# Source code for rdflib.plugins.shared.jsonld.context

    # -*- coding: utf-8 -*-
    """
    Implementation of the JSON-LD Context structure. See:

        http://json-ld.org/

    """
    # https://github.com/RDFLib/rdflib-jsonld/blob/feature/json-ld-1.1/rdflib_jsonld/context.py

    from collections import namedtuple
    from rdflib.namespace import RDF

    from .keys import (
        BASE,
        CONTAINER,
        CONTEXT,
        GRAPH,
        ID,
        IMPORT,
        INCLUDED,
        INDEX,
        JSON,
        LANG,
        LIST,
        NEST,
        NONE,
        PREFIX,
        PROPAGATE,
        PROTECTED,
        REV,
        SET,
        TYPE,
        VALUE,
        VERSION,
        VOCAB,
    )
    from .errors import (
        INVALID_REMOTE_CONTEXT,
        RECURSIVE_CONTEXT_INCLUSION,
        INVALID_CONTEXT_ENTRY,
    )
    from .util import source_to_json, urljoin, urlsplit, split_iri, norm_url

    NODE_KEYS = {GRAPH, ID, INCLUDED, JSON, LIST, NEST, NONE, REV, SET, TYPE, VALUE, LANG}

    class Defined(int):
        pass

    UNDEF = Defined(0)

    # From <https://tools.ietf.org/html/rfc3986#section-2.2>
    URI_GEN_DELIMS = (":", "/", "?", "#", "[", "]", "@")

    class Context(object):

        def __init__(self, source=None, base=None, version=None):
            self.version = version or 1.0
            self.language = None
            self.vocab = None
            self.base = base
            self.doc_base = base
            self.terms = {}
            # _alias maps NODE_KEY to list of aliases
            self._alias = {}
            self._lookup = {}
            self._prefixes = {}
            self.active = False
            self.parent = None
            self.propagate = True
            self._context_cache = {}
            if source:
                self.load(source)

        @property
        def base(self):
            return self._base

        @base.setter
        def base(self, base):
            if base:
                hash_index = base.find("#")
                if hash_index > -1:
                    base = base[0:hash_index]
            self._base = (
                self.resolve_iri(base)
                if (hasattr(self, "_base") and base is not None)
                else base
            )
            self._basedomain = "%s://%s" % urlsplit(base)[0:2] if base else None

        def subcontext(self, source, propagate=True):
            # IMPROVE: to optimize, implement SubContext with parent fallback support
            parent = self.parent if self.propagate is False else self
            return parent._subcontext(source, propagate)

        def _subcontext(self, source, propagate):
            ctx = Context(version=self.version)
            ctx.propagate = propagate
            ctx.parent = self
            ctx.language = self.language
            ctx.vocab = self.vocab
            ctx.base = self.base
            ctx.doc_base = self.doc_base
            ctx._alias = {k: l[:] for k, l in self._alias.items()}
            ctx.terms = self.terms.copy()
            ctx._lookup = self._lookup.copy()
            ctx._prefixes = self._prefixes.copy()
            ctx._context_cache = self._context_cache
            ctx.load(source)
            return ctx

        def _clear(self):
            self.language = None
            self.vocab = None
            self.terms = {}
            self._alias = {}
            self._lookup = {}
            self._prefixes = {}
            self.active = False
            self.propagate = True

        def get_context_for_term(self, term):
            if term and term.context is not UNDEF:
                return self._subcontext(term.context, propagate=True)
            return self

        def get_context_for_type(self, node):
            if self.version >= 1.1:
                rtype = self.get_type(node) if isinstance(node, dict) else None
                if not isinstance(rtype, list):
                    rtype = [rtype] if rtype else []

                for rt in rtype:
                    typeterm = self.terms.get(rt)
                    if typeterm:
                        break
                else:
                    typeterm = None

                if typeterm and typeterm.context:
                    subcontext = self.subcontext(typeterm.context, propagate=False)
                    if subcontext:
                        return subcontext

            return self.parent if self.propagate is False else self

        def get_id(self, obj):
            return self._get(obj, ID)

        def get_type(self, obj):
            return self._get(obj, TYPE)

        def get_language(self, obj):
            return self._get(obj, LANG)

        def get_value(self, obj):
            return self._get(obj, VALUE)

        def get_graph(self, obj):
            return self._get(obj, GRAPH)

        def get_list(self, obj):
            return self._get(obj, LIST)

        def get_set(self, obj):
            return self._get(obj, SET)

        def get_rev(self, obj):
            return self._get(obj, REV)

        def _get(self, obj, key):
            for alias in self._alias.get(key, []):
                if alias in obj:
                    return obj.get(alias)
            return obj.get(key)

        def get_key(self, key):
            for alias in self.get_keys(key):
                return alias

        def get_keys(self, key):
            if key in self._alias:
                for alias in self._alias[key]:
                    yield alias
            yield key

        lang_key = property(lambda self: self.get_key(LANG))
        id_key = property(lambda self: self.get_key(ID))
        type_key = property(lambda self: self.get_key(TYPE))
        value_key = property(lambda self: self.get_key(VALUE))
        list_key = property(lambda self: self.get_key(LIST))
        rev_key = property(lambda self: self.get_key(REV))
        graph_key = property(lambda self: self.get_key(GRAPH))

        def add_term(
            self,
            name,
            idref,
            coercion=UNDEF,
            container=UNDEF,
            index=None,
            language=UNDEF,
            reverse=False,
            context=UNDEF,
            prefix=None,
            protected=False,
        ):
            if self.version < 1.1 or prefix is None:
                prefix = isinstance(idref, str) and idref.endswith(URI_GEN_DELIMS)

            if not self._accept_term(name):
                return

            if self.version >= 1.1:
                existing = self.terms.get(name)
                if existing and existing.protected:
                    return

            if isinstance(container, (list, set, tuple)):
                container = set(container)
            else:
                container = set([container])

            term = Term(
                idref,
                name,
                coercion,
                container,
                index,
                language,
                reverse,
                context,
                prefix,
                protected,
            )

            self.terms[name] = term

            for container_key in (LIST, LANG, SET):  # , INDEX, ID, GRAPH):
                if container_key in container:
                    break
            else:
                container_key = UNDEF

            self._lookup[(idref, coercion or language, container_key, reverse)] = term

            if term.prefix is True:
                self._prefixes[idref] = name

        def find_term(
            self, idref, coercion=None, container=UNDEF, language=None, reverse=False
        ):
            lu = self._lookup

            if coercion is None:
                coercion = language

            if coercion is not UNDEF and container:
                found = lu.get((idref, coercion, container, reverse))
                if found:
                    return found

            if coercion is not UNDEF:
                found = lu.get((idref, coercion, UNDEF, reverse))
                if found:
                    return found

            if container:
                found = lu.get((idref, coercion, container, reverse))
                if found:
                    return found
            elif language:
                found = lu.get((idref, UNDEF, LANG, reverse))
                if found:
                    return found
            else:
                found = lu.get((idref, coercion or UNDEF, SET, reverse))
                if found:
                    return found

            return lu.get((idref, UNDEF, UNDEF, reverse))

        def resolve(self, curie_or_iri):
            iri = self.expand(curie_or_iri, False)
            if self.isblank(iri):
                return iri
            if " " in iri:
                return ""
            return self.resolve_iri(iri)

        def resolve_iri(self, iri):
            return norm_url(self._base, iri)

        def isblank(self, ref):
            return ref.startswith("_:")

        def expand(self, term_curie_or_iri, use_vocab=True):
            if not isinstance(term_curie_or_iri, str):
                return term_curie_or_iri

            if not self._accept_term(term_curie_or_iri):
                return ""

            if use_vocab:
                term = self.terms.get(term_curie_or_iri)
                if term:
                    return term.id

            is_term, pfx, local = self._prep_expand(term_curie_or_iri)
            if pfx == "_":
                return term_curie_or_iri

            if pfx is not None:
                ns = self.terms.get(pfx)
                if ns and ns.prefix and ns.id:
                    return ns.id + local
            elif is_term and use_vocab:
                if self.vocab:
                    return self.vocab + term_curie_or_iri
                return None

            return self.resolve_iri(term_curie_or_iri)

        def shrink_iri(self, iri):
            ns, name = split_iri(str(iri))
            pfx = self._prefixes.get(ns)
            if pfx:
                return ":".join((pfx, name))
            elif self._base:
                if str(iri) == self._base:
                    return ""
                elif iri.startswith(self._basedomain):
                    return iri[len(self._basedomain) :]
            return iri

        def to_symbol(self, iri):
            iri = str(iri)
            term = self.find_term(iri)
            if term:
                return term.name
            ns, name = split_iri(iri)
            if ns == self.vocab:
                return name
            pfx = self._prefixes.get(ns)
            if pfx:
                return ":".join((pfx, name))
            return iri

        def load(self, source, base=None, referenced_contexts=None):
            self.active = True
            sources = []
            source = source if isinstance(source, list) else [source]
            referenced_contexts = referenced_contexts or set()
            self._prep_sources(base, source, sources, referenced_contexts)
            for source_url, source in sources:
                if source is None:
                    self._clear()
                else:
                    self._read_source(source, source_url, referenced_contexts)

        def _accept_term(self, key):
            if self.version < 1.1:
                return True
            if key and len(key) > 1 and key[0] == "@" and key[1].isalnum():
                return key in NODE_KEYS
            else:
                return True

        def _prep_sources(
            self, base, inputs, sources, referenced_contexts, in_source_url=None
        ):

            for source in inputs:
                source_url = in_source_url
                if isinstance(source, str):
                    source_url = source
                    source_doc_base = base or self.doc_base
                    new_ctx = self._fetch_context(
                        source, source_doc_base, referenced_contexts
                    )
                    if new_ctx is None:
                        continue
                    else:
                        if base:
                            base = urljoin(source_doc_base, source_url)
                        source = new_ctx

                if isinstance(source, dict):
                    if CONTEXT in source:
                        source = source[CONTEXT]
                        source = source if isinstance(source, list) else [source]

                if isinstance(source, list):
                    self._prep_sources(
                        base, source, sources, referenced_contexts, source_url
                    )
                else:
                    sources.append((source_url, source))

        def _fetch_context(self, source, base, referenced_contexts):
            source_url = urljoin(base, source)

            if source_url in referenced_contexts:
                raise RECURSIVE_CONTEXT_INCLUSION
            referenced_contexts.add(source_url)

            if source_url in self._context_cache:
                return self._context_cache[source_url]

            source = source_to_json(source_url)
            if source and CONTEXT not in source:
                raise INVALID_REMOTE_CONTEXT
            self._context_cache[source_url] = source

            return source

        def _read_source(self, source, source_url=None, referenced_contexts=None):
            imports = source.get(IMPORT)
            if imports:
                if not isinstance(imports, str):
                    raise INVALID_CONTEXT_ENTRY

                imported = self._fetch_context(
                    imports, self.base, referenced_contexts or set()
                )
                if not isinstance(imported, dict):
                    raise INVALID_CONTEXT_ENTRY

                imported = imported[CONTEXT]
                imported.update(source)
                source = imported

            self.vocab = source.get(VOCAB, self.vocab)
            self.version = source.get(VERSION, self.version)
            protected = source.get(PROTECTED, False)

            for key, value in source.items():
                if key in {VOCAB, VERSION, IMPORT, PROTECTED}:
                    continue
                elif key == PROPAGATE and isinstance(value, bool):
                    self.propagate = value
                elif key == LANG:
                    self.language = value
                elif key == BASE:
                    if not source_url and not imports:
                        self.base = value
                else:
                    self._read_term(source, key, value, protected)

        def _read_term(self, source, name, dfn, protected=False):
            idref = None
            if isinstance(dfn, dict):
                # term = self._create_term(source, key, value)
                rev = dfn.get(REV)
                protected = dfn.get(PROTECTED, protected)

                coercion = dfn.get(TYPE, UNDEF)
                if coercion and coercion not in (ID, TYPE, VOCAB):
                    coercion = self._rec_expand(source, coercion)

                idref = rev or dfn.get(ID, UNDEF)
                if idref == TYPE:
                    idref = str(RDF.type)
                    coercion = VOCAB
                elif idref is not UNDEF:
                    idref = self._rec_expand(source, idref)
                elif ":" in name:
                    idref = self._rec_expand(source, name)
                elif self.vocab:
                    idref = self.vocab + name

                context = dfn.get(CONTEXT, UNDEF)

                self.add_term(
                    name,
                    idref,
                    coercion,
                    dfn.get(CONTAINER, UNDEF),
                    dfn.get(INDEX, UNDEF),
                    dfn.get(LANG, UNDEF),
                    bool(rev),
                    context,
                    dfn.get(PREFIX),
                    protected=protected,
                )
            else:
                if isinstance(dfn, str):
                    if not self._accept_term(dfn):
                        return
                    idref = self._rec_expand(source, dfn)

                self.add_term(name, idref, protected=protected)

            if idref in NODE_KEYS:
                self._alias.setdefault(idref, []).append(name)

        def _rec_expand(self, source, expr, prev=None):
            if expr == prev or expr in NODE_KEYS:
                return expr

            is_term, pfx, nxt = self._prep_expand(expr)
            if pfx:
                iri = self._get_source_id(source, pfx)
                if iri is None:
                    if pfx + ":" == self.vocab:
                        return expr
                    else:
                        term = self.terms.get(pfx)
                        if term:
                            iri = term.id

                if iri is None:
                    nxt = expr
                else:
                    nxt = iri + nxt
            else:
                nxt = self._get_source_id(source, nxt) or nxt
                if ":" not in nxt and self.vocab:
                    return self.vocab + nxt

            return self._rec_expand(source, nxt, expr)

        def _prep_expand(self, expr):
            if ":" not in expr:
                return True, None, expr
            pfx, local = expr.split(":", 1)
            if not local.startswith("//"):
                return False, pfx, local
            else:
                return False, None, expr

        def _get_source_id(self, source, key):
            # .. from source dict or if already defined
            term = source.get(key)
            if term is None:
                dfn = self.terms.get(key)
                if dfn:
                    term = dfn.id
            elif isinstance(term, dict):
                term = term.get(ID)
            return term

    Term = namedtuple(
        "Term",
        "id, name, type, container, index, language, reverse, context," "prefix, protected",
    )
    Term.__new__.__defaults__ = (UNDEF, UNDEF, UNDEF, UNDEF, False, UNDEF, False, False)  # type: ignore[attr-defined]