import distutils.ccompiler
import distutils.log
import distutils.sysconfig
import os
import shutil
import tempfile

import cffi


# Also look in these directories for include files, i.e. notmuch.h (-I)
INCLUDE_DIRS = ["../../lib"]

# Also look in these directories for libraries, i.e. libnotmuch.so.5 (-L)
LIBRARY_DIRS = ["../../lib"]

# Add extra linker flags, e.g. -Wl,--enable-new-dtags,-R/path/to/notmuch/libdir
EXTRA_LINK_ARGS = ["-Wl,--enable-new-dtags,-R/home/flub/Projects/notmuch/lib"]


def extract_functions():
    """Extract the function definitions from notmuch.h.

    This creates a .h file with a single `#include <notmuch.h>` line
    in it.  It then runs the C preprocessor with the PY_CFFI symbol
    defined to create an output file which contains all function
    definitions found in `notmuch.h`.
    """
    distutils.log.set_verbosity(distutils.log.INFO)
    cc = distutils.ccompiler.new_compiler(force=True)
    distutils.sysconfig.customize_compiler(cc)
    tmpdir = tempfile.mkdtemp()
    try:
        src_name = os.path.join(tmpdir, "include.h")
        dst_name = os.path.join(tmpdir, "expanded.h")
        with open(src_name, "w") as src_fp:
            src_fp.write("#include <notmuch.h>")
        cc.preprocess(
            source=src_name,
            output_file=dst_name,
            include_dirs=INCLUDE_DIRS,
            macros=[("PY_CFFI", "1")],
        )
        with open(dst_name, "r") as dst_fp:
            return dst_fp.read()
    finally:
        shutil.rmtree(tmpdir)


ffibuilder = cffi.FFI()
ffibuilder.set_source(
    "notmuch2._capi",
    r"""
    #include <stdlib.h>
    #include <time.h>
    #include <notmuch.h>

    #if LIBNOTMUCH_MAJOR_VERSION < 5
        #error libnotmuch version not supported by notmuch2 python bindings
    #endif
    #if LIBNOTMUCH_MINOR_VERSION < 1
        #ERROR libnotmuch  version < 5.1 not supported
    #endif
    """,
    include_dirs=INCLUDE_DIRS,
    library_dirs=LIBRARY_DIRS,
    extra_link_args=EXTRA_LINK_ARGS,
    libraries=["notmuch"],
)
ffibuilder.cdef(
    r"""
    void free(void *ptr);
    typedef int... time_t;

    #define LIBNOTMUCH_MAJOR_VERSION ...
    #define LIBNOTMUCH_MINOR_VERSION ...
    #define LIBNOTMUCH_MICRO_VERSION ...

    #define NOTMUCH_TAG_MAX ...
    """
)
ffibuilder.cdef(extract_functions())


if __name__ == "__main__":
    ffibuilder.compile(verbose=True)