from typing import List

class Position(object):
  def __init__(self, x, y):
    self._x = x
    self._y = y

  @property
  def x(self):
    return _x

  @property
  def y(self):
    return _y

class ComponentField(object):
  names = ["Reference", "Value", "Footprint", "Datasheet"]
  def __init__(self, index, name, value, position):
    self._index = index
    self._name = name if index >= len(ComponentField.names) else ComponentField.names[index]
    self._value = value
    self._position = position

  @property
  def index(self):
    return self._index

  @property
  def name(self):
    return self._name

  @property
  def value(self):
    return self._value

  @property
  def position(self):
    return self._position

class Component(object):
  def __init__(self, position, timestamp, library, name, unit, ref, fields):
    self._position = position
    self._timestamp = timestamp
    self._library = library
    self._name = name
    self._unit = unit
    self._ref = ref
    self._fields = fields # type List[ComponentField]

  @property
  def unit(self):
    return self._unit

  @property
  def ref(self):
    return self._ref

  @property
  def value(self):
    return self._fields[1].value

  @property
  def footprint(self):
    return self._fields[2].value

  @property
  def fields(self) -> List[ComponentField]:
    return list(self._fields)

  @property
  def named_fields(self):
    return [f for f in self._fields if f.name]

class Sheet(object):
  def __init__(self):
    self._components = []
    pass

  @property
  def components(self):
    return frozenset(self._components)

  def add_component(self, component):
    self._components.append(component)

class Library(object):
  def __init__(self, name):
    self.name = name

class Schematic(object):
  def __init__(self):
    self._libraries = set()
    self._sheets = [Sheet()]
    pass

  @property
  def first_sheet(self):
    return self._sheets[0]

  @property
  def libraries(self):
    return frozenset(self._libraries)

  def add_library(self, library):
    self._libraries.add(Library(library))

  # Getters
  @property
  def components(self):
    a = []
    for s in self._sheets:
      for c in s.components:
        a.append(c)
    return a

  def get_component(self, ref, unit = 1):
    for c in self.components:
      if c.ref == ref and unit == unit:
        return c
    
    raise KeyError("No such component: {}".format(ref))