from exceptions import InvalidJobError

class Job:

    existing_jobs = set()

    def __init__(self, location=None, start_time=None, end_time=None,
                 name=None, capacity_demand=0, capacity_dimension=0,
                 service_time=0, skill_requirements=()):

        # Validate inputs
        if not any([location, start_time, end_time]):
            raise InvalidJobError("All jobs must have a location, a start "
                                  "time and and end time.")

        try:
            self.start_time = int(start_time)
            self.end_time = int(end_time)
        except (ValueError, TypeError):
            raise InvalidJobError("Could not discern time slot for job "
                                  "at location: {}".format(location))

        if self.start_time > self.end_time:
            raise InvalidJobError("Start time greater than end time for: "
                                  "{}".format(location))

        self.location = location
        self.name = name if name else self.location

        if self.name in Job.existing_jobs:
            raise InvalidJobError("Jobs with duplicate locations must be given"
                                  " unique names. Location: {}".format(location)
                                  )

        self.capacity_demand = int(capacity_demand)
        self.capacity_dimension = int(capacity_dimension)
        self.service_time = int(service_time)
        if not skill_requirements:
            self.skill_requirements = {-1}
        else:
            try:
                self.skill_requirements = set(skill_requirements)
            except TypeError:
                raise InvalidJobError("Skill requirements must be a sequence, "
                                      "location: {}".format(self.location))