##! The input framework provides a way to read previously stored data either
##! as an event stream or into a bro table.

module Input;

export {
         
	## The default input reader used. Defaults to `READER_ASCII`.
	const default_reader = READER_ASCII &redef;

	const default_mode = MANUAL &redef;

	## TableFilter description type used for the `table` method.
	type TableDescription: record {
		## Common definitions for tables and events
		
		## String that allows the reader to find the source.
		## For `READER_ASCII`, this is the filename.
		source: string;
		
		## Reader to use for this steam
		reader: Reader &default=default_reader;

		## Read mode to use for this stream
		mode: Mode &default=default_mode;

		## Automatically start the input stream after the first filter has been added
		autostart: bool &default=T;

		## Descriptive name. Used to remove a filter at a later time
		name: string; 

		## Special definitions for tables

		## Table which will contain the data read by the input framework
		destination: any;
		## Record that defines the values used as the index of the table
		idx: any;
		## Record that defines the values used as the values of the table
		## If val is undefined, destination has to be a set.
		val: any &optional;
		## Defines if the value of the table is a record (default), or a single value.
		## Val can only contain one element when this is set to false.
		want_record: bool &default=T;

		## The event that is raised each time a value is added to, changed in or removed from the table.
		## The event will receive an Input::Event enum as the first argument, the idx record as the second argument
		## and the value (record) as the third argument.
		ev: any &optional; # event containing idx, val as values.		

		## Predicate function, that can decide if an insertion, update or removal should really be executed.
		## Parameters are the same as for the event. If true is returned, the update is performed. If false
		## is returned, it is skipped
		pred: function(typ: Input::Event, left: any, right: any): bool &optional;
	};

	## EventFilter description type used for the `event` method.
	type EventDescription: record {
		## Common definitions for tables and events
		
		## String that allows the reader to find the source.
		## For `READER_ASCII`, this is the filename.
		source: string;
		
		## Reader to use for this steam
		reader: Reader &default=default_reader;

		## Read mode to use for this stream
		mode: Mode &default=default_mode;

		## Automatically start the input stream after the first filter has been added
		autostart: bool &default=T;

		## Descriptive name. Used to remove a filter at a later time
		name: string; 

		## Special definitions for events
	
		## Record describing the fields to be retrieved from the source input.
		fields: any;
		## If want_record if false (default), the event receives each value in fields as a seperate argument.
		## If it is set to true, the event receives all fields in a signle record value.
		want_record: bool &default=F;

		## The event that is rised each time a new line is received from the reader.
		## The event will receive an Input::Event enum as the first element, and the fields as the following arguments.
		ev: any; 

	};

	## Create a new table input from a given source. Returns true on success.
	##
	## description: `TableDescription` record describing the source.
	global add_table: function(description: Input::TableDescription) : bool;
	
	## Create a new event input from a given source. Returns true on success.
	##
	## description: `TableDescription` record describing the source.
	global add_event: function(description: Input::EventDescription) : bool;

	## Remove a input stream. Returns true on success and false if the named stream was not found.
	##
	## id: string value identifying the stream to be removed
	global remove: function(id: string) : bool;

	## Forces the current input to be checked for changes.
	## Returns true on success and false if the named stream was not found
	##
	## id: string value identifying the stream
	global force_update: function(id: string) : bool;

	## Event that is called, when the update of a specific source is finished
	global update_finished: event(name: string, source:string);
}

@load base/input.bif


module Input;

#global streams: table[string] of Filter;
# ^ change to set containing the names

function add_table(description: Input::TableDescription) : bool
	{
	return __create_table_stream(description);
	}

function add_event(description: Input::EventDescription) : bool
	{
	return __create_event_stream(description);
	}

function remove(id: string) : bool
	{
	return __remove_stream(id);
	}

function force_update(id: string) : bool
	{
	return __force_update(id);
	}