/*
 *  R : A Computer Langage for Statistical Data Analysis
 *  Copyright (C) 1998-2004   Lyndon Drake
 *                            and the R Development Core Team
 *
 *  This program is free software; you can redistribute it and/or modify
 *  it under the terms of the GNU General Public License as published by
 *  the Free Software Foundation; either version 2 of the License, or
 *  (at your option) any later version.
 *
 *  This program is distributed in the hope that it will be useful,
 *  but WITHOUT ANY WARRANTY; without even the implied warranty of
 *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 *  GNU General Public License for more details.
 *
 *  You should have received a copy of the GNU General Public License
 *  along with this program; if not, write to the Free Software
 *  Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
 */

/* Avoid braced-groups warning from -Wall */
#define G_STMT_START do
#define G_STMT_END   while(0)

#include "gnome-find-dialog.h"
#include "terminal.h"
#include "terminal-find.h"

#include <gnome.h>
#include <sys/types.h>

#include <regex.h>

#define ERRBUF_SIZE 500
#define MSGBUF_SIZE 2000


/* indexes for a find match */
typedef struct _find_selection find_selection;

struct _find_selection {
  int select_start;
  int select_end;
};


static GnomeFindDialogParams find_params; /* find parameters from dialog box */

static gint find_pos, find_pos_max; /* current position of the find 'cursor', and the max (min is 0) */
static gint find_pos_init; /* the initial find position (for wrapped searches) */
static gboolean search_wrapped; /* used to determine if a search has wrapped */

static gchar *find_text_cache; /* cache of the console text */

static gboolean line_cache_update; /* TRUE if line cache needs updating */
static gint line_cache_start, line_cache_end; /* indexes into find_text_cache of the area covered by the line cache */
static GList *find_current_match;  /* List of matches on currently cached line */

regex_t *preg; /* compiled regular expression structure */


/* FIXME: wrapped searches */

void find_update_text_cache(void)
{
  /* update text cache */
  find_text_cache = gtk_editable_get_chars(GTK_EDITABLE(R_gtk_terminal_text), 0, -1);
  find_pos_max = gtk_text_get_length(GTK_TEXT(R_gtk_terminal_text)) - 1;

  /* force line cache update */
  line_cache_update = TRUE;
}

void find_compile_regex(GnomeFindDialog *find_dialog)
{
  int cflags;
  int regex_result;
  char errbuf[ERRBUF_SIZE];
  char messagebuf[MSGBUF_SIZE];

  GtkWidget *message_dialog;

  if(find_params.regex == TRUE) {
    /* compile the regular expression */
    cflags = REG_EXTENDED;
    if(find_params.case_sensitive == FALSE) {
      cflags = cflags | REG_ICASE;
    }

    preg = (regex_t *) g_malloc(sizeof(regex_t));

    regex_result = regcomp(preg, find_params.find_text, cflags);

    if(regex_result != 0) {
      regerror(regex_result, preg, errbuf, ERRBUF_SIZE);
      g_snprintf(messagebuf, MSGBUF_SIZE, "Error compiling regular expression: %s", errbuf);

      message_dialog = gnome_message_box_new(messagebuf,
					     GNOME_MESSAGE_BOX_ERROR,
					     GNOME_STOCK_BUTTON_OK,
					     NULL);
      if (find_dialog != NULL ) {
	gnome_dialog_set_parent(GNOME_DIALOG(message_dialog), GTK_WINDOW(find_dialog));
      }
      else {
	gnome_dialog_set_parent(GNOME_DIALOG(message_dialog), GTK_WINDOW(R_gtk_main_window));
      }
      gnome_dialog_run_and_close(GNOME_DIALOG(message_dialog));

      return;
    }
  }
}

void find_free_regex(void)
{
  if(preg != NULL) {
    regfree(preg);
    preg = NULL;
  }
}

void find_free_select(gpointer data, gpointer user_data)
{
  if(data != NULL) {
    g_free(data);
  }
}

int find_update_line_cache(GnomeFindDialog *find_dialog)
{
  int find_text_len;
  int eflags;
  regmatch_t pmatch[1];
  int regex_result;
  char errbuf[ERRBUF_SIZE];
  char messagebuf[MSGBUF_SIZE];
  int strcmp_result;
  int tmp_find_pos;
  gchar *find_line_cache;
  find_selection *find_select;

  GtkWidget *message_dialog;

  /* initialisation */
  find_line_cache = NULL;
  find_text_len = strlen(find_params.find_text);
  line_cache_update = FALSE;

  /* free matches list if necessary */
  if (find_current_match != NULL) {
    find_current_match = g_list_first(find_current_match);
    g_list_foreach(find_current_match, find_free_select, NULL);
    g_list_free(find_current_match);
    find_current_match = NULL;
  }

  /* Move one line */
  switch (find_params.direction) {
  case GNOME_FIND_FORWARDS:
    do {
      if(find_pos > find_pos_max) {
	if(find_params.wrap_search == TRUE) {
	  find_pos = 0;
	  search_wrapped = TRUE;
	}
	else {
	  return GNOME_FIND_NOMATCH;
	}
      }
      else {
	find_pos++;
	if((search_wrapped) && (find_pos >= find_pos_init)) {
	  return GNOME_FIND_NOMATCH;
	}
      }
    } while (find_text_cache[find_pos] == '\n');
    break;
    
  case GNOME_FIND_BACKWARDS:
    do {
      if(find_pos < 0) {
	if(find_params.wrap_search == TRUE) {
	  find_pos = find_pos_max;
	  search_wrapped = TRUE;
	}
	else {
	  return GNOME_FIND_NOMATCH;
	}
      }
      else {
	find_pos--;
	if((search_wrapped) && (find_pos <= find_pos_init)) {
	  return GNOME_FIND_NOMATCH;
	}
      }
    } while (find_text_cache[find_pos] == '\n');
    break;
  }

  line_cache_start = line_cache_end = find_pos;

  while ((line_cache_start > 0) && (find_text_cache[line_cache_start - 1] != '\n')) {
    line_cache_start--;
  }
  while ((line_cache_end < find_pos_max) && (find_text_cache[line_cache_end + 1] != '\n')) {
    line_cache_end++;
  }
  
  /* Grab the line */
  find_line_cache = g_strndup(find_text_cache + line_cache_start,
			      line_cache_end - line_cache_start + 1);

  /* Search line */
  if (find_params.regex == TRUE) {
    /* Regular expression search */
    tmp_find_pos = 0; 
    eflags = 0;
    do {
      if (tmp_find_pos != 0) {
	eflags = REG_NOTBOL;
      }

      /* execute the match */
      regex_result = regexec(preg, find_line_cache + tmp_find_pos, 1, pmatch, eflags);

      if(regex_result == 0) {
	/* construct list item if found */
	find_select = g_new(find_selection, 1);
	find_select->select_start = line_cache_start + tmp_find_pos + pmatch[0].rm_so;
	find_select->select_end = line_cache_start + tmp_find_pos + pmatch[0].rm_eo;
	find_current_match = g_list_append(find_current_match, (gpointer) find_select);

	tmp_find_pos += pmatch[0].rm_so + 1;
      }
      else if (regex_result != REG_NOMATCH) {
	/* report regexec errors and terminate the search */
	regerror(regex_result, preg, errbuf, ERRBUF_SIZE);
	g_snprintf(messagebuf, MSGBUF_SIZE,
		   "Error matching regular expression: %s", errbuf);

	message_dialog = gnome_message_box_new(messagebuf,
					       GNOME_MESSAGE_BOX_ERROR,
					       GNOME_STOCK_BUTTON_OK,
					       NULL);
	if (find_dialog != NULL ) {
	  gnome_dialog_set_parent(GNOME_DIALOG(message_dialog), GTK_WINDOW(find_dialog));
	}
	else {
	  gnome_dialog_set_parent(GNOME_DIALOG(message_dialog), GTK_WINDOW(R_gtk_main_window));
	}
	gnome_dialog_run_and_close(GNOME_DIALOG(message_dialog));

	if (find_line_cache != NULL) {
	  g_free(find_line_cache);
	}

	return GNOME_FIND_NOMATCH;
      }
    } while ((tmp_find_pos <= (line_cache_end - line_cache_start)) && (regex_result == 0));
  }
  else {
    /* Literal search */
    for (tmp_find_pos = line_cache_start; tmp_find_pos <= line_cache_end; tmp_find_pos++) {
      if (find_params.case_sensitive == TRUE) {
	strcmp_result = strncmp(find_params.find_text,
				find_text_cache + tmp_find_pos,	find_text_len);
      }
      else {
	strcmp_result = g_strncasecmp(find_params.find_text,
				      find_text_cache + tmp_find_pos, 
				      find_text_len);
      }

      /* construct list item if found */
      if(strcmp_result == 0) {
	find_select = g_new(find_selection, 1);
	find_select->select_start = tmp_find_pos;
	find_select->select_end = tmp_find_pos + find_text_len;
	find_current_match = g_list_append(find_current_match, (gpointer) find_select);
      }
    }
  }

  if (find_line_cache != NULL) {
    g_free(find_line_cache);
  }

  /* Return result */
  if (find_current_match != NULL) {
    if(find_params.direction == GNOME_FIND_BACKWARDS)
      find_current_match = g_list_last(find_current_match);
    return GNOME_FIND_MATCH;
  }

  return GNOME_FIND_NOTFOUND;
}

void find_process_result(GnomeFindDialog *find_dialog, int find_result)
{
  find_selection *find_select;

  GtkWidget *message_dialog;

  if (find_dialog != NULL)
    g_return_if_fail(GNOME_IS_FIND_DIALOG(find_dialog));

  switch (find_result) {
  case GNOME_FIND_NOMATCH:
    message_dialog = gnome_message_box_new("Could not find text in console output.",
					   GNOME_MESSAGE_BOX_WARNING,
					   GNOME_STOCK_BUTTON_OK,
					   NULL);
    if (find_dialog != NULL ) {
      gnome_dialog_set_parent(GNOME_DIALOG(message_dialog), GTK_WINDOW(find_dialog));
    }
    else {
      gnome_dialog_set_parent(GNOME_DIALOG(message_dialog), GTK_WINDOW(R_gtk_main_window));
    }
    gnome_dialog_run_and_close (GNOME_DIALOG(message_dialog));
    if(find_dialog != NULL) 
    gnome_dialog_set_default(GNOME_DIALOG(find_dialog), GNOME_FIND_BUTTON_FIND);
    break;
    
  case GNOME_FIND_MATCH:
    find_select = (find_selection *) find_current_match->data;
    gtk_editable_set_position(GTK_EDITABLE(R_gtk_terminal_text),
				find_select->select_end);
    gtk_editable_select_region(GTK_EDITABLE(R_gtk_terminal_text),
				 find_select->select_start,
				 find_select->select_end);
    break;
  }
}

void R_gtk_terminal_find(GnomeFindDialog *find_dialog)
{
  int find_result;
  find_selection *find_select;

  if(find_dialog != NULL)
    g_return_if_fail(GNOME_IS_FIND_DIALOG(find_dialog));

  if(find_params.find_text == NULL)
    return;

  /* update the text cache if necessary */
  if(find_text_cache == NULL) {
    find_update_text_cache();
  }

  /* compile the regular expression */
  find_compile_regex(find_dialog);

  /* do the actual find */
  find_result = GNOME_FIND_NOTFOUND;

  while (find_result == GNOME_FIND_NOTFOUND) {
    if ((line_cache_update == TRUE) || (find_pos < line_cache_start) || (find_pos > line_cache_end)) {
      find_result = find_update_line_cache(find_dialog);
    }
    else if (find_params.direction == GNOME_FIND_FORWARDS) {
      if ((find_current_match == NULL) || (find_current_match->next == NULL)) {
	find_pos = line_cache_end + 1;
	find_result = find_update_line_cache(find_dialog);
      }
      else {
	find_select = (find_selection *) find_current_match->next->data;
	if ((search_wrapped) && (find_select->select_start >= find_pos_init)) {
	  find_result = GNOME_FIND_NOMATCH;
	}
	else {
	  find_current_match = find_current_match->next;
	  find_result = GNOME_FIND_MATCH;
	}
      }
    }
    else if (find_params.direction == GNOME_FIND_BACKWARDS) {
      if ((find_current_match == NULL) || (find_current_match->prev == NULL)) {
	find_pos = line_cache_start - 1;
	find_result = find_update_line_cache(find_dialog);
      }
      else {
	find_select = (find_selection *) find_current_match->prev->data;
	if ((search_wrapped) && (find_select->select_start <= find_pos_init)) {
	  find_result = GNOME_FIND_NOMATCH;
	}
	else {
	  find_current_match = find_current_match->prev;
	  find_result = GNOME_FIND_MATCH;
	}
      }
    }
  }

  /* update UI based on result */
  find_process_result(find_dialog, find_result);

  /* free the compiled regex */
  find_free_regex();
}

static void find_console_changed(GtkWidget *widget, gpointer data)
{
  if (find_text_cache != NULL) {
    g_free(find_text_cache);
    find_text_cache = NULL;
  }
}

static void find_dialog_cb(GtkWidget *widget, gpointer data)
{
  gchar *tmp_text;

  g_return_if_fail(widget != NULL);
  g_return_if_fail(GNOME_IS_FIND_DIALOG(widget));

  tmp_text = gnome_find_dialog_get_find_text(GNOME_FIND_DIALOG(widget));

  if(find_params.find_text != NULL) {
    if(strcmp(find_params.find_text, tmp_text) != 0) {
      line_cache_update = TRUE;
    }
    g_free(find_params.find_text);
  }

  if(find_params.regex != GNOME_FIND_DIALOG(widget)->params.regex)
    line_cache_update = TRUE;

  find_params = GNOME_FIND_DIALOG(widget)->params;
  find_params.find_text = tmp_text;

  switch(find_params.start_pos) {
  case GNOME_FIND_TOP:
    find_pos = 0;
    break;

  case GNOME_FIND_CURSOR:
    find_pos = gtk_editable_get_position(GTK_EDITABLE(R_gtk_terminal_text));
    break;

  case GNOME_FIND_BOTTOM:
    find_pos = gtk_text_get_length(GTK_TEXT(R_gtk_terminal_text)) - 1;
    break;
  }

  find_pos_init = find_pos;
  search_wrapped = FALSE;

  R_gtk_terminal_find(GNOME_FIND_DIALOG(widget));
}

static void find_again_dialog_cb(GtkWidget *widget, gpointer data)
{
  gchar *tmp_text;

  g_return_if_fail(widget != NULL);
  g_return_if_fail(GNOME_IS_FIND_DIALOG(widget));

  tmp_text = gnome_find_dialog_get_find_text(GNOME_FIND_DIALOG(widget));

  if(find_params.find_text != NULL) {
    if(strcmp(find_params.find_text, tmp_text) != 0) {
      line_cache_update = TRUE;
    }
    g_free(find_params.find_text);
  }

  if(find_params.regex != GNOME_FIND_DIALOG(widget)->params.regex)
    line_cache_update = TRUE;

  find_params = GNOME_FIND_DIALOG(widget)->params;
  find_params.find_text = tmp_text;

  R_gtk_terminal_find(GNOME_FIND_DIALOG(widget));
}

void edit_find_cb(GtkWidget *widget, gpointer data)
{
  GtkWidget *find_dialog;

  find_dialog = gnome_find_dialog_new("Find text", &find_params, TRUE, TRUE, TRUE);

  gnome_dialog_set_parent(GNOME_DIALOG(find_dialog), GTK_WINDOW(R_gtk_main_window));

  gtk_signal_connect(GTK_OBJECT(find_dialog),
		     "find",
		     (GtkSignalFunc) find_dialog_cb,
		     NULL);
  gtk_signal_connect(GTK_OBJECT(find_dialog),
		     "find_again",
		     (GtkSignalFunc) find_again_dialog_cb,
		     NULL);

  gtk_widget_show(find_dialog);
}

void edit_find_again_cb(GtkWidget *widget, gpointer data)
{
  R_gtk_terminal_find(NULL);
}

void R_gtk_terminal_find_init()
{
  /* Find functionality */
  find_params.find_text = NULL;
  find_params.direction = GNOME_FIND_FORWARDS;
  find_params.start_pos = GNOME_FIND_TOP;
  find_params.case_sensitive = FALSE;
  find_params.wrap_search = FALSE;
  find_params.regex = FALSE;
  find_pos = 0;
  find_pos_init = 0;
  search_wrapped = FALSE;
  find_text_cache = NULL;
  line_cache_update = TRUE;
  find_current_match = NULL;
  preg = NULL;
  
  gtk_signal_connect(GTK_OBJECT(R_gtk_terminal_text), "changed",
		     (GtkSignalFunc) find_console_changed,
		     NULL);
}