import atexit
import os
import shutil
import tempfile
import functools

from .display import print_warning
from .version import app_full_version_for_env


def try_remove(path):
    try:
        os.remove(path)
    except:  # pylint: disable=bare-except
        print_warning("Please manually remove the file `{}`".format(path))


# emulate .ino concatenation to speed up compilation times
def merge_cpp(sources, output):
    with tempfile.TemporaryFile() as tmp:
        tmp.write(b"// !!! Automatically generated file; DO NOT EDIT !!! \n")
        tmp.write(b'#include "espurna.h"\n')
        for source in sources:
            src_include = '#include "{}"\n'.format(source)
            tmp.write(src_include.encode("utf-8"))

        tmp.seek(0)

        with open(output, "wb") as fobj:
            shutil.copyfileobj(tmp, fobj)
        atexit.register(try_remove, output)


def firmware_prefix(env):
    return "espurna-{}".format(app_full_version_for_env(env))


# generate an common name for the current build
def firmware_filename(env):
    suffix = "{}.bin".format(env["ESPURNA_BUILD_NAME"] or env["PIOENV"])
    return "-".join([firmware_prefix(env), suffix])


def firmware_destination(env):
    destdir = env["ESPURNA_BUILD_DESTINATION"] or env["PROJECT_DIR"]
    subdir = os.path.join(destdir, firmware_prefix(env))

    return os.path.join(subdir, firmware_filename(env))


def app_add_target_build_and_copy(env):
    from SCons.Script import Copy

    copy_dest = firmware_destination(env)
    copy = env.Command(
        copy_dest, "${BUILD_DIR}/${PROGNAME}.bin", Copy("$TARGET", "$SOURCE")
    )
    env.AddTarget(
        "build-and-copy",
        copy_dest,
        actions=None,  # command invocation already handles this
        title="Build firmware.bin and store a copy",
        description="Build and store firmware.bin as $ESPURNA_BUILD_DESTINATION/espurna-<version>-$ESPURNA_BUILD_NAME.bin (default destination is $PROJECT_DIR)",
    )


# TODO: *could* be a Builder object, just the same it will detect targets via src_suffix & suffix properties
#       but, notice that:
#       - constantly re-generating files in $project_dir only useful in development, as the source tree includes already 'compiled' .re.cpp.inc
#       - .cpp.re.inc <-> .re dependency will be injected into the scons database of the *environment*,
#         which may accidentally cause a rebuild when using 2 envs at the same time
#       - .cpp file `#include`ing the .inc file may be built before the file is actually generated by the re2c (or, in a parallel job)
#         scons has a C source scanner that is tracking `#include` directives. but, file may *already* exist at the scanning phase and
#         it may be assumed something static during the build (as most include directives are for the system, sdk, and the build-tree headers)


def app_add_target_build_re2c(env):
    from SCons.Script import COMMAND_LINE_TARGETS

    targets = [
        env.File(target) for target in COMMAND_LINE_TARGETS if ".re.cpp.inc" in target
    ]
    cmd = "re2c --no-generation-date --case-ranges -W -Werror -o {} {}"
    if targets:
        sources = [
            target.File("{}".format(target.name.replace(".cpp.inc", "")))
            for target in targets
        ]
        for target, source in zip(targets, sources):
            env.Execute(
                env.VerboseAction(
                    cmd.format(target, source), "Generating {}".format(target.name)
                )
            )
        env.Exit(0)