# Status: ported.
# Base revision: 40480

#  Copyright (C) Vladimir Prus 2002. Permission to copy, use, modify, sell and
#  distribute this software is granted provided this copyright notice appears in
#  all copies. This software is provided "as is" without express or implied
#  warranty, and with no claim as to its suitability for any purpose.

import hashlib

from b2.util.utility import *
import property, feature
import b2.build.feature
from b2.exceptions import *
from b2.build.property import get_abbreviated_paths
from b2.util.sequence import unique
from b2.util.set import difference
from b2.util import cached, abbreviate_dashed

from b2.manager import get_manager


def reset ():
    """ Clear the module state. This is mainly for testing purposes.
    """
    global __cache

    # A cache of property sets
    # TODO: use a map of weak refs?
    __cache = {}

reset ()


def create (raw_properties = []):
    """ Creates a new 'PropertySet' instance for the given raw properties,
        or returns an already existing one.
    """
    # FIXME: propagate to callers.
    if len(raw_properties) > 0 and isinstance(raw_properties[0], property.Property):
        x = raw_properties
    else:
        x = [property.create_from_string(ps) for ps in raw_properties]
    x.sort()
    x = unique(x, stable=True)

    # FIXME: can we do better, e.g. by directly computing
    # hash value of the list?
    key = tuple(x)

    if not __cache.has_key (key):
        __cache [key] = PropertySet(x)

    return __cache [key]

def create_with_validation (raw_properties):
    """ Creates new 'PropertySet' instances after checking
        that all properties are valid and converting implicit
        properties into gristed form.
    """
    properties = [property.create_from_string(s) for s in raw_properties]
    property.validate(properties)

    return create(properties)

def empty ():
    """ Returns PropertySet with empty set of properties.
    """
    return create ()

def create_from_user_input(raw_properties, jamfile_module, location):
    """Creates a property-set from the input given by the user, in the
    context of 'jamfile-module' at 'location'"""

    properties = property.create_from_strings(raw_properties, True)
    properties = property.translate_paths(properties, location)
    properties = property.translate_indirect(properties, jamfile_module)

    project_id = get_manager().projects().attributeDefault(jamfile_module, 'id', None)
    if not project_id:
        project_id = os.path.abspath(location)
    properties = property.translate_dependencies(properties, project_id, location)
    properties = property.expand_subfeatures_in_conditions(properties)
    return create(properties)


def refine_from_user_input(parent_requirements, specification, jamfile_module,
                           location):
    """Refines requirements with requirements provided by the user.
    Specially handles "-<property>value" syntax in specification
     to remove given requirements.
     - parent-requirements -- property-set object with requirements
       to refine
     - specification -- string list of requirements provided by the use
     - project-module -- the module to which context indirect features
       will be bound.
     - location -- the path to which path features are relative."""


    if not specification:
        return parent_requirements


    add_requirements = []
    remove_requirements = []

    for r in specification:
        if r[0] == '-':
            remove_requirements.append(r[1:])
        else:
            add_requirements.append(r)

    if remove_requirements:
        # Need to create property set, so that path features
        # and indirect features are translated just like they
        # are in project requirements.
        ps = create_from_user_input(remove_requirements,
                                    jamfile_module, location)

        parent_requirements = create(difference(parent_requirements.all(),
                                                ps.all()))
        specification = add_requirements

    requirements = create_from_user_input(specification,
                                          jamfile_module, location)

    return parent_requirements.refine(requirements)

class PropertySet:
    """ Class for storing a set of properties.
        - there's 1<->1 correspondence between identity and value. No
          two instances of the class are equal. To maintain this property,
          the 'PropertySet.create' rule should be used to create new instances.
          Instances are immutable.

        - each property is classified with regard to it's effect on build
          results. Incidental properties have no effect on build results, from
          Boost.Build point of view. Others are either free, or non-free, which we
          call 'base'. Each property belong to exactly one of those categories and
          it's possible to get list of properties in each category.

          In addition, it's possible to get list of properties with specific
          attribute.

        - several operations, like and refine and as_path are provided. They all use
          caching whenever possible.
    """
    def __init__ (self, properties = []):


        raw_properties = []
        for p in properties:
            raw_properties.append(p.to_raw())

        self.all_ = properties
        self.all_raw_ = raw_properties
        self.all_set_ = set(properties)

        self.incidental_ = []
        self.free_ = []
        self.base_ = []
        self.dependency_ = []
        self.non_dependency_ = []
        self.conditional_ = []
        self.non_conditional_ = []
        self.propagated_ = []
        self.link_incompatible = []

        # A cache of refined properties.
        self.refined_ = {}

        # A cache of property sets created by adding properties to this one.
        self.added_ = {}

        # Cache for the default properties.
        self.defaults_ = None

        # Cache for the expanded properties.
        self.expanded_ = None

        # Cache for the expanded composite properties
        self.composites_ = None

        # Cache for property set with expanded subfeatures
        self.subfeatures_ = None

        # Cache for the property set containing propagated properties.
        self.propagated_ps_ = None

        # A map of features to its values.
        self.feature_map_ = None

        # A tuple (target path, is relative to build directory)
        self.target_path_ = None

        self.as_path_ = None

        # A cache for already evaluated sets.
        self.evaluated_ = {}

        for p in raw_properties:
            if not get_grist (p):
                raise BaseException ("Invalid property: '%s'" % p)

            att = feature.attributes (get_grist (p))

            if 'propagated' in att:
                self.propagated_.append (p)

            if 'link_incompatible' in att:
                self.link_incompatible.append (p)

        for p in properties:

            # A feature can be both incidental and free,
            # in which case we add it to incidental.
            if p.feature().incidental():
                self.incidental_.append(p)
            elif p.feature().free():
                self.free_.append(p)
            else:
                self.base_.append(p)

            if p.condition():
                self.conditional_.append(p)
            else:
                self.non_conditional_.append(p)

            if p.feature().dependency():
                self.dependency_.append (p)
            else:
                self.non_dependency_.append (p)


    def all(self):
        return self.all_

    def raw (self):
        """ Returns the list of stored properties.
        """
        return self.all_raw_

    def __str__(self):
        return ' '.join(str(p) for p in self.all_)

    def base (self):
        """ Returns properties that are neither incidental nor free.
        """
        return self.base_

    def free (self):
        """ Returns free properties which are not dependency properties.
        """
        return self.free_

    def non_free(self):
        return self.base_ + self.incidental_

    def dependency (self):
        """ Returns dependency properties.
        """
        return self.dependency_

    def non_dependency (self):
        """ Returns properties that are not dependencies.
        """
        return self.non_dependency_

    def conditional (self):
        """ Returns conditional properties.
        """
        return self.conditional_

    def non_conditional (self):
        """ Returns properties that are not conditional.
        """
        return self.non_conditional_

    def incidental (self):
        """ Returns incidental properties.
        """
        return self.incidental_

    def refine (self, requirements):
        """ Refines this set's properties using the requirements passed as an argument.
        """
        assert isinstance(requirements, PropertySet)
        if not self.refined_.has_key (requirements):
            r = property.refine(self.all_, requirements.all_)

            self.refined_[requirements] = create(r)

        return self.refined_[requirements]

    def expand (self):
        if not self.expanded_:
            expanded = feature.expand(self.all_)
            self.expanded_ = create(expanded)
        return self.expanded_

    def expand_subfeatures(self):
        if not self.subfeatures_:
            self.subfeatures_ = create(feature.expand_subfeatures(self.all_))
        return self.subfeatures_

    def evaluate_conditionals(self, context=None):
        if not context:
            context = self

        if not self.evaluated_.has_key(context):
            # FIXME: figure why the call messes up first parameter
            self.evaluated_[context] = create(
                property.evaluate_conditionals_in_context(self.all(), context))

        return self.evaluated_[context]

    def propagated (self):
        if not self.propagated_ps_:
            self.propagated_ps_ = create (self.propagated_)
        return self.propagated_ps_

    def add_defaults (self):
        # FIXME: this caching is invalidated when new features
        # are declare inside non-root Jamfiles.
        if not self.defaults_:
            expanded = feature.add_defaults(self.all_)
            self.defaults_ = create(expanded)
        return self.defaults_

    def as_path (self):
        if not self.as_path_:

            def path_order (p1, p2):

                i1 = p1.feature().implicit()
                i2 = p2.feature().implicit()

                if i1 != i2:
                    return i2 - i1
                else:
                    return cmp(p1.feature().name(), p2.feature().name())

            # trim redundancy
            properties = feature.minimize(self.base_)

            # sort according to path_order
            properties.sort (path_order)

            components = []
            for p in properties:
                if p.feature().implicit():
                    components.append(p.value())
                else:
                    value = p.feature().name() + "-" + p.value()
                    if property.get_abbreviated_paths():
                        value = abbreviate_dashed(value)
                    components.append(value)

            self.as_path_ = '/'.join (components)

        return self.as_path_

    def target_path (self):
        """ Computes the target path that should be used for
            target with these properties.
            Returns a tuple of
              - the computed path
              - if the path is relative to build directory, a value of
                'true'.
        """
        if not self.target_path_:
            # The <location> feature can be used to explicitly
            # change the location of generated targets
            l = self.get ('<location>')
            if l:
                computed = l[0]
                is_relative = False

            else:
                p = self.as_path()
                if hash_maybe:
                    p = hash_maybe(p)

                # Really, an ugly hack. Boost regression test system requires
                # specific target paths, and it seems that changing it to handle
                # other directory layout is really hard. For that reason,
                # we teach V2 to do the things regression system requires.
                # The value o '<location-prefix>' is predended to the path.
                prefix = self.get ('<location-prefix>')

                if prefix:
                    if len (prefix) > 1:
                        raise AlreadyDefined ("Two <location-prefix> properties specified: '%s'" % prefix)

                    computed = os.path.join(prefix[0], p)

                else:
                    computed = p

                if not computed:
                    computed = "."

                is_relative = True

            self.target_path_ = (computed, is_relative)

        return self.target_path_

    def add (self, ps):
        """ Creates a new property set containing the properties in this one,
            plus the ones of the property set passed as argument.
        """
        if not self.added_.has_key(ps):
            self.added_[ps] = create(self.all_ + ps.all())
        return self.added_[ps]

    def add_raw (self, properties):
        """ Creates a new property set containing the properties in this one,
            plus the ones passed as argument.
        """
        return self.add (create (properties))


    def get (self, feature):
        """ Returns all values of 'feature'.
        """
        if type(feature) == type([]):
            feature = feature[0]
        if not isinstance(feature, b2.build.feature.Feature):
            feature = b2.build.feature.get(feature)

        if not self.feature_map_:
            self.feature_map_ = {}

            for v in self.all_:
                if not self.feature_map_.has_key(v.feature()):
                    self.feature_map_[v.feature()] = []
                self.feature_map_[v.feature()].append(v.value())

        return self.feature_map_.get(feature, [])

    @cached
    def get_properties(self, feature):
        """Returns all contained properties associated with 'feature'"""

        if not isinstance(feature, b2.build.feature.Feature):
            feature = b2.build.feature.get(feature)

        result = []
        for p in self.all_:
            if p.feature() == feature:
                result.append(p)
        return result

    def __contains__(self, item):
        return item in self.all_set_
    
def hash(p):
    m = hashlib.md5()
    m.update(p)
    return m.hexdigest()

hash_maybe = hash if "--hash" in bjam.variable("ARGV") else None

