#include <stdlib.h>
#include <string.h>
#include <grass/gis.h>
#include <grass/dbmi.h>
#include <grass/form.h>

/* Generate form in HTML/TXT format.
 *  Pointer to resulting string is stored to 'form'. This string must be freed by application.
 *
 *  returns: -1 error 
 *            0 success
 */
int
F_generate(char *drvname, char *dbname, char *tblname, char *key, int keyval,
	   char *frmname, char *frmmapset,
	   int edit_mode, int format, char **form)
{
    int col, ncols, ctype, sqltype, more;
    char buf[5000], buf1[100];
    const char *colname;
    dbString sql, html, str;
    dbDriver *driver;
    dbHandle handle;
    dbCursor cursor;
    dbTable *table;
    dbColumn *column;
    dbValue *value;

    int i = 0;

    /* see /usr/lib/tcl8.4/encoding/ */
    static char *encoding_list[] = {
	"utf-8",
	"ascii",
	"iso8859-1",
	"iso8859-2",
	"iso8859-15",
	"iso2022-jp",
	"koi8-r",
	"euc-jp",
	NULL
    };
    const char *enc_env;

    G__read_env();
    enc_env = G__getenv("GRASS_DB_ENCODING");

    /* TODO: support 'format' (txt, html), currently html only */

    G_debug(2,
	    "F_generate(): drvname = '%s', dbname = '%s'\n      tblname = '%s', key = '%s', keyval = %d\n"
	    "    form = '%s', form_mapset = '%s'\n      edit_mode = %d",
	    drvname, dbname, tblname, key, keyval, frmname, frmmapset,
	    edit_mode);

    db_init_string(&sql);
    db_init_string(&html);	/* here is the result stored */
    db_init_string(&str);

    G_debug(2, "Open driver");
    driver = db_start_driver(drvname);
    if (driver == NULL) {
	G_warning("Cannot open driver\n");
	sprintf(buf, "Cannot open driver '%s'<BR>", drvname);
	*form = G_store(buf);
	return -1;
    }
    G_debug(2, "Driver opened");

    db_init_handle(&handle);
    db_set_handle(&handle, dbname, NULL);
    G_debug(2, "Open database");
    if (db_open_database(driver, &handle) != DB_OK) {
	G_warning("Cannot open database\n");
	db_shutdown_driver(driver);
	sprintf(buf, "Cannot open database '%s' by driver '%s'<BR>", dbname,
		drvname);
	*form = G_store(buf);
	return -1;
    }
    G_debug(2, "Database opened");

    /* TODO: test if table exist first, but this should be tested by application befor
     *        F_generate() is called, because it may be correct (connection defined in DB
     *        but table does not exist) */

    sprintf(buf, "select * from %s where %s = %d", tblname, key, keyval);
    G_debug(2, "%s", buf);
    db_set_string(&sql, buf);
    if (db_open_select_cursor(driver, &sql, &cursor, DB_SEQUENTIAL) != DB_OK) {
	G_warning("Cannot open select cursor\n");
	db_close_database(driver);
	db_shutdown_driver(driver);
	sprintf(buf,
		"Cannot open select cursor:<BR>'%s'<BR>on database '%s' by driver '%s'<BR>",
		db_get_string(&sql), dbname, drvname);
	*form = G_store(buf);
	return -1;
    }
    G_debug(2, "Select Cursor opened");

    table = db_get_cursor_table(&cursor);

    if (db_fetch(&cursor, DB_NEXT, &more) != DB_OK) {
	G_warning("Cannot fetch next record\n");
	db_close_cursor(&cursor);
	db_close_database(driver);
	db_shutdown_driver(driver);
	*form = G_store("Cannot fetch next record");
	return -1;
    }

    if (!more) {
	G_warning("No database record");
	if (format == F_HTML) {
	    *form = G_store("No record selected.<BR>");
	}
	else {
	    *form = G_store("No record selected.");
	}
    }
    else {
	ncols = db_get_table_number_of_columns(table);

	/* Start form */
	if (format == F_HTML) {
	    if (edit_mode == F_EDIT) {
		db_append_string(&html, "<FORM>");

		sprintf(buf, "<INPUT type=hidden name=%s value=\"%s\">",
			F_DRIVER_FNAME, drvname);
		db_append_string(&html, buf);
		/* Note: because html_library.tcl failes to parse
		 *  <INPUT name=abc value='dbname=xxx'> and returnes
		 *  name="xxx" value="dbname=xxx" order of value and name parameters is changed */
		sprintf(buf, "<INPUT type=hidden value=\"%s\" name=%s>",
			dbname, F_DATABASE_FNAME);
		db_append_string(&html, buf);
		sprintf(buf, "<INPUT type=hidden name=%s value=\"%s\">",
			F_TABLE_FNAME, tblname);
		db_append_string(&html, buf);
		sprintf(buf, "<INPUT type=hidden name=%s value=\"%s\">",
			F_KEY_FNAME, key);
		db_append_string(&html, buf);

	    }

	    for (col = 0; col < ncols; col++) {
		column = db_get_table_column(table, col);
		sqltype = db_get_column_sqltype(column);
		ctype = db_sqltype_to_Ctype(sqltype);
		value = db_get_column_value(column);
		db_convert_value_to_string(value, sqltype, &str);
		colname = db_get_column_name(column);

		G_debug(2, "%s: %s", colname, db_get_string(&str));

		if (edit_mode == F_VIEW) {
		    sprintf(buf, "<B>%s : </B> %s <BR>", colname,
			    db_get_string(&str));
		    db_append_string(&html, buf);
		}
		else {
		    sprintf(buf, "<B>%s : </B>", colname);
		    db_append_string(&html, buf);

		    if (G_strcasecmp(colname, key) == 0) {
			sprintf(buf,
				"%s<BR> <INPUT type=hidden name=%s value=\"%s\">",
				db_get_string(&str), colname,
				db_get_string(&str));
		    }
		    else {
			switch (ctype) {
			case DB_C_TYPE_INT:
			    sprintf(buf1, "20");
			    break;
			case DB_C_TYPE_DOUBLE:
			    sprintf(buf1, "30");
			    break;
			case DB_C_TYPE_STRING:
			    sprintf(buf1, "%d", db_get_column_length(column));
			    break;
			case DB_C_TYPE_DATETIME:
			    sprintf(buf1, "20");
			    break;
			}
			sprintf(buf,
				"<INPUT type=text size=%s name=%s value=\"%s\"><BR>",
				buf1, colname, db_get_string(&str));
		    }
		    db_append_string(&html, buf);
		}
	    }

	    if (edit_mode == F_EDIT) {
		sprintf(buf,
			"<HR>   Assume data encoding as:<BR><BR><SELECT NAME=%s SIZE=4><HR><BR>",
			F_ENCODING);
		db_append_string(&html, buf);

		i = 0;
		while (encoding_list[i] != NULL) {

		    if (G_strcasecmp(encoding_list[i], enc_env) == 0)
			sprintf(buf, "<OPTION VALUE=\"%s\" SELECTED>%s",
				encoding_list[i], encoding_list[i]);
		    else
			sprintf(buf, "<OPTION VALUE=\"%s\">%s",
				encoding_list[i], encoding_list[i]);
		    ++i;
		    db_append_string(&html, buf);
		}

		sprintf(buf, "</SELECT>");
		db_append_string(&html, buf);
	    }

	    /* Close form */
	    if (edit_mode == F_EDIT) {
		db_append_string(&html, "</FORM>");
	    }
	}
	else {			/* F_TXT */
	    for (col = 0; col < ncols; col++) {
		column = db_get_table_column(table, col);
		sqltype = db_get_column_sqltype(column);
		ctype = db_sqltype_to_Ctype(sqltype);
		value = db_get_column_value(column);
		db_convert_value_to_string(value, sqltype, &str);
		colname = db_get_column_name(column);

		G_debug(2, "%s: %s", colname, db_get_string(&str));

		sprintf(buf, "%s : %s\n", colname, db_get_string(&str));
		db_append_string(&html, buf);
	    }
	}
    }
    G_debug(2, "FORM STRING:\n%s\n", db_get_string(&html));

    db_close_cursor(&cursor);
    db_close_database(driver);
    db_shutdown_driver(driver);

    *form = G_store(db_get_string(&html));

    db_free_string(&sql);
    db_free_string(&html);
    db_free_string(&str);

    return 0;
}