using System;
using System.IO;

namespace MAME.Core
{
    public unsafe class K054539
    {
        public struct k054539_channel
        {
            public int pos;
            public int pfrac;
            public int val;
            public int pval;
        }
        public struct k054539_info
        {
            public double[] voltab;
            public double[] pantab;

            public double[] k054539_gain;
            public byte[][] k054539_posreg_latch;
            public int k054539_flags;

            public byte[] regs;
            public short[] ram;
            public int reverb_pos;

            public int cur_ptr;
            public int cur_limit;
            public byte[] cur_zone;
            public byte[] rom;
            public int rom_size;
            public uint rom_mask;

            public k054539_channel[] channels;
        }
        public static byte[] k054539rom;
        public static k054539_info info;
        public static int zoneflag, zonedata;
        public static apanhandler apan;
        public static irqhandler irq;
        public delegate void apanhandler(double d1, double d2);
        public delegate void irqhandler();
        public static bool k054539_regupdate()
        {
            return (info.regs[0x22f] & 0x80) == 0;
        }
        public static void k054539_keyon(int channel)
        {
            if (k054539_regupdate())
            {
                info.regs[0x22c] |= (byte)(1 << channel);
            }
        }
        public static void k054539_keyoff(int channel)
        {
            if (k054539_regupdate())
            {
                info.regs[0x22c] &= (byte)(~(1 << channel));
            }
        }
        public static void k054539_update(int offset, int length)
        {
            short[] dpcm = new short[16] {
                0<<8, 1<<8, 4<<8, 9<<8, 16<<8, 25<<8, 36<<8, 49<<8,
                -64<<8, -49<<8, -36<<8, -25<<8, -16<<8, -9<<8, -4<<8, -1<<8
            };
            int j, ch, reverb_pos;
            byte[] samples;
            int rom_mask;
            int offset1;
            int base1_offset, base2_offset;
            k054539_channel chan;
            int cur_pos, cur_pfrac, cur_val, cur_pval;
            int delta, rdelta, fdelta, pdelta;
            int vol, bval, pan, i;
            double gain, lvol, rvol, rbvol;
            reverb_pos = info.reverb_pos;
            for (i = 0; i < 2; i++)
            {
                for (j = 0; j < length; j++)
                {
                    Sound.k054539stream.streamoutput_Ptrs[i][offset + j] = 0;
                }
            }
            samples = k054539rom;//info.rom;
            rom_mask = (int)info.rom_mask;
            if ((info.regs[0x22f] & 1) == 0)
            {
                return;
            }
            info.reverb_pos = (reverb_pos + length) & 0x3fff;
            for (ch = 0; ch < 8; ch++)
            {
                if ((info.regs[0x22c] & (1 << ch)) != 0)
                {
                    base1_offset = 0x20 * ch;
                    base2_offset = 0x200 + 0x2 * ch;
                    chan = info.channels[ch];
                    delta = info.regs[base1_offset + 0x00] | (info.regs[base1_offset + 0x01] << 8) | (info.regs[base1_offset + 0x02] << 16);
                    vol = info.regs[base1_offset + 0x03];
                    bval = vol + info.regs[base1_offset + 0x04];
                    if (bval > 255)
                    {
                        bval = 255;
                    }
                    pan = info.regs[base1_offset + 0x05];
                    if (pan >= 0x81 && pan <= 0x8f)
                    {
                        pan -= 0x81;
                    }
                    else if (pan >= 0x11 && pan <= 0x1f)
                    {
                        pan -= 0x11;
                    }
                    else
                    {
                        pan = 0x18 - 0x11;
                    }
                    gain = info.k054539_gain[ch];
                    lvol = info.voltab[vol] * info.pantab[pan] * gain;
                    if (lvol > 1.80)
                    {
                        lvol = 1.80;
                    }
                    rvol = info.voltab[vol] * info.pantab[0xe - pan] * gain;
                    if (rvol > 1.80)
                    {
                        rvol = 1.80;
                    }
                    rbvol = info.voltab[bval] * gain / 2;
                    if (rbvol > 1.80)
                    {
                        rbvol = 1.80;
                    }
                    rdelta = (info.regs[base1_offset + 6] | (info.regs[base1_offset + 7] << 8)) >> 3;
                    rdelta = (int)(rdelta + reverb_pos) & 0x3fff;
                    cur_pos = (info.regs[base1_offset + 0x0c] | (info.regs[base1_offset + 0x0d] << 8) | (info.regs[base1_offset + 0x0e] << 16)) & rom_mask;
                    offset1 = offset;
                    if ((info.regs[base2_offset + 0] & 0x20) != 0)
                    {
                        delta = -delta;
                        fdelta = +0x10000;
                        pdelta = -1;
                    }
                    else
                    {
                        fdelta = -0x10000;
                        pdelta = +1;
                    }
                    if (cur_pos != chan.pos)
                    {
                        chan.pos = cur_pos;
                        cur_pfrac = 0;
                        cur_val = 0;
                        cur_pval = 0;
                    }
                    else
                    {
                        cur_pfrac = chan.pfrac;
                        cur_val = chan.val;
                        cur_pval = chan.pval;
                    }
                    switch (info.regs[base2_offset + 0] & 0xc)
                    {
                        case 0x0:
                            {
                                for (i = 0; i < length; i++)
                                {
                                    cur_pfrac += delta;
                                    while ((cur_pfrac & ~0xffff) != 0)
                                    {
                                        cur_pfrac += fdelta;
                                        cur_pos += pdelta;
                                        cur_pval = cur_val;
                                        cur_val = (short)(samples[cur_pos] << 8);
                                        if (cur_val == unchecked((short)0x8000))
                                        {
                                            if ((info.regs[base2_offset + 1] & 1) != 0)
                                            {
                                                cur_pos = (info.regs[base1_offset + 0x08] | (info.regs[base1_offset + 0x09] << 8) | (info.regs[base1_offset + 0x0a] << 16)) & rom_mask;
                                                cur_val = (short)(samples[cur_pos] << 8);
                                                if (cur_val != (int)(unchecked((short)0x8000)))
                                                {
                                                    continue;
                                                }
                                            }
                                            k054539_keyoff(ch);
                                            goto end_channel_0;
                                        }
                                    }
                                    Sound.k054539stream.streamoutput_Ptrs[0][offset1] += (short)(cur_val * lvol);
                                    Sound.k054539stream.streamoutput_Ptrs[1][offset1] += (short)(cur_val * rvol);
                                    offset1++;
                                    info.ram[rdelta] += (short)(cur_val * rbvol);
                                    rdelta++;
                                    rdelta &= 0x3fff;
                                }
                            end_channel_0:
                                break;
                            }
                        case 0x4:
                            {
                                pdelta <<= 1;

                                for (i = 0; i < length; i++)
                                {
                                    cur_pfrac += delta;
                                    while ((cur_pfrac & ~0xffff) != 0)
                                    {
                                        cur_pfrac += fdelta;
                                        cur_pos += pdelta;

                                        cur_pval = cur_val;
                                        cur_val = (short)(samples[cur_pos] | samples[cur_pos + 1] << 8);
                                        if (cur_val == unchecked((short)0x8000))
                                        {
                                            if ((info.regs[base2_offset + 1] & 1) != 0)
                                            {
                                                cur_pos = (info.regs[base1_offset + 0x08] | (info.regs[base1_offset + 0x09] << 8) | (info.regs[base1_offset + 0x0a] << 16)) & rom_mask;
                                                cur_val = (short)(samples[cur_pos] | samples[cur_pos + 1] << 8);
                                                if (cur_val != unchecked((short)0x8000))
                                                    continue;
                                            }
                                            k054539_keyoff(ch);
                                            goto end_channel_4;
                                        }
                                    }
                                    Sound.k054539stream.streamoutput_Ptrs[0][offset1] += (short)(cur_val * lvol);
                                    Sound.k054539stream.streamoutput_Ptrs[1][offset1] += (short)(cur_val * rvol);
                                    offset1++;
                                    info.ram[rdelta] += (short)(cur_val * rbvol);
                                    rdelta++;
                                    rdelta &= 0x3fff;
                                }
                            end_channel_4:
                                break;
                            }
                        case 0x8:
                            {
                                cur_pos <<= 1;
                                cur_pfrac <<= 1;
                                if ((cur_pfrac & 0x10000) != 0)
                                {
                                    cur_pfrac &= 0xffff;
                                    cur_pos |= 1;
                                }
                                for (i = 0; i < length; i++)
                                {
                                    cur_pfrac += delta;
                                    while ((cur_pfrac & ~0xffff) != 0)
                                    {
                                        cur_pfrac += fdelta;
                                        cur_pos += pdelta;
                                        cur_pval = cur_val;
                                        cur_val = samples[cur_pos >> 1];
                                        if (cur_val == 0x88)
                                        {
                                            if ((info.regs[base2_offset + 1] & 1) != 0)
                                            {
                                                cur_pos = ((info.regs[base1_offset + 0x08] | (info.regs[base1_offset + 0x09] << 8) | (info.regs[base1_offset + 0x0a] << 16)) & rom_mask) << 1;
                                                cur_val = samples[cur_pos >> 1];
                                                if (cur_val != 0x88)
                                                    goto next_iter;
                                            }
                                            k054539_keyoff(ch);
                                            goto end_channel_8;
                                        }
                                    next_iter:
                                        if ((cur_pos & 1) != 0)
                                        {
                                            cur_val >>= 4;
                                        }
                                        else
                                        {
                                            cur_val &= 15;
                                        }
                                        cur_val = cur_pval + dpcm[cur_val];
                                        if (cur_val < -32768)
                                        {
                                            cur_val = -32768;
                                        }
                                        else if (cur_val > 32767)
                                        {
                                            cur_val = 32767;
                                        }
                                    }
                                    Sound.k054539stream.streamoutput_Ptrs[0][offset1] += (short)(cur_val * lvol);
                                    Sound.k054539stream.streamoutput_Ptrs[1][offset1] += (short)(cur_val * rvol);
                                    offset1++;
                                    info.ram[rdelta] += (short)(cur_val * rbvol);
                                    rdelta++;
                                    rdelta &= 0x3fff;
                                }
                            end_channel_8:
                                cur_pfrac >>= 1;
                                if ((cur_pos & 1) != 0)
                                {
                                    cur_pfrac |= 0x8000;
                                }
                                cur_pos >>= 1;
                                break;
                            }
                        default:
                            break;
                    }
                    chan.pos = cur_pos;
                    chan.pfrac = cur_pfrac;
                    chan.pval = cur_pval;
                    chan.val = cur_val;
                    if (k054539_regupdate())
                    {
                        info.regs[base1_offset + 0x0c] = (byte)(cur_pos & 0xff);
                        info.regs[base1_offset + 0x0d] = (byte)(cur_pos >> 8 & 0xff);
                        info.regs[base1_offset + 0x0e] = (byte)(cur_pos >> 16 & 0xff);
                    }
                }
            }
            if ((info.k054539_flags & 2) == 0)
            {
                for (i = 0; i < length; i++)
                {
                    short val = info.ram[(i + reverb_pos) & 0x3fff];
                    Sound.k054539stream.streamoutput_Ptrs[0][offset + i] += val;
                    Sound.k054539stream.streamoutput_Ptrs[1][offset + i] += val;
                }
            }
            if (reverb_pos + length > 0x4000)
            {
                i = 0x4000 - reverb_pos;
                for (j = 0; j < i; j++)
                {
                    info.ram[reverb_pos + j] = 0;
                }
                for (j = 0; j < length - i; j++)
                {
                    info.ram[j] = 0;
                }
            }
            else
            {
                for (j = 0; j < length; j++)
                {
                    info.ram[reverb_pos + j] = 0;
                }
            }
        }
        public static void k054539_irq()
        {
            if ((info.regs[0x22f] & 0x20) != 0)
            {
                irq();
            }
        }
        public static void k054539_init_chip(int clock)
        {
            int i;
            info.k054539_flags |= 4;
            info.ram = new short[0x4000 + clock / 50];
            info.reverb_pos = 0;
            info.cur_ptr = 0;
            info.rom_size = k054539rom.Length;
            info.rom_mask = 0xffffffff;
            for (i = 0; i < 32; i++)
            {
                if ((1U << i) >= info.rom_size)
                {
                    info.rom_mask = (1U << i) - 1;
                    break;
                }
            }
            if (irq != null)
            {
                EmuTimer.timer_pulse_internal(new Atime(0, (long)(1e18 / 480)), EmuTimer.TIME_ACT.K054539_k054539_irq);
            }
        }
        static void k054539_w(int chip, int offset, byte data)
        {
            int latch, offs, ch, pan;
            int regptr_offset;
            latch = ((info.k054539_flags & 4) != 0) && ((info.regs[0x22f] & 1) != 0) ? 1 : 0;
            if (latch != 0 && offset < 0x100)
            {
                offs = (offset & 0x1f) - 0xc;
                ch = offset >> 5;
                if (offs >= 0 && offs <= 2)
                {
                    info.k054539_posreg_latch[ch][offs] = data;
                    return;
                }
            }
            else
            {
                switch (offset)
                {
                    case 0x13f:
                        pan = data >= 0x11 && data <= 0x1f ? data - 0x11 : 0x18 - 0x11;
                        if (apan != null)
                        {
                            apan(info.pantab[pan], info.pantab[0xe - pan]);
                        }
                        break;
                    case 0x214:
                        if (latch != 0)
                        {
                            for (ch = 0; ch < 8; ch++)
                            {
                                if ((data & (1 << ch)) != 0)
                                {
                                    regptr_offset = (ch << 5) + 0xc;
                                    info.regs[regptr_offset] = info.k054539_posreg_latch[ch][0];
                                    info.regs[regptr_offset + 1] = info.k054539_posreg_latch[ch][1];
                                    info.regs[regptr_offset + 2] = info.k054539_posreg_latch[ch][2];
                                    k054539_keyon(ch);
                                }
                            }
                        }
                        else
                        {
                            for (ch = 0; ch < 8; ch++)
                            {
                                if ((data & (1 << ch)) != 0)
                                {
                                    k054539_keyon(ch);
                                }
                            }
                        }
                        break;
                    case 0x215:
                        for (ch = 0; ch < 8; ch++)
                        {
                            if ((data & (1 << ch)) != 0)
                            {
                                k054539_keyoff(ch);
                            }
                        }
                        break;
                    case 0x22d:
                        if (info.regs[0x22e] == 0x80)
                        {
                            if (zoneflag == 1)
                            {
                                if (info.cur_ptr % 2 == 0)
                                {
                                    info.ram[info.cur_ptr / 2] = (short)((data << 8) | (info.ram[info.cur_ptr / 2] & 0xff));
                                }
                                else if (info.cur_ptr % 2 == 1)
                                {
                                    info.ram[info.cur_ptr / 2] = (short)((info.ram[info.cur_ptr / 2] & 0xff00) | data);
                                }
                            }
                            else if (zoneflag == 2)
                            {
                                k054539rom[zonedata + info.cur_ptr] = data;
                            }
                        }
                        info.cur_ptr++;
                        if (info.cur_ptr == info.cur_limit)
                        {
                            info.cur_ptr = 0;
                        }
                        break;
                    case 0x22e:
                        if (data == 0x80)
                        {
                            zoneflag = 1;
                        }
                        else
                        {
                            zoneflag = 2;
                            zonedata = 0x20000 * data;
                        }
                        info.cur_limit = data == 0x80 ? 0x4000 : 0x20000;
                        info.cur_ptr = 0;
                        break;
                    default:
                        break;
                }
            }
            info.regs[offset] = data;
        }
        public static byte k054539_r(int chip, int offset)
        {
            switch (offset)
            {
                case 0x22d:
                    if ((info.regs[0x22f] & 0x10) != 0)
                    {
                        byte res = 0;
                        if (zoneflag == 1)
                        {
                            if (info.cur_ptr % 2 == 0)
                            {
                                res = (byte)(info.ram[info.cur_ptr / 2] >> 8);
                            }
                            else if (info.cur_ptr % 2 == 1)
                            {
                                res = (byte)info.ram[info.cur_ptr / 2];
                            }
                        }
                        else if (zoneflag == 2)
                        {
                            res = k054539rom[zonedata + info.cur_ptr];
                        }
                        info.cur_ptr++;
                        if (info.cur_ptr == info.cur_limit)
                        {
                            info.cur_ptr = 0;
                        }
                        return res;
                    }
                    else
                    {
                        return 0;
                    }
                case 0x22c:
                    break;
                default:
                    break;
            }
            return info.regs[offset];
        }
        public static void k054539_start(int clock)
        {
            int i;
            info = new k054539_info();
            info.voltab = new double[256];
            info.pantab = new double[0xf];
            info.k054539_gain = new double[8];
            info.k054539_posreg_latch = new byte[8][];
            info.regs = new byte[0x230];

            for (i = 0; i < 8; i++)
            {
                info.k054539_gain[i] = 1.0;
                info.k054539_posreg_latch[i] = new byte[3];
            }
            info.k054539_flags = 0;
            info.channels = new k054539_channel[8];
            irq = null;
            switch (Machine.sBoard)
            {
                case "Konami 68000":
                    switch (Machine.sName)
                    {
                        case "prmrsocr":
                            irq = Konami68000.sound_nmi;
                            break;
                    }
                    break;
            }
            for (i = 0; i < 256; i++)
            {
                info.voltab[i] = Math.Pow(10.0, (-36.0 * (double)i / (double)0x40) / 20.0) / 4.0;
            }
            for (i = 0; i < 0xf; i++)
            {
                info.pantab[i] = Math.Sqrt(i) / Math.Sqrt(0xe);
            }
            k054539_init_chip(clock);
        }
        public static void k054539_0_w(int offset, byte data)
        {
            k054539_w(0, offset, data);
        }
        public static byte k054539_0_r(int offset)
        {
            return k054539_r(0, offset);
        }
        public static void SaveStateBinary(BinaryWriter writer)
        {
            int i, j;
            for (i = 0; i < 8; i++)
            {
                for (j = 0; j < 3; j++)
                {
                    writer.Write(info.k054539_posreg_latch[i][j]);
                }
            }
            writer.Write(info.k054539_flags);
            writer.Write(info.regs, 0, 0x230);
            for (i = 0; i < info.ram.Length; i++)
            {
                writer.Write(info.ram[i]);
            }
            writer.Write(info.reverb_pos);
            writer.Write(info.cur_ptr);
            writer.Write(info.cur_limit);
            for (i = 0; i < 8; i++)
            {
                writer.Write(info.channels[i].pos);
                writer.Write(info.channels[i].pfrac);
                writer.Write(info.channels[i].val);
                writer.Write(info.channels[i].pval);
            }
            writer.Write(zoneflag);
            writer.Write(zonedata);
        }
        public static void LoadStateBinary(BinaryReader reader)
        {
            int i, j;
            for (i = 0; i < 8; i++)
            {
                for (j = 0; j < 3; j++)
                {
                    info.k054539_posreg_latch[i][j] = reader.ReadByte();
                }
            }
            info.k054539_flags = reader.ReadInt32();
            info.regs = reader.ReadBytes(0x230);
            for (i = 0; i < info.ram.Length; i++)
            {
                info.ram[i] = reader.ReadInt16();
            }
            info.reverb_pos = reader.ReadInt32();
            info.cur_ptr = reader.ReadInt32();
            info.cur_limit = reader.ReadInt32();
            for (i = 0; i < 8; i++)
            {
                info.channels[i].pos = reader.ReadInt32();
                info.channels[i].pfrac = reader.ReadInt32();
                info.channels[i].val = reader.ReadInt32();
                info.channels[i].pval = reader.ReadInt32();
            }
            zoneflag = reader.ReadInt32();
            zonedata = reader.ReadInt32();
        }
    }
}