#include <stdlib.h>

#include <devices/ahi.h>
#include <proto/exec.h>

#ifndef __MORPHOS__
#define AllocTaskPooled(size) AllocMem(size, MEMF_ANY)
#define FreeTaskPooled(mem, size) FreeMem(mem, size)
#endif

#include "uadeconstants.h"
#include "audio.h"
#include "uade123.h"

/* this is hardcoded baby! */
#if (UADE_BYTES_PER_SAMPLE == 1)
  #if (UADE_CHANNELS == 1)
    #define type AHIST_M8S
  #elif (UADE_CHANNELS == 2)
    #define type AHIST_S8S
  #else
    #error Invalid channel number.
  #endif
#elif (UADE_BYTES_PER_SAMPLE == 2)
  #if (UADE_CHANNELS == 1)
    #define type AHIST_M16S
  #elif (UADE_CHANNELS == 2)
    #define type AHIST_S16S
  #else
    #error Invalid channel number.
  #endif
#else
  #error Invalid bytes per sample value.
#endif

#define BUFSIZE (8192 * UADE_BYTES_PER_SAMPLE * UADE_CHANNELS)
static char AHIBuf[2][BUFSIZE];

static ULONG rate;
static struct MsgPort *AHIPort = NULL;
static struct AHIRequest *AHIReq[2] = { NULL, NULL };

static int active = 0;
static int slots = 2;

void audio_close (void)
{
	if (AHIReq[1])
	{
		if (!CheckIO((struct IORequest *) AHIReq[1]))
		{
			AbortIO((struct IORequest *) AHIReq[1]);
			WaitIO((struct IORequest *) AHIReq[1]);
		}
		FreeTaskPooled(AHIReq[1], sizeof(struct AHIRequest));
		AHIReq[1] = NULL;
	}
	
	if (AHIReq[0])
	{
		if (!CheckIO((struct IORequest *) AHIReq[0]))
		{
			AbortIO((struct IORequest *) AHIReq[0]);
			WaitIO((struct IORequest *) AHIReq[0]);
		}
		if (AHIReq[0]->ahir_Std.io_Device)
		{
			CloseDevice((struct IORequest *) AHIReq[0]);
			AHIReq[0]->ahir_Std.io_Device = NULL;
		}
		DeleteIORequest((struct IORequest *) AHIReq[0]);
		AHIReq[0] = NULL;
	}
	
	if (AHIPort)
	{
		DeleteMsgPort(AHIPort);
		AHIPort = NULL;
	}
}

int audio_init(const struct uade_config *uc)
{
	if (uade_no_audio_output)
		return 1;
		
	rate = uc->frequency;

	if ((AHIPort = CreateMsgPort()))
	{
		if ((AHIReq[0] = (struct AHIRequest *) CreateIORequest(AHIPort, sizeof(struct AHIRequest))))
		{
			AHIReq[0]->ahir_Version = 4;
			if ((AHIReq[1] = (struct AHIRequest *) AllocTaskPooled(sizeof(struct AHIRequest))))
			{
				if (!OpenDevice("ahi.device", AHI_DEFAULT_UNIT, (struct IORequest *)AHIReq[0], 0))
				{
					AHIReq[0]->ahir_Std.io_Command = CMD_WRITE;
					AHIReq[0]->ahir_Std.io_Offset = 0;
					AHIReq[0]->ahir_Type = type;
					AHIReq[0]->ahir_Frequency = rate;
					AHIReq[0]->ahir_Volume = 0x10000;
					AHIReq[0]->ahir_Position = 0x8000;

					CopyMemQuick(AHIReq[0], AHIReq[1], sizeof(struct AHIRequest));
					return 1;
				}
				FreeTaskPooled(AHIReq[1], sizeof(struct AHIRequest));
			}
			DeleteIORequest((struct IORequest *) AHIReq[0]);
		}
		DeleteMsgPort(AHIPort);
	}

	return 0;
}

int audio_play(unsigned char* output_samples, int num_bytes)
{
	int size;

	if (uade_no_audio_output)
		return 1;

	while (num_bytes)
	{
		WaitIO((struct IORequest *) AHIReq[active]);
			
		size = (BUFSIZE > num_bytes) ? num_bytes : BUFSIZE;
		CopyMem(output_samples, AHIBuf[active], num_bytes);
		num_bytes -= size;
		
		AHIReq[active]->ahir_Std.io_Data = AHIBuf[active];
		AHIReq[active]->ahir_Std.io_Length = size;
		AHIReq[active]->ahir_Link = AHIReq[active ^ 1];

		SendIO((struct IORequest *) AHIReq[active]);
		
		// swap buffers
		active ^= 1;
	}

	return 1;
}