# ===----------------------------------------------------------------------===##
#
# Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
# See https://llvm.org/LICENSE.txt for license information.
# SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
#
# ===----------------------------------------------------------------------===##

import os


def _getSubstitution(substitution, config):
    for (orig, replacement) in config.substitutions:
        if orig == substitution:
            return replacement
    raise ValueError("Substitution {} is not in the config.".format(substitution))


def _appendToSubstitution(substitutions, key, value):
    return [(k, v + " " + value) if k == key else (k, v) for (k, v) in substitutions]


def configure(parameters, features, config, lit_config):
    note = lambda s: lit_config.note("({}) {}".format(config.name, s))
    config.environment = dict(os.environ)

    # Apply the actions supplied by parameters to the configuration first, since
    # parameters are things that we request explicitly and which might influence
    # what features are implicitly made available next.
    for param in parameters:
        actions = param.getActions(config, lit_config.params)
        for action in actions:
            action.applyTo(config)
            if lit_config.debug:
                note(
                    "Applied '{}' as a result of parameter '{}'".format(
                        action.pretty(config, lit_config.params),
                        param.pretty(config, lit_config.params),
                    )
                )

    # Then, apply the automatically-detected features.
    for feature in features:
        actions = feature.getActions(config)
        for action in actions:
            action.applyTo(config)
            if lit_config.debug:
                note(
                    "Applied '{}' as a result of implicitly detected feature '{}'".format(
                        action.pretty(config, lit_config.params), feature.pretty(config)
                    )
                )

    # Print the basic substitutions
    for sub in ("%{cxx}", "%{flags}", "%{compile_flags}", "%{link_flags}", "%{benchmark_flags}", "%{exec}"):
        note("Using {} substitution: '{}'".format(sub, _getSubstitution(sub, config)))

    # Print all available features
    note("All available features: {}".format(", ".join(sorted(config.available_features))))