note
	description: "An AUDIO_SOUND witch data came from a WAV file."
	author: "Louis Marchand"
	date: "Tue, 21 Feb 2017 00:15:23 +0000"
	revision: "2.1"

class 
	AUDIO_SOUND_WAV_FILE

create 
	make

feature {NONE} -- Initialization

	make (a_filename: READABLE_STRING_GENERAL)
			-- Initialization of Current using a_filename to load data.
		do
			default_create
			create file.make_with_name (a_filename)
			is_finished := False
		end

	process_chunks
			-- Read every WAV chunks information and store them inside attributes.
		local
			chunk_id, chunk_data_size: NATURAL_32
			cur_offset: INTEGER_32
			fmt_found, data_found: BOOLEAN
		do
			from
				fmt_found := False
				data_found := False
				has_error := False
			until
				data_found or has_error
			loop
				if file.can_read_64 then
					file.read_natural_32_big_endian
					chunk_id := file.last_natural_32;
					file.read_natural_32_little_endian
					chunk_data_size := file.last_natural_32
					cur_offset := file.position
					if chunk_id = 1684108385 then
						data_starting_offset := cur_offset
						data_size := chunk_data_size
						data_found := True
						if not fmt_found then
							put_error ("Cannot read WAV data chunks.", "Data deteted but not the fmt")
						end
					else
						if chunk_id = 1718449184 then
							process_fmt
							fmt_found := True
						end;
						file.go (cur_offset + chunk_data_size.to_integer_32)
					end
				else
					put_error ("Cannot read WAV data chunks.", "The file has stop before the end of a WAV chunk.")
				end
			end
			has_ressource_error := has_error
		end

	process_fmt
			-- Read and store chunk's format informations (fmt tag)
		do
			if file.can_read_64 then
				file.read_natural_16_little_endian
				if file.last_natural_16 /= 1 then
					put_error ("WAV format not supported.", "Audio format is not PCM.")
				else
					file.read_natural_16_little_endian
					channel_count_internal := file.last_natural_16.as_integer_32;
					file.read_natural_32_little_endian
					frequency_internal := file.last_natural_32.as_integer_32
					if file.can_read_64 then
						file.read_natural_32_little_endian
						byte_rate := file.last_natural_32.to_integer_32;
						file.read_natural_16_little_endian
						bytes_per_sample := file.last_natural_16.to_integer_32;
						file.read_natural_16_little_endian
						bits_per_sample_internal := file.last_natural_16.as_integer_32
					else
						put_error ("WAV format not supported.", "The file has stop before the end of a WAV fmt.")
					end
				end
			else
				put_error ("WAV format not supported.", "The file has stop before the end of a WAV fmt.")
			end
			has_ressource_error := has_error
		end

	process_header
			-- Look inside the file to see if it is a valid
			-- WAV file and retreive attrbutes
		do
			if file.can_read_32 then
				file.read_natural_32_big_endian
				if file.last_natural_32 /= 1380533830 then
					put_error ("Cannot open WAV file.", "The RIFF header is not found")
				else
					if file.can_read_64 then
						file.read_natural_32_big_endian;
						file.read_natural_32_big_endian
						if file.last_natural_32 /= 1463899717 then
							put_error ("Cannot open WAV file.", "The WAVE header is not found")
						else
							process_chunks
						end
					else
						put_error ("Cannot open WAV file.", "The file has stop before the end of the WAV header.")
					end
				end
			else
				put_error ("Cannot open WAV file.", "The file has stop before the end of the WAV header.")
			end
			has_ressource_error := has_error
		end
	
feature -- Access

	bits_per_sample: INTEGER_32
			-- Get the bit resolution of one frame of Current.
		require -- from AUDIO_SOUND
			sound_is_open: is_open
		do
			Result := bits_per_sample_internal
		end

	channel_count: INTEGER_32
			-- Get the channel number of Current (1=mono, 2=stereo, etc.).
		require -- from AUDIO_SOUND
			sound_is_open: is_open
		do
			Result := channel_count_internal
		end

	close
			-- Stop the management of the stream
		require -- from AUDIO_SOUND
			sound_is_open: is_open
		do
			file.close
			is_open := False
		ensure -- from AUDIO_SOUND
			sound_is_closed: not is_open
		end

	frequency: INTEGER_32
			-- Get the frequency (sample rate) of Current.
		require -- from AUDIO_SOUND
			sound_is_open: is_open
		do
			Result := frequency_internal
		end

	generating_type: TYPE [detachable AUDIO_SOUND_WAV_FILE]
			-- Type of current object
			-- (type of which it is a direct instance)
			-- (from ANY)
		external
			"built_in"
		ensure -- from ANY
			generating_type_not_void: Result /= Void
		end

	generator: STRING_8
			-- Name of current object's generating class
			-- (base class of the type of which it is a direct instance)
			-- (from ANY)
		external
			"built_in"
		ensure -- from ANY
			generator_not_void: Result /= Void
			generator_not_empty: not Result.is_empty
		end

	has_ressource_error: BOOLEAN
			-- Has an error occured while opening Current
			-- (from GAME_RESSOURCE)

	has_error: BOOLEAN
			-- Is the library has generate an error
			-- (from GAME_ERROR_MANAGER)

	is_open: BOOLEAN
			-- Is Current has been properly opened
			-- (from GAME_RESSOURCE)

	is_openable: BOOLEAN
			-- Can Current be open
		do
			Result := file.exists and then file.is_readable
		end

	is_seekable: BOOLEAN
			-- Return true if Current support the seek functionnality.
		require -- from AUDIO_SOUND
			sound_is_open: is_open
		do
			Result := True
		end

	is_signed: BOOLEAN
			-- True if the frames in the buffer are signed.
		require -- from AUDIO_SOUND
			sound_is_open: is_open
		do
			Result := not (bits_per_sample_internal = 8)
		end

	last_error: READABLE_STRING_GENERAL
			-- The last error generate by the library
			-- (from GAME_ERROR_MANAGER)
		do
			if attached message as la_message then
				Result := la_message
			else
				Result := ""
			end
		end

	open
			-- Open Current
		require -- from GAME_RESSOURCE
			ressource_is_openable: is_openable
			ressource_is_not_open: not is_open and not has_ressource_error
		do
			file.open_read
			process_header
			is_finished := False
			is_open := not has_error
			has_ressource_error := has_error
		ensure -- from GAME_RESSOURCE
			ressource_is_open: is_open or has_ressource_error
		end

	restart
			-- Restart Current to the beginning.
		require -- from AUDIO_SOUND
			sound_is_open: is_open
		do
			file.go (data_starting_offset)
			is_finished := False
		end

	sample_count: INTEGER_64
			-- The total number of frames in Current
		require -- from AUDIO_SOUND
			sound_is_open: is_open
			is_seekable: is_seekable
		do
			Result := data_size.to_integer_64 // byte_per_buffer_sample.to_integer_64
		end

	sample_position: INTEGER_64
			-- The number of frames since the beginning of Current
		require -- from AUDIO_SOUND
			sound_is_open: is_open
			is_seekable: is_seekable
		do
			Result := ((file.position - data_starting_offset) // byte_per_buffer_sample) + 1.to_integer_64
		end

	sample_seek (a_frame_number: INTEGER_64)
			-- Seek at the frame a_frame_number from the beginning of Current
		require -- from AUDIO_SOUND
			sound_is_open: is_open
			is_seekable: is_seekable
			is_seek_inside: a_frame_number >= 1 and a_frame_number <= sample_count
		do
			file.go ((data_starting_offset.to_integer_64 + (byte_per_buffer_sample.to_integer_64 * (a_frame_number - 1))).to_integer_32)
			is_finished := False
		end
	
feature --Access

	is_finished: BOOLEAN
			-- Current has finished it's playback
			-- (from AUDIO_SOUND)

	time_count: INTEGER_64
			-- The total number of milliseconds in Current
			-- (from AUDIO_SOUND)
		require -- from AUDIO_SOUND
			sound_is_open: is_open
			is_seekable: is_seekable
		do
			Result := (sample_count * 1000) // frequency.to_integer_64
		end

	time_position: INTEGER_64
			-- The number of milliseconds since the beginning of Current
			-- (from AUDIO_SOUND)
		require -- from AUDIO_SOUND
			sound_is_open: is_open
			is_seekable: is_seekable
		do
			Result := ((sample_position - 1) * 1000) // frequency.to_integer_64
		end

	time_seek (a_milliseconds: INTEGER_64)
			-- Seek at a_milliseconds from the beginning of Current
			-- (from AUDIO_SOUND)
		require -- from AUDIO_SOUND
			sound_is_open: is_open
			is_seekable: is_seekable
			is_seek_inside: a_milliseconds >= 1 and a_milliseconds <= time_count
		do
			sample_seek (((a_milliseconds * frequency.to_integer_64) // 1000) + 1)
		end
	
feature -- Comparison

	frozen deep_equal (a: detachable ANY; b: like arg #1): BOOLEAN
			-- Are a and b either both void
			-- or attached to isomorphic object structures?
			-- (from ANY)
		do
			if a = Void then
				Result := b = Void
			else
				Result := b /= Void and then a.is_deep_equal (b)
			end
		ensure -- from ANY
			instance_free: class
			shallow_implies_deep: standard_equal (a, b) implies Result
			both_or_none_void: (a = Void) implies (Result = (b = Void))
			same_type: (Result and (a /= Void)) implies (b /= Void and then a.same_type (b))
			symmetric: Result implies deep_equal (b, a)
		end

	frozen equal (a: detachable ANY; b: like arg #1): BOOLEAN
			-- Are a and b either both void or attached
			-- to objects considered equal?
			-- (from ANY)
		do
			if a = Void then
				Result := b = Void
			else
				Result := b /= Void and then a.is_equal (b)
			end
		ensure -- from ANY
			instance_free: class
			definition: Result = (a = Void and b = Void) or else ((a /= Void and b /= Void) and then a.is_equal (b))
		end

	frozen is_deep_equal alias "≡≡≡" (other: AUDIO_SOUND_WAV_FILE): BOOLEAN
			-- Are Current and other attached to isomorphic object structures?
			-- (from ANY)
		require -- from ANY
			other_not_void: other /= Void
		external
			"built_in"
		ensure -- from ANY
			shallow_implies_deep: standard_is_equal (other) implies Result
			same_type: Result implies same_type (other)
			symmetric: Result implies other.is_deep_equal (Current)
		end

	is_equal (other: AUDIO_SOUND_WAV_FILE): BOOLEAN
			-- Is other attached to an object considered
			-- equal to current object?
			-- (from ANY)
		require -- from ANY
			other_not_void: other /= Void
		external
			"built_in"
		ensure -- from ANY
			symmetric: Result implies other ~ Current
			consistent: standard_is_equal (other) implies Result
		end

	frozen standard_equal (a: detachable ANY; b: like arg #1): BOOLEAN
			-- Are a and b either both void or attached to
			-- field-by-field identical objects of the same type?
			-- Always uses default object comparison criterion.
			-- (from ANY)
		do
			if a = Void then
				Result := b = Void
			else
				Result := b /= Void and then a.standard_is_equal (b)
			end
		ensure -- from ANY
			instance_free: class
			definition: Result = (a = Void and b = Void) or else ((a /= Void and b /= Void) and then a.standard_is_equal (b))
		end

	frozen standard_is_equal alias "≜" (other: AUDIO_SOUND_WAV_FILE): BOOLEAN
			-- Is other attached to an object of the same type
			-- as current object, and field-by-field identical to it?
			-- (from ANY)
		require -- from ANY
			other_not_void: other /= Void
		external
			"built_in"
		ensure -- from ANY
			same_type: Result implies same_type (other)
			symmetric: Result implies other.standard_is_equal (Current)
		end
	
feature -- Status report

	conforms_to (other: ANY): BOOLEAN
			-- Does type of current object conform to type
			-- of other (as per Eiffel: The Language, chapter 13)?
			-- (from ANY)
		require -- from ANY
			other_not_void: other /= Void
		external
			"built_in"
		end

	same_type (other: ANY): BOOLEAN
			-- Is type of current object identical to type of other?
			-- (from ANY)
		require -- from ANY
			other_not_void: other /= Void
		external
			"built_in"
		ensure -- from ANY
			definition: Result = (conforms_to (other) and other.conforms_to (Current))
		end
	
feature -- Duplication

	frozen clone (other: detachable ANY): like other
		obsolete "Use `twin' instead. [2017-05-31]"
			-- Void if other is void; otherwise new object
			-- equal to other
			--
			-- For non-void other, clone calls copy;
			-- to change copying/cloning semantics, redefine copy.
			-- (from ANY)
		do
			if other /= Void then
				Result := other.twin
			end
		ensure -- from ANY
			instance_free: class
			equal: Result ~ other
		end

	copy (other: AUDIO_SOUND_WAV_FILE)
			-- Update current object using fields of object attached
			-- to other, so as to yield equal objects.
			-- (from ANY)
		require -- from ANY
			other_not_void: other /= Void
			type_identity: same_type (other)
		external
			"built_in"
		ensure -- from ANY
			is_equal: Current ~ other
		end

	frozen deep_clone (other: detachable ANY): like other
		obsolete "Use `deep_twin' instead. [2017-05-31]"
			-- Void if other is void: otherwise, new object structure
			-- recursively duplicated from the one attached to other
			-- (from ANY)
		do
			if other /= Void then
				Result := other.deep_twin
			end
		ensure -- from ANY
			instance_free: class
			deep_equal: deep_equal (other, Result)
		end

	frozen deep_copy (other: AUDIO_SOUND_WAV_FILE)
			-- Effect equivalent to that of:
			--		copy (other . deep_twin)
			-- (from ANY)
		require -- from ANY
			other_not_void: other /= Void
		do
			copy (other.deep_twin)
		ensure -- from ANY
			deep_equal: deep_equal (Current, other)
		end

	frozen deep_twin: AUDIO_SOUND_WAV_FILE
			-- New object structure recursively duplicated from Current.
			-- (from ANY)
		external
			"built_in"
		ensure -- from ANY
			deep_twin_not_void: Result /= Void
			deep_equal: deep_equal (Current, Result)
		end

	frozen standard_clone (other: detachable ANY): like other
		obsolete "Use `standard_twin' instead. [2017-05-31]"
			-- Void if other is void; otherwise new object
			-- field-by-field identical to other.
			-- Always uses default copying semantics.
			-- (from ANY)
		do
			if other /= Void then
				Result := other.standard_twin
			end
		ensure -- from ANY
			instance_free: class
			equal: standard_equal (Result, other)
		end

	frozen standard_copy (other: AUDIO_SOUND_WAV_FILE)
			-- Copy every field of other onto corresponding field
			-- of current object.
			-- (from ANY)
		require -- from ANY
			other_not_void: other /= Void
			type_identity: same_type (other)
		external
			"built_in"
		ensure -- from ANY
			is_standard_equal: standard_is_equal (other)
		end

	frozen standard_twin: AUDIO_SOUND_WAV_FILE
			-- New object field-by-field identical to other.
			-- Always uses default copying semantics.
			-- (from ANY)
		external
			"built_in"
		ensure -- from ANY
			standard_twin_not_void: Result /= Void
			equal: standard_equal (Result, Current)
		end

	frozen twin: AUDIO_SOUND_WAV_FILE
			-- New object equal to Current
			-- twin calls copy; to change copying/twinning semantics, redefine copy.
			-- (from ANY)
		external
			"built_in"
		ensure -- from ANY
			twin_not_void: Result /= Void
			is_equal: Result ~ Current
		end
	
feature -- Basic operations

	frozen as_attached: attached AUDIO_SOUND_WAV_FILE
		obsolete "Remove calls to this feature. [2017-05-31]"
			-- Attached version of Current.
			-- (Can be used during transitional period to convert
			-- non-void-safe classes to void-safe ones.)
			-- (from ANY)
		do
			Result := Current
		end

	frozen default: detachable AUDIO_SOUND_WAV_FILE
			-- Default value of object's type
			-- (from ANY)
		do
		end

	frozen default_pointer: POINTER
			-- Default value of type POINTER
			-- (Avoid the need to write p.default for
			-- some p of type POINTER.)
			-- (from ANY)
		do
		ensure -- from ANY
			instance_free: class
		end

	default_rescue
			-- Process exception for routines with no Rescue clause.
			-- (Default: do nothing.)
			-- (from ANY)
		do
		end

	frozen do_nothing
			-- Execute a null action.
			-- (from ANY)
		do
		ensure -- from ANY
			instance_free: class
		end
	
feature {NONE} -- Implementation

	clear_error
			-- Remove error pending in Current
			-- (from GAME_ERROR_MANAGER)
		do
			has_error := False
		ensure -- from GAME_ERROR_MANAGER
			no_error: not has_error
		end

	disable_print_on_error
			-- Desactive the print_on_error functionnality.
			-- (from GAME_ERROR_MANAGER)
		do
			Print_on_error_internal.put (False)
		end

	enable_print_on_error
			-- Active the print_on_error functionnality.
			-- (from GAME_ERROR_MANAGER)
		do
			Print_on_error_internal.put (True)
		end

	message: detachable READABLE_STRING_GENERAL
			-- The specific message for the last error
			-- (from GAME_ERROR_MANAGER)

	print_on_error: BOOLEAN
			-- When an error occured, the library will print
			-- informations about the error on the error console
			-- output (default is True).
			-- (from GAME_ERROR_MANAGER)
		do
			Result := Print_on_error_internal.item
		end

	Print_on_error_internal: CELL [BOOLEAN]
			-- True when an error occured,
			-- The library will print it right away.
			-- (from GAME_ERROR_MANAGER)
		once ("PROCESS")
			create Result.put (True)
		end

	put_error (a_general_message, a_specific_error: READABLE_STRING_GENERAL)
			-- Create an error using a_general_error for the debug information
			-- and a_specific_error for the lasting information
			-- (from GAME_ERROR_MANAGER)
		local
			l_converter: UTF_CONVERTER
		do
			message := a_specific_error
			has_error := True
			if Print_on_error_internal.item then
				if a_general_message.is_valid_as_string_8 then
					Io.Error.put_string (a_general_message.to_string_8 + "%N")
				else
					create l_converter;
					Io.Error.put_string (l_converter.string_32_to_utf_8_string_8 (a_general_message.to_string_32) + "%N")
				end
				if a_specific_error.is_valid_as_string_8 then
					Io.Error.put_string (a_specific_error.to_string_8 + "%N")
				else
					create l_converter;
					Io.Error.put_string (l_converter.string_32_to_utf_8_string_8 (a_specific_error.to_string_32) + "%N")
				end
			end
		ensure -- from GAME_ERROR_MANAGER
				has_error
		end

	set_print_on_error (a_value: BOOLEAN)
			-- Assign to print_on_error the value of a_value
			-- (from GAME_ERROR_MANAGER)
		do
			if a_value then
				enable_print_on_error
			else
				disable_print_on_error
			end
		ensure -- from GAME_ERROR_MANAGER
			is_assign: print_on_error ~ a_value
		end
	
feature {AUDIO_SOURCE}{AUDIO_SOURCE} 

	byte_per_buffer_sample: INTEGER_32
			-- The number of byte for one frame of Current.
		require -- from AUDIO_SOUND
			sound_is_open: is_open
		do
			Result := bytes_per_sample.to_integer_32
		end

	fill_buffer (a_buffer: POINTER; a_max_length: INTEGER_32)
			-- Fill the next data samples in a_buffer (no more than a_max_length byte)
			-- The actual number of byte placed in a_buffer will be available in last_buffer_size
			-- Warning: side effect on a_buffer
		require -- from AUDIO_SOUND
			sound_is_open: is_open
		local
			l_managed_pointer: MANAGED_POINTER
		do
			if file.readable then
				create l_managed_pointer.share_from_pointer (a_buffer, a_max_length);
				file.read_to_managed_pointer (l_managed_pointer, 0, a_max_length)
				last_buffer_size := file.bytes_read
			else
				last_buffer_size := 0
			end
			if last_buffer_size = 0 then
				is_finished := True
			end
		end
	
feature {AUDIO_SOURCE} 

	last_buffer_size: INTEGER_32
			-- The size of the last buffer filled by fill_buffer
			-- (from AUDIO_SOUND)
	
feature {NONE} -- Implementation - Variable

	bits_per_sample_internal: INTEGER_32
			-- The bit resolution of one frame of Current.

	byte_rate: INTEGER_32

	bytes_per_sample: INTEGER_32
			-- The number of byte for one frame of Current.

	channel_count_internal: INTEGER_32
			-- The number of channel of Current

	data_size: NATURAL_32
			-- The size of a data in the file

	data_starting_offset: INTEGER_32
			-- Where in the file start the data

	file: GAME_FILE
			-- The file used to read Currents data

	frequency_internal: INTEGER_32
			-- The frequency (sample rate) of Current.
	
feature {NONE} -- Initialisation

	default_create
			-- Initialization of Current
			-- (from GAME_RESSOURCE)
		require -- from  ANY
			True
		do
			is_open := False
			has_ressource_error := False
		end
	
feature -- Output

	Io: STD_FILES
			-- Handle to standard file setup
			-- (from ANY)
		once
			create Result;
			Result.set_output_default
		ensure -- from ANY
			instance_free: class
			io_not_void: Result /= Void
		end

	out: STRING_8
			-- New string containing terse printable representation
			-- of current object
			-- (from ANY)
		do
			Result := tagged_out
		ensure -- from ANY
			out_not_void: Result /= Void
		end

	print (o: detachable ANY)
			-- Write terse external representation of o
			-- on standard output.
			-- (from ANY)
		local
			s: READABLE_STRING_8
		do
			if attached o then
				s := o.out
				if attached {READABLE_STRING_32} s as s32 then
					Io.put_string_32 (s32)
				elseif attached {READABLE_STRING_8} s as s8 then
					Io.put_string (s8)
				else
					Io.put_string_32 (s.as_string_32)
				end
			end
		ensure -- from ANY
			instance_free: class
		end

	frozen tagged_out: STRING_8
			-- New string containing terse printable representation
			-- of current object
			-- (from ANY)
		external
			"built_in"
		ensure -- from ANY
			tagged_out_not_void: Result /= Void
		end
	
feature -- Platform

	Operating_environment: OPERATING_ENVIRONMENT
			-- Objects available from the operating system
			-- (from ANY)
		once
			create Result
		ensure -- from ANY
			instance_free: class
			operating_environment_not_void: Result /= Void
		end
	
feature {NONE} -- Retrieval

	frozen internal_correct_mismatch
			-- Called from runtime to perform a proper dynamic dispatch on correct_mismatch
			-- from MISMATCH_CORRECTOR.
			-- (from ANY)
		local
			l_msg: STRING_32
			l_exc: EXCEPTIONS
		do
			if attached {MISMATCH_CORRECTOR} Current as l_corrector then
				l_corrector.correct_mismatch
			else
				create l_msg.make_from_string ("Mismatch: ".as_string_32)
				create l_exc;
				l_msg.append (generating_type.name_32);
				l_exc.raise_retrieval_exception (l_msg)
			end
		end
	
invariant
		-- from AUDIO_SOUND
	errors_valid: has_error ~ has_ressource_error

		-- from ANY
	reflexive_equality: standard_is_equal (Current)
	reflexive_conformance: conforms_to (Current)

end -- class AUDIO_SOUND_WAV_FILE

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