/*
 * dirax.c
 *
 * Invoke the DirAx auto-indexing program
 * also: handle DirAx input files
 *
 * (c) 2007 Thomas White <taw27@cam.ac.uk>
 *
 *  dtr - Diffraction Tomography Reconstruction
 *
 */

#ifdef HAVE_CONFIG_H
#include <config.h>
#endif

#include <glib.h>
#include <stdlib.h>
#include <stdio.h>
#include <math.h>
#include <string.h>
#include <pty.h>
#include <unistd.h>
#include <sys/wait.h>
#include <fcntl.h>
#include <assert.h>
#include <sys/ioctl.h>
#include <termio.h>
#include <sgtty.h>	

#include "control.h"
#include "reflections.h"
#include "utils.h"
#include "basis.h"
#include "displaywindow.h"

typedef enum {
	DIRAX_INPUT_NONE,
	DIRAX_INPUT_LINE,
	DIRAX_INPUT_PROMPT
} DirAxInputType;

static void dirax_parseline(const char *line, ControlContext *ctx) {
	
	int i, rf;
	char *copy;
	
	copy = strdup(line);
	for ( i=0; i<strlen(copy); i++ ) {
		if ( copy[i] == '\r' ) copy[i]='r';
		if ( copy[i] == '\n' ) copy[i]='\0';
	}
	printf("DX: DirAx: %s\n", copy);
	free(copy);
	
	if ( strstr(line, "reflections from file") ) {
		displaywindow_error("DirAx can't understand this data.", ctx->dw);
		return;
	}
	
	/* Is this the first line of a unit cell specification? */
	rf = 0; i = 0;
	while ( (i<strlen(line)) && ((line[i] == 'R') || (line[i] == 'D') || (line[i] == ' ')) ) {
		if ( line[i] == 'R' ) rf = 1;
		if ( (line[i] == 'D') && rf ) {
			ctx->dirax_read_cell = 1;
			if ( ctx->cell ) {
				free(ctx->cell);
			}
			ctx->cell = malloc(sizeof(Basis));
			ctx->cell->a.x = 0.0;  ctx->cell->a.y = 0.0;  ctx->cell->a.z = 0.0;
			ctx->cell->b.x = 0.0;  ctx->cell->b.y = 0.0;  ctx->cell->b.z = 0.0;
			ctx->cell->c.x = 0.0;  ctx->cell->c.y = 0.0;  ctx->cell->c.z = 0.0;
			return;
		}
		i++;
	}
	
	/* Parse unit cell vectors as appropriate */
	if ( ctx->dirax_read_cell == 1 ) {
		/* First row of unit cell values */
		float x1, x2, x3;
		sscanf(line, "%f %f %f", &x1, &x2, &x3);
		ctx->cell->a.x = x1*1e10;  ctx->cell->b.x = x2*1e10;  ctx->cell->c.x = x3*1e10;
		ctx->dirax_read_cell++;
		return;
	} else if ( ctx->dirax_read_cell == 2 ) {
		/* First row of unit cell values */
		float y1, y2, y3;
		sscanf(line, "%f %f %f", &y1, &y2, &y3);
		ctx->cell->a.y = y1*1e10;  ctx->cell->b.y = y2*1e10;  ctx->cell->c.y = y3*1e10;
		ctx->dirax_read_cell++;
		return;
	} else if ( ctx->dirax_read_cell == 3 ) {
		/* First row of unit cell values */
		float z1, z2, z3;
		sscanf(line, "%f %f %f", &z1, &z2, &z3);
		ctx->cell->a.z = z1*1e10;  ctx->cell->b.z = z2*1e10;  ctx->cell->c.z = z3*1e10;
		printf("DX: Read a reciprocal unit cell\n");
		displaywindow_update(ctx->dw);
		ctx->dirax_read_cell = 0;
		return;
	}
	
	ctx->dirax_read_cell = 0;

}

static void dirax_sendline(const char *line, ControlContext *ctx) {
	
	char *copy;
	int i;
	
	write(ctx->dirax_pty, line, strlen(line));
	
	copy = strdup(line);
	for ( i=0; i<strlen(copy); i++ ) {
		if ( copy[i] == '\r' ) copy[i]='\0';
		if ( copy[i] == '\n' ) copy[i]='\0';
	}
	printf("DX: Sent '%s'\n", copy);	/* No newline here */
	free(copy);
	
}
/* Send a "user" command to DirAx, failing if DirAx is not idle */
static void dirax_sendline_if_idle(const char *line, ControlContext *ctx) {

	if ( ctx->dirax_step != 0 ) {
		printf("DX: DirAx not idle\n");
		return;
	}
	
	dirax_sendline(line, ctx);

}

static void dirax_send_next(ControlContext *ctx) {

	switch ( ctx->dirax_step ) {
	
		case 1 : {
			dirax_sendline("\\echo off\n", ctx);
			ctx->dirax_step++;
			break;
		}
		
		case 2 : {
			dirax_sendline("read dtr.drx\n", ctx);
			ctx->dirax_step++;
			break;
		}
		
		case 3 : {
			dirax_sendline("dmax 10\n", ctx);
			ctx->dirax_step++;
			break;
		}
		
		case 4 : {
			dirax_sendline("indexfit 6\n", ctx);
			ctx->dirax_step++;
			break;
		}
		
		case 5 : {
			dirax_sendline("levelfit 300\n", ctx);
			ctx->dirax_step++;
			break;
		}
		
		case 6 : {
			dirax_sendline("go\n", ctx);
			ctx->dirax_step++;
			break;
		}
		
		case 7 : {
			dirax_sendline("cell\n", ctx);
			ctx->dirax_step++;
			break;
		}
				
		default: {
			ctx->dirax_step = 0;
			printf("DX: Prompt.  DirAx is idle\n");
		}
		
	}
	
}

static gboolean dirax_readable(GIOChannel *dirax, GIOCondition condition, ControlContext *ctx) {
	
	int rval;
	
	rval = read(ctx->dirax_pty, ctx->dirax_rbuffer+ctx->dirax_rbufpos, ctx->dirax_rbuflen-ctx->dirax_rbufpos);
	
	if ( (rval == -1) || (rval == 0) ) {
	
		printf("DX: Lost connection to DirAx\n");
		waitpid(ctx->dirax_pid, NULL, 0);
		g_io_channel_shutdown(ctx->dirax, FALSE, NULL);
		ctx->dirax = NULL;
		displaywindow_update_dirax(ctx, ctx->dw);
		return FALSE;
		
	} else {
	
		int no_string = 0;
		
		ctx->dirax_rbufpos += rval;
		assert(ctx->dirax_rbufpos <= ctx->dirax_rbuflen);
		
		while ( (!no_string) && (ctx->dirax_rbufpos > 0) ) {
	
			int i;
			int block_ready = 0;
			DirAxInputType type = DIRAX_INPUT_NONE;
			
			/* See if there's a full line in the buffer yet */
			for ( i=0; i<ctx->dirax_rbufpos-1; i++ ) {	/* Means the last value looked at is rbufpos-2 */
			
				/* Is there a prompt in the buffer? */
				if ( i+7 <= ctx->dirax_rbufpos ) {
					if ( strncmp(ctx->dirax_rbuffer+i, "Dirax> ", 7) == 0 ) {
						block_ready = 1;
						type = DIRAX_INPUT_PROMPT;
						break;
					}
				}
				
				if ( (ctx->dirax_rbuffer[i] == '\r') && (ctx->dirax_rbuffer[i+1] == '\n') ) { 
					block_ready = 1;
					type = DIRAX_INPUT_LINE;
					break;
				}
				
			}
			
			if ( block_ready ) {
			
				unsigned int new_rbuflen;
				unsigned int endbit_length;
				
				switch ( type ) {
				
					case DIRAX_INPUT_LINE : {
					
						char *block_buffer = NULL;
						
						block_buffer = malloc(i+1);
						memcpy(block_buffer, ctx->dirax_rbuffer, i);
						block_buffer[i] = '\0';
						
						if ( block_buffer[0] == '\r' ) {
							memmove(block_buffer, block_buffer+1, i);
						}
						
						dirax_parseline(block_buffer, ctx);
						free(block_buffer);
						endbit_length = i+2;
						
						break;
						
					}
					
					case DIRAX_INPUT_PROMPT : {
						
						dirax_send_next(ctx);
						endbit_length = i+7;
						break;
					
					}
					
					default : {
						printf("DX: Unrecognised input mode (this never happens!)\n");
						abort();
					}
				
				}
			
				/* Now the block's been parsed, it should be forgotten about */
				memmove(ctx->dirax_rbuffer, ctx->dirax_rbuffer + endbit_length, ctx->dirax_rbuflen - endbit_length);
				
				/* Subtract the number of bytes removed */
				ctx->dirax_rbufpos = ctx->dirax_rbufpos - endbit_length;
				new_rbuflen = ctx->dirax_rbuflen - endbit_length;
				if ( new_rbuflen == 0 ) {
					new_rbuflen = 256;
				}
				ctx->dirax_rbuffer = realloc(ctx->dirax_rbuffer, new_rbuflen);
				ctx->dirax_rbuflen = new_rbuflen;
				
			} else {
			
				if ( ctx->dirax_rbufpos == ctx->dirax_rbuflen ) {
			
					/* More buffer space is needed */
					ctx->dirax_rbuffer = realloc(ctx->dirax_rbuffer, ctx->dirax_rbuflen + 256);
					ctx->dirax_rbuflen = ctx->dirax_rbuflen + 256;
					/* The new space gets used at the next read, shortly... */
			
				}
				no_string = 1;
			
			}
			
		}
		
	}
	
	return TRUE;
	
}

void dirax_stop(ControlContext *ctx) {

	dirax_sendline_if_idle("end\n", ctx);
	
}

void dirax_invoke(ControlContext *ctx) {

	FILE *fh;
	Reflection *ref;
	unsigned int opts;
	int saved_stderr;
	
	if ( ctx->dirax ) {
		printf("DX: DirAx is already running.\n");
		return;
	}
	
	printf("DX: Starting DirAx...\n");
	
	fh = fopen("dtr.drx", "w");
	if ( !fh ) {
		printf("DX: Couldn't open temporary file dtr.drx\n");
		return;
	}
	fprintf(fh, "%f\n", 0.5);  /* Lie about the wavelength.  DirAx can't handle the truth. */
	ref = ctx->reflectionlist->reflections;
	while ( ref ) {
		fprintf(fh, "%10f %10f %10f %8f\n", ref->x/1e10, ref->y/1e10, ref->z/1e10, ref->intensity);
		ref = ref->next;
	}
	fclose(fh);
	
	saved_stderr = dup(STDERR_FILENO);
	ctx->dirax_pid = forkpty(&ctx->dirax_pty, NULL, NULL, NULL);
	if ( ctx->dirax_pid == -1 ) {
		printf("DX: Failed to fork.\n");
		return;
	}
	if ( ctx->dirax_pid == 0 ) {
		
		/* Child process: invoke DirAx */
		struct termios t;
		
		/* Turn echo off */
		tcgetattr(STDIN_FILENO, &t);
		t.c_lflag &= ~(ECHO | ECHOE | ECHOK | ECHONL);
		tcsetattr(STDIN_FILENO, TCSANOW, &t);
		
		/* Reconnect stderr */
		dup2(saved_stderr, STDERR_FILENO);
		
		execlp("dirax", "", (char *)NULL);
		printf("(from the Other Side) Failed to invoke DirAx.\n");
		_exit(0);
		
	}
		
	ctx->dirax_rbuffer = malloc(256);
	ctx->dirax_rbuflen = 256;
	ctx->dirax_rbufpos = 0;
	
	/* Set non-blocking */
	opts = fcntl(ctx->dirax_pty, F_GETFL);
	fcntl(ctx->dirax_pty, F_SETFL, opts | O_NONBLOCK);

	ctx->dirax_step = 1;	/* This starts the "initialisation" procedure */
	ctx->dirax_read_cell = 0;
	ctx->dirax = g_io_channel_unix_new(ctx->dirax_pty);
	g_io_add_watch(ctx->dirax, G_IO_IN | G_IO_HUP, (GIOFunc)dirax_readable, ctx);
	
	displaywindow_update_dirax(ctx, ctx->dw);
	
	return;
	
}

/* Despite being part of the same module, this has very little to do with invoking DirAx */
ReflectionList *dirax_load(const char *filename) {

	FILE *fh;
	char line[256];
	ReflectionList *list;
	int lambda_set = 0;
	
	fh = fopen(filename, "r");
	if ( !fh ) {
		printf("Couldn't open file '%s'\n", filename);
		return 0;
	}
	
	list = reflectionlist_new();
	
	while ( !feof(fh) ) {
	
		size_t ptr;
		float lambda, theta, chib, phib;
		
		fgets(line, 255, fh);
		ptr = skipspace(line);
		if ( line[ptr] == '!' ) continue;
		if ( line[ptr] == '\n' ) continue;
		if ( line[ptr] == '\r' ) continue;
		if ( sscanf(line+ptr, "%f %f %f\n", &theta, &phib, &chib) == 3 ) {
			
			double s, x, y, z;
			float blah, intensity;
			
			/* Try to find an intensity value. Use dummy value if it fails */
			if ( sscanf(line+ptr, "%f %f %f %f\n", &blah, &blah, &blah, &intensity) != 4 ) {
				intensity = 1.0;
			}
				
			if ( !lambda_set ) {
				printf("DX: Wavelength not specified\n");
				continue;
			}
			
			chib = deg2rad(chib);
			phib = deg2rad(phib);
			theta = deg2rad(theta);
			s = 2*(sin(theta)/lambda);
			x = -s*cos(chib)*sin(phib);
			y = +s*cos(chib)*cos(phib);
			z = +s*sin(chib);
			reflection_add(list, x, y, z, 1.0, REFLECTION_NORMAL);
			
			continue;
			
		}
		if ( sscanf(line+ptr, "%f\n", &lambda) == 1 ) {
			if ( lambda_set ) {
				printf("DX: Warning: Found something which looks like a second wavelength\n");
			}
			lambda /= 1e10; /* Convert from A to m */
			lambda_set = 1;
		}
		
	}
	
	fclose(fh);
	
	return list;
	
}

int dirax_is_drxfile(const char *filename) {

	FILE *fh;
	float lambda;
	char line[256];
	
	fh = fopen(filename, "r");
	if ( !fh ) {
		printf("Couldn't open file '%s'\n", filename);
		return 0;
	}
	
	while ( !feof(fh) ) {
	
		size_t ptr;
		
		fgets(line, 255, fh);
		ptr = skipspace(line);
		if ( line[ptr] == '!' ) continue;
		if ( line[ptr] == '\n' ) continue;
		if ( line[ptr] == '\r' ) continue;
		fscanf(fh, "%f\n", &lambda);
		fclose(fh);
		if ( lambda > 0.5 ) {
			return 1;
		} else {
			return 0;
		}
		
	}
	
	fclose(fh);
	
	return 0;
	
}