#===============================================================================
# CAM Top Synthesis Makefile
# Targets: synth, hier, flat, clean
# Usage:
#   make -C hw/syn synth                          (defaults, output in build/)
#   make -C hw/syn synth OUT_DIR=/some/path       (mirror artifacts)
#   make -C hw/syn synth NUM_ROWS=8192            (override parameter)
#   make -C hw/syn hier                           (hierarchy-only pass)
#   make -C hw/syn flat                           (flattened-synthesis pass)
#   make -C hw/syn clean                          (remove build/)
#===============================================================================

# ── Configurable variables (defaults) ─────────────────────────────────────────
YOSYS    ?= yosys
TOP      ?= cam_top
NUM_ROWS ?= 4096
HASH_BITS ?= 512
LANES    ?= 8
TOPK_K   ?= 4
FIFO_DEPTH ?= 16
OUT_DIR  ?= build

# ── TOP enforcement (only cam_top is supported) ───────────────────────────────
ifneq ($(TOP),cam_top)
$(error error: only TOP=cam_top is supported)
endif

# ── Internal build directory ──────────────────────────────────────────────────
BUILD_DIR := build

# ── Fixed script and artifact names ───────────────────────────────────────────
HIER_SCRIPT := synth_cam_top_hier.ys
FLAT_SCRIPT := synth_cam_top_flat.ys

HIER_LOG := yosys_hier.log
FLAT_LOG := yosys_flat.log
HIER_JSON := cam_top_hier_resources.json
FLAT_JSON := cam_top_flat_resources.json
SYNTH_V   := cam_top_synth.v

ARTIFACTS := $(HIER_JSON) $(FLAT_JSON) $(SYNTH_V) $(HIER_LOG) $(FLAT_LOG)

# ── Yosys command-line defines (always passed) ────────────────────────────────
# cam_params.svh uses `ifndef guards, so -D on the Yosys CLI overrides defaults.
# Use -D NAME=value syntax (Yosys 0.62); do NOT use -define.
YOSYS_DEFINES := -D NUM_ROWS=$(NUM_ROWS) -D HASH_BITS=$(HASH_BITS) -D LANES=$(LANES) -D TOPK_K=$(TOPK_K) -D FIFO_DEPTH=$(FIFO_DEPTH)

# ── Targets ───────────────────────────────────────────────────────────────────
.PHONY: synth hier flat clean

# ── Hierarchy resource reference pass ─────────────────────────────────────────
hier:
	mkdir -p $(BUILD_DIR)
	$(YOSYS) $(YOSYS_DEFINES) -l $(BUILD_DIR)/$(HIER_LOG) -s $(HIER_SCRIPT)

# ── Flattened Xilinx synthesis pass ───────────────────────────────────────────
flat:
	mkdir -p $(BUILD_DIR)
	$(YOSYS) $(YOSYS_DEFINES) -l $(BUILD_DIR)/$(FLAT_LOG) -s $(FLAT_SCRIPT)

# ── Full synthesis: hier + flat, then mirror artifacts to OUT_DIR if different ─
synth: hier flat
	@if [ "$(abspath $(OUT_DIR))" != "$(abspath $(BUILD_DIR))" ]; then \
		set -e; \
		echo "Mirroring artifacts to $(OUT_DIR) ..."; \
		mkdir -p "$(OUT_DIR)"; \
		for f in $(ARTIFACTS); do \
			if [ ! -f "$(BUILD_DIR)/$$f" ]; then \
				echo "error: missing artifact $(BUILD_DIR)/$$f" >&2; \
				exit 1; \
			fi; \
			cp "$(BUILD_DIR)/$$f" "$(OUT_DIR)/$$f"; \
		done; \
	fi

# ── Clean ─────────────────────────────────────────────────────────────────────
clean:
	rm -rf $(BUILD_DIR)