# distutils: language = c++
# cython: c_string_encoding=ascii, language_level=3

from libcpp.pair cimport pair
from libcpp.string cimport string
from libcpp.vector cimport vector
from libc.stdint cimport uint32_t, int

from .common cimport CANParser as cpp_CANParser
from .common cimport dbc_lookup, Msg, DBC, CanData

import numbers
from collections import defaultdict


cdef class CANParser:
  cdef:
    cpp_CANParser *can
    const DBC *dbc
    set addresses

  cdef readonly:
    dict vl
    dict vl_all
    dict ts_nanos
    string dbc_name
    uint32_t bus

  def __init__(self, dbc_name, messages, bus=0):
    self.dbc_name = dbc_name
    self.bus = bus
    self.dbc = dbc_lookup(dbc_name)
    if not self.dbc:
      raise RuntimeError(f"Can't find DBC: {dbc_name}")

    self.vl = {}
    self.vl_all = {}
    self.ts_nanos = {}
    self.addresses = set()

    # Convert message names into addresses and check existence in DBC
    cdef vector[pair[uint32_t, int]] message_v
    for i in range(len(messages)):
      c = messages[i]
      try:
        m = self.dbc.addr_to_msg.at(c[0]) if isinstance(c[0], numbers.Number) else self.dbc.name_to_msg.at(c[0])
      except IndexError:
        raise RuntimeError(f"could not find message {repr(c[0])} in DBC {self.dbc_name}")

      address = m.address
      message_v.push_back((address, c[1]))
      self.addresses.add(address)

      name = m.name.decode("utf8")
      signal_names = [sig.name.decode("utf-8") for sig in (<Msg*>m).sigs]

      self.vl[address] = {name: 0.0 for name in signal_names}
      self.vl[name] = self.vl[address]
      self.vl_all[address] = defaultdict(list)
      self.vl_all[name] = self.vl_all[address]
      self.ts_nanos[address] = {name: 0.0 for name in signal_names}
      self.ts_nanos[name] = self.ts_nanos[address]

    cdef string cpp_dbc_name
    if isinstance(dbc_name, str):
      cpp_dbc_name = (<str>dbc_name).encode('utf-8')
    else:
      cpp_dbc_name = dbc_name  # Assume bytes
    cdef int cpp_bus = bus
    with nogil:
      self.can = new cpp_CANParser(cpp_bus, cpp_dbc_name, message_v)

  def __dealloc__(self):
    if self.can:
      with nogil:
        del self.can

  def update_strings(self, strings, sendcan=False):
    # input format:
    # [nanos, [[address, data, src], ...]]
    # [[nanos, [[address, data, src], ...], ...]]
    for address in self.addresses:
      self.vl_all[address].clear()

    cdef vector[CanData] can_data_array

    try:
      if len(strings) and not isinstance(strings[0], (list, tuple)):
        strings = [strings]

      can_data_array.reserve(len(strings))
      for s in strings:
        can_data = &(can_data_array.emplace_back())
        can_data.nanos = s[0]
        can_data.frames.reserve(len(s[1]))
        for address, dat, src in s[1]:
          source_bus = <uint32_t>src
          if source_bus == self.bus:
            frame = &(can_data.frames.emplace_back())
            frame.address = address
            frame.dat = dat
            frame.src = source_bus
    except TypeError:
      raise RuntimeError("invalid parameter")

    with nogil:
      updated_addrs = self.can.update(can_data_array)

    for addr in updated_addrs:
      vl = self.vl[addr]
      vl_all = self.vl_all[addr]
      ts_nanos = self.ts_nanos[addr]

      with nogil:
        state = self.can.getMessageState(addr)
      for i in range(state.parse_sigs.size()):
        name = <unicode>state.parse_sigs[i].name
        vl[name] = state.vals[i]
        vl_all[name] = state.all_vals[i]
        ts_nanos[name] = state.last_seen_nanos

    return updated_addrs

  @property
  def can_valid(self):
    cdef bint valid
    with nogil:
      valid = self.can.can_valid
    return valid

  @property
  def bus_timeout(self):
    cdef bint timeout
    with nogil:
      timeout = self.can.bus_timeout
    return timeout


cdef class CANDefine():
  cdef:
    const DBC *dbc

  cdef public:
    dict dv
    string dbc_name

  def __init__(self, dbc_name):
    self.dbc_name = dbc_name
    self.dbc = dbc_lookup(dbc_name)
    if not self.dbc:
      raise RuntimeError(f"Can't find DBC: '{dbc_name}'")

    dv = defaultdict(dict)

    for i in range(self.dbc[0].vals.size()):
      val = self.dbc[0].vals[i]

      sgname = val.name.decode("utf8")
      def_val = val.def_val.decode("utf8")
      address = val.address
      try:
        m = self.dbc.addr_to_msg.at(address)
      except IndexError:
        raise KeyError(address)
      msgname = m.name.decode("utf-8")

      # separate definition/value pairs
      def_val = def_val.split()
      values = [int(v) for v in def_val[::2]]
      defs = def_val[1::2]

      # two ways to lookup: address or msg name
      dv[address][sgname] = dict(zip(values, defs))
      dv[msgname][sgname] = dv[address][sgname]

    self.dv = dict(dv)