from litescope.common import *
from migen.flow.plumbing import Buffer

class LiteScopeSubSamplerUnit(Module):
	def __init__(self, dw):
		self.sink = sink = Sink(data_layout(dw))
		self.source = source = Source(data_layout(dw))
		self.value = Signal(32)
		###
		self.submodules.counter = Counter(bits_sign=32)
		done = Signal()
		self.comb += [
			done.eq(self.counter.value >= self.value),
			Record.connect(sink, source),
			source.stb.eq(sink.stb & done),
			self.counter.ce.eq(source.ack),
			self.counter.reset.eq(source.stb & source.ack & done)
		]

class LiteScopeSubSampler(LiteScopeSubSamplerUnit, AutoCSR):
	def __init__(self, dw):
		LiteScopeSubSamplerUnit.__init__(self, dw)
		self._value = CSRStorage(32)
		###
		self.comb += self.value.eq(self._value.storage)

class LiteScopeRunLengthEncoderUnit(Module):
	def __init__(self, dw, length):
		self.dw = dw
		self.length = length
		if dw < (log2_int(length) + 1):
			raise ValueError("Not enough bits to encode RLE length, increase dw or reduce RLE length")

		self.sink = sink = Sink(data_layout(dw))
		self.source = source = Source(data_layout(dw))

		self.enable = Signal()
		###
		self.submodules.buf = buf = Buffer(sink.description)
		self.comb += Record.connect(sink, buf.d)

		self.submodules.counter = counter = Counter(max=length)
		counter_done = Signal()
		self.comb += counter_done.eq(counter.value == length-1)

		change = Signal()
		self.comb += change.eq(
			sink.stb &
			(sink.data != buf.q.data)
		)

		self.submodules.fsm = fsm = FSM(reset_state="BYPASS")
		fsm.act("BYPASS",
			Record.connect(buf.q, source),
			counter.reset.eq(1),
			If(sink.stb & ~change,
				If(self.enable,
					NextState("COUNT")
				)
			)
		)
		fsm.act("COUNT",
			buf.q.ack.eq(1),
			counter.ce.eq(sink.stb),
			If(~self.enable,
				NextState("BYPASS")
			).Elif(change | counter_done,
				source.stb.eq(1),
				source.data[:flen(counter.value)].eq(counter.value),
				source.data[-1].eq(1), # Set RLE bit
				buf.q.ack.eq(source.ack),
				If(source.ack,
					NextState("BYPASS")
				)
			)
		)

class LiteScopeRunLengthEncoder(LiteScopeRunLengthEncoderUnit, AutoCSR):
	def __init__(self, dw, length=1024):
		LiteScopeRunLengthEncoderUnit.__init__(self, dw, length)
		self._enable = CSRStorage()
		self.external_enable = Signal(reset=1)
		###
		self.comb += self.enable.eq(self._enable.storage & self.external_enable)

class LiteScopeRecorderUnit(Module):
	def __init__(self, dw, depth):
		self.dw = dw
		self.depth = depth

		self.trigger_sink = trigger_sink = Sink(hit_layout())
		self.data_sink = data_sink = Sink(data_layout(dw))

		self.trigger = Signal()
		self.qualifier = Signal()
		self.length = Signal(bits_for(depth))
		self.offset = Signal(bits_for(depth))
		self.done = Signal()
		self.post_hit = Signal()

		self.source = Source(data_layout(dw))

		###

		fifo = InsertReset(SyncFIFO(data_layout(dw), depth, buffered=True))
		self.submodules += fifo

		fsm = FSM(reset_state="IDLE")
		self.submodules += fsm
		self.comb += [
			self.source.stb.eq(fifo.source.stb),
			self.source.data.eq(fifo.source.data)
		]
		fsm.act("IDLE",
			self.done.eq(1),
			If(self.trigger,
				NextState("PRE_HIT_RECORDING"),
				fifo.reset.eq(1),
			),
			fifo.source.ack.eq(self.source.ack)
		)
		fsm.act("PRE_HIT_RECORDING",
			fifo.sink.stb.eq(data_sink.stb),
			fifo.sink.data.eq(data_sink.data),
			data_sink.ack.eq(fifo.sink.ack),

			fifo.source.ack.eq(fifo.fifo.level >= self.offset),
			If(trigger_sink.stb & trigger_sink.hit, NextState("POST_HIT_RECORDING"))
		)
		fsm.act("POST_HIT_RECORDING",
			self.post_hit.eq(1),
			If(self.qualifier,
				fifo.sink.stb.eq(trigger_sink.stb & trigger_sink.hit & data_sink.stb)
			).Else(
				fifo.sink.stb.eq(data_sink.stb)
			),
			fifo.sink.data.eq(data_sink.data),
			data_sink.ack.eq(fifo.sink.ack),

			If(~fifo.sink.ack | (fifo.fifo.level >= self.length), NextState("IDLE"))
		)

class LiteScopeRecorder(LiteScopeRecorderUnit, AutoCSR):
	def __init__(self, dw, depth):
		LiteScopeRecorderUnit.__init__(self, dw, depth)

		self._trigger = CSR()
		self._qualifier = CSRStorage()
		self._length = CSRStorage(bits_for(depth))
		self._offset = CSRStorage(bits_for(depth))
		self._done = CSRStatus()

		self._source_stb = CSRStatus()
		self._source_ack = CSR()
		self._source_data = CSRStatus(dw)

		###

		self.comb += [
			self.trigger.eq(self._trigger.re),
			self.qualifier.eq(self._qualifier.storage),
			self.length.eq(self._length.storage),
			self.offset.eq(self._offset.storage),
			self._done.status.eq(self.done),

			self._source_stb.status.eq(self.source.stb),
			self._source_data.status.eq(self.source.data),
			self.source.ack.eq(self._source_ack.re)
		]