from pypy.rpython.lltypesystem.lltype import \
     Primitive, Ptr, typeOf, RuntimeTypeInfo, \
     Struct, Array, FuncType, PyObject, Void, \
     ContainerType, OpaqueType, FixedSizeArray, _uninitialized
from pypy.rpython.lltypesystem import lltype, rffi
from pypy.rpython.lltypesystem.llmemory import WeakRef, _WeakRefType, GCREF
from pypy.rpython.lltypesystem.rffi import CConstant
from pypy.rpython.lltypesystem import llgroup
from pypy.tool.sourcetools import valid_identifier
from pypy.translator.c.primitive import PrimitiveName, PrimitiveType
from pypy.translator.c.node import StructDefNode, ArrayDefNode
from pypy.translator.c.node import FixedSizeArrayDefNode, BareBoneArrayDefNode
from pypy.translator.c.node import ContainerNodeFactory, ExtTypeOpaqueDefNode
from pypy.translator.c.support import cdecl, CNameManager
from pypy.translator.c.support import log, barebonearray
from pypy.translator.c.extfunc import do_the_getting
from pypy import conftest
from pypy.translator.c import gc
from pypy.tool.identity_dict import identity_dict


class NoCorrespondingNode(Exception):
    pass

# ____________________________________________________________

class LowLevelDatabase(object):
    gctransformer = None

    def __init__(self, translator=None, standalone=False,
                 gcpolicyclass=None,
                 stacklesstransformer=None,
                 thread_enabled=False,
                 sandbox=False):
        self.translator = translator
        self.standalone = standalone
        self.sandbox    = sandbox
        self.stacklesstransformer = stacklesstransformer
        if gcpolicyclass is None:
            gcpolicyclass = gc.RefcountingGcPolicy
        self.gcpolicy = gcpolicyclass(self, thread_enabled)

        self.structdefnodes = {}
        self.pendingsetupnodes = []
        self.containernodes = {}
        self.containerlist = []
        self.idelayedfunctionnames = identity_dict()
        self.delayedfunctionptrs = []
        self.completedcontainers = 0
        self.containerstats = {}
        self.externalfuncs = {}
        self.helper2ptr = {}

        # late_initializations is for when the value you want to
        # assign to a constant object is something C doesn't think is
        # constant
        self.late_initializations = []
        self.namespace = CNameManager()

        if translator is None or translator.rtyper is None:
            self.exctransformer = None
        else:
            self.exctransformer = translator.getexceptiontransformer()
        if translator is not None:
            self.gctransformer = self.gcpolicy.transformerclass(translator)
        self.completed = False

        self.instrument_ncounter = 0

    def gettypedefnode(self, T, varlength=1):
        if varlength <= 1:
            varlength = 1   # it's C after all
            key = T
        else:
            key = T, varlength
        try:
            node = self.structdefnodes[key]
        except KeyError:
            if isinstance(T, Struct):
                if isinstance(T, FixedSizeArray):
                    node = FixedSizeArrayDefNode(self, T)
                else:
                    node = StructDefNode(self, T, varlength)
            elif isinstance(T, Array):
                if barebonearray(T):
                    node = BareBoneArrayDefNode(self, T, varlength)
                else:
                    node = ArrayDefNode(self, T, varlength)
            elif isinstance(T, OpaqueType) and T.hints.get("render_structure", False):
                node = ExtTypeOpaqueDefNode(self, T)
            elif T == WeakRef:
                REALT = self.gcpolicy.get_real_weakref_type()
                node = self.gettypedefnode(REALT)
            else:
                raise NoCorrespondingNode("don't know about %r" % (T,))
            self.structdefnodes[key] = node
            self.pendingsetupnodes.append(node)
        return node

    def gettype(self, T, varlength=1, who_asks=None, argnames=[]):
        if isinstance(T, Primitive) or T == GCREF:
            return PrimitiveType[T]
        elif isinstance(T, Ptr):
            if (isinstance(T.TO, OpaqueType) and
                T.TO.hints.get('c_pointer_typedef') is not None):
                return '%s @' % T.TO.hints['c_pointer_typedef']
            try:
                node = self.gettypedefnode(T.TO)
            except NoCorrespondingNode:
                pass
            else:
                if hasattr(node, 'getptrtype'):
                    return node.getptrtype()   # special-casing because of C
            typename = self.gettype(T.TO)   # who_asks not propagated
            return typename.replace('@', '*@')
        elif isinstance(T, (Struct, Array, _WeakRefType)):
            node = self.gettypedefnode(T, varlength=varlength)
            if who_asks is not None:
                who_asks.dependencies[node] = True
            return node.gettype()
        elif T == PyObject:
            return 'PyObject @'
        elif isinstance(T, FuncType):
            resulttype = self.gettype(T.RESULT)
            argtypes = []
            for i in range(len(T.ARGS)):
                if T.ARGS[i] is not Void:
                    argtype = self.gettype(T.ARGS[i])
                    try:
                        argname = argnames[i]
                    except IndexError:
                        argname = ''
                    argtypes.append(cdecl(argtype, argname))
            argtypes = ', '.join(argtypes) or 'void'
            return resulttype.replace('@', '(@)(%s)' % argtypes)
        elif isinstance(T, OpaqueType):
            if T == RuntimeTypeInfo:
                return  self.gcpolicy.rtti_type()
            elif T.hints.get("render_structure", False):
                node = self.gettypedefnode(T, varlength=varlength)
                if who_asks is not None:
                    who_asks.dependencies[node] = True
                return 'struct %s @' % node.name
            elif T.hints.get('external', None) == 'C':
                return '%s @' % T.hints['c_name']
            else:
                #raise Exception("don't know about opaque type %r" % (T,))
                return 'struct %s @' % (
                    valid_identifier('pypy_opaque_' + T.tag),)
        elif isinstance(T, llgroup.GroupType):
            return "/*don't use me*/ void @"
        else:
            raise Exception("don't know about type %r" % (T,))

    def getcontainernode(self, container, _dont_write_c_code=True, **buildkwds):
        try:
            node = self.containernodes[container]
        except KeyError:
            T = typeOf(container)
            if isinstance(T, (lltype.Array, lltype.Struct)):
                if hasattr(self.gctransformer, 'consider_constant'):
                    self.gctransformer.consider_constant(T, container)
            nodefactory = ContainerNodeFactory[T.__class__]
            node = nodefactory(self, T, container, **buildkwds)
            self.containernodes[container] = node
            # _dont_write_c_code should only be False for a hack in
            # weakrefnode_factory()
            if not _dont_write_c_code:
                return node
            kind = getattr(node, 'nodekind', '?')
            self.containerstats[kind] = self.containerstats.get(kind, 0) + 1
            self.containerlist.append(node)
            if self.completed:
                pass # we would like to fail here, but a few containers
                     # are found very late, e.g. _subarrays via addresses
                     # introduced by the GC transformer, or the type_info_table
        return node

    def get(self, obj):
        if isinstance(obj, CConstant):
            return obj.c_name  # without further checks
        T = typeOf(obj)
        if isinstance(T, Primitive) or T == GCREF:
            return PrimitiveName[T](obj, self)
        elif isinstance(T, Ptr):
            if (isinstance(T.TO, OpaqueType) and
                T.TO.hints.get('c_pointer_typedef') is not None):
                if obj._obj is not None:
                    value = rffi.cast(rffi.SSIZE_T, obj)
                    return '((%s) %s)' % (cdecl(self.gettype(T), ''),
                                          self.get(value))
            if obj:   # test if the ptr is non-NULL
                try:
                    container = obj._obj
                except lltype.DelayedPointer:
                    # hack hack hack
                    name = obj._obj0
                    assert name.startswith('delayed!')
                    n = len('delayed!')
                    if len(name) == n:
                        raise
                    if isinstance(lltype.typeOf(obj).TO, lltype.FuncType):
                        if obj in self.idelayedfunctionnames:
                            return self.idelayedfunctionnames[obj][0]
                        funcname = name[n:]
                        funcname = self.namespace.uniquename('g_'+funcname)
                        self.idelayedfunctionnames[obj] = funcname, obj
                    else:
                        funcname = None      # can't use the name of a
                                             # delayed non-function ptr
                    self.delayedfunctionptrs.append(obj)
                    return funcname
                    # /hack hack hack
                else:
                    # hack hack hack
                    if obj in self.idelayedfunctionnames:
                        # this used to be a delayed function,
                        # make sure we use the same name
                        forcename = self.idelayedfunctionnames[obj][0]
                        node = self.getcontainernode(container,
                                                     forcename=forcename)
                        assert node.getptrname() == forcename
                        return forcename
                    # /hack hack hack

                if isinstance(container, int):
                    # special case for tagged odd-valued pointers
                    return '((%s) %d)' % (cdecl(self.gettype(T), ''),
                                          obj._obj)
                node = self.getcontainernode(container)
                return node.getptrname()
            else:
                return '((%s) NULL)' % (cdecl(self.gettype(T), ''), )
        else:
            raise Exception("don't know about %r" % (obj,))

    def complete(self, show_progress=True):
        assert not self.completed
        if self.translator and self.translator.rtyper:
            do_the_getting(self, self.translator.rtyper)
        def dump():
            lst = ['%s: %d' % keyvalue
                   for keyvalue in self.containerstats.items()]
            lst.sort()
            log.event('%8d nodes  [ %s ]' % (i, '  '.join(lst)))
        i = self.completedcontainers
        if show_progress:
            show_i = (i//1000 + 1) * 1000
        else:
            show_i = -1

        # The order of database completion is fragile with stackless and
        # gc transformers.  Here is what occurs:
        #
        # 1. follow dependencies recursively from the entry point: data
        #    structures pointing to other structures or functions, and
        #    constants in functions pointing to other structures or functions.
        #    Because of the mixlevelannotator, this might find delayed
        #    (not-annotated-and-rtyped-yet) function pointers.  They are
        #    not followed at this point.  User finalizers (__del__) on the
        #    other hand are followed during this step too.
        #
        # 2. gctransformer.finish_helpers() - after this, all functions in
        #    the program have been rtyped.
        #
        # 3. follow new dependencies.  All previously delayed functions
        #    should have been resolved by 2 - they are gc helpers, like
        #    ll_finalize().  New FuncNodes are built for them.  No more
        #    FuncNodes can show up after this step.
        #
        # 4. stacklesstransform.finish() - freeze the stackless resume point
        #    table.
        #
        # 5. follow new dependencies (this should be only the new frozen
        #    table, which contains only numbers and already-seen function
        #    pointers).
        #
        # 6. gctransformer.finish_tables() - freeze the gc types table.
        #
        # 7. follow new dependencies (this should be only the gc type table,
        #    which contains only numbers and pointers to ll_finalizer
        #    functions seen in step 3).
        #
        # I think that there is no reason left at this point that force
        # step 4 to be done before step 6, nor to have a follow-new-
        # dependencies step inbetween.  It is important though to have step 3
        # before steps 4 and 6.
        #
        # This is implemented by interleaving the follow-new-dependencies
        # steps with calls to the next 'finish' function from the following
        # list:
        finish_callbacks = []
        if self.gctransformer:
            finish_callbacks.append(('GC transformer: finished helpers',
                                     self.gctransformer.finish_helpers))
        if self.stacklesstransformer:
            finish_callbacks.append(('Stackless transformer: finished',
                                     self.stacklesstransformer.finish))
        if self.gctransformer:
            finish_callbacks.append(('GC transformer: finished tables',
                                     self.gctransformer.get_finish_tables()))

        def add_dependencies(newdependencies):
            for value in newdependencies:
                #if isinstance(value, _uninitialized):
                #    continue
                if isinstance(typeOf(value), ContainerType):
                    self.getcontainernode(value)
                else:
                    self.get(value)

        while True:
            while True:
                while self.pendingsetupnodes:
                    lst = self.pendingsetupnodes
                    self.pendingsetupnodes = []
                    for nodedef in lst:
                        nodedef.setup()
                if i == len(self.containerlist):
                    break
                node = self.containerlist[i]
                add_dependencies(node.enum_dependencies())
                i += 1
                self.completedcontainers = i
                if i == show_i:
                    dump()
                    show_i += 1000

            if self.delayedfunctionptrs:
                lst = self.delayedfunctionptrs
                self.delayedfunctionptrs = []
                progress = False
                for fnptr in lst:
                    try:
                        fnptr._obj
                    except lltype.DelayedPointer:   # still not resolved
                        self.delayedfunctionptrs.append(fnptr)
                    else:
                        self.get(fnptr)
                        progress = True
                if progress:
                    continue   # progress - follow all dependencies again

            if finish_callbacks:
                logmsg, finish = finish_callbacks.pop(0)
                if not hasattr(finish, 'next'):
                    newdependencies = finish()
                else:
                    # if 'finish' is a generator, consume the next element
                    # and put the generator again in the queue
                    try:
                        newdependencies = finish.next()
                        finish_callbacks.insert(0, (None, finish))
                    except StopIteration:
                        newdependencies = None
                if logmsg:
                    log.database(logmsg)
                if newdependencies:
                    add_dependencies(newdependencies)
                continue       # progress - follow all dependencies again

            break     # database is now complete

        assert not self.delayedfunctionptrs
        self.completed = True
        if show_progress:
            dump()
        log.database("Completed")

    def globalcontainers(self):
        for node in self.containerlist:
            if node.globalcontainer:
                yield node

    def get_lltype_of_exception_value(self):
        if self.translator is not None and self.translator.rtyper is not None:
            exceptiondata = self.translator.rtyper.getexceptiondata()
            return exceptiondata.lltype_of_exception_value
        else:
            return Ptr(PyObject)

    def getstructdeflist(self):
        # return the StructDefNodes sorted according to dependencies
        result = []
        seen = {}
        def produce(node):
            if node not in seen:
                deps = node.dependencies.keys()
                deps.sort(key=lambda x: x.name)
                for othernode in deps:
                    produce(othernode)
                result.append(node)
                seen[node] = True
        nodes = self.structdefnodes.values()
        nodes.sort(key=lambda x: x.name)
        for node in nodes:
            produce(node)
        return result

    def need_sandboxing(self, fnobj):
        if not self.sandbox:
            return False
        if hasattr(fnobj, '_safe_not_sandboxed'):
            return not fnobj._safe_not_sandboxed
        else:
            return "if_external"

    def prepare_inline_helpers(self):
        all_nodes = self.globalcontainers()
        funcnodes = [node for node in all_nodes if node.nodekind == 'func']
        graphs = []
        for node in funcnodes:
            for graph in node.graphs_to_patch():
                graphs.append(graph)
        self.gctransformer.prepare_inline_helpers(graphs)

    def all_graphs(self):
        graphs = []
        for node in self.containerlist:
            if node.nodekind == 'func':
                for graph in node.graphs_to_patch():
                    graphs.append(graph)
        return graphs