# Copyright (C) 2010 Google Inc. All rights reserved.
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# modification, are permitted provided that the following conditions are
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#
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# in the documentation and/or other materials provided with the
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"""Wrapper objects for WebKit-specific utility routines."""

# FIXME: This file needs to be unified with common/config/ports.py .

import logging

from webkitpy.common import webkit_finder
from webkitpy.common.memoized import memoized


_log = logging.getLogger(__name__)

#
# FIXME: This is used to record if we've already hit the filesystem to look
# for a default configuration. We cache this to speed up the unit tests,
# but this can be reset with clear_cached_configuration(). This should be
# replaced with us consistently using MockConfigs() for tests that don't
# hit the filesystem at all and provide a reliable value.
#
_have_determined_configuration = False
_configuration = "Release"


def clear_cached_configuration():
    global _have_determined_configuration, _configuration
    _have_determined_configuration = False
    _configuration = "Release"


@memoized
def apple_additions():
    try:
        # A level of 0 means that only absolute paths will be used.
        return __import__('apple_additions', globals=globals(), locals=None, fromlist=[], level=0)
    except ImportError:
        return None


class Config(object):
    _FLAGS_FROM_CONFIGURATIONS = {
        "Debug": "--debug",
        "Release": "--release",
    }

    def __init__(self, executive, filesystem, port_implementation=None):
        self._executive = executive
        self._filesystem = filesystem
        self._webkit_finder = webkit_finder.WebKitFinder(self._filesystem)
        self._default_configuration = None
        self._build_directories = {}
        self._port_implementation = port_implementation

    def build_directory(self, configuration):
        """Returns the path to the build directory for the configuration."""
        if configuration:
            flags = ["--configuration", self.flag_for_configuration(configuration)]
        else:
            configuration = ""
            flags = []

        if self._port_implementation:
            flags.append('--' + self._port_implementation)

        if not self._build_directories.get(configuration):
            args = ["perl", self._webkit_finder.path_to_script("webkit-build-directory")] + flags
            output = self._executive.run_command(args, cwd=self._webkit_finder.webkit_base(), return_stderr=False).rstrip()
            parts = output.split("\n")
            self._build_directories[configuration] = parts[0]

            if len(parts) == 2:
                default_configuration = parts[1][len(parts[0]):]
                if default_configuration.startswith("/"):
                    default_configuration = default_configuration[1:]
                self._build_directories[default_configuration] = parts[1]

        return self._build_directories[configuration]

    def flag_for_configuration(self, configuration):
        return self._FLAGS_FROM_CONFIGURATIONS[configuration]

    def default_configuration(self):
        """Returns the default configuration for the user.

        Returns the value set by 'set-webkit-configuration', or "Release"
        if that has not been set. This mirrors the logic in webkitdirs.pm."""
        if not self._default_configuration:
            self._default_configuration = self._determine_configuration()
        if not self._default_configuration:
            self._default_configuration = 'Release'
        if self._default_configuration not in self._FLAGS_FROM_CONFIGURATIONS:
            _log.warn("Configuration \"%s\" is not a recognized value.\n" % self._default_configuration)
            _log.warn("Scripts may fail.  See 'set-webkit-configuration --help'.")
        return self._default_configuration

    def _determine_configuration(self):
        # This mirrors the logic in webkitdirs.pm:determineConfiguration().
        #
        # FIXME: See the comment at the top of the file regarding unit tests
        # and our use of global mutable static variables.
        # FIXME: We should just @memoize this method and then this will only
        # be read once per object lifetime (which should be sufficiently fast).
        global _have_determined_configuration, _configuration
        if not _have_determined_configuration:
            contents = self._read_configuration()
            if not contents:
                contents = "Release"
            if contents == "Deployment":
                contents = "Release"
            if contents == "Development":
                contents = "Debug"
            _configuration = contents
            _have_determined_configuration = True
        return _configuration

    def _read_configuration(self):
        try:
            configuration_path = self._filesystem.join(self.build_directory(None), "Configuration")
            if not self._filesystem.exists(configuration_path):
                return None
        except:
            return None

        return self._filesystem.read_text_file(configuration_path).rstrip()