#
#     This file is part of CasADi.
#
#     CasADi -- A symbolic framework for dynamic optimization.
#     Copyright (C) 2010-2014 Joel Andersson, Joris Gillis, Moritz Diehl,
#                             K.U. Leuven. All rights reserved.
#     Copyright (C) 2011-2014 Greg Horn
#
#     CasADi is free software; you can redistribute it and/or
#     modify it under the terms of the GNU Lesser General Public
#     License as published by the Free Software Foundation; either
#     version 3 of the License, or (at your option) any later version.
#
#     CasADi is distributed in the hope that it will be useful,
#     but WITHOUT ANY WARRANTY; without even the implied warranty of
#     MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
#     Lesser General Public License for more details.
#
#     You should have received a copy of the GNU Lesser General Public
#     License along with CasADi; if not, write to the Free Software
#     Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301  USA
#
#
from casadi import *


import numpy as np
import operator
import sys

if sys.version_info >= (3, 0):
  import builtins
else:
  import __builtin__
  builtins = __builtin__
import collections

def is_integer(a):
  return isinstance(a,int) or isinstance(a,np.integer)

def is_string(a):
  return isinstance(a,str)

def isIterable(a):
  return isinstance(a,list) or isinstance(a,tuple)

# StructIndex :tuple/list of strings
# canonicalIndex : tuple/list of string or numbers
# powerIndex: tuple/list of string, numbers, lists, slices, dicts

# flatIndex

# Primitive helpers
def lpack(L): return [[x] for x in L]

def combine(*args):
  if len(args)==0:
    return [[]]
  else:
    return [a + b for a in args[0] for b in combine(*args[1:])]

def listindices(dims,nest=False):
  if len(dims)==0:
    if nest:
      return [[[]]]
    else:
      return [[]]
  else:
    tail = listindices(dims[1:])
    if nest:
      return [combine([[i]],tail) for i in range(dims[0])]
    else:
      return combine(lpack(list(range(dims[0]))),tail)

def intersperseIt(*args):
  iterators = list(map(iter,args))
  active = [True]*len(args)
  i = 0
  while any(active):
    try:
      yield next(iterators[i])
    except:
      active[i] = False
    i = (i + 1) % len(args)

def intersperse(*args):
   return list(intersperseIt(*args))

def canonicalIndexAncestors(ind):
  if len(ind)==0: return []
  return [ind] + canonicalIndexAncestors(ind[:-(list(map(is_string,ind[::-1])).index(True)+1)])

def canonical(ind,s):
  if ind < 0:
    return ind + s
  else:
    return ind

def vec(e):
  if any(isinstance(i,list) for i in e):
    return sum(list(map(vec,e)),[])
  else:
    return e


def correct_vector_indexing(x, i):
  return casadi.reshape(x[i], i.shape)

# Decoraters

def properGetitem(f):
  """
    This decorator modifies a __getitem__/__setitem__ method such that it will always receive a tuple
  """
  def proper(self,mbt,*args):
    if not isinstance(mbt,tuple):
      mbt = (mbt,)
    return f(self,mbt,*args)
  return proper

# Enhanced standard classes
class SafeDict(dict):
  def __getitem__(self,k):
    if k not in self:
      raise Exception("Unknown keyword '%s'. Available entries: %s" % (k,str(list(self.keys()))))
    return dict.__getitem__(self,k)

# Placeholder classes and instances
class Repeater:
  def __init__(self,e): self.e = e

def repeated(e):
  """
    From the arguemnt, constructs something that acts like a 'list' with the argument repeated the 'correct' number of times

    s = struct_symSX([entry("x",repeat=6)])
    s["x"] = repeated(12)

  """
  return Repeater(e)

class NestedDictLiteral:
  """
    NestedDictLiteral will cause all dictionaries to become explicit recursively
  """

nesteddict = NestedDictLiteral()

# Casadi-independent Structure framework

def payloadUnpack(payload,i):
  if is_string(i):
    raise Exception("Got string %s where number expected."% i)
  if isIterable(payload):
    if i>=len(payload):
      raise Exception("Rhs out of range. Got list index %s but rhs list is only of length %s." % (i,len(payload)))
    return payload[i]
  elif isinstance(payload,Repeater):
    return payload.e
  else:
    return payload

class StructEntry:
  def __init__(self,name,struct=None,data=None,dims=[]):
    self.name = name
    self.dims = dims
    self.struct = struct

  def __str__(self,compact=False):
     s=''
     if len(self.dims)>=1:
       s+= "repeated(%s): " % str(self.dims)
     if self.isPrimitive():
       s+=self.primitiveString()
     else:
       s+=self.struct.__str__(compact=True)
     return s

  __repr__ = __str__

  def primitiveString(self):
    return "*"

  def isPrimitive(self):
    return self.struct is None

  def traverseCanonicalIndex(self,nest=False,limit=1000):
    children = [[]] if (self.struct is None or limit==0) else self.struct.traverseCanonicalIndex(limit=limit-1)
    li = listindices(self.dims,nest)
    n = [[self.name]]
    if nest:
      return [combine(n,i,children) for i in li]
    else:
      return combine(n,li,children)

  def getStructEntryByStructIndex(self,structIndex):
    return self.struct.getStructEntryByStructIndex(structIndex)

  def traverseByPowerIndex(self,powerIndex,dims=None,canonicalIndex=(),dispatcher=None,payload=None):
    try:
      if dims is None: dims = self.dims
      # At the end of powerIndex, pending : are added automatically if dims is not exhausted
      if len(powerIndex)==0:
        if len(dims)>0:
          return self.traverseByPowerIndex(
                   [slice(None) for i in dims],
                   dims=dims,
                   canonicalIndex=canonicalIndex,
                   dispatcher=dispatcher,
                   payload=payload
                 )
        else:
          return dispatcher(payload,canonicalIndex,entry=self)

      if len(dims)==0:
        if self.isPrimitive(): # Pass on remainder of powerIndex to dispatcher
          return dispatcher(payload,canonicalIndex,extraIndex=tuple(powerIndex),entry=self)
        else:
          return self.struct.traverseByPowerIndex(
                   powerIndex,
                   canonicalIndex=canonicalIndex,
                   dispatcher=dispatcher,
                   payload=payload
                 )
      else:
        p = powerIndex[0]
        s = dims[0]
        if isinstance(p,slice): # Expand slice
          p = list(range(*p.indices(s)))
        if is_integer(p):
          return self.traverseByPowerIndex(
                   powerIndex[1:],
                   dims=dims[1:],
                   canonicalIndex=canonicalIndex+(canonical(p,s),),
                   dispatcher=dispatcher,
                   payload=payload
                 )
        elif isinstance(p,list):
          return [
                    self.traverseByPowerIndex(
                      powerIndex[1:],
                      dims=dims[1:],
                      canonicalIndex=canonicalIndex+(canonical(i,s),),
                      dispatcher=dispatcher,
                      payload = payloadUnpack(payload,i)
                    )
                 for i in p]
        elif isinstance(p,dict):
          raise Exception("powerIndex entry {} cannot be used in list context.")
        elif isinstance(p,set):
          raise Exception("""powerIndex entry {"foo","bar"} cannot be used in list context.""")
        elif isinstance(p,NestedDictLiteral):
          return [
                    self.traverseByPowerIndex(
                      [p],
                      dims=dims[1:],
                      canonicalIndex=canonicalIndex+(canonical(i,s),),
                      dispatcher=dispatcher,
                      payload = payloadUnpack(payload,i)
                    )
                 for i in range(s)]
        elif isinstance(p, collections.Callable):
          r = p(self.traverseByPowerIndex(
                powerIndex[1:],
                dims=dims,
                canonicalIndex=canonicalIndex,
                dispatcher=dispatcher.callableInner(),
                payload=payload
              ))
          return dispatcher.callableOuter(payload,canonicalIndex,extraIndex=None,entry=None,inner=r)
        else:
          raise Exception("I don't know what to do with this: %s" % str(p))
    except Exception as e:
      raise Exception("Error occured in entry context with powerIndex %s, at canonicalIndex %s" % (str(powerIndex),str(canonicalIndex))) from e

class Structure(object):
  def __init__(self,entries,order=None):
    self.entries = entries

    self.order = [e.name for e in self.entries] if order is None else order
    self.keyslist = sum([ list(i) if isinstance(i,tuple) else list([i]) for i in self.order],[])

    self.dict = SafeDict([(e.name,e) for e in self.entries])

    for e in self.order:
      if is_string(e):
        if e not in self.dict:
          raise Exception("Order '%s' is invalid." % e)
      elif isinstance(e,tuple):
        for ee in e:
          if ee not in self.dict:
            raise Exception("Order '%s' is invalid." % ee)

  def keys(self):
    return self.keyslist

  def __str__(self,compact=False):
     s=''
     if compact:
       s+= "{" + ",".join(k + ": " +  v.__str__(compact=True) for k,v in list(self.dict.items())) + "}"
     else:
       s+= "Structure holding %d entries.\n" % len(self.dict)
       s+="  Order: %s\n" % str(self.order)
       for k,v in list(self.dict.items()):
          s+= "  " + k + " = " +  v.__str__(compact=True) + "\n"
     return s

  __repr__ = __str__

  def traverseCanonicalIndex(self,limit=1000):
    ret = []
    for d in self.order:
      if isinstance(d,tuple):
        for v in intersperse(*[self.dict[de].traverseCanonicalIndex(True,limit=limit-1) for de in d]):
          ret += v
      else:
        ret += self.dict[d].traverseCanonicalIndex(limit=limit-1)
    return ret

  def getStructEntryByStructIndex(self,structIndex):
    e = self.dict[structIndex[0]]
    if len(structIndex)>1:
      return e.getStructEntryByStructIndex(structIndex[1:])
    else:
      return e

  def getStructEntryByCanonicalIndex(self,indices):
    return self.getStructEntryByStructIndex([x for x in indices if is_string(x)])

  def getStruct(self,name):
    if name not in self.struct.dict:
      raise Exception("Cannot find entry with key '%s'. Candidates: " % (str(name),str(list(name.keys()))))
    ret = self.struct.dict[name].struct
    if ret is None:
      raise Exception("Entry '%s' has no structure." % (name))
    else:
      return ret

  def traverseByPowerIndex(self,powerIndex,canonicalIndex=(),dispatcher=None,payload=None):
      try:
        if len(powerIndex)==0: return dispatcher(payload,canonicalIndex)
        p = powerIndex[0]
        if is_string(p):
          return self.dict[p].traverseByPowerIndex(
            powerIndex[1:],
            canonicalIndex=canonicalIndex+(p,),
            dispatcher=dispatcher,
            payload=payload
          )
        elif isinstance(p,slice):
          raise Exception("slice not allowed here, did you mean '...' ?")
        elif isinstance(p,type(Ellipsis)):
          """
             Why ellipsis? Because it's all or nothing
          """
          return [
                     self.dict[k].traverseByPowerIndex(
                       powerIndex[1:],
                       canonicalIndex=canonicalIndex+(k,),
                       dispatcher=dispatcher,
                       payload=payloadUnpack(payload,i)
                     )
                  for i,k in enumerate(self.keys())]
        elif isinstance(p,dict) or isinstance(p,NestedDictLiteral):
          if isinstance(payload,dict):
            return dict([
                    ( k,
                      self.dict[k].traverseByPowerIndex(
                        powerIndex[1:] if isinstance(p,dict) else [p],
                        canonicalIndex=canonicalIndex+(k,),
                        dispatcher=dispatcher,
                        payload=v
                      )
                    ) for k,v in payload.items()
                   ])
          else:
            return dict([
                    ( k,
                      v.traverseByPowerIndex(
                        powerIndex[1:] if isinstance(p,dict) else [p],
                        canonicalIndex=canonicalIndex+(k,),
                        dispatcher=dispatcher,
                        payload=payload
                      )
                    ) for k,v in self.dict.items()
                   ])
        elif isinstance(p,set):
          if isinstance(payload,dict):
            return dict([
                    ( k,
                      self.dict[k].traverseByPowerIndex(
                        powerIndex[1:],
                        canonicalIndex=canonicalIndex+(k,),
                        dispatcher=dispatcher,
                        payload=v
                      )
                    ) for k,v in payload.items() if k in p
                   ])
          else:
            return dict([
                    ( k,
                      self.dict[k].traverseByPowerIndex(
                        powerIndex[1:],
                        canonicalIndex=canonicalIndex+(k,),
                        dispatcher=dispatcher,
                        payload=payload
                      )
                    ) for k in p
                   ])
        elif isinstance(p,list):
          return [
                     self.traverseByPowerIndex(
                       powerIndex[1:],
                       canonicalIndex=canonicalIndex+(s,),
                       dispatcher=dispatcher,
                       payload=payloadUnpack(payload,i)
                     )
                 for i,s in enumerate(p)]
        elif isinstance(p, collections.Callable):
          r = p(self.traverseByPowerIndex(
                powerIndex[1:],
                canonicalIndex=canonicalIndex,
                dispatcher=dispatcher.callableInner(),
                payload=payload
              ))
          return dispatcher.callableOuter(payload,canonicalIndex,extraIndex=None,entry=None,inner=r)
        else:
          raise Exception("I don't know what to do with this: %s" % str(p))
      except Exception as e:
        raise Exception("Error occured in struct context with powerIndex %s, at canonicalIndex %s" % (str(powerIndex),str(canonicalIndex))) from e
# Casadi-dependent Structure framework

class Dispatcher:
  def __init__(self,**args):
    for k,v in list(args.items()):
      setattr(self,k,v)

  def callableInner(self):
    return self

  def callableOuter(self,payload,canonicalIndex,extraIndex=None,entry=None,inner=None):
    return inner


#Mixins
class CasadiStructureDerivable:

  def argtype(self,arg):
    mtype = None
    if isinstance(arg,DM):
      a = arg
      mtype = DM
    elif not isinstance(arg,MX) and not isinstance(arg,SX):
      try:
        a = DM(arg)
        mtype = DM
      except:
        pass

    if mtype is None:
      if isinstance(arg,MX):
        a = arg
        mtype = MX
      else:
        try:
          a = MX(arg)
          mtype = MX
        except:
          pass

    if mtype is None:
      if isinstance(arg,SX):
        a = arg
        mtype = SX
      else:
        try:
          a = SX(arg)
          mtype = SX
        except:
          raise Exception("Call to Structure has weird argument: expecting DM-like or MX-like or SXMatrix-like")

    return (a,mtype)

  def __call__(self,arg=0):
    (a,mtype) = self.argtype(arg)

    if isinstance(a,DM):
      if a.shape[0] == 1 and a.shape[1] == 1 and self.size!=1:
        a = DM.ones(self.size,1)*a
      return DMStruct(self,data=a)

    if isinstance(a,MX):
      return MXStruct(self,data=a)

    if isinstance(a,SX):
      return SXStruct(self,data=a)

  def repeated(self,arg=0):
    (a,mtype) = self.argtype(arg)

    if not(a.shape[0] == self.size):
       raise Exception("Expecting %d x n DM. Got %s" % (self.size,a.dim()))
    s = struct([entry("t",struct=self,repeat=a.shape[1])])

    for (t,c) in [(DM,DMStruct), (MX, MXStruct), (SX, SXStruct)]:
      if isinstance(a,t):
        numbers = c(s,data=DataReferenceRepeated(a,a.shape[1]))

    p = numbers.prefix["t"]
    p.castmaster = True
    return p

  def squared(self,arg=0):
    (a,mtype) = self.argtype(arg)

    if a.shape[0] == 1 and a.shape[1] == 1 and self.size!=1:
       a = DM.ones(self.size,self.size)*a
    if not(a.shape[1] == a.shape[0] and a.shape[0]==self.size):
       raise Exception("Expecting square DM of size %s. Got %s" % (self.size,a.dim()))
    s = struct([entry("t",shapestruct=(self,self))])
    for (t,c) in [(DM,DMStruct), (MX, MXStruct), (SX, SXStruct)]:
      if isinstance(a,t):
        numbers = c(s,data=DataReferenceSquared(a,a.shape[0]))
    p = numbers.prefix["t"]
    p.castmaster = True
    return p

  def product(self,otherstruct,arg=0):
    (a,mtype) = self.argtype(arg)

    if a.shape[0] == 1 and a.shape[1] == 1 and self.size!=1:
       a = DM.ones(self.size,otherstruct.size)*a
    if not(a.shape[1]==otherstruct.size and a.shape[0]==self.size):
       raise Exception("Expecting DM of shape (%s,%s). Got %s" % (self.size,otherstruct.size,a.dim()))
    s = struct([entry("t",shapestruct=(self,otherstruct))])
    for (t,c) in [(DM,DMStruct), (MX, MXStruct), (SX, SXStruct)]:
      if isinstance(a,t):
        numbers = c(s,data=DataReferenceProduct(a,a.shape[0],a.shape[1]))
    p = numbers.prefix["t"]
    p.castmaster = True
    return p

  def squared_repeated(self,arg=0):
    (a,mtype) = self.argtype(arg)

    if not(a.shape[0]==self.size and a.shape[1] % self.size == 0):
       raise Exception("Expecting square (%d) DM by N. Got %s" % (self.size,a.dim()))
    s = struct([entry("t",shapestruct=(self,self),repeat=int(a.shape[1] / self.size))])

    for (t,c) in [(DM,DMStruct), (MX, MXStruct), (SX, SXStruct)]:
      if isinstance(a,t):
        numbers = c(s,data=DataReferenceSquaredRepeated(a,self.size,int(a.shape[1] / self.size)))

    p = numbers.prefix["t"]
    p.castmaster = True
    return p

class GetterDispatcher(Dispatcher):
  def __call__(self,payload,canonicalIndex,extraIndex=None,entry=None):
    type = None if entry is None else entry.type
    if canonicalIndex in self.struct.map:

      if canonicalIndex in self.priority_object_map and (extraIndex is None or len(extraIndex)==0):
        r = self.priority_object_map[canonicalIndex]
        if type is None:
          return r
        elif type=="symm":
          return triu2symm(r)
        else:
          raise Exception("Cannot handle type '%s'." % entry.type)

      i = performExtraIndex(self.struct.map[canonicalIndex],extraIndex=extraIndex,entry=entry)

      try:
        if type is None:
          return correct_vector_indexing(self.master, i)
        elif type=="symm":
          return triu2symm(self.master[i])
        else:
          raise Exception("Cannot handle type '%s'." % entry.type)
      except Exception as e:
        raise Exception("Error in powerIndex slicing for canonicalIndex %s" % (str(canonicalIndex))) from e
    else:
      raise Exception("Canonical index %s does not exist." % str(canonicalIndex))

class SetterDispatcher(Dispatcher):
  def __call__(self,payload,canonicalIndex,extraIndex=None,entry=None):
    payload_ = self.mtype(payload)
    type = None if entry is None else entry.type
    if canonicalIndex in self.struct.map:
      i = performExtraIndex(self.struct.map[canonicalIndex],extraIndex=extraIndex,entry=entry)
      try:
        if type is None:
          self.master[i] = payload_
        elif type=="symm":
          iflip = performExtraIndex(self.struct.map[canonicalIndex],extraIndex=extraIndex,entry=entry,flip=True)
          if payload_.is_scalar():
            self.master[i] = payload_
            self.master[iflip] = payload_
          else:
            oi = performExtraIndex(DM.ones(entry.originalsparsity),extraIndex=extraIndex,entry=entry)
            if oi.sparsity()!=payload_.sparsity():
              raise Exception("Payload sparsity " + payload_.dim() +  " does not match lhs sparisty " + oi.dim() + "." )
            self.master[iflip] = payload_.T[iflip.sparsity()]
            self.master[i] = payload_[i.sparsity()]
        else:
          raise Exception("Cannot handle type '%s'." % entry.type)
      except NotImplementedError as e:
        raise CompatibilityException("Error in canonicalIndex slicing for %s: Incompatible types in a[i]=b with a %s (%s) and b %s (%s) and i %s (%s). Error: %s" % (str(canonicalIndex),str(self.master),str(builtins.type(self.master)),str(payload),str(builtins.type(payload)),str(i),str(builtins.type(i)),str(e)))
      except Exception as e:
        raise Exception("Error in powerIndex slicing for canonicalIndex %s" % (str(canonicalIndex))) from e
    else:
      raise Exception("Canonical index %s does not exist." % str(canonicalIndex))

  def callableInner(self):
    return CasadiStructure.IMDispatcher(struct=self.struct)

  def callableOuter(self,payload,canonicalIndex,extraIndex=None,entry=None,inner=None):
    try:
      self.master[inner] = payload
    except NotImplementedError:
      raise CompatibilityException("Error in canonicalIndex slicing for %s: Incompatible types in a[i]=b with a %s and b %s." % (str(canonicalIndex),str(self.master),str(payload)))
    except Exception as e:
      raise Exception("Error in powerIndex slicing for canonicalIndex %s" % (str(canonicalIndex))) from e
      
class MasterGettable:
  @properGetitem
  def __getitem__(self,powerIndex):
    return self.struct.traverseByPowerIndex(powerIndex,dispatcher=GetterDispatcher(struct=self.struct,master=self.master,priority_object_map=self.priority_object_map))

class MasterSettable:
  @properGetitem
  def __setitem__(self,powerIndex,value):
    return self.struct.traverseByPowerIndex(powerIndex,dispatcher=
    SetterDispatcher(struct=self.struct,master=self.master,mtype=self.mtype),payload=value)

def delegation(extraIndex,entry,i):
  if is_string(extraIndex) or (isinstance(extraIndex,list) and len(extraIndex)>0 and all([is_string(e) for e in extraIndex])):
    extraIndex = FlatIndexDelegater(extraIndex)
  if isinstance(extraIndex,Delegater):
    if entry is None: raise Exception("Cannot use delayed index without supplied entry.")
    if entry.shapestruct is None: raise Exception("Cannot use delayed index without supplied shapestruct.")
    if not(isinstance(entry.shapestruct[i],Structure)) : raise Exception("Cannot use delayed index with a integer shapestruct argument.")
    return extraIndex(entry.shapestruct[i])
  else:
    return extraIndex

def performExtraIndex(i,extraIndex=None,entry=None,flip=False):
  if extraIndex is None or len(extraIndex)==0:
    return i
  if isinstance(extraIndex[0], collections.Callable) and not isinstance(extraIndex[0],Delegater):
    return extraIndex[0](performExtraIndex(i,extraIndex=extraIndex[1:],entry=entry,flip=flip))
  if not(isinstance(extraIndex[0],NestedDictLiteral)):
    if len(extraIndex)>2 or len(extraIndex)==0:
      raise Exception("Powerindex exhausted. Remaining %s is interpreted as extraIndex, but length must be 1 or 2." % str(extraIndex))
    try:
      if len(extraIndex)==1:
        a = extraIndex[0]
        a = delegation(a,entry,0)
        return i.__getitem__(a)
      else:
        a,b = extraIndex
        a = delegation(a,entry,0)
        b = delegation(b,entry,1)
        return i.__getitem__((b,a) if flip else (a,b))
    except NotImplementedError:
       raise Exception("Powerindex exhausted. Passing on %s to %s, but it doesn't know what to do with it" % (str(extraIndex),str(type(i))))
  else:
    return i


class Prefixer:
  def __init__(self,struct,prefix,castmaster=False):
    self.struct = struct
    self.prefix = prefix
    self.castmaster = castmaster

    methods = [ "__DM__", "__SX__","__MX__"]
    for m in methods:
      if hasattr(self.struct,m):
        setattr(self,m,self.cast)

  def __setstate__(self,state):
    self.__init__(state["struct"],state["prefix"],state["castmaster"])

  def __getstate__(self):
    return {"struct": self.struct, "prefix": self.prefix,"castmaster": self.castmaster}

  def __getattr__(self,name):
    # When attributes are not found, delegate to self()
    # This allows for e.g. sin(x) and x+1 to work
    if isinstance(self.struct.master,DataReference):
      t = self.struct.master.a
    else:
      t = self.struct.master
    if not(isinstance(t,list) or isinstance(t,dict) or isinstance(t,tuple)):
      return getattr(t,name)

  def cast(self):
    if self.castmaster:
      if isinstance(self.struct.master,DataReference):
        return self.struct.master.a
      else:
        return self.struct.master
    else:
      return self()

  def __str__(self):
    return "prefix( " + str(self.prefix) + "," + self.struct.__str__(compact=True) + ")"

  __repr__ = __str__

  def __call__(self):
    return self.struct.__getitem__(self.prefix)

  @properGetitem
  def __getitem__(self,powerIndex):
    return self.struct.__getitem__(self.prefix + powerIndex)

  @properGetitem
  def __setitem__(self,powerIndex,data):
    return self.struct.__setitem__(self.prefix + powerIndex,data)

class PrefixConstructor:

  def __str__(self):
    return "prefixConstructor(" + self.struct.__str__(compact=True) + ")"

  __repr__ = __str__

  def __init__(self,struct,castmaster=False):
    self.struct = struct
    self.castmaster=castmaster

  @properGetitem
  def __getitem__(self,prefix):
    return Prefixer(self.struct,prefix,castmaster=self.castmaster)

class CasadiStructure(Structure,CasadiStructureDerivable):
  """
    size
    map
  """

  def save(self,filename):
    import pickle
    pickle.dump(self,file(filename,"wb"),2)

  class FlatIndexDispatcher(Dispatcher):
    def __call__(self,payload,canonicalIndex,extraIndex=None,entry=None):
      if canonicalIndex in self.struct.map:
        res = performExtraIndex(self.struct.map[canonicalIndex],extraIndex=extraIndex,entry=entry)
        if isinstance(res,DM):
          assert res.is_dense()
          return list(map(int,list(res.nonzeros())))
        return list(res)
      else:
        raise Exception("Canonical index %s not found." % str(canonicalIndex))

  class IMDispatcher(Dispatcher):
    def __call__(self,payload,canonicalIndex,extraIndex=None,entry=None):
      if canonicalIndex in self.struct.map:
        return performExtraIndex(self.struct.map[canonicalIndex],extraIndex=extraIndex,entry=entry)
      else:
        raise Exception("Canonical index %s not found." % str(canonicalIndex))

  def __setstate__(self,state):
    self.__init__(*state["args"],**state["kwargs"])

  def __getstate__(self):
    return self.initializer

  def __init__(self,*args,**kwargs):
    self.initializer = {"args": args, "kwargs": kwargs}
    Structure.__init__(self,*args,**kwargs)

    self.map = {}
    self.lookuptable = []

    hmap = {}
    k = 0 # Global index counter
    for i in self.traverseCanonicalIndex():
      e = self.getStructEntryByCanonicalIndex(i)
      sp = Sparsity.dense(1,1) if e.sparsity is None else e.sparsity
      m = DM(sp,list(range(k,k+sp.nnz())))
      k += sp.nnz()
      it = tuple(i)
      self.map[it] = m
      self.lookuptable+=[(it,kk,p) for kk,p in enumerate(zip(sp.get_col(),sp.row()))]
      for a in canonicalIndexAncestors(it)[1:]:
        if a in hmap:
          hmap[a].append(m)
        else:
          hmap[a] = [m]
    self.size = k
    for k,v in hmap.items():
      hmap[k] = vertcat(*[i.nz[:] for i in v])
    self.map.update(hmap)

    class StructureGetter:
      def __init__(self,struct):
        self.struct = struct

    class IMGetter(StructureGetter):
      @properGetitem
      def __getitem__(self,powerIndex):
        return self.struct.traverseByPowerIndex(powerIndex,dispatcher=CasadiStructure.IMDispatcher(struct=self.struct))

    class FlatIndexGetter(StructureGetter):
      @properGetitem
      def __getitem__(self,powerIndex):
        return vec(self.struct.traverseByPowerIndex(powerIndex,dispatcher=CasadiStructure.FlatIndexDispatcher(struct=self.struct)))

    self.i = IMGetter(self)
    self.f = FlatIndexGetter(self)
    self.struct = self

  def __str__(self,compact=False):
    return ("" if compact else "Structure with total size %d.\n" % self.size)+ Structure.__str__(self,compact=compact)

  def getCanonicalIndex(self,i,extraMode=1):
    """
      Returns the canonicalIndex of the entry with a given flatIndex
      extraMode influences wether nothing (0), [i] (1) or [i,j] (2) will be returned as extra index
    """
    if i<0 or i>=self.size:
      raise Exception("Lookup index out of range. Got %d, but structure is of size %d" % (i,self.size))
    can,k,p = self.lookuptable[i]
    if extraMode==0:
      return can
    elif extraMode==1:
      return can+(k,)
    else:
      return can+p

  def canonicalIndices(self,extraMode=1):
    return [self.getCanonicalIndex(i,extraMode=extraMode) for i in range(self.size)]

  def getLabel(self,i,extraMode=1):
    t = self.getCanonicalIndex(i,extraMode=extraMode)
    return "["+ ",".join(map(str,t)) + "]"

  def labels(self,extraMode=1):
    return [self.getLabel(i,extraMode=extraMode) for i in range(self.size)]

class Structured(object):
  description = "Generic Structured object"

  def __init__(self,structure):
    self.struct = structure.struct
    self.i = self.struct.i
    self.f = self.struct.f
    self.getStruct = self.struct.getStruct
    self.prefix = PrefixConstructor(self)

  @property
  def size(self):
    return self.struct.size

  @property
  def cat(self):
    if isinstance(self.master,DataReference):
      return self.master.a
    else:
      return self.master

  def __str__(self,compact=False):
    if compact is False:
      return self.description + " with following structure:\n" + self.struct.__str__()
    else:
      return self.description + " (" + self.struct.__str__(compact=True) + ")"

  def keys(self):
    return list(self.struct.keys())

class CasadiStructured(Structured,CasadiStructureDerivable):
  description = "Generic Structured object"

  def __setstate__(self,state):
    cs = CasadiStructure.__new__(CasadiStructure)
    cs.__setstate__({"args": state["args"],"kwargs": state["kwargs"]})
    self.__init__(cs,order=state["order"])

  def __getstate__(self):
    d = self.struct.__getstate__()
    d["order"] = self.order
    return d

  def __init__(self,struct,order=None):
    self.order = order
    if hasattr(struct,"struct"):
      Structured.__init__(self,struct.struct)
      self.entries = []
    else:
      entrylist = EntryList(struct,order=order)
      self.entries = entrylist.entries
      Structured.__init__(self,CasadiStructure(self.entries, order=entrylist.order))

    self.getCanonicalIndex = self.struct.getCanonicalIndex
    self.canonicalIndices = self.struct.canonicalIndices
    self.getLabel = self.struct.getLabel
    self.labels = self.struct.labels
    self.priority_object_map = {}

  @property
  def shape(self):
    return (self.size,1)

  def sparsity(self):
    return Sparsity.dense(self.size,1)

  def getCanonicalIndex(self,*args,**kwargs):
    return self.struct.lookup(*args,**kwargs)

class CompatibilityException(Exception):
  pass

class ssymStruct(CasadiStructured,MasterGettable):
  description = "symbolic SX"
  def __init__(self,struct,order=None):
    CasadiStructured.__init__(self,struct,order=order)

    if any(e.expr is not None for e in self.entries):
      raise Exception("struct_symSX does not accept entries with an 'expr' argument, because such an element is not purely symbolic.")

    s = []
    for i in self.struct.traverseCanonicalIndex():
      e = self.struct.getStructEntryByCanonicalIndex(i)
      s.append(SX.sym("_".join(map(str,i)),e.sparsity.nnz()))

    self.master = vertcat(*[i.nz[:] for i in s])

    for e in self.entries:
      if e.sym is not None:
        self.master[self.i[e.name]] = e.sym

  def __SX__(self):
    return self.cat

class VertsplitStructure:
  def buildMap(self,struct=None,parentIndex = (),parent=None):
    if struct is None:  struct = self.struct
    if parent is None:  parent = self.master

    if isinstance(parent,DataReference):
      parent = parent.a

    ks  = []
    its = []
    sps = []
    es  = []
    k = 0 # Global index counter
    for i in struct.traverseCanonicalIndex(limit=1):
      e = struct.getStructEntryByCanonicalIndex(i)
      sp = None
      if e.isPrimitive():
        sp = Sparsity.dense(1,1) if e.sparsity is None else e.sparsity
      else:
        sp = Sparsity.dense(e.struct.size,1)
      ks.append(k)
      it = tuple(i)
      es.append(e)
      its.append(it)
      sps.append(sp)
      k += sp.nnz()
    ks.append(parent.size1())

    for it, k, sp,e in zip(its,vertsplit(parent,ks),sps,es):
      if not(e.isPrimitive()):
        self.buildMap(struct=e.struct,parentIndex = parentIndex + it,parent=k)
      self.priority_object_map[parentIndex+it] = k if k.sparsity()==sp else MX(sp,k) #[IM(sp,range(sp.nnz()))]

class msymStruct(CasadiStructured,MasterGettable,VertsplitStructure):
  description = "MX.sym"
  def __init__(self,struct,order=None):
    CasadiStructured.__init__(self,struct,order=order)

    if any(e.expr is not None for e in self.entries):
      raise Exception("struct_symMX does not accept entries with an 'expr' argument, because such an element is not purely symbolic.")
    if any(e.sym is not None for e in self.entries):
      raise Exception("struct_symMX does not accept entries with an 'sym' argument.")

    self.master = MX.sym("V",self.size,1)

    self.buildMap()

  def __MX__(self):
    return self.cat




class MatrixStruct(CasadiStructured,MasterGettable,MasterSettable):

  @property
  def description(self):
    return "Mutable " + self.mtype.__name__

  def __init__(self,struct,mtype,data=None,order=None):
    CasadiStructured.__init__(self,struct,order=None)
    if any(e.expr is None for e in self.entries):
      raise Exception("struct_SX does only accept entries with an 'expr' argument.")

    self.mtype = mtype
    if isinstance(data,mtype) or isinstance(data,DataReference):
      self.master = data
    elif data is None:
      self.master = mtype.nan(self.size,1)
    else:
      self.master = mtype(data)

    if self.master.shape[0]!=self.size:
      raise Exception("MatrixStruct: dimension error. Expecting %d-by-1, but got %s" % (self.size,self.master.dim()))
    if self.master.shape[1]!=1 and self.master.shape[0]>0:
      raise Exception("MatrixStruct: dimension error. Expecting %d-by-1, but got %s" % (self.size,self.master.dim()))

    for e in self.entries:
      self[e.name] = e.expr

class DMStruct(MatrixStruct):

  def save(self,filename):
    import pickle
    pickle.dump(self,file(filename,"wb"),2)

  def __setstate__(self,state):
    cs = CasadiStructure.__new__(CasadiStructure)
    cs.__setstate__({"args": state["args"],"kwargs": state["kwargs"]})
    self.__init__(cs,data=state["master"])

  def __getstate__(self):
    d = self.struct.__getstate__()
    d["master"] = self.master
    return d

  def __init__(self,struct,data=None):
    MatrixStruct.__init__(self,struct,DM,data=data)

  def __DM__(self):
    return self.cat

class SXStruct(MatrixStruct):
  def __init__(self,struct,data=None):
    MatrixStruct.__init__(self,struct,SX,data=data)

  def __SX__(self):
    return self.cat

class MXStruct(MatrixStruct,VertsplitStructure):
  def __init__(self,struct,data=None):
    MatrixStruct.__init__(self,struct,MX,data=data)

    self.buildMap()

  def __MX__(self):
    return self.cat

class MXVeccatStruct(CasadiStructured,MasterGettable):
  description = "Partially mutable MX"
  def __init__(self,arg,order=None):
    CasadiStructured.__init__(self,arg,order=order)
    if any(e.expr is None for e in self.entries):
      raise Exception("struct_MX does only accept entries with an 'expr' argument.")

    self.storage = []
    self.mapping = {}
    for k,i in enumerate(self.struct.traverseCanonicalIndex(limit=1)):
      self.storage.append(None)
      self.mapping[tuple(i)] = k

    for e in self.entries:
      self[e.name] = e.expr

    self.dirty = True

  def __setitem__(self,powerIndex,value):
    if not isinstance(powerIndex,tuple):
      powerIndex = (powerIndex,)

    def inject(payload,canonicalIndex,extraIndex=None,entry=None):
      if extraIndex is not None:
        raise Exception("An MX veccat structure does not accept indexing on MX level for __setitem__.")
      if not hasattr(self,"sparsity"):
        raise Exception("An MX veccat structure __setitem__ accepts only objects that have sparsity.")

      if canonicalIndex in self.mapping:
        if self.struct.map[canonicalIndex].sparsity()!=payload.sparsity():
          raise Exception("Error in powerIndex slicing %s for canonicalIndex %s: Shape mismatch. lhs is %s, rhs is %s." % (str(powerIndex),str(canonicalIndex),self.struct.map[canonicalIndex].sparsity().dim(),payload.sparsity().dim()))
        self.storage[self.mapping[canonicalIndex]] = payload
      else:
        raise Exception("Not found: %s " % str(canonicalIndex))
      self.dirty = True
    return self.struct.traverseByPowerIndex(powerIndex,dispatcher=inject,payload=value)

  def __MX__(self):
    return self.cat

  @property
  def master(self):
    if any(e is None for e in self.storage):
      missing = [k for k in list(self.mapping.keys()) if self.storage[self.mapping[k]] is None]
      raise Exception("Problem in MX vecNZcat structure cat: missing expressions. The following entries are missing: %s" % str(missing))

    if self.dirty:
      self.master_cached = vertcat(*[casadi.vec(i if i.is_dense() else i.nz[:]) for i in self.storage])

    return self.master_cached


struct_symSX = ssymStruct
struct_symMX = msymStruct
struct_SX = SXStruct
struct_MX_mutable = MXStruct
struct_MX = MXVeccatStruct
struct = CasadiStructured



entry = StructEntry

class CasadiStructEntry(StructEntry):
  def __init__(self,*args,**kwargs):
    if len(args)==0:
      raise Exception("Missing name argument (first argument of Entry)")
    else:
      self.name = args[0]
    self.dict = kwargs

    if len(args)>1:
      raise Exception("Don't know what to do with unnamed arguments %s" % str(args[1:]))



    kw = list(kwargs.keys())
    kws = ['repeat','shape','sym','expr','struct','shapestruct','type']
    for k in kw:
      if k not in kws:
        raise Exception("Unknown keyword argument '%s'. Please use one of %s." % (k,str(kws)))



    for kc, fk in [
          ('shape',['struct']),
          ('struct',['shape','shapestruct']),
          ('shapestruct',['struct']), # You might have a sparse matrix with shapestruct
          ('sym',['shape','repeat','expr']),
          ('expr',['shape','repeat','sym'])
        ]:
        if kc in kwargs:
          for fki in fk:
            if fki in kwargs:
              raise Exception("You supplied keyword argument '%s', but it cannot be combined with keyword argument '%s'." % (kc,fki))

    #     repeat   argument
    self.repeat = []

    if 'repeat' in kwargs:
      self.repeat = kwargs["repeat"] if isinstance(kwargs["repeat"],list) else [kwargs["repeat"]]
    
    if not all([is_integer(x) for x in self.repeat]):
      raise Exception("The 'repeat' argument, if present, must be a list of integers, but got %s" % str(self.repeat))


    self.struct = None
    #     struct   argument
    if 'struct' in kwargs:
      struct = kwargs["struct"]
      if isinstance(struct,Structure):
        self.struct = struct
      elif isinstance(struct,Structured):
        self.struct = struct.struct


    self.sparsity = None
    #     shape   argument
    if 'shape' in kwargs:
      shape = kwargs["shape"]
      if is_integer(shape) :
        self.sparsity = Sparsity.dense(shape,1)
      elif isinstance(shape,list) or isinstance(shape,tuple):
        if len(shape)==0 or len(shape)>2:
          raise Exception("The 'shape' argument, if present, must be an integer, a tuple of 1 or 2 integers, a sparsity pattern.")
        else:
          self.sparsity = Sparsity.dense(*shape)
      elif isinstance(shape,Sparsity):
        self.sparsity = shape
      else:
        raise Exception("The 'shape' argument, if present, must be an integer, a tuple of 1 or 2 integers, or a sparsity pattern. Got %s " % str(shape))
    else:
      self.sparsity = Sparsity.dense(1,1)

    self.shapestruct = None
    #     shapestruct  argument
    if 'shapestruct' in kwargs:
      shapestruct = kwargs["shapestruct"]
      if isinstance(shapestruct,Structured) or isinstance(shapestruct,Structure):
        self.shapestruct = (shapestruct.struct,1)
      elif isinstance(shapestruct,tuple):
        if not(all([isinstance(e,Structured) or isinstance(e,Structure) or is_integer(e) for e in shapestruct])) or len(shapestruct)==0 or len(shapestruct)>2:
          raise Exception("The 'shapestruct' argument, if present, must be a structure or a tuple of structures or numbers")
        self.shapestruct = tuple([e if is_integer(e) else e.struct for e in shapestruct])
      else:
        raise Exception("The 'shapestruct' argument, if present, must be a structure or a tuple of at most structures")

      if 'shape' not in kwargs:
        self.sparsity = Sparsity.dense(*[e if is_integer(e) else e.size for e in self.shapestruct])

    #     sym    argument
    self.sym = None
    if 'sym' in kwargs:
      sym = kwargs["sym"]
      if isinstance(sym,SX) and sym.is_valid_input():
        self.sym = sym
      elif isinstance(sym,Structured):
        self.struct = sym.struct
        self.sym = sym.cat
      else:
        raise Exception("The 'sym' argument must be a purely symbolic SX or a structured symbolic. Got %s instead." % str(self.sym))
      self.sparsity = self.sym.sparsity()

    #     expr    argument
    self.expr = None
    if 'expr' in kwargs:
      self.expr = kwargs["expr"]

      def getPrimitive(e,repeat=[]):
        if isinstance(e,list):
          if len(e)==0:
            return None,repeat+[0]
          else:
            return getPrimitive(e[0],repeat=repeat+[len(e)])
        else:
          return e,repeat


      p,r = getPrimitive(self.expr)

      if p is None:
        self.repeat = [0]
        self.sparsity = Sparsity.dense(0,0)
      else:
        self.repeat = r

        if hasattr(p,"sparsity"):
          self.sparsity = p.sparsity()
        else:
          raise Exception("The 'expr' argument must be a matrix expression or nested list of matrix expressions. Got %s instead." % str(p))

    self.type = None
    #     class   argument
    if 'type' in kwargs:
      self.type= kwargs["type"]
      allowedclass = ['symm']
      if self.type not in allowedclass:
        raise Exception("You supplied a type argument '%s' but it is not recognised. Use one of %s" % (str(self.type,str(allowedclass))))
      if self.type=="symm":
        if self.sparsity.size1() != self.sparsity.size2():
          raise Exception("You supplied a type 'symm', but matrix is not square. Got " % self.sparsity.dim() + ".")
        self.originalsparsity = self.sparsity
        self.sparsity = self.sparsity*Sparsity.upper(self.sparsity.size1())



    StructEntry.__init__(self,self.name,struct=self.struct,dims=self.repeat,data=self.sparsity)

  def primitiveString(self):
    if self.type is None:
      return self.sparsity.dim()
    elif self.type=="symm":
      return "symm(" +  self.sparsity.dim() + ")"

  def __getstate__(self):
    return dict((k,getattr(self,k)) for k in ["name", "struct", "sparsity","type","repeat","shapestruct","dims"])


def entry(*args,**kwargs):
  if len(args)==1 and isinstance(args[0],CasadiStructEntry):
    return args[0]
  return CasadiStructEntry(*args,**kwargs)

class EntryList:
  def __init__(self,arg,order = None):
    self.entries = []
    self.order = []

    if not isinstance(arg,list):
      raise Exception("Expecting list of entries, with possible tuples for grouping, but got %s" % str(arg))

    for e in arg:
      if isinstance(e,tuple):
        entries = list(map(entry,e))
        self.order.append(tuple(x.name for x in entries))
        self.entries+=entries
      else:
        ee = entry(e)
        self.order.append(ee.name)
        self.entries.append(ee)

    # Override order
    if order is not None:
      if any(isinstance(e,tuple) for e in self.order):
        raise Exception("You supplied an order by using tuple syntax on entries %s, but you overwrite it with the 'order' keyword. Use one or the other, not both.")
      self.order = order
    self.names = [x.name for x in self.entries]
    if len(self.names)!=len(set(self.names)):
      duplicates = []
      for i,e in enumerate(self.names):
        if e in self.names[:i] or e in self.names[i+1:]:
          duplicates.append(e)
      raise Exception("Your list of entries contains duplicates: %s" % str(list(set(duplicates))))


class Delegater:
  def __init__(self,arg):
    self.arg = arg

  def __str__(self):
    return "%s[%s]" % (self.__class__.__name__,str(self.arg))

  __repr__ = __str__


class IndexDelegater(Delegater):
  def __call__(self,struct):
    return struct.i.__getitem__(self.arg)

class FlatIndexDelegater(Delegater):
  def __call__(self,struct):
    return struct.f.__getitem__(self.arg)


class DelegaterConstructor:
  """
    Creates an object that delegates a slicing operation.

    Example usage:
      s = struct_symSX([])
      x = struct_symSX(entry("x",Sparsity.diag(4)))
      x["x",0,index[:]]

  """
  def __init__(self,delegater,prepend=()):
    self.prepend = prepend
    self.delegater = delegater

  @properGetitem
  def __getitem__(self,arg):
    return self.delegater(self.prepend + arg)

index  = DelegaterConstructor(IndexDelegater)
indexf = DelegaterConstructor(FlatIndexDelegater)

class DataReference:
  @property
  def shape(self):
    return self.v.shape

  def dim(self):
    return self.v.dim()


class DataReferenceRepeated(DataReference):
  def __init__(self,a,n):
    assert(a.is_dense())
    self.a = a
    self.n = n
    self.v = a.reshape((n*a.size1(),1))

  def __setitem__(self,a,b):
    self.v.nz[a] = b
    I = self.a.sparsity().find()
    self.a.nz[I] = self.v.nz[I]

  def __getitem__(self,a):
    return self.v.nz[a]

class DataReferenceSquared(DataReference):
  def __init__(self,a,n):
    assert(a.is_dense())
    self.a = a
    self.v = a
    self.n = n

  def __setitem__(self,a,b):
    self.a.nz[a] = b

  def __getitem__(self,a):
    return self.a.nz[a]

  @property
  def shape(self):
    return (self.n*self.n,1)

class DataReferenceProduct(DataReference):
  def __init__(self,a,n,m):
    assert(a.is_dense())
    self.a = a
    self.v = a
    self.n = n
    self.m = m

  def __setitem__(self,a,b):
    self.a.nz[a] = b

  def __getitem__(self,a):
    return self.a.nz[a]

  @property
  def shape(self):
    return (self.n*self.m,1)

  def size1(self):
    return self.n

  def size2(self):
    return self.m

class DataReferenceSquaredRepeated(DataReference):
  def __init__(self,a,n,N):
    assert(a.is_dense())
    self.a = a
    self.n = n
    self.N = N
    self.v = a.reshape((n*n*N,1))

  def __setitem__(self,a,b):
    self.v.nz[a] = b
    I = self.a.sparsity().find()
    self.a.nz[I] = self.v.nz[I]

  def __getitem__(self,a):
    return self.v.nz[a]

def struct_load(filename):
    import pickle
    return pickle.load(file(filename,"rb"))
