# -*- mode: python; -*-

import hashlib

# Default and alternative generator definitions go here.


# This is the key/value mapping that will be returned by the buildInfo command and
# printed by the --version command-line option to mongod.
# Each mapped value is in turn a dict consisting of:
#   key: <string>
#   value: <string>
#   inBuildInfo: <bool> : should it be included in buildInfo output
#   inVersion: <bool> : should it be included in --version output
# The `value` field will be passed through env.subst, so you can use any SCons variables you
# want to define them.
def default_buildinfo_environment_data():
    data = (
        (
            "distmod",
            "$MONGO_DISTMOD",
            True,
            True,
        ),
        (
            "distarch",
            "$MONGO_DISTARCH",
            True,
            True,
        ),
        (
            "cc",
            "$CC_VERSION",
            True,
            False,
        ),
        (
            "ccflags",
            "$CCFLAGS",
            True,
            False,
        ),
        (
            "cxx",
            "$CXX_VERSION",
            True,
            False,
        ),
        (
            "cxxflags",
            "$CXXFLAGS",
            True,
            False,
        ),
        (
            "linkflags",
            "$LINKFLAGS",
            True,
            False,
        ),
        (
            "target_arch",
            "$TARGET_ARCH",
            True,
            True,
        ),
        (
            "target_os",
            "$TARGET_OS",
            True,
            False,
        ),
        (
            "cppdefines",
            "$CPPDEFINES",
            True,
            False,
        ),
    )
    return {
        k: {"key": k, "value": v, "inBuildInfo": ibi, "inVersion": iv} for k, v, ibi, iv in data
    }


# If you want buildInfo and --version to be relatively empty, set
# MONGO_BUILDINFO_ENVIRONMENT_DATA = empty_buildinfo_environment_data()
def empty_buildinfo_environment_data():
    return {}


# Special cases - if debug is not enabled and optimization is not specified,
# default to full optimizationm otherwise turn it off.
def get_opt_options(env) -> str:
    if env.GetOption("opt") == "auto":
        return "on" if not env.GetOption("dbg") == "on" else "off"
    else:
        return env.GetOption("opt")


def default_variant_dir_generator(target, source, env, for_signature):
    if env.GetOption("cache") is not None:
        return "cached"

    # If an option should affect the variant directory, name it here.
    variant_options = [
        "opt",
        "dbg",
    ]

    # Hash the named options and their values, and take the first 8 characters of the hash as
    # the variant name
    hasher = hashlib.md5()
    for option in variant_options:
        hasher.update(option.encode("utf-8"))
        if option == "opt":
            hasher.update(get_opt_options(env).encode("utf-8"))
        else:
            hasher.update(str(env.GetOption(option)).encode("utf-8"))
    variant_dir = str(hasher.hexdigest()[0:8])

    # If our option hash yields a well known hash, replace it with its name.
    known_variant_hashes = {
        "343e6678": "debug",
        "85fcf9b0": "opt",
        "981ce870": "debug",
        "9fface73": "optdebug",
        "c52b1cc3": "opt",
    }

    return known_variant_hashes.get(variant_dir, variant_dir)


def os_specific_variant_dir_generator(target, source, env, for_signature):
    return "-".join(
        [
            env["TARGET_OS"],
            default_variant_dir_generator(target, source, env, for_signature),
        ]
    )