from collections import OrderedDict

from conans.errors import ConanException
from conans.model.recipe_ref import RecipeReference
from conans.model.conanfile_interface import ConanFileInterface


class UserRequirementsDict(object):
    """ user facing dict to allow access of dependencies by name
    """
    def __init__(self, data, require_filter=None):
        self._data = data  # dict-like
        self._require_filter = require_filter  # dict {trait: value} for requirements

    def filter(self, require_filter):
        def filter_fn(require):
            for k, v in require_filter.items():
                if getattr(require, k) != v:
                    return False
            return True
        data = OrderedDict((k, v) for k, v in self._data.items() if filter_fn(k))
        return UserRequirementsDict(data, require_filter)

    def __bool__(self):
        return bool(self._data)

    def get(self, ref, build=None, **kwargs):
        return self._get(ref, build, **kwargs)[1]

    def _get(self, ref, build=None, **kwargs):
        if build is None:
            current_filters = self._require_filter or {}
            if "build" not in current_filters:
                # By default we search in the "host" context
                kwargs["build"] = False
        else:
            kwargs["build"] = build
        data = self.filter(kwargs)
        ret = []
        if "/" in ref:
            # FIXME: Validate reference
            ref = RecipeReference.loads(ref)
            for require, value in data.items():
                if require.ref == ref:
                    ret.append((require, value))
        else:
            name = ref
            for require, value in data.items():
                if require.ref.name == name:
                    ret.append((require, value))
        if len(ret) > 1:
            current_filters = data._require_filter or "{}"
            requires = "\n".join(["- {}".format(require) for require, _ in ret])
            raise ConanException("There are more than one requires matching the specified filters:"
                                 " {}\n{}".format(current_filters, requires))
        if not ret:
            raise KeyError("'{}' not found in the dependency set".format(ref))

        key, value = ret[0]
        return key, value

    def __getitem__(self, name):
        return self.get(name)

    def __delitem__(self, name):
        r, _ = self._get(name)
        del self._data[r]

    def items(self):
        return self._data.items()

    def values(self):
        return self._data.values()


class ConanFileDependencies(UserRequirementsDict):

    @staticmethod
    def from_node(node):
        d = OrderedDict((require, ConanFileInterface(transitive.node.conanfile))
                        for require, transitive in node.transitive_deps.items())
        return ConanFileDependencies(d)

    def filter(self, require_filter):
        # FIXME: Copy of hte above, to return ConanFileDependencies class object
        def filter_fn(require):
            for k, v in require_filter.items():
                if getattr(require, k) != v:
                    return False
            return True

        data = OrderedDict((k, v) for k, v in self._data.items() if filter_fn(k))
        return ConanFileDependencies(data, require_filter)

    def transitive_requires(self, other):
        data = OrderedDict()
        for k, v in self._data.items():
            for otherk, otherv in other._data.items():
                if v == otherv:
                    data[k] = v
        return ConanFileDependencies(data)

    @property
    def topological_sort(self):
        # Return first independent nodes, final ones are the more direct deps
        result = OrderedDict()
        opened = self._data.copy()

        while opened:
            opened_values = set(opened.values())
            new_opened = OrderedDict()
            for req, conanfile in opened.items():
                deps_in_opened = any(d in opened_values for d in conanfile.dependencies.values())
                if deps_in_opened:
                    new_opened[req] = conanfile  # keep it for next iteration
                else:
                    result[req] = conanfile  # No dependencies in open set!

            opened = new_opened
        return ConanFileDependencies(result)

    @property
    def direct_host(self):
        return self.filter({"build": False, "direct": True, "test": False, "skip": False})

    @property
    def direct_build(self):
        return self.filter({"build": True, "direct": True})

    @property
    def host(self):
        return self.filter({"build": False, "test": False, "skip": False})

    @property
    def test(self):
        # Not needed a direct_test because they are visible=False so only the direct consumer
        # will have them in the graph
        return self.filter({"build": False, "test": True, "skip": False})

    @property
    def build(self):
        return self.filter({"build": True})


def get_transitive_requires(consumer, dependency):
    """ the transitive requires that we need are the consumer ones, not the current dependencey
    ones, so we get the current ones, then look for them in the consumer, and return those
    """
    pkg_deps = dependency.dependencies.filter({"direct": True})
    result = consumer.dependencies.transitive_requires(pkg_deps)
    result = result.filter({"skip": False})
    return result
