Import("env")

def gen_clangd(target, source, env):
    _ = target
    _ = source
    from subprocess import run
    import shlex
    from pathlib import Path

    SDCC = run(shlex.split("which sdcc"), capture_output=True).stdout.decode().strip()
    # SDCC = '/home/fpasqua/.platformio/packages/toolchain-sdcc/bin/sdcc'
    p = Path(SDCC).parent.parent  # toolchain root
    SDCC_INCLUDE = p / 'share' / 'sdcc' / 'include'
    # SDCC_INCLUDE = '/home/fpasqua/.platformio/packages/toolchain-sdcc/share/sdcc/include/'
    GETDEFINEFLAGS = '-E -dM -mstm8 -x c /dev/null'
    res = run([SDCC] + shlex.split(GETDEFINEFLAGS), capture_output=True)
    res.check_returncode()
    defines_raw = res.stdout.decode().strip().split('\n')
    defines = [d.replace('#define ', '-D').replace(' ', '=') for d in defines_raw]
    sdcc_defines = ", ".join(defines)

    sdccext_defines = ", ".join(['-D__trap=', '-D__interrupt(x)='])

    SUPPRESSED = [
        "clang-diagnostic-main-return-type",
        "clang-diagnostic-empty-body",
        "pp_including_mainfile_in_preamble",
    ]

    with open('.clangd', 'w') as f:
        f.writelines([
            'CompileFlags:\n',
            f'  Add: [-I{SDCC_INCLUDE}, {sdcc_defines}, {sdccext_defines}]\n'
            '  Remove: [--opt-code-size, -mstm8]\n',
            'Index:\n',
            '  StandardLibrary: No\n',
            'Diagnostics:\n',
            '  Suppress:\n',
            *[f'    - "{s}"\n' for s in SUPPRESSED],
            '  UnusedIncludes: None\n',
        ])
    print("Project .clangd created")

    o = run(shlex.split(f'ln -s -f {env["PROJECT_DIR"]}/.clangd .clangd'), cwd=p)
    o.check_returncode()
    print(f"Symlink to toolchain {p / '.clangd'} done.")

# include toolchain paths
env.Replace(COMPILATIONDB_INCLUDE_TOOLCHAIN=True)

# custom .clangd initialization
env.AddCustomTarget(
    name='clangd',
    dependencies=None,
    actions=gen_clangd,
    title='Gen .clangd',
    description='Generate required files for clangd to work properly.',
    always_build=True,
)

# TODO: add target to load the .clangd in the sdcc toolchain too