# Firmware build entry points.
#
# Wraps cargo with the env tweaks needed on hosts where libxml2 has bumped
# past .so.2 (Ubuntu Questing 25.10+ ships .so.16). The .lib/libxml2.so.2
# symlink in this directory points at the system library so esp-clang loads.
#
# Cargo handles its own incremental rebuilds, so these are all phony.

LIB_DIR := $(CURDIR)/.lib
LIBXML2_COMPAT := $(LIB_DIR)/libxml2.so.2
SYSTEM_LIBXML2 := $(firstword $(wildcard /usr/lib/x86_64-linux-gnu/libxml2.so.16 /usr/lib/libxml2.so.16))

export LD_LIBRARY_PATH := $(LIB_DIR):$(LD_LIBRARY_PATH)

# Inject the absolute path to partitions.csv via a generated overlay file.
# ESP-IDF resolves relative CONFIG_PARTITION_TABLE_FILENAME against an
# internal CMake source dir under target/, not against this directory, so
# baking a relative path into the committed sdkconfig.defaults would fail.
# Generating the overlay here keeps the committed config portable.
GEN_DIR := $(CURDIR)/target/gen
GEN_PARTITIONS_SDKCONFIG := $(GEN_DIR)/sdkconfig.defaults.partitions
PARTITIONS_CSV := $(CURDIR)/partitions.csv

# esp-idf-sys reads ESP_IDF_SDKCONFIG_DEFAULTS as the list of project sdkconfig
# defaults files (it then internally builds its own SDKCONFIG_DEFAULTS env var
# for cmake by prepending its generated defaults).
export ESP_IDF_SDKCONFIG_DEFAULTS := $(CURDIR)/sdkconfig.defaults;$(GEN_PARTITIONS_SDKCONFIG)

CARGO ?= cargo
BIN := target/xtensa-esp32-espidf/release/sound-machine
BOOTLOADER_BIN := target/xtensa-esp32-espidf/release/bootloader.bin
# First /dev/ttyUSB* / /dev/ttyACM* found, used for headless flashing.
# Override on the command line: `make flash PORT=/dev/ttyUSB1`
PORT ?= $(firstword $(wildcard /dev/ttyUSB* /dev/ttyACM*))

# Firmware version, parsed from Cargo.toml. Used for the OTA filename and
# the latest_version MQTT publish.
VERSION := $(shell sed -nE '0,/^version *= *"([^"]+)"/{s//\1/p}' Cargo.toml)
OTA_BIN := sound-machine-$(VERSION).bin

.PHONY: build check flash flash-monitor monitor clean help ota-publish $(LIBXML2_COMPAT)

build: $(LIBXML2_COMPAT) $(GEN_PARTITIONS_SDKCONFIG)
	$(CARGO) build --release

check: $(LIBXML2_COMPAT) $(GEN_PARTITIONS_SDKCONFIG)
	$(CARGO) check

# Headless flash — builds, then writes to the device with no interactive
# monitor. Safe to run from any shell, including non-TTY contexts. Auto-
# detects the first ttyUSB*/ttyACM*; override with PORT=/dev/...
flash: build
	@if [ -z "$(PORT)" ]; then \
		echo "no serial port found (looked for /dev/ttyUSB* and /dev/ttyACM*)"; \
		exit 1; \
	fi
	espflash flash --port $(PORT) \
		--bootloader $(BOOTLOADER_BIN) \
		--partition-table $(PARTITIONS_CSV) \
		--erase-parts otadata \
		$(BIN)

# Interactive flash + monitor — builds, flashes, attaches the serial monitor.
# Needs a TTY (the monitor writes to terminal and reads keyboard input).
flash-monitor: $(LIBXML2_COMPAT) $(GEN_PARTITIONS_SDKCONFIG)
	$(CARGO) run --release

monitor:
	espflash monitor

# Publish a new firmware version. Reads OTA_LOCAL_DIR / OTA_URL_BASE / MQTT_URL
# from the environment (sourced via direnv from .envrc.private). Builds the
# release binary, generates the flat .bin via espflash save-image, copies it
# into the static-HTTP serve directory, then publishes the new latest_version
# retained to the shared MQTT topic. Both nightstands' HA update cards light
# up the moment the publish lands.
ota-publish: build
	@if [ -z "$(OTA_LOCAL_DIR)" ]; then \
		echo "OTA_LOCAL_DIR is not set (see .envrc.private.example)"; exit 1; \
	fi
	@if [ -z "$(OTA_URL_BASE)" ]; then \
		echo "OTA_URL_BASE is not set (see .envrc.private.example)"; exit 1; \
	fi
	@if [ -z "$(MQTT_URL)" ]; then \
		echo "MQTT_URL is not set (see .envrc.private.example)"; exit 1; \
	fi
	@if [ -z "$(VERSION)" ]; then \
		echo "could not parse version from Cargo.toml"; exit 1; \
	fi
	@echo "publishing v$(VERSION) → $(OTA_URL_BASE)/$(OTA_BIN)"
	espflash save-image --chip esp32 --flash-size 4mb $(BIN) $(OTA_LOCAL_DIR)/$(OTA_BIN)
	mosquitto_pub \
		-L "$(MQTT_URL)/sound-machine/firmware/latest" \
		-r \
		-m "$(VERSION)"
	@echo "done. devices will see the update in HA within a few seconds."

clean:
	$(CARGO) clean

# The compat symlink. Created on demand if the system has libxml2.so.16.
# Skipped silently if it already exists or the system has a newer libxml2.
$(LIBXML2_COMPAT):
	@if [ ! -e "$@" ]; then \
		if [ -n "$(SYSTEM_LIBXML2)" ]; then \
			mkdir -p $(LIB_DIR); \
			ln -sf $(SYSTEM_LIBXML2) $@; \
			echo "linked $@ -> $(SYSTEM_LIBXML2)"; \
		else \
			echo "warning: no system libxml2.so.16 found; esp-clang may fail to load"; \
		fi; \
	fi

# Generated sdkconfig overlay carrying the absolute path to partitions.csv.
# Regenerated whenever the CSV or this Makefile changes.
$(GEN_PARTITIONS_SDKCONFIG): $(PARTITIONS_CSV) $(MAKEFILE_LIST)
	@mkdir -p $(GEN_DIR)
	@printf 'CONFIG_PARTITION_TABLE_CUSTOM_FILENAME="%s"\nCONFIG_PARTITION_TABLE_FILENAME="%s"\n' \
		'$(PARTITIONS_CSV)' '$(PARTITIONS_CSV)' > $@
	@echo "generated $@"

help:
	@echo "firmware targets:"
	@echo "  build          cargo build --release (default)"
	@echo "  check          cargo check"
	@echo "  flash          headless: build + flash, no monitor (works in any shell)"
	@echo "  flash-monitor  interactive: build + flash + serial monitor (needs a TTY)"
	@echo "  monitor        espflash monitor only"
	@echo "  ota-publish    save .bin to \$$OTA_LOCAL_DIR + publish latest_version to MQTT"
	@echo "  clean          cargo clean"