/**************************************************************************
* SAE - Scripted Amiga Emulator
*
* https://github.com/naTmeg/ScriptedAmigaEmulator
*
* ©2012 Rupert Hausberger
* Commercial use is prohibited.
*
***************************************************************************
* Notes: Ported from WinUAE 2.5.0
* 
**************************************************************************/

//copper_states
const COP_stop = 0;
const COP_waitforever = 1;
const COP_read1 = 2;
const COP_read2 = 3;
const COP_bltwait = 4;
const COP_wait_in2 = 5;
const COP_skip_in2 = 6;
const COP_wait1 = 7;
const COP_wait = 8;
const COP_skip1 = 9;
const COP_strobe_delay1 = 10;
const COP_strobe_delay2 = 11;
const COP_strobe_delay1x = 12;
const COP_strobe_delay2x = 13;
const COP_strobe_extra = 14;
const COP_start_delay = 15;

function Copper() {
	const customdelay = [
		1,1,1,1,0,0,0,0,0,0,0,0,0,0,0,0,1,1,0,0,1,1,1,1,0,0,0,0,0,0,0,0, /* 32 0x00 - 0x3e */
		0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0, /* 0x40 - 0x5e */
		0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0, /* 0x60 - 0x7e */
		0,0,0,0,1,1,1,1,1,1,1,1,0,0,0,0, /* 0x80 - 0x9e */
		1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1, /* 32 0xa0 - 0xde */
		/* BPLxPTH/BPLxPTL */
		0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0, /* 16 */
		/* BPLCON0-3,BPLMOD1-2 */
		0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0, /* 16 */
		/* SPRxPTH/SPRxPTL */
		1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1, /* 16 */
		/* SPRxPOS/SPRxCTL/SPRxDATA/SPRxDATB */
		1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,
		/* COLORxx */
		0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,
		/* RESERVED */
		0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0
	];
	this.cop1lc = 0;
	this.cop2lc = 0;
	this.copcon = 0;
	this.enabled_thisline = false;
	this.access = false;
	this.last_copper_hpos = 0;

	var cop_state = {
		/* The current instruction words.  */
		i1:0, i2:0,
		saved_i1:0, saved_i2:0,
		state:0, state_prev:0,
		/* Instruction pointer.  */
		ip:0, saved_ip:0,
		hpos:0, vpos:0,
		ignore_next:0,
		vcmp:0, hcmp:0,

		strobe:0, /* COPJMP1 / COPJMP2 accessed */
		last_write:0, last_write_hpos:0,
		moveaddr:0, movedata:0, movedelay:0
	};

	this.reset = function () {
      this.copcon = 0;
      cop_state.state = COP_stop;
   };

	this.reset2 = function () {
      cop_state.hpos = 0;
      cop_state.last_write = 0;
      this.compute_spcflag_copper(AMIGA.playfield.maxhpos);
   };

	this.COPCON = function (v) {
      this.copcon = v;
   };
	this.COP1LCH = function (v) {
      this.cop1lc = ((v << 16) | (this.cop1lc & 0xffff)) >>> 0;
   };
	this.COP1LCL = function (v) {
      this.cop1lc = ((this.cop1lc & 0xffff0000) | (v & 0xfffe)) >>> 0;
   };
	this.COP2LCH = function (v) {
      this.cop2lc = ((v << 16) | (this.cop2lc & 0xffff)) >>> 0;
   };
	this.COP2LCL = function (v) {
      this.cop2lc = ((this.cop2lc & 0xffff0000) | (v & 0xfffe)) >>> 0;
   };

	this.COPJMP = function (num, vblank) {
      var oldstrobe = cop_state.strobe;

      //if (AMIGA.dmaen(DMAF_COPEN) && (cop_state.saved_i1 != 0xffff || cop_state.saved_i2 != 0xfffe))
      //BUG.info('COPJMP(%d) vblank without copper ending %08x (%08x %08x) (%08x %08x)', num, cop_state.ip, this.cop1lc, this.cop2lc, cop_state.saved_i1, cop_state.saved_i2);

      clr_special(SPCFLAG_COPPER);
      cop_state.ignore_next = 0;
      if (!oldstrobe)
         cop_state.state_prev = cop_state.state;

      if ((cop_state.state == COP_wait || cop_state.state == COP_waitforever) && !vblank)
         cop_state.state = COP_strobe_delay1x;
      else
         cop_state.state = vblank ? COP_start_delay : (this.access ? COP_strobe_delay1 : COP_strobe_extra);

      //BUG.info('COPJMP(%d) %d', num, cop_state.state);

      cop_state.vpos = AMIGA.playfield.vpos;
      cop_state.hpos = AMIGA.playfield.hpos() & ~1;
      cop_state.strobe = num;
      this.enabled_thisline = false;

      if (0) {
         this.immediate_copper(num);
         return;
      }

      if (AMIGA.dmaen(DMAF_COPEN))
         this.compute_spcflag_copper(AMIGA.playfield.hpos());
      else if (oldstrobe > 0 && oldstrobe != num && cop_state.state_prev == COP_wait) {
         /* dma disabled, copper idle and accessed both COPxJMPs -> copper stops! */
         cop_state.state = COP_stop;
         //BUG.info('COPJMP(%d) COP_stop');
      }
   };

	/*function get_copper_address(copno) {
		switch (copno) {
			case 1: return this.cop1lc;
			case 2: return this.cop2lc;
			case -1: return cop_state.ip;
			default: return 0;
		}
	}*/

	this.test_copper_dangerous = function (address) {
      var addr = address & 0x1fe;
      if (addr < ((this.copcon & 2) ? ((AMIGA.config.chipset.mask & CSMASK_ECS_AGNUS) ? 0 : 0x40) : 0x80)) {
         cop_state.state = COP_stop;
         this.enabled_thisline = false;
         clr_special(SPCFLAG_COPPER);
         return true;
      }
      return false;
   };

	this.immediate_copper = function (num) {
      var pos = 0;
      var oldpos = 0;

      cop_state.state = COP_stop;
      cop_state.vpos = AMIGA.playfield.vpos;
      cop_state.hpos = AMIGA.playfield.hpos() & ~1;
      cop_state.ip = num == 1 ? this.cop1lc : this.cop2lc;

      while (pos < (AMIGA.playfield.maxvpos << 5)) {
         if (oldpos > pos)
            pos = oldpos;
         if (!AMIGA.dmaen(DMAF_COPEN))
            break;
         if (cop_state.ip >= AMIGA.mem.chip.size)
            break;
         pos++;
         oldpos = pos;
         //cop_state.i1 = AMIGA.mem.load16_chip(cop_state.ip);
         //cop_state.i2 = AMIGA.mem.load16_chip(cop_state.ip + 2);
         cop_state.i1 = AMIGA.mem.chip.data[cop_state.ip >>> 1];
         cop_state.i2 = AMIGA.mem.chip.data[(cop_state.ip + 2) >>> 1];
         AMIGA.custom.last_value = cop_state.i2;
         cop_state.ip += 4;
         if (!(cop_state.i1 & 1)) { // move
            cop_state.i1 &= 0x1fe;
            if (cop_state.i1 == 0x88) {
               cop_state.ip = this.cop1lc;
               continue;
            }
            if (cop_state.i1 == 0x8a) {
               cop_state.ip = this.cop2lc;
               continue;
            }
            if (this.test_copper_dangerous(cop_state.i1))
               break;
            AMIGA.custom.store16_real(0, cop_state.i1, cop_state.i2, 0);
         } else { // wait or skip
            if ((cop_state.i1 >> 8) > ((pos >> 5) & 0xff))
               pos = (((pos >> 5) & 0x100) | ((cop_state.i1 >> 8)) << 5) | ((cop_state.i1 & 0xff) >> 3);
            if (cop_state.i1 >= 0xffdf && cop_state.i2 == 0xfffe)
               break;
         }
      }
      cop_state.state = COP_stop;
      clr_special(SPCFLAG_COPPER);
   };

	this.copper_cant_read = function (hpos, alloc) {
      //BUG.info('copper_cant_read2() hpos %d / %d', hpos, AMIGA.playfield.maxhpos);
      if (hpos + 1 >= AMIGA.playfield.maxhpos) // first refresh slot
         return 1;
      if ((hpos == AMIGA.playfield.maxhpos - 3) && (AMIGA.playfield.maxhpos & 1) && alloc >= 0) {
         return -1;
      }
      return AMIGA.playfield.is_bitplane_dma(hpos);
   };

	this.custom_store16_copper = function (hpos, addr, value, noget) {
      //if (addr == 0x88 || addr == 0x8a)
      //BUG.info('custom_store16_copper() addr %08x, value %04x | vpos %d hpos %d %d cvcmp %d chcmp %d chpos %d cvpos %d', addr, value, AMIGA.playfield.vpos, AMIGA.playfield.hpos(), hpos, cop_state.vcmp, cop_state.hcmp, cop_state.hpos, cop_state.vpos);
      //value = debug_wputpeekdma (0xdff000 + addr, value);
      this.access = true;
      var v = AMIGA.custom.store16_real(hpos, addr, value, noget);
      this.access = false;
      return v;
   };

	this.dump_copper = function (error, until_hpos) {
      BUG.info('\n');
      BUG.info('%s: vpos=%d until_hpos=%d vp=%d', error, AMIGA.playfield.vpos, until_hpos, AMIGA.playfield.vpos & (((cop_state.saved_i2 >> 8) & 0x7f) | 0x80));
      BUG.info('cvcmp=%d chcmp=%d chpos=%d cvpos=%d ci1=%04X ci2=%04X', cop_state.vcmp, cop_state.hcmp, cop_state.hpos, cop_state.vpos, cop_state.saved_i1, cop_state.saved_i2);
      BUG.info('cstate=%d ip=%x SPCFLAGS=%x iscline=%d', cop_state.state, cop_state.ip, AMIGA.spcflags, this.enabled_thisline ? 1 : 0);
      BUG.info('\n');
   };

	this.update = function (until_hpos) {
      var vp = AMIGA.playfield.vpos & (((cop_state.saved_i2 >> 8) & 0x7f) | 0x80);
      var c_hpos = cop_state.hpos;

      //BUG.info('update() until_hpos %d, vp %d', until_hpos, vp);

      if (cop_state.state == COP_wait && vp < cop_state.vcmp) {
         this.dump_copper('error2', until_hpos);
         this.enabled_thisline = false;
         cop_state.state = COP_stop;
         clr_special(SPCFLAG_COPPER);
         return;
      }

      if (until_hpos <= this.last_copper_hpos)
         return;

      if (until_hpos > (AMIGA.playfield.maxhpos & ~1))
         until_hpos = AMIGA.playfield.maxhpos & ~1;

      for (; ;) {
         var old_hpos = c_hpos;
         var hp;

         if (c_hpos >= until_hpos)
            break;

         /* So we know about the fetch state.  */
         AMIGA.playfield.decide_line(c_hpos);
         AMIGA.playfield.decide_fetch(c_hpos);

         if (cop_state.movedelay > 0) {
            cop_state.movedelay--;
            if (cop_state.movedelay == 0) {
               this.custom_store16_copper(c_hpos, cop_state.moveaddr, cop_state.movedata, 0);
            }
         }

         if ((c_hpos == AMIGA.playfield.maxhpos - 3) && (AMIGA.playfield.maxhpos & 1))
            c_hpos += 1;
         else
            c_hpos += 2;

         switch (cop_state.state) {
            case COP_wait_in2:
            {
               if (this.copper_cant_read(old_hpos, 0))
                  continue;
               cop_state.state = COP_wait1;
               break;
            }
            case COP_skip_in2:
            {
               if (this.copper_cant_read(old_hpos, 0))
                  continue;
               cop_state.state = COP_skip1;
               break;
            }
            case COP_strobe_extra:
            {
               // Wait 1 copper cycle doing nothing
               cop_state.state = COP_strobe_delay1;
               break;
            }
            case COP_strobe_delay1:
            {
               // First cycle after COPJMP is just like normal first read cycle
               // Cycle is used and needs to be free.
               if (this.copper_cant_read(old_hpos, 1))
                  continue;
               cop_state.state = COP_strobe_delay2;
               cop_state.ip += 2;
               break;
            }
            case COP_strobe_delay2:
            {
               // Second cycle after COPJMP. This is the strange one.
               // This cycle does not need to be free
               // But it still gets allocated by copper if it is free = CPU and blitter can't use it.
               cop_state.state = COP_read1;
               // Next cycle finally reads from new pointer
               if (cop_state.strobe == 1)
                  cop_state.ip = this.cop1lc;
               else
                  cop_state.ip = this.cop2lc;
               cop_state.strobe = 0;
               break;
            }
            case COP_strobe_delay1x:
            {
               // First cycle after COPJMP and Copper was waiting. This is the buggy one.
               // Cycle can be free and copper won't allocate it.
               // If Blitter uses this cycle = Copper's address gets copied blitter DMA pointer..
               cop_state.state = COP_strobe_delay2x;
               break;
            }
            case COP_strobe_delay2x:
            {
               // Second cycle fetches following word and tosses it away. Must be free cycle
               // but is not allocated, blitter or cpu can still use it.
               if (this.copper_cant_read(old_hpos, 1))
                  continue;
               cop_state.state = COP_read1;
               // Next cycle finally reads from new pointer
               if (cop_state.strobe == 1)
                  cop_state.ip = this.cop1lc;
               else
                  cop_state.ip = this.cop2lc;
               cop_state.strobe = 0;
               break;
            }
            case COP_start_delay:
            {
               if (this.copper_cant_read(old_hpos, 1))
                  continue;
               cop_state.state = COP_read1;
               cop_state.ip = this.cop1lc;
               break;
            }
            case COP_read1:
            {
               if (this.copper_cant_read(old_hpos, 1))
                  continue;
               /* workaround for a bug in kick 1.x */
               if (cop_state.ip == 0x00000004 || cop_state.ip == 0x00000676 || cop_state.ip == 0x00c00276) {
                  //BUG.info('COP_read1() invalid addr $%08x', cop_state.ip);
                  cop_state.state = COP_stop;
                  this.enabled_thisline = false;
                  clr_special(SPCFLAG_COPPER);
                  return;
               }
               //cop_state.i1 = AMIGA.mem.load16_chip(cop_state.ip);
               cop_state.i1 = AMIGA.custom.last_value = AMIGA.mem.chip.data[cop_state.ip >>> 1];
               cop_state.ip += 2;
               cop_state.state = COP_read2;
               break;
            }
            case COP_read2:
            {
               if (this.copper_cant_read(old_hpos, 1))
                  continue;
               //cop_state.i2 = AMIGA.mem.load16_chip(cop_state.ip);
               cop_state.i2 = AMIGA.custom.last_value = AMIGA.mem.chip.data[cop_state.ip >>> 1];
               cop_state.ip += 2;
               cop_state.saved_i1 = cop_state.i1;
               cop_state.saved_i2 = cop_state.i2;
               cop_state.saved_ip = cop_state.ip;

               if (cop_state.i1 & 1) { // WAIT or SKIP
                  cop_state.ignore_next = 0;
                  if (cop_state.i2 & 1)
                     cop_state.state = COP_skip_in2;
                  else
                     cop_state.state = COP_wait_in2;
               } else { // MOVE
                  //uaecptr debugip = cop_state.ip;
                  var reg = cop_state.i1 & 0x1fe;
                  var data = cop_state.i2;
                  cop_state.state = COP_read1;
                  this.test_copper_dangerous(reg);
                  if (!this.enabled_thisline) {
                     //goto out; // was 'dangerous' register -> copper stopped
                     cop_state.hpos = c_hpos;
                     this.last_copper_hpos = until_hpos;
                     return;
                  }
                  if (cop_state.ignore_next)
                     reg = 0x1fe;

                  cop_state.last_write = reg;
                  cop_state.last_write_hpos = old_hpos;
                  if (reg == 0x88) {
                     cop_state.strobe = 1;
                     cop_state.state = COP_strobe_delay1;
                  } else if (reg == 0x8a) {
                     cop_state.strobe = 2;
                     cop_state.state = COP_strobe_delay1;
                  } else {
                     /*if (0) {
                      AMIGA.events.newevent2(1, (reg << 16) | data, function(v) { //copper_write);
                      AMIGA.copper.custom_store16_copper(AMIGA.playfield.hpos(), v >>> 16, v & 0xffff, 0);
                      });
                      //this.custom_store16_copper(old_hpos, reg, data, 0);
                      } else*/
                     {
                        // FIX: all copper writes happen 1 cycle later than CPU writes
                        if (customdelay[reg >> 1]) {
                           cop_state.moveaddr = reg;
                           cop_state.movedata = data;
                           cop_state.movedelay = customdelay[cop_state.moveaddr >> 1];
                        } else {
                           var hpos2 = old_hpos;
                           this.custom_store16_copper(hpos2, reg, data, 0);
                           hpos2++;
                           if (reg >= 0x140 && reg < 0x180 && hpos2 >= SPR0_HPOS && hpos2 < SPR0_HPOS + 4 * MAX_SPRITES)
                              AMIGA.playfield.do_sprites(hpos2);
                        }
                     }
                  }
                  cop_state.ignore_next = 0;
               }
               break;
            }
            case COP_wait1:
            {
               /*#if 0
                if (c_hpos >= (AMIGA.playfield.maxhpos & ~1) || (c_hpos & 1)) break;
                #endif*/
               cop_state.state = COP_wait;

               cop_state.vcmp = (cop_state.saved_i1 & (cop_state.saved_i2 | 0x8000)) >> 8;
               cop_state.hcmp = (cop_state.saved_i1 & cop_state.saved_i2 & 0xfe);

               vp = AMIGA.playfield.vpos & (((cop_state.saved_i2 >> 8) & 0x7f) | 0x80);

               if (cop_state.saved_i1 == 0xffff && cop_state.saved_i2 == 0xfffe) {
                  cop_state.state = COP_waitforever;
                  this.enabled_thisline = false;
                  clr_special(SPCFLAG_COPPER);
                  //goto out;
                  cop_state.hpos = c_hpos;
                  this.last_copper_hpos = until_hpos;
                  return;
               }
               if (vp < cop_state.vcmp) {
                  this.enabled_thisline = false;
                  clr_special(SPCFLAG_COPPER);
                  //goto out;
                  cop_state.hpos = c_hpos;
                  this.last_copper_hpos = until_hpos;
                  return;
               }
            }
            /* fall through */
            case COP_wait:
            {
               var ch_comp = c_hpos;
               if (ch_comp & 1)
                  ch_comp = 0;

               if (this.copper_cant_read(old_hpos, 0))
                  continue;

               hp = ch_comp & (cop_state.saved_i2 & 0xfe);
               if (vp == cop_state.vcmp && hp < cop_state.hcmp)
                  break;

               /* Now we know that the comparisons were successful.  We might still have to wait for the blitter though.  */
               if ((cop_state.saved_i2 & 0x8000) == 0) {
                  if (AMIGA.blitter.getState() != BLT_done) {
                     //We need to wait for the blitter.
                     cop_state.state = COP_bltwait;
                     this.enabled_thisline = false;
                     clr_special(SPCFLAG_COPPER);
                     //goto out;
                     cop_state.hpos = c_hpos;
                     this.last_copper_hpos = until_hpos;
                     return;
                  }
               }
               cop_state.state = COP_read1;
               break;
            }
            case COP_skip1:
            {
               var vcmp, hcmp, vp1, hp1;

               if (c_hpos >= (AMIGA.playfield.maxhpos & ~1) || (c_hpos & 1))
                  break;

               if (this.copper_cant_read(old_hpos, 0))
                  continue;

               vcmp = (cop_state.saved_i1 & (cop_state.saved_i2 | 0x8000)) >> 8;
               hcmp = (cop_state.saved_i1 & cop_state.saved_i2 & 0xfe);
               vp1 = AMIGA.playfield.vpos & (((cop_state.saved_i2 >> 8) & 0x7f) | 0x80);
               hp1 = c_hpos & (cop_state.saved_i2 & 0xfe);

               if ((vp1 > vcmp || (vp1 == vcmp && hp1 >= hcmp)) && ((cop_state.saved_i2 & 0x8000) != 0 || AMIGA.blitter.getState() == BLT_done))
                  cop_state.ignore_next = 1;

               cop_state.state = COP_read1;
               break;
            }
         }
      }

      //out:
      cop_state.hpos = c_hpos;
      this.last_copper_hpos = until_hpos;
   };

	this.compute_spcflag_copper = function (hpos) {
      //BUG.info('compute_spcflag_copper() hpos %d', hpos);
      var wasenabled = this.enabled_thisline;

      this.enabled_thisline = false;
      clr_special(SPCFLAG_COPPER);
      if (!AMIGA.dmaen(DMAF_COPEN) || cop_state.state == COP_stop || cop_state.state == COP_waitforever || cop_state.state == COP_bltwait)
         return;

      if (cop_state.state == COP_wait) {
         var vp = AMIGA.playfield.vpos & (((cop_state.saved_i2 >> 8) & 0x7f) | 0x80);

         if (vp < cop_state.vcmp)
            return;
      }
      // do not use past cycles if starting for the first time in this line
      // (write to DMACON for example) hpos+1 for long lines
      if (!wasenabled && cop_state.hpos < hpos && hpos < AMIGA.playfield.maxhpos) {
         hpos = (hpos + 2) & ~1;
         if (hpos > AMIGA.playfield.maxhpos_short)
            hpos = AMIGA.playfield.maxhpos_short;
         cop_state.hpos = hpos;
         //BUG.info('compute_spcflag_copper() hpos %d %d', hpos, AMIGA.playfield.maxhpos_short);
      }

      // if COPJMPx was written while DMA was disabled, advance to next state,
      // COP_strobe_extra is single cycle only and does not need free bus.
      // (copper state emulation does not run if DMA is disabled)
      if (!wasenabled && cop_state.state == COP_strobe_extra)
         cop_state.state = COP_strobe_delay1;

      this.enabled_thisline = true;
      set_special(SPCFLAG_COPPER);
   };

	this.blitter_done_notify = function (hpos) {
      if (cop_state.state != COP_bltwait)
         return;

      //BUG.info('blitter_done_notify() hpos %d', hpos);

      var vp = AMIGA.playfield.vpos;
      hpos += 3;
      hpos &= ~1;
      if (hpos >= AMIGA.playfield.maxhpos) {
         hpos -= AMIGA.playfield.maxhpos;
         vp++;
      }
      cop_state.hpos = hpos;
      cop_state.vpos = vp;
      cop_state.state = COP_read1;

      if (AMIGA.dmaen(DMAF_COPEN) && vp == AMIGA.playfield.vpos) {
         this.enabled_thisline = true;
         set_special(SPCFLAG_COPPER);
      }
   };

	this.cycle = function () {
      this.update(AMIGA.playfield.hpos());
   };

	this.sync_copper_with_cpu = function (hpos, do_schedule) {
      /* Need to let the copper advance to the current position.  */
      if (this.enabled_thisline)
         this.update(hpos);
   };

	/*this.check = function (n) {
		if (cop_state.state == COP_wait) {
			var vp = AMIGA.playfield.vpos & (((cop_state.saved_i2 >> 8) & 0x7f) | 0x80);
			if (vp < cop_state.vcmp) {
				if (this.enabled_thisline)
					BUG.info('COPPER BUG %d: vp=%d vpos=%d vcmp=%d thisline=%d', n, vp, AMIGA.playfield.vpos, cop_state.vcmp, this.enabled_thisline?1:0);
			}
		}
	}*/
}