritten,

		0);

	/* heuristics: interactive input? */

	if (ncunits <= 4) {

		ntcon->get_console_screen_buffer_info(

			tctx->hout,

			&tctx->screen_info);

		ntcon->set_console_cursor_position(

			tctx->hout,

			tctx->screen_info.cursor_position);

	}

	tctx->wch_con = tctx->data.screen;

	return tctx->wch_con;

}