SHELL := /usr/bin/env bash

GO ?= go
GOFMT ?= gofmt
INSTALL ?= install
PREFIX ?= $(HOME)/.local
BINDIR ?= $(PREFIX)/bin
LIBDIR ?= $(PREFIX)/lib
DESTDIR ?=
BUILD_DIR ?= build
BUILD_BIN_DIR ?= $(BUILD_DIR)/bin
BUILD_MANUAL_DIR ?= $(BUILD_DIR)/manual
BANGER_BIN ?= $(BUILD_BIN_DIR)/banger
BANGERD_BIN ?= $(BUILD_BIN_DIR)/bangerd
VSOCK_AGENT_BIN ?= $(BUILD_BIN_DIR)/banger-vsock-agent
BINARIES := $(BANGER_BIN) $(BANGERD_BIN) $(VSOCK_AGENT_BIN)
GO_SOURCES := $(shell find cmd internal -type f -name '*.go' | sort)
# BUILD_INPUTS is everything that can change a binary's bytes: Go sources
# plus embedded assets (catalog.json, future static files). Listing
# everything is cheaper than missing a rebuild — go's own cache absorbs
# any redundant invocations.
BUILD_INPUTS := $(shell find cmd internal -type f | sort)
SHELL_SOURCES := $(shell find scripts -type f -name '*.sh' | sort)
VERSION ?= $(shell git describe --tags --exact-match 2>/dev/null || echo dev)
COMMIT ?= $(shell git rev-parse --verify HEAD 2>/dev/null || echo unknown)
BUILT_AT ?= $(shell date -u +%Y-%m-%dT%H:%M:%SZ)
GO_LDFLAGS := -X banger/internal/buildinfo.Version=$(VERSION) -X banger/internal/buildinfo.Commit=$(COMMIT) -X banger/internal/buildinfo.BuiltAt=$(BUILT_AT)

.DEFAULT_GOAL := help

.PHONY: help build banger bangerd test fmt tidy clean install bench-create lint lint-go lint-shell

help:
	@printf '%s\n' \
	  'Targets:' \
	  '  make build        Build ./build/bin/banger, ./build/bin/bangerd, and ./build/bin/banger-vsock-agent' \
	  '  make install      Build and install banger, bangerd, and the companion vsock helper' \
	  '  make test         Run go test ./...' \
	  '  make lint         Run gofmt + go vet + shellcheck (errors)' \
	  '  make fmt          Format Go sources under cmd/ and internal/' \
	  '  make tidy         Run go mod tidy' \
	  '  make clean        Remove built Go binaries' \
	  '  make bench-create Benchmark vm create and SSH readiness with scripts/bench-create.sh'

build: $(BINARIES)

$(BANGER_BIN): $(BUILD_INPUTS) go.mod go.sum
	mkdir -p "$(BUILD_BIN_DIR)"
	$(GO) build -ldflags '$(GO_LDFLAGS)' -o "$(BANGER_BIN)" ./cmd/banger

$(BANGERD_BIN): $(BUILD_INPUTS) go.mod go.sum
	mkdir -p "$(BUILD_BIN_DIR)"
	$(GO) build -ldflags '$(GO_LDFLAGS)' -o "$(BANGERD_BIN)" ./cmd/bangerd

$(VSOCK_AGENT_BIN): $(BUILD_INPUTS) go.mod go.sum
	mkdir -p "$(BUILD_BIN_DIR)"
	CGO_ENABLED=0 GOOS=linux GOARCH=amd64 $(GO) build -ldflags '$(GO_LDFLAGS)' -o "$(VSOCK_AGENT_BIN)" ./cmd/banger-vsock-agent

test:
	$(GO) test ./...

lint: lint-go lint-shell

lint-go:
	@unformatted="$$($(GOFMT) -l $(GO_SOURCES))"; \
	if [ -n "$$unformatted" ]; then \
	  printf 'gofmt: the following files are not formatted:\n%s\n' "$$unformatted" >&2; \
	  exit 1; \
	fi
	$(GO) vet ./...

lint-shell:
	@command -v shellcheck >/dev/null 2>&1 || { echo 'shellcheck is required for make lint-shell' >&2; exit 1; }
	shellcheck --severity=error $(SHELL_SOURCES)

fmt:
	$(GOFMT) -w $(GO_SOURCES)

tidy:
	$(GO) mod tidy

clean:
	rm -rf "$(BUILD_BIN_DIR)"

bench-create: build
	BANGER_BIN="$(abspath $(BANGER_BIN))" bash ./scripts/bench-create.sh $(ARGS)

install: build
	mkdir -p "$(DESTDIR)$(BINDIR)"
	mkdir -p "$(DESTDIR)$(LIBDIR)/banger"
	$(INSTALL) -m 0755 "$(BANGER_BIN)" "$(DESTDIR)$(BINDIR)/banger"
	$(INSTALL) -m 0755 "$(BANGERD_BIN)" "$(DESTDIR)$(BINDIR)/bangerd"
	$(INSTALL) -m 0755 "$(VSOCK_AGENT_BIN)" "$(DESTDIR)$(LIBDIR)/banger/banger-vsock-agent"