# ============================================================================
# Bastion kernel - Top-Level Build System
#
# Usage:
#   make ARCH=x86_64 defconfig   — Create default .config for x86_64
#   make ARCH=aarch64 defconfig  — Create default .config for aarch64
#   make ARCH=x86_64 build       — Build for x86_64
#   make ARCH=aarch64 build      — Build for aarch64
#   make ARCH=x86_64 run         — Build + run in QEMU
#   make ARCH=aarch64 run        — Build + run in QEMU
#   make all                     — Build both architectures
#   make clean                   — Remove build artifacts and objects
#   make distclean               — Remove build + generated config
# ============================================================================

VERSION = 0
PATCHLEVEL = 0
SUBLEVEL = 1
NAME = Husky

.PHONY: all build clean distclean configure defconfig disk run check-config

RESULT_DIR   := result
CONFIG_FILE  := .config
CONFIG_H     := include/kernel/config.h
CONFIG_MK    := config_generated.mk
CONFIGURE    := python3 scripts/configure.py #TODO: change to $(python)

-include $(CONFIG_MK)

# ── ARCH validation ────────────────────────────────────────────────────────

# Default ARCH if not specified
ARCH ?= $(shell uname -m)

ifneq ($(ARCH),x86_64)
ifneq ($(ARCH),aarch64)
    $(error ARCH must be x86_64 or aarch64 (got: $(ARCH)))
endif
endif

# Derive EFI binary name from ARCH
# TODO: maybe add name of this artifact to config
ifeq ($(ARCH),x86_64)
    EFI_BINARY := BOOTX64.EFI
else
    EFI_BINARY := BOOTAA64.EFI
endif

ARCH_RESULT_DIR := $(RESULT_DIR)/$(ARCH)

# ── Build ──────────────────────────────────────────────────────────────────

all build: check-config
	@echo "══════════════════════════════════════════"
	@echo "  Building Bastion — $(ARCH)"
	@echo "══════════════════════════════════════════"
	@echo "  v.$(VERSION).$(PATCHLEVEL).$(SUBLEVEL) — $(NAME)"
	@echo "══════════════════════════════════════════"
	@echo "  Build boot"
	@echo "══════════════════════════════════════════"
	$(MAKE) -C boot ARCH=$(ARCH) RESULT_DIR=$(CURDIR)/$(ARCH_RESULT_DIR)/boot
	@echo "══════════════════════════════════════════"
	@echo "  Build kernel"
	@echo "══════════════════════════════════════════"
	$(MAKE) -C kernel ARCH=$(ARCH) RESULT_DIR=$(CURDIR)/$(ARCH_RESULT_DIR)/kernel

# ── Configuration ───────────────────────────────────────────────────────────

defconfig:
	@cp configs/default_$(ARCH) $(CONFIG_FILE)
	@echo "Created .config from configs/default_$(ARCH)"
	@$(CONFIGURE) --arch $(ARCH)
	@echo ""

# Regenerate config.h and config_generated.mk from .config
configure: $(CONFIG_FILE)
	@$(CONFIGURE) --arch $(ARCH)

# Auto-generate config.h if .config exists but config.h is stale or broken or missing
check-config: $(CONFIG_FILE)
	@if [ ! -f $(CONFIG_H) ] || [ $(CONFIG_FILE) -nt $(CONFIG_H) ] || [ scripts/configure.py -nt $(CONFIG_H) ]; then \
		$(CONFIGURE) --arch $(ARCH); \
	fi

# If .config doesn't exist, tell the user
$(CONFIG_FILE):
	@echo "═══════════════════════════════════════════════════════════"
	@echo "  ERROR: No .config file found."
	@echo ""
	@echo "  Create one with:"
	@echo "    make defconfig"
	@echo "    make ARCH=x86_64 defconfig"
	@echo "    make ARCH=aarch64 defconfig"
	@echo ""
	@echo "  Or copy manually:"
	@echo "    cp configs/default_x86_64 .config"
	@echo "═══════════════════════════════════════════════════════════"
	@exit 1

# ── Disk images ─────────────────────────────────────────────────────────────

disk: build
	bash scripts/create_disk.sh $(ARCH) \
		$(ARCH_RESULT_DIR)/boot/$(EFI_BINARY) \
		$(ARCH_RESULT_DIR)/kernel/$(CONFIG_KERNEL_FILE_NAME) \
		$(ARCH_RESULT_DIR)/bastion.img

# ── QEMU ────────────────────────────────────────────────────────────────────

run: disk
	@bash scripts/run_qemu.sh $(ARCH) $(ARCH_RESULT_DIR)/bastion.img

# ── Clean ───────────────────────────────────────────────────────────────────

clean:
	rm -rf $(RESULT_DIR)
	$(MAKE) -C boot ARCH=$(ARCH) clean
	$(MAKE) -C kernel ARCH=$(ARCH) clean
	@echo "Clean."

# Remove everything including generated config (but not .config itself)
distclean: clean
	rm -f $(CONFIG_H) $(CONFIG_MK)
	@echo "Distclean."