(**
 	Module: Interpreter	
	Description: Input wave -> interpretation -> output wave
	@author WANG Haisheng	
	Created: 15/05/2013	Modified: 04/06/2013
*)

open Faustexp;;
open Interpreter;;

(* EXCEPTIONS *)

(** Exception raised when no string expression of faust process is typed in console.*)
exception Missing_Expression;;



(* MACRO *)

(** Macro constants of input/output route.*)
type io_macro = 
  | Input_Route_string
  | Output_Route_string
  | Dsp_Route_string;;

(** val io_macro_to_string : io_macro -> string.*)
let io_macro_to_string m = match m with
  | Input_Route_string -> "input_sounds/"
  | Output_Route_string -> "output_sounds/"
  | Dsp_Route_string -> "dsp_files/";;


(** val set_GC : unit -> unit *)
let set_GC () = 
	let _ = Gc.set { (Gc.get()) with Gc.minor_heap_size = 0xFFFFFF } in
	let _ = Gc.set { (Gc.get()) with Gc.major_heap_increment = 0xFFFFFF } in
	let _ = Gc.set { (Gc.get()) with Gc.space_overhead = 100 } in
	let _ = Gc.set { (Gc.get()) with Gc.max_overhead = 0xFFFFF } in
	let _ = Gc.set { (Gc.get()) with Gc.stack_limit = 0xFFFFF } in
	let _ = Gc.set { (Gc.get()) with Gc.allocation_policy = 0 } in
	() ;;

(* INPUT && OUTPUT*)

(** val read_input_wave : string array -> int list * float array list
    [read_input_wave argv] gets information from command line, 
    returns sample rate list and data (in form of float array) list. 
*)
let read_input_wave = fun argv ->
        let n_input = (Array.length argv) - 3 in
	if n_input < 0 then 
	        raise Missing_Expression
	else if n_input = 0 then 
	        ([], [])
	else
	        (* open wave file *)
		let file_string_array = Array.sub argv 3 n_input in
		let make_chemin s = io_macro_to_string Input_Route_string ^ s in
		let file_chemin_string_array = Array.map make_chemin file_string_array in
		let file_array = Array.map Sndfile.openfile file_chemin_string_array in
		let file_list = Array.to_list file_array in

		(* prepare data container *)
		let frames_array = Array.map Int64.to_int (Array.map Sndfile.frames file_array) in
		let create_data_array num = Array.create num 1. in
		let data_float_array_array = Array.map create_data_array frames_array in
		let data_float_array_list = Array.to_list data_float_array_array in
		
		(* read sample rates and data *)
		let rate_list = List.map Sndfile.samplerate file_list in
		let _ = List.map2 Sndfile.read file_list data_float_array_list in
		let _ = List.map Sndfile.close file_list in
		(rate_list, data_float_array_list);;


(** val write_output_wave : int list -> int list -> float_array_list -> unit.
    [write_output_wave channel_numbers sample_rates data]
*)
let write_output_wave = fun channel_int_list -> fun rate_int_list -> fun data_float_array_list ->
  	let () = print_endline("Making output wave files...") in
	
	(* make output wave file names : output0, output1, ... *)
	let n_output = List.length data_float_array_list in
	let n_array = Array.init n_output (fun n -> n) in
	let make_file_name i = "output" ^ (string_of_int i) ^ ".wav" in

	(* make output wave file routes *)
	let make_chemin s = io_macro_to_string Output_Route_string ^ s in
	let file_name_string_array = Array.map make_file_name n_array in
	let file_chemin_string_array = Array.map make_chemin file_name_string_array in
	let file_chemin_string_list = Array.to_list file_chemin_string_array in

	(* open files for writing with respects to channel numbers and sample rates *)
	let file_format = Sndfile.format Sndfile.MAJOR_WAV Sndfile.MINOR_PCM_16 in
	let openwr = fun file_chemin_string -> fun channel -> fun rate -> 
	  Sndfile.openfile ~info:(Sndfile.RDWR, file_format, channel, rate) file_chemin_string in
	let openwr_fun_list = fun fl -> fun cl -> fun rl -> fun i -> 
	  openwr (List.nth fl i) (List.nth cl i) (List.nth rl i) in
	let output_file_list = List.map 
	    (openwr_fun_list file_chemin_string_list channel_int_list rate_int_list) 
	    (Array.to_list (Array.init n_output (fun n -> n))) in

	(* write data into files *)
	let _ = List.map2 Sndfile.write output_file_list data_float_array_list in
	let _ = List.map Sndfile.close output_file_list in
	print_endline("Success.");;


let write_output_txt = fun channel_int_list -> fun data_float_array_list ->
        let () = print_endline("Making output txt files...") in

	(* make output txt file names : output0, output1, ... *)
	let n_output = List.length data_float_array_list in
	let n_array = Array.init n_output (fun n -> n) in
	let make_file_name i = "output" ^ (string_of_int i) ^ ".csv" in

	(* make output wave file routes *)
	let make_chemin s = io_macro_to_string Output_Route_string ^ s in
	let file_name_string_array = Array.map make_file_name n_array in
	let file_chemin_string_array = Array.map make_chemin file_name_string_array in
	let file_chemin_string_list = Array.to_list file_chemin_string_array in

	(* open output channels *)
        let file_list = List.map open_out file_chemin_string_list in
	let array_to_string = fun data_float_array -> fun channel_int ->
	  let data_length = Array.length data_float_array in
	  let rec to_string_rec = 
	    fun data -> fun channel -> fun n -> fun i -> fun column ->
	      if i < n then 
		(
		let element = string_of_float (data.(i)) in
		if column < (channel - 1) then 
		  element ^ "," ^ (to_string_rec data channel n (i + 1) (column + 1))
		else if column = (channel - 1) then
		  element ^ "\n" ^ (to_string_rec data channel n (i + 1) 0)
		else raise (Invalid_argument "write_output_txt.")
		    )
	      else "" in
	  to_string_rec data_float_array channel_int data_length 0 0 in

	let data_string_list = List.map2 array_to_string data_float_array_list channel_int_list in
	let _ = List.map2 output_string file_list data_string_list in
	let _ = List.map close_out file_list in
	print_endline("Success");;


(* MAIN *)

(** val main : unit -> unit
main function reads console input strings (Sys.argv) with
input: string of faust process, input waves in default directory 'input_sounds/'
output: output waves in default directory 'output_sounds/'.*)

let main () = 

        (* ignore system alarm clock *)
        let _ = Sys.signal Sys.sigalrm Sys.Signal_ignore in

	(* set garbage collector *)
	let _ = set_GC () in

	(* read input wave files *)
	let (input_rate_list, input_float_array_list) = read_input_wave Sys.argv in
	
	(* select output type *)
	let output_type = Sys.argv.(1) in

	try
	        (* preprocess *)
		let dsp_file_route_string = (io_macro_to_string Dsp_Route_string) ^ Sys.argv.(2) in
		let exp_string = Preprocess.preprocess(dsp_file_route_string) in

		(* parsing *)
		let exp_faust = exp_of_string exp_string in

		(* interpretation *)
		let (output_channel_list, output_rate_list, output_float_array_list) = 
		  interpreter exp_faust (input_rate_list, input_float_array_list) in

	        (* make output wave files *)
		if output_type = "-wav" then
		  write_output_wave output_channel_list output_rate_list output_float_array_list
		else if output_type = "-txt" then
		  write_output_txt output_channel_list output_float_array_list
		else raise (Invalid_argument ("Unkown option: " ^ output_type))

	with NotYetDone ->
		print_endline("Operation not yet programed..");;

main();;