/* winstuff.c - windows interface routines for xlisp */
/* Written by Chris Tchou. */
/* This file contains the stuff that the other xlisp files call directly. */

/* Changes by Roger Dannenberg, Jan 2006:
Previously, the input thread would block on input, so if a command line
instantiation of Nyquist called (EXIT), the process would still block
in getchar() until the user typed a newline. Now, I only start the 
input thread if ostgetc is called (input is really needed). This will
still read ahead and block, but only in cases where you are already
interactive.

/* Changes by Roger Dannenberg, April 2004:
To support interrupts to Lisp processing, XLISP call oscheck frequently to
test for an abort or break condition. This condition can be activated by
special handlers, e.g. if a software interrupt is generated by Ctrl-C.
Alternatively, the application can read ahead and look for break characters
in the input stream. A third approach, implemented by Ning Hu for her
Delphi-based IDE, is to send a Windows message to the process. Unfortunately,
the Java IDE does not support sending a Windows message, nor can console
IO be used to read ahead (console IO does not work because, when started by
Java, Nyquist standard IO is redirected through pipes). The two solutions
to enable break character prcessing seem to be:
  1) extend Java with C code to find the process and send Windows messages
  2) add a thread to perform read ahead and break character processing
Option 2 contains the ugliness to Nyquist IO, which is already big and ugly,
and leaves Java alone, which is something I don't know much about anyway,
so I have chosen option 2: create a thread and read ahead. This uses only
about 50 lines of code.

A shortcoming of this approach is that, except for Ctrl-C, break characters
like ^P, ^B, and ^U require the user to type RETURN to end the input line
and allow the character to be processed.

The thread will set a signal whenever a line of input is delivered so that
Nyquist can block waiting for input. The signal will also be set when a
^C or ^G is detected.

For flexibility, compatibility with the Delphi IDE (NyqIDE) is retained by
continuing to check for Windows process messages.
*/

#include <windows.h>  /* Added by Ning Hu	Apr.2001 */
#include <process.h>  /* Added by Dannenberg Apr 2004 */
#include <signal.h>   /* Added by Dannneberg, Apr 2004 */
#include "exitpa.h"   /* Added by Dannneberg, Apr 2004 */


const char os_pathchar = '\\';
const char os_sepchar = ',';


#undef ERROR
#include <stdio.h>
//#include <QuickDraw.h>	/* for Random */
#include <memory.h>		/* for DisposPtr */
#include <string.h>
//#include <SegLoad.h>	/* for ExitToShell */
#include "xlisp.h"
#include "cext.h"
#include "userio.h"
#include "sliders.h"
#include "sound.h" /* define nosc_enabled */

/* externals */
extern FILE *tfp;  /* transcript file pointer */
extern int cursorPos;
extern char *macgets (void);
//Added by Ning Hu	Apr.2001
extern int _isatty(int);					
extern int redirect_flag;
//Add end

/* local variables */
int lposition;
static char *linebuf = NULL, *lineptr;
static int numChars;

/* input thread */
unsigned long input_thread_handle = -1;
#define NEED_INPUT if (input_thread_handle == -1) start_input_thread();
#define input_buffer_max 1024
#define input_buffer_mask (input_buffer_max - 1)
char input_buffer[1024];
volatile int input_buffer_head = 0;
volatile int input_buffer_tail = 0;
volatile int buffer_eof = 0;
HANDLE input_buffer_ready = NULL;

BOOL WINAPI ctrl_c_handler(DWORD dwCtrlType)
{
    if (dwCtrlType == CTRL_C_EVENT) {
        abort_flag = ABORT_LEVEL;
        return TRUE;
    }
    return FALSE;
}

#ifdef DEBUG_INPUT
extern FILE *to_input_buffer;
#endif

void input_thread_run(void *args)
{
    int c;
    /* this gets called, possible later, in io_init() in userio.c, but
     * that doesn't seem to prevent this thread from being killed by
     * CTRL-C, so call it here to be safe.
     */
    SetConsoleCtrlHandler(ctrl_c_handler, TRUE);
    /* printf("input_thread_run\n"); */

    while (!buffer_eof) {
        int head;
        c = getchar();
        if (c == EOF && abort_flag) {
            // when user types ^C, an EOF is generated for some reason. 
			// Ignore it...
            if (abort_flag == ABORT_LEVEL) c = ABORT_CHAR;
            else c = BREAK_CHAR;
        } else if (c == ABORT_CHAR) {
            abort_flag = ABORT_LEVEL;
        } else if (!abort_flag && c == BREAK_CHAR) {
            // notice that a break will be ignored until XLISP
            // handles the ABORT_LEVEL
            abort_flag = BREAK_LEVEL;
        } else if (c == BREAK_CHAR) {
            ; // ignore this because abort_flag is set to ABORT_LEVEL
		} else if (c == '\005' || c == '\006') { // control-e or control-f
		  ; // ignore these. IDE will send control-f to turn off echo, but
			  // under Windows, echo is already turned off. We filter control-f
			  // here to avoid generating an error message. Maybe the IDE should
		  // not send control-f in the first place, but the IDE is cross-platform
		  // and does not know it's running under Windows, whereas this file
		  // is platform dependent.
        } else if (c == '\016') { // begin hidden message
#define MSGBUF_MAX 64
            char msgbuf[MSGBUF_MAX];
            int msgbufx = 0;
            char type_char = getchar(); // read message type character
            printf("begin hidden message: %c\n", type_char);
            if (type_char == EOF) buffer_eof = TRUE;
            else {
                // message is terminated by '\021'
                while ((c = getchar()) != '\021' && 
                       c != EOF &&
                       msgbufx < MSGBUF_MAX - 1) {
                    msgbuf[msgbufx++] = c;
                }
                msgbuf[msgbufx++] = 0;
                printf("message: %s\n", msgbuf);
                if (c == EOF) buffer_eof = TRUE;
                else if (msgbufx < MSGBUF_MAX) {
                    if (type_char == 'S') {  // slider change message
                        // message format is index<space>value
                        int index;
                        float value;
                        if (sscanf(msgbuf, "%d %g", &index, &value) == 2) {
                            set_slider(index, value);
                            printf("set_slider %d %g\n", index, value);
                        }
                    }
                }
            }
		} else if (c == EOF) {
			buffer_eof = TRUE;
        } else {
            // insert character into the FIFO
            head = (input_buffer_head + 1) & input_buffer_mask;
            while (head == input_buffer_tail) Sleep(100);
            input_buffer[input_buffer_head] = c;
#ifdef DEBUG_INPUT
			if (to_input_buffer) putc(c, to_input_buffer);
#endif
            input_buffer_head = head;
        }
        if (c == '\n' || abort_flag || buffer_eof) {
            SetEvent(input_buffer_ready);
            // wake up Nyquist if it is waiting for input
        }
    } 
    // printf("Input thread exiting\n");
}

//int isascii (char c) { return 1; }  /* every char is an ascii char, isn't it? */

void start_input_thread()
{
    // create thread to process input
    input_thread_handle = _beginthread(input_thread_run, 0, NULL);
    if (input_thread_handle == -1) {
        printf("Unable to create input thread, errno = %d\n", errno);
        EXIT(1);
    }
}

void osinit (char *banner) 
{
    printf(banner);
    if (_isatty( _fileno( stdin ) ) ){
        redirect_flag = 0;
#ifdef DEBUG
        printf( "stdout has not been redirected to a file\n" );		//for debugging use
#endif
    } else {
        redirect_flag = 1;
#ifdef DEBUG
        printf( "stdout has been redirected to a file\n");			//for debugging use
#endif
    }
    // signal when input is ready
    input_buffer_ready = CreateEvent(NULL, FALSE, FALSE, NULL);
    if (input_buffer_ready == NULL) {
        printf("Unable to create Event object\n");
        EXIT(1);
    }
}

FILE *osaopen (char *name, char *mode) {
    return fopen (name, mode);
}

FILE *osbopen (char *name, char *mode) {
    char nmode[4];
    strcpy (nmode, mode); strcat (nmode, "b");
    return (fopen (name, nmode));
}

int osclose (FILE *fp) { return (fclose (fp)); }
int osaputc (int ch, FILE *fp) { return (putc (ch, fp)); }
int osbputc (int ch, FILE *fp) { return (putc (ch, fp)); }
void osoutflush(FILE *fp) { fflush(fp); }

/* osagetc - get a character from an ascii file */
int osagetc(fp)
  FILE *fp;
{
    return (getc(fp));
}

extern int abort_flag;
extern int redirect_flag;			//Added by Ning Hu	Apr.2001
int ostgetc (void) 
{
    int c;
	NEED_INPUT;
    while (!buffer_eof && (input_buffer_tail == input_buffer_head)) {
        oscheck();
        WaitForSingleObject(input_buffer_ready, INFINITE);
    }
	if (buffer_eof) c = EOF;
	else {
        c = input_buffer[input_buffer_tail];
	    input_buffer_tail = (input_buffer_tail + 1) & input_buffer_mask;
	}
    if (c == '\025') { // control-u
        xlcleanup();
    } else if (c == '\020') { // control-p
        xlcontinue();
    } else if (c == '\024') { // control-t
        xinfo();
    }
    return c;
}


void ostputc (int ch) {
//	macputc (ch);
    putchar(ch);			// console

    if (tfp) osaputc (ch, tfp);
}

void ostoutflush()
{
    if (tfp) fflush(tfp);
    fflush(stdout);
}


void osflush (void) {
    lineptr = linebuf;
    numChars = 0;
    lposition = 0;
}


void oscheck (void) {				
    MSG lpMsg;

#if OSC
    if (nosc_enabled) nosc_poll();
#endif

    // check_aborted();	-- call to userio.c superceded by code here in winstuff.c
//	printf("Current Thread: %d\n", GetCurrentThreadId());		//for debugging use
	// look for Windows messages from NyqIDE (a Delphi program)
    if ((redirect_flag) && (PeekMessage(&lpMsg, NULL, 0, 0, PM_REMOVE)!=0)) { 
        if (lpMsg.message == WM_CHAR) {
            switch (lpMsg.wParam) {
                case ABORT_CHAR: abort_flag = ABORT_LEVEL;
                                break;
                case BREAK_CHAR: // for nyquist, defined to be 2
                case 7:          // NyqIDE sends 7 (BEL) as break character
                    abort_flag = BREAK_LEVEL;
                    break;
            }
            // printf("Get message: %d %d %d\n", lpMsg.wParam, BREAK_CHAR, abort_flag);				//for debugging use
        }
    }	
    if (abort_flag == ABORT_LEVEL) {	
        abort_flag = 0;
        osflush();
        xltoplevel();
    } else if (abort_flag == BREAK_LEVEL) {
        abort_flag = 0;
        osflush();
        xlbreak("BREAK", s_unbound);
    }
}
//Update end

void oserror (char *msg) {
    char line[100], *p;
    sprintf (line,"error: %s\n",msg);
    for (p = line; *p != '\0'; ++p) ostputc (*p);
}

void osfinish(void) {
    portaudio_exit();
    /* dispose of everything... */
//	if (linebuf) DisposPtr (linebuf);
//	MacWrapUp ();
//	ExitToShell ();
}

int renamebackup (char *filename) { return 0; }




static WIN32_FIND_DATA FindFileData;
static HANDLE hFind = INVALID_HANDLE_VALUE;
#define OSDIR_LIST_READY 0
#define OSDIR_LIST_STARTED 1
#define OSDIR_LIST_DONE 2
static int osdir_list_status = OSDIR_LIST_READY;
#define OSDIR_MAX_PATH 256
static char osdir_path[OSDIR_MAX_PATH];

// osdir_list_start -- prepare to list a directory
int osdir_list_start(char *path)
{
    if (strlen(path) >= OSDIR_MAX_PATH - 2) {
        xlcerror("LISTDIR path too big", "return nil", NULL);
        return FALSE;
    }
    strcpy(osdir_path, path);
    strcat(osdir_path, "/*"); // make a pattern to match all files
    if (osdir_list_status != OSDIR_LIST_READY) {
        osdir_list_finish(); // close previously interrupted listing
    }
    hFind = FindFirstFile(osdir_path, &FindFileData); // get the "."
    if (hFind == INVALID_HANDLE_VALUE) return FALSE;
    if (FindNextFile(hFind, &FindFileData) == 0) return FALSE; // get the ".."
    osdir_list_status = OSDIR_LIST_STARTED;
    return TRUE;
}


char *osdir_list_next()
{
    if (FindNextFile(hFind, &FindFileData) == 0) {
        osdir_list_status = OSDIR_LIST_DONE;
        return NULL;
    }
    return FindFileData.cFileName;
}

void osdir_list_finish()
{
    if (osdir_list_status != OSDIR_LIST_READY) {
        FindClose(hFind);
    }
    osdir_list_status = OSDIR_LIST_READY;
}


/* xechoenabled -- set/clear echo_enabled flag (unix only) */
LVAL xechoenabled()
{
	int flag = (xlgetarg() != NULL);
    xllastarg();
	// echo_enabled = flag; -- do nothing in Windows
	return NULL;
}