// SPDX-FileCopyrightText: 2002-2026 PCSX2 Dev Team
// SPDX-License-Identifier: GPL-3.0+

#include "Common.h"
#include "GS.h"
#include "Gif.h"
#include "Gif_Unit.h"
#include "MTVU.h"
#include "Vif.h"
#include "Vif_Dma.h"
#include "Vif_Dynarec.h"

alignas(16) vifStruct vif0, vif1;

void vif0Reset()
{
	/* Reset the whole VIF, meaning the internal pcsx2 vars and all the registers */
	std::memset(&vif0, 0, sizeof(vif0));
	std::memset(&vif0Regs, 0, sizeof(vif0Regs));

	resetNewVif(0);
}

void vif1Reset()
{
	/* Reset the whole VIF, meaning the internal pcsx2 vars, and all the registers */
	std::memset(&vif1, 0, sizeof(vif1));
	std::memset(&vif1Regs, 0, sizeof(vif1Regs));

	resetNewVif(1);
}

bool SaveStateBase::vif0Freeze()
{
	if (!FreezeTag("VIF0dma"))
		return false;

	Freeze(g_vif0Cycles);

	Freeze(vif0);

	Freeze(nVif[0].bSize);
	FreezeMem(nVif[0].buffer, nVif[0].bSize);

	return IsOkay();
}

bool SaveStateBase::vif1Freeze()
{
	if (!FreezeTag("VIF1dma"))
		return false;

	Freeze(g_vif1Cycles);

	Freeze(vif1);

	Freeze(nVif[1].bSize);
	FreezeMem(nVif[1].buffer, nVif[1].bSize);

	return IsOkay();
}

//------------------------------------------------------------------
// Vif0/Vif1 Write32
//------------------------------------------------------------------

__fi void vif0FBRST(u32 value)
{
	VIF_LOG("VIF0_FBRST write32 0x%8.8x", value);
	/* Fixme: Forcebreaks are pretty unknown for operation, presumption is it just stops it what its doing
			  usually accompanied by a reset, but if we find a broken game which falls here, we need to see it! (Refraction) */
	if (value & 0x2) // Forcebreak Vif,
	{
		/* I guess we should stop the VIF dma here, but not 100% sure (linuz) */
		cpuRegs.interrupt &= ~1; //Stop all vif0 DMA's
		vif0Regs.stat.VFS = true;
		vif0Regs.stat.VPS = VPS_IDLE;
		Console.WriteLn("vif0 force break");
	}

	if (value & 0x4) // Stop Vif.
	{
		// Not completely sure about this, can't remember what game, used this, but 'draining' the VIF helped it, instead of
		//  just stoppin the VIF (linuz).
		vif0Regs.stat.VSS = true;
		vif0Regs.stat.VPS = VPS_IDLE;
		vif0.vifstalled.enabled = VifStallEnable(vif0ch);
		vif0.vifstalled.value = VIF_IRQ_STALL;
	}

	if (value & 0x8) // Cancel Vif Stall.
	{
		bool cancel = false;

		/* Cancel stall, first check if there is a stall to cancel, and then clear VIF0_STAT VSS|VFS|VIS|INT|ER0|ER1 bits */
		if (vif0Regs.stat.test(VIF0_STAT_VSS | VIF0_STAT_VIS | VIF0_STAT_VFS))
			cancel = true;

		vif0Regs.stat.clear_flags(VIF0_STAT_VSS | VIF0_STAT_VFS | VIF0_STAT_VIS |
								  VIF0_STAT_INT | VIF0_STAT_ER0 | VIF0_STAT_ER1);
		if (cancel)
		{
			g_vif0Cycles = 0;
			// loop necessary for spiderman
			if (vif0ch.chcr.STR)
				CPU_INT(DMAC_VIF0, 0); // Gets the timing right - Flatout
		}
	}

	if (value & 0x1) // Reset Vif.
	{
		//Console.WriteLn("Vif0 Reset %x", vif0Regs.stat._u32);
		u128 SaveCol;
		u128 SaveRow;

		//	if(vif0ch.chcr.STR) DevCon.Warning("FBRST While Vif0 active");
		//Must Preserve Row/Col registers! (Downhill Domination for testing)
		SaveCol._u64[0] = vif0.MaskCol._u64[0];
		SaveCol._u64[1] = vif0.MaskCol._u64[1];
		SaveRow._u64[0] = vif0.MaskRow._u64[0];
		SaveRow._u64[1] = vif0.MaskRow._u64[1];
		std::memset(&vif0, 0, sizeof(vif0));
		vif0.MaskCol._u64[0] = SaveCol._u64[0];
		vif0.MaskCol._u64[1] = SaveCol._u64[1];
		vif0.MaskRow._u64[0] = SaveRow._u64[0];
		vif0.MaskRow._u64[1] = SaveRow._u64[1];
		vif0ch.qwc = 0; //?
		cpuRegs.interrupt &= ~1; //Stop all vif0 DMA's
		psHu64(VIF0_FIFO) = 0;
		psHu64(VIF0_FIFO + 8) = 0;
		vif0.vifstalled.enabled = false;
		vif0.irqoffset.enabled = false;
		vif0.inprogress = 0;
		vif0.cmd = 0;
		vif0.done = true;
		vif0ch.chcr.STR = false;
		vif0Regs.err.reset();
		vif0Regs.stat.clear_flags(VIF0_STAT_FQC | VIF0_STAT_INT | VIF0_STAT_VSS | VIF0_STAT_VIS | VIF0_STAT_VFS | VIF0_STAT_VPS); // FQC=0
	}
}

__fi void vif1FBRST(u32 value)
{
	VIF_LOG("VIF1_FBRST write32 0x%8.8x", value);

	/* Fixme: Forcebreaks are pretty unknown for operation, presumption is it just stops it what its doing
			  usually accompanied by a reset, but if we find a broken game which falls here, we need to see it! (Refraction) */

	if (FBRST(value).FBK) // Forcebreak Vif.
	{
		/* I guess we should stop the VIF dma here, but not 100% sure (linuz) */
		vif1Regs.stat.VFS = true;
		vif1Regs.stat.VPS = VPS_IDLE;
		cpuRegs.interrupt &= ~((1 << 1) | (1 << 10)); //Stop all vif1 DMA's
		vif1.vifstalled.enabled = VifStallEnable(vif1ch);
		vif1.vifstalled.value = VIF_IRQ_STALL;
		Console.WriteLn("vif1 force break");
	}

	if (FBRST(value).STP) // Stop Vif.
	{
		// Not completely sure about this, can't remember what game used this, but 'draining' the VIF helped it, instead of
		// just stoppin the VIF (linuz).
		vif1Regs.stat.VSS = true;
		vif1Regs.stat.VPS = VPS_IDLE;
		vif1.vifstalled.enabled = VifStallEnable(vif1ch);
		vif1.vifstalled.value = VIF_IRQ_STALL;
	}

	if (FBRST(value).STC) // Cancel Vif Stall.
	{
		bool cancel = false;
		//DevCon.Warning("Cancel stall. Stat = %x", vif1Regs.stat._u32);
		// Cancel stall, first check if there is a stall to cancel, and then clear VIF1_STAT VSS|VFS|VIS|INT|ER0|ER1 bits
		if (vif1Regs.stat.test(VIF1_STAT_VSS | VIF1_STAT_VIS | VIF1_STAT_VFS))
		{
			cancel = true;
		}

		vif1Regs.stat.clear_flags(VIF1_STAT_VSS | VIF1_STAT_VFS | VIF1_STAT_VIS |
								  VIF1_STAT_INT | VIF1_STAT_ER0 | VIF1_STAT_ER1);

		if (cancel)
		{
			g_vif1Cycles = 0;
			// loop necessary for spiderman
			switch (dmacRegs.ctrl.MFD)
			{
			case MFD_VIF1:
				//Console.WriteLn("MFIFO Stall");
				//MFIFO active and not empty
				if (vif1ch.chcr.STR && !vif1Regs.stat.test(VIF1_STAT_FDR))
					CPU_INT(DMAC_MFIFO_VIF, 0);
				break;

			case NO_MFD:
			case MFD_RESERVED:
			case MFD_GIF: // Wonder if this should be with VIF?
				// Gets the timing right - Flatout
				if (vif1ch.chcr.STR && !vif1Regs.stat.test(VIF1_STAT_FDR))
					CPU_INT(DMAC_VIF1, 0);
				break;
			}

			//vif1ch.chcr.STR = true;
		}
	}

	if (FBRST(value).RST) // Reset Vif.
	{
		u128 SaveCol;
		u128 SaveRow;
		//if(vif1ch.chcr.STR) DevCon.Warning("FBRST While Vif1 active");
		//Must Preserve Row/Col registers! (Downhill Domination for testing) - Really shouldnt be part of the vifstruct.
		SaveCol._u64[0] = vif1.MaskCol._u64[0];
		SaveCol._u64[1] = vif1.MaskCol._u64[1];
		SaveRow._u64[0] = vif1.MaskRow._u64[0];
		SaveRow._u64[1] = vif1.MaskRow._u64[1];
		u8 mfifo_empty = vif1.inprogress & 0x10;
		std::memset(&vif1, 0, sizeof(vif1));
		vif1.MaskCol._u64[0] = SaveCol._u64[0];
		vif1.MaskCol._u64[1] = SaveCol._u64[1];
		vif1.MaskRow._u64[0] = SaveRow._u64[0];
		vif1.MaskRow._u64[1] = SaveRow._u64[1];


		GUNIT_WARN(Color_Red, "VIF FBRST Reset MSK = %x", vif1Regs.mskpath3);
		vif1Regs.mskpath3 = false;
		gifRegs.stat.M3P = 0;
		vif1Regs.err.reset();
		vif1.inprogress = mfifo_empty;
		vif1.cmd = 0;
		vif1.vifstalled.enabled = false;
		vif1Regs.stat._u32 = 0;
	}
}

__fi void vif1STAT(u32 value)
{
	VIF_LOG("VIF1_STAT write32 0x%8.8x", value);

	/* Only FDR bit is writable, so mask the rest */
	if ((vif1Regs.stat.FDR) ^ ((tVIF_STAT&)value).FDR)
	{
		bool isStalled = false;
		// different so can't be stalled
		if (vif1Regs.stat.test(VIF1_STAT_INT | VIF1_STAT_VSS | VIF1_STAT_VIS | VIF1_STAT_VFS))
		{
			DbgCon.WriteLn("changing dir when vif1 fifo stalled done = %x qwc = %x stat = %x", vif1.done, vif1ch.qwc, vif1Regs.stat._u32);
			isStalled = true;
		}

		//Hack!! Hotwheels seems to leave 1QW in the fifo and expect the DMA to be ready for a reverse FIFO
		//There's no important data in there so for it to work, we will just end it.
		//Hotwheels had this in the "direction when stalled" area, however Sled Storm seems to keep an eye on the dma
		//position, as we clear it and set it to the end well before the interrupt, the game assumes it's finished,
		//then proceeds to reverse the dma before we have even done it ourselves. So lets just make sure VIF is ready :)
		if (vif1ch.qwc > 0 || isStalled == false)
		{
			if (vif1ch.chcr.STR)
			{
				vif1ch.qwc = 0;
				hwDmacIrq(DMAC_VIF1);
				vif1ch.chcr.STR = false;
			}
			cpuRegs.interrupt &= ~((1 << DMAC_VIF1) | (1 << DMAC_MFIFO_VIF));
		}
		//This is actually more important for our handling, else the DMA for reverse fifo doesnt start properly.
	}

	vif1Regs.stat.FDR = VIF_STAT(value).FDR;

	if (vif1Regs.stat.FDR) // Vif transferring to memory.
	{
		// Hack but it checks this is true before transfer? (fatal frame)
		// Update Refraction: Use of this function has been investigated and understood.
		// Before this ever happens, a DIRECT/HL command takes place sending the transfer info to the GS
		// One of the registers told about this is TRXREG which tells us how much data is going to transfer (th x tw) in words
		// As far as the GS is concerned, the transfer starts as soon as TRXDIR is accessed, which is why fatal frame
		// was expecting data, the GS should already be sending it over (buffering in the FIFO)

		vif1Regs.stat.FQC = std::min((u32)16, vif1.GSLastDownloadSize);
		//Console.Warning("Reversing VIF Transfer for %x QWC", vif1.GSLastDownloadSize);
	}
	else // Memory transferring to Vif.
	{
		//Sometimes the value from the GS is bigger than vif wanted, so it just sets it back and cancels it.
		//Other times it can read it off ;)
		vif1Regs.stat.FQC = 0;
		if (vif1ch.chcr.STR)
			CPU_INT(DMAC_VIF1, 0);
	}
}

#define caseVif(x) (idx ? VIF1_##x : VIF0_##x)

_vifT __fi u32 vifRead32(u32 mem)
{
	vifStruct& vif = MTVU_VifX;
	bool wait = idx && THREAD_VU1;

	switch (mem)
	{
		case caseVif(ROW0):
			if (wait)
				vu1Thread.WaitVU();
			return vif.MaskRow._u32[0];
		case caseVif(ROW1):
			if (wait)
				vu1Thread.WaitVU();
			return vif.MaskRow._u32[1];
		case caseVif(ROW2):
			if (wait)
				vu1Thread.WaitVU();
			return vif.MaskRow._u32[2];
		case caseVif(ROW3):
			if (wait)
				vu1Thread.WaitVU();
			return vif.MaskRow._u32[3];

		case caseVif(COL0):
			if (wait)
				vu1Thread.WaitVU();
			return vif.MaskCol._u32[0];
		case caseVif(COL1):
			if (wait)
				vu1Thread.WaitVU();
			return vif.MaskCol._u32[1];
		case caseVif(COL2):
			if (wait)
				vu1Thread.WaitVU();
			return vif.MaskCol._u32[2];
		case caseVif(COL3):
			if (wait)
				vu1Thread.WaitVU();
			return vif.MaskCol._u32[3];
	}

	return psHu32(mem);
}

// returns FALSE if no writeback is needed (or writeback is handled internally)
// returns TRUE if the caller should writeback the value to the eeHw register map.
_vifT __fi bool vifWrite32(u32 mem, u32 value)
{
	vifStruct& vif = GetVifX;

	switch (mem)
	{
		case caseVif(MARK):
			VIF_LOG("VIF%d_MARK write32 0x%8.8x", idx, value);
			vifXRegs.stat.MRK = false;
			//vifXRegs.mark	   = value;
			break;

		case caseVif(FBRST):
			if (!idx)
				vif0FBRST(value);
			else
				vif1FBRST(value);
			return false;

		case caseVif(STAT):
			if (idx)
			{ // Only Vif1 does this stuff?
				vif1STAT(value);
			}
			return false;

		case caseVif(ERR):
		case caseVif(MODE):
			// standard register writes -- handled by caller.
			break;

		case caseVif(ROW0):
			vif.MaskRow._u32[0] = value;
			vu1Thread.WriteRow(vif);
			return false;
		case caseVif(ROW1):
			vif.MaskRow._u32[1] = value;
			vu1Thread.WriteRow(vif);
			return false;
		case caseVif(ROW2):
			vif.MaskRow._u32[2] = value;
			vu1Thread.WriteRow(vif);
			return false;
		case caseVif(ROW3):
			vif.MaskRow._u32[3] = value;
			vu1Thread.WriteRow(vif);
			return false;

		case caseVif(COL0):
			vif.MaskCol._u32[0] = value;
			vu1Thread.WriteCol(vif);
			return false;
		case caseVif(COL1):
			vif.MaskCol._u32[1] = value;
			vu1Thread.WriteCol(vif);
			return false;
		case caseVif(COL2):
			vif.MaskCol._u32[2] = value;
			vu1Thread.WriteCol(vif);
			return false;
		case caseVif(COL3):
			vif.MaskCol._u32[3] = value;
			vu1Thread.WriteCol(vif);
			return false;
	}

	// fall-through case: issue standard writeback behavior.
	return true;
}

template u32 vifRead32<0>(u32 mem);
template u32 vifRead32<1>(u32 mem);

template bool vifWrite32<0>(u32 mem, u32 value);
template bool vifWrite32<1>(u32 mem, u32 value);