/*
 * call-seq:
 *    res.cmd_status() -> String
 *
 * Returns the status string of the last query command.
 */
static VALUE
pgresult_cmd_status(VALUE self)
{
	VALUE ret = rb_tainted_str_new2(PQcmdStatus(pgresult_get(self)));
	ASSOCIATE_INDEX(ret, self);
	return ret;
}

/*
 * call-seq:
 *    res.error_message() -> String
 *
 * Returns the error message of the command as a string.
 */
static VALUE
pgresult_error_message(VALUE self)
{
	VALUE ret = rb_tainted_str_new2(PQresultErrorMessage(pgresult_get(self)));
	ASSOCIATE_INDEX(ret, self);
	return ret;
}

/*
 * call-seq:
 *    res.clear() -> nil
 *
 * Clears the PG::Result object as the result of the query.
 */
VALUE
pg_result_clear(VALUE self)
{
	PQclear(pgresult_get(self));
	DATA_PTR(self) = NULL;
	return Qnil;
}

/*
 * call-seq:
 *    res.cmd_tuples() -> Fixnum
 *
 * Returns the number of tuples (rows) affected by the SQL command.
 *
 * If the SQL command that generated the PG::Result was not one of:
 * * +INSERT+
 * * +UPDATE+
 * * +DELETE+
 * * +MOVE+
 * * +FETCH+
 * or if no tuples were affected, <tt>0</tt> is returned.
 */
static VALUE
pgresult_cmd_tuples(VALUE self)
{
	long n;
	n = strtol(PQcmdTuples(pgresult_get(self)),NULL, 10);
	return INT2NUM(n);
}

/*
 * Make a Ruby array out of the encoded values from the specified
 * column in the given result.
 */
static VALUE
make_column_result_array( VALUE self, int col )
{
	PGresult *result = pgresult_get( self );
	int rows = PQntuples( result );
	int i;
	VALUE val = Qnil;
	VALUE results = rb_ary_new2( rows );

	if ( col >= PQnfields(result) )
		rb_raise( rb_eIndexError, "no column %d in result", col );

	for ( i=0; i < rows; i++ ) {
		val = rb_tainted_str_new( PQgetvalue(result, i, col),
		                          PQgetlength(result, i, col) );

#ifdef M17N_SUPPORTED
		/* associate client encoding for text format only */
		if ( 0 == PQfformat(result, col) ) {
			ASSOCIATE_INDEX( val, self );
		} else {
			rb_enc_associate( val, rb_ascii8bit_encoding() );
		}
#endif

		rb_ary_store( results, i, val );
	}

	return results;
}

/*
 * call-seq:
 *    res.getvalue( tup_num, field_num )
 *
 * Returns the value in tuple number _tup_num_, field _field_num_,
 * or +nil+ if the field is +NULL+.
 */
static VALUE
pgresult_getvalue(VALUE self, VALUE tup_num, VALUE field_num)
{
	VALUE val;
	PGresult *result;
	int i = NUM2INT(tup_num);
	int j = NUM2INT(field_num);

	result = pgresult_get(self);
	if(i < 0 || i >= PQntuples(result)) {
		rb_raise(rb_eArgError,"invalid tuple number %d", i);
	}
	if(j < 0 || j >= PQnfields(result)) {
		rb_raise(rb_eArgError,"invalid field number %d", j);
	}
	if(PQgetisnull(result, i, j))
		return Qnil;
	val = rb_tainted_str_new(PQgetvalue(result, i, j),
				PQgetlength(result, i, j));

#ifdef M17N_SUPPORTED
	/* associate client encoding for text format only */
	if ( 0 == PQfformat(result, j) ) {
		ASSOCIATE_INDEX( val, self );
	} else {
		rb_enc_associate( val, rb_ascii8bit_encoding() );
	}
#endif

	return val;
}

static VALUE
pg_tmbc_fit_to_result( VALUE self, VALUE result )
{
	int nfields;
	t_tmbc *this = DATA_PTR( self );
	t_typemap *default_tm;
	VALUE sub_typemap;

	nfields = PQnfields( pgresult_get(result) );
	if ( this->nfields != nfields ) {
		rb_raise( rb_eArgError, "number of result fields (%d) does not match number of mapped columns (%d)",
				nfields, this->nfields );
	}

	/* Ensure that the default type map fits equaly. */
	default_tm = DATA_PTR( this->typemap.default_typemap );
	sub_typemap = default_tm->funcs.fit_to_result( this->typemap.default_typemap, result );

	/* Did the default type return the same object ? */
	if( sub_typemap == this->typemap.default_typemap ){
		return self;
	} else {
		/* Our default type map built a new object, so we need to propagate it
		 * and build a copy of this type map and set it as default there.. */
		VALUE new_typemap = pg_tmbc_s_allocate( rb_cTypeMapByColumn );
		size_t struct_size = sizeof(t_tmbc) + sizeof(struct pg_tmbc_converter) * nfields;
		t_tmbc *p_new_typemap = (t_tmbc *)xmalloc(struct_size);

		memcpy( p_new_typemap, this, struct_size );
		p_new_typemap->typemap.default_typemap = sub_typemap;
		DATA_PTR(new_typemap) = p_new_typemap;
		return new_typemap;
	}
}

/*
 * call-seq:
 *    res.nparams() -> Fixnum
 *
 * Returns the number of parameters of a prepared statement.
 * Only useful for the result returned by conn.describePrepared
 */
static VALUE
pgresult_nparams(VALUE self)
{
	PGresult *result;

	result = pgresult_get(self);
	return INT2FIX(PQnparams(result));
}

/*
 * call-seq:
 *    res.paramtype( param_number ) -> Oid
 *
 * Returns the Oid of the data type of parameter _param_number_.
 * Only useful for the result returned by conn.describePrepared
 */
static VALUE
pgresult_paramtype(VALUE self, VALUE param_number)
{
	PGresult *result;

	result = pgresult_get(self);
	return INT2FIX(PQparamtype(result,NUM2INT(param_number)));
}

/*
 * call-seq:
 *    res.clear() -> nil
 *
 * Clears the PG::Result object as the result of the query.
 *
 * If PG::Result#autoclear? is true then the result is marked as cleared
 * and the underlying C struct will be cleared automatically by libpq.
 *
 */
VALUE
pg_result_clear(VALUE self)
{
	t_pg_result *this = pgresult_get_this(self);
	if( !this->autoclear )
		PQclear(pgresult_get(self));
	this->pgresult = NULL;
	return Qnil;
}

/*
 * call-seq:
 *    res.oid_value() -> Fixnum
 *
 * Returns the +oid+ of the inserted row if applicable,
 * otherwise +nil+.
 */
static VALUE
pgresult_oid_value(VALUE self)
{
	Oid n = PQoidValue(pgresult_get(self));
	if (n == InvalidOid)
		return Qnil;
	else
		return INT2FIX(n);
}

/*
 * call-seq:
 *    res.ftype( column_number )
 *
 * Returns the data type associated with _column_number_.
 *
 * The integer returned is the internal +OID+ number (in PostgreSQL)
 * of the type. To get a human-readable value for the type, use the
 * returned OID and the field's #fmod value with the format_type() SQL
 * function:
 *
 *   # Get the type of the second column of the result 'res'
 *   typename = conn.
 *     exec( "SELECT format_type($1,$2)", [res.ftype(1), res.fmod(1)] ).
 *     getvalue( 0, 0 )
 *
 * Raises an ArgumentError if _column_number_ is out of range.
 */
static VALUE
pgresult_ftype(VALUE self, VALUE index)
{
	PGresult* result = pgresult_get(self);
	int i = NUM2INT(index);
	if (i < 0 || i >= PQnfields(result)) {
		rb_raise(rb_eArgError, "invalid field number %d", i);
	}
	return INT2NUM(PQftype(result, i));
}

/*
 * call-seq:
 *    res.each{ |tuple| ... }
 *
 * Invokes block for each tuple in the result set.
 */
static VALUE
pgresult_each(VALUE self)
{
	PGresult *result = pgresult_get(self);
	int tuple_num;

	for(tuple_num = 0; tuple_num < PQntuples(result); tuple_num++) {
		rb_yield(pgresult_aref(self, INT2NUM(tuple_num)));
	}
	return self;
}

/*
 * call-seq:
 *    res.fformat( column_number ) -> Fixnum
 *
 * Returns the format (0 for text, 1 for binary) of column
 * _column_number_.
 *
 * Raises ArgumentError if _column_number_ is out of range.
 */
static VALUE
pgresult_fformat(VALUE self, VALUE column_number)
{
	PGresult *result = pgresult_get(self);
	int fnumber = NUM2INT(column_number);
	if (fnumber < 0 || fnumber >= PQnfields(result)) {
		rb_raise(rb_eArgError, "Column number is out of range: %d",
			fnumber);
	}
	return INT2FIX(PQfformat(result, fnumber));
}

/*
 *  call-seq:
 *     res.field_values( field )   -> array
 *
 *  Returns an Array of the values from the given _field_ of each tuple in the result.
 *
 */
static VALUE
pgresult_field_values( VALUE self, VALUE field )
{
	PGresult *result = pgresult_get( self );
	const char *fieldname = StringValuePtr( field );
	int fnum = PQfnumber( result, fieldname );

	if ( fnum < 0 )
		rb_raise( rb_eIndexError, "no such field '%s' in result", fieldname );

	return make_column_result_array( self, fnum );
}

/*
 * call-seq:
 *    res.ftable( column_number ) -> Fixnum
 *
 * Returns the Oid of the table from which the column _column_number_
 * was fetched.
 *
 * Raises ArgumentError if _column_number_ is out of range or if
 * the Oid is undefined for that column.
 */
static VALUE
pgresult_ftable(VALUE self, VALUE column_number)
{
	Oid n ;
	int col_number = NUM2INT(column_number);
	PGresult *pgresult = pgresult_get(self);

	if( col_number < 0 || col_number >= PQnfields(pgresult))
		rb_raise(rb_eArgError,"Invalid column index: %d", col_number);

	n = PQftable(pgresult, col_number);
	return INT2FIX(n);
}

/*
 * call-seq:
 *    res.fnumber( name ) -> Fixnum
 *
 * Returns the index of the field specified by the string +name+.
 * The given +name+ is treated like an identifier in an SQL command, that is,
 * it is downcased unless double-quoted. For example, given a query result
 * generated from the SQL command:
 *
 *   result = conn.exec( %{SELECT 1 AS FOO, 2 AS "BAR"} )
 *
 * we would have the results:
 *
 *   result.fname( 0 )            # => "foo"
 *   result.fname( 1 )            # => "BAR"
 *   result.fnumber( "FOO" )      # => 0
 *   result.fnumber( "foo" )      # => 0
 *   result.fnumber( "BAR" )      # => ArgumentError
 *   result.fnumber( %{"BAR"} )   # => 1
 *
 * Raises an ArgumentError if the specified +name+ isn't one of the field names;
 * raises a TypeError if +name+ is not a String.
 */
static VALUE
pgresult_fnumber(VALUE self, VALUE name)
{
	int n;

	Check_Type(name, T_STRING);

	n = PQfnumber(pgresult_get(self), StringValuePtr(name));
	if (n == -1) {
		rb_raise(rb_eArgError,"Unknown field: %s", StringValuePtr(name));
	}
	return INT2FIX(n);
}

/*
 * call-seq:
 *    res.fmod( column_number )
 *
 * Returns the type modifier associated with column _column_number_. See
 * the #ftype method for an example of how to use this.
 *
 * Raises an ArgumentError if _column_number_ is out of range.
 */
static VALUE
pgresult_fmod(VALUE self, VALUE column_number)
{
	PGresult *result = pgresult_get(self);
	int fnumber = NUM2INT(column_number);
	int modifier;
	if (fnumber < 0 || fnumber >= PQnfields(result)) {
		rb_raise(rb_eArgError, "Column number is out of range: %d",
			fnumber);
	}
	modifier = PQfmod(result,fnumber);

	return INT2NUM(modifier);
}

/*
 * call-seq:
 *    res.error_field(fieldcode) -> String
 *
 * Returns the individual field of an error.
 *
 * +fieldcode+ is one of:
 * * +PG_DIAG_SEVERITY+
 * * +PG_DIAG_SQLSTATE+
 * * +PG_DIAG_MESSAGE_PRIMARY+
 * * +PG_DIAG_MESSAGE_DETAIL+
 * * +PG_DIAG_MESSAGE_HINT+
 * * +PG_DIAG_STATEMENT_POSITION+
 * * +PG_DIAG_INTERNAL_POSITION+
 * * +PG_DIAG_INTERNAL_QUERY+
 * * +PG_DIAG_CONTEXT+
 * * +PG_DIAG_SOURCE_FILE+
 * * +PG_DIAG_SOURCE_LINE+
 * * +PG_DIAG_SOURCE_FUNCTION+
 *
 * An example:
 *
 *   begin
 *       conn.exec( "SELECT * FROM nonexistant_table" )
 *   rescue PG::Error => err
 *       p [
 *           err.result.error_field( PG::Result::PG_DIAG_SEVERITY ),
 *           err.result.error_field( PG::Result::PG_DIAG_SQLSTATE ),
 *           err.result.error_field( PG::Result::PG_DIAG_MESSAGE_PRIMARY ),
 *           err.result.error_field( PG::Result::PG_DIAG_MESSAGE_DETAIL ),
 *           err.result.error_field( PG::Result::PG_DIAG_MESSAGE_HINT ),
 *           err.result.error_field( PG::Result::PG_DIAG_STATEMENT_POSITION ),
 *           err.result.error_field( PG::Result::PG_DIAG_INTERNAL_POSITION ),
 *           err.result.error_field( PG::Result::PG_DIAG_INTERNAL_QUERY ),
 *           err.result.error_field( PG::Result::PG_DIAG_CONTEXT ),
 *           err.result.error_field( PG::Result::PG_DIAG_SOURCE_FILE ),
 *           err.result.error_field( PG::Result::PG_DIAG_SOURCE_LINE ),
 *           err.result.error_field( PG::Result::PG_DIAG_SOURCE_FUNCTION ),
 *       ]
 *   end
 *
 * Outputs:
 *
 *   ["ERROR", "42P01", "relation \"nonexistant_table\" does not exist", nil, nil,
 *    "15", nil, nil, nil, "path/to/parse_relation.c", "857", "parserOpenTable"]
 */
static VALUE
pgresult_error_field(VALUE self, VALUE field)
{
	PGresult *result = pgresult_get( self );
	int fieldcode = NUM2INT( field );
	char * fieldstr = PQresultErrorField( result, fieldcode );
	VALUE ret = Qnil;

	if ( fieldstr ) {
		ret = rb_tainted_str_new2( fieldstr );
		ASSOCIATE_INDEX( ret, self );
	}

	return ret;
}

/*
 * call-seq:
 *    res.fname( index ) -> String
 *
 * Returns the name of the column corresponding to _index_.
 */
static VALUE
pgresult_fname(VALUE self, VALUE index)
{
	VALUE fname;
	PGresult *result;
	int i = NUM2INT(index);

	result = pgresult_get(self);
	if (i < 0 || i >= PQnfields(result)) {
		rb_raise(rb_eArgError,"invalid field number %d", i);
	}
	fname = rb_tainted_str_new2(PQfname(result, i));
	ASSOCIATE_INDEX(fname, self);
	return fname;
}