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

from libc.stdint cimport uint8_t, uint32_t
from libcpp.string cimport string
from libcpp.vector cimport vector

from .common cimport CANPacker as cpp_CANPacker
from .common cimport dbc_lookup, SignalPackValue, DBC, Msg


cdef class CANPacker:
  cdef:
    cpp_CANPacker *packer
    const DBC *dbc

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

    cdef string cpp_dbc_name
    if isinstance(dbc_name, str):
      cpp_dbc_name = dbc_name.encode('utf-8')
    else:
      cpp_dbc_name = dbc_name
    with nogil:
      self.packer = new cpp_CANPacker(cpp_dbc_name)

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

  cdef vector[uint8_t] pack(self, addr, values):
    cdef vector[SignalPackValue] values_thing
    cdef uint32_t value_len = len(values)
    with nogil:
      values_thing.reserve(value_len)

    cdef SignalPackValue spv
    for name, value in values.iteritems():
      spv.name = name.encode("utf8")
      spv.value = value
      with nogil:
        values_thing.push_back(spv)

    cdef vector[uint8_t] result
    cdef uint32_t addr_cpp = addr
    with nogil:
      result = self.packer.pack(addr_cpp, values_thing)
    return result

  cpdef make_can_msg(self, name_or_addr, bus, values):
    cdef uint32_t addr = 0
    cdef const Msg* m
    if isinstance(name_or_addr, int):
      addr = name_or_addr
    else:
      try:
        m = self.dbc.name_to_msg.at(name_or_addr.encode("utf8"))
        addr = m.address
      except IndexError:
        # The C++ pack function will log an error message for invalid addresses
        pass

    cdef vector[uint8_t] val = self.pack(addr, values)
    return addr, (<char *>&val[0])[:val.size()], bus