helldivers-controller

load("@rules_cc//cc:defs.bzl", "cc_binary", "cc_library")

# Bazel build targets for the Helldivers stratagem controller.
#
# Native AVR build:
#   bazel build //:firmware   — compiles sketch + Arduino core with avr-gcc
#   bazel build //:hex        — produces flashable Intel HEX from the ELF
#
# Code quality:
#   bazel build //:lint                    — clang-tidy static analysis
#   bazel build //:format_check            — clang-format style check
#   bazel build //:generate_compile_commands — compile_commands.json for IDE/lint
#
# Prerequisites — install once via arduino-cli:
#   arduino-cli core install arduino:avr SparkFun:avr
#   arduino-cli lib install "ezButton"

SKETCH     = "src/helldivers-controller.ino"
BOARD_FQBN = "SparkFun:avr:promicro"

# Homebrew LLVM tools (keg-only, not linked into /usr/local/bin by default).
CLANG_TIDY   = "/usr/local/opt/llvm/bin/clang-tidy"
CLANG_FORMAT = "/usr/local/opt/llvm/bin/clang-format"

# ---------------------------------------------------------------------------
# bazel build //:generate_compile_commands
#
# Emits compile_commands.json so that clang-tidy and IDEs can resolve
# Arduino/AVR headers accurately.  Run this before :lint for best results.
# ---------------------------------------------------------------------------
genrule(
    name = "generate_compile_commands",
    srcs = [SKETCH],
    outs = ["compile_commands.json"],
    cmd = """
        TMP_DIR=$$(mktemp -d)
        arduino-cli compile \\
            --fqbn {fqbn} \\
            --build-property "compiler.cpp.extra_flags=-MJ $$TMP_DIR/cmd.json" \\
            --output-dir $$TMP_DIR \\
            $(location {sketch}) \\
            2>/dev/null || true
        if [ -f "$$TMP_DIR/cmd.json" ]; then
            echo "[" > $@
            cat "$$TMP_DIR/cmd.json" >> $@
            echo "]" >> $@
        else
            echo "[]" > $@
        fi
    """.format(fqbn = BOARD_FQBN, sketch = SKETCH),
    local = True,
    message = "Generating compile_commands.json",
)

# ---------------------------------------------------------------------------
# bazel build //:lint
#
# Runs clang-tidy on the sketch.  If compile_commands.json exists in the
# workspace root (produced by :generate_compile_commands), it is used for
# accurate include resolution.  Otherwise falls back to a minimal flag set.
# ---------------------------------------------------------------------------
genrule(
    name = "lint",
    srcs = [
        SKETCH,
        ".clang-tidy",
    ] + glob(["stubs/**"]),
    outs = ["lint.log"],
    cmd = """
        SKETCH=$(location {sketch})
        if [ -f compile_commands.json ]; then
            {clang_tidy} "$$SKETCH" 2>&1 | tee $@
        else
            {clang_tidy} "$$SKETCH" \\
                -- \\
                -x c++ \\
                -std=gnu++11 \\
                -DARDUINO=10607 \\
                -DARDUINO_AVR_PROMICRO \\
                -DARDUINO_ARCH_AVR \\
                -DF_CPU=8000000L \\
                -isystem $$(pwd)/stubs \\
                2>&1 | tee $@
        fi
    """.format(sketch = SKETCH, clang_tidy = CLANG_TIDY),
    local = True,
    message = "Running clang-tidy",
)

# ---------------------------------------------------------------------------
# bazel build //:format_check
#
# Verifies that the sketch matches .clang-format style.
# Exits non-zero if any formatting differs.
# To auto-fix: clang-format -i helldivers-controller.ino
# ---------------------------------------------------------------------------
genrule(
    name = "format_check",
    srcs = [
        SKETCH,
        ".clang-format",
    ],
    outs = ["format_check.log"],
    cmd = """
        SKETCH=$(location {sketch})
        {clang_format} --dry-run --Werror "$$SKETCH" 2>&1 | tee $@
    """.format(sketch = SKETCH, clang_format = CLANG_FORMAT),
    local = True,
    message = "Checking formatting with clang-format",
)

# ---------------------------------------------------------------------------
# bazel build //:firmware
#
# Compiles the sketch and all Arduino dependencies (core, HID, Keyboard, Mouse,
# ezButton) using avr-gcc.  The output is an ELF binary suitable for objcopy.
#
# Bazel's cc rules only compile files with recognised C++ extensions; sketch_cpp
# exists solely to give Bazel a .cpp handle on the .ino source.
# ---------------------------------------------------------------------------
genrule(
    name = "sketch_cpp",
    srcs = [SKETCH],
    outs = ["helldivers_controller.cpp"],
    cmd = "cp $< $@",
)

cc_library(
    name = "headers",
    hdrs = [
        "src/debug.h",
        "src/stratagem-assignments.h",
        "src/time-constants.h",
    ],
    strip_include_prefix = "src",
    visibility = ["//visibility:public"],
)

cc_binary(
    name = "firmware",
    srcs = [":sketch_cpp"],
    deps = [
        ":headers",
        "@arduino_keyboard//:keyboard",
        "@arduino_mouse//:mouse",
        "@ezbutton//:ezbutton",
    ],
    linkstatic = True,
)

# ---------------------------------------------------------------------------
# bazel build //:hex
#
# Converts the ELF produced by :firmware into an Intel HEX file ready to flash:
#   avrdude -c avr109 -p atmega32u4 -P /dev/cu.usbmodem* \
#           -U flash:w:bazel-bin/helldivers-controller.hex
# ---------------------------------------------------------------------------
genrule(
    name = "hex",
    srcs = [":firmware"],
    outs = ["helldivers-controller.hex"],
    tools = ["@avr_gcc//:objcopy_files"],
    cmd = "$(location @avr_gcc//:objcopy_files) -O ihex -R .eeprom $(location :firmware) $@",
    local = True,
    message = "Converting ELF to Intel HEX",
)