import itertools import operator from django.db.models import Count, Min from symposion.schedule.models import Room, Slot, SlotRoom class TimeTable(object): def __init__(self, day): self.day = day def slots_qs(self): qs = Slot.objects.all() qs = qs.filter(day=self.day) return qs def rooms(self): qs = Room.objects.all() qs = qs.filter(schedule=self.day.schedule) qs = qs.filter(pk__in=SlotRoom.objects.filter(slot__in=self.slots_qs().values("pk")).values("room")) qs = qs.order_by("order") return qs def __iter__(self): times = sorted(set(itertools.chain(*self.slots_qs().values_list("start", "end")))) slots = Slot.objects.filter(pk__in=self.slots_qs().values("pk")) slots = slots.annotate(room_count=Count("slotroom"), order=Min("slotroom__room__order")) slots = slots.order_by("start", "order") row = [] for time, next_time in pairwise(times): row = {"time": time, "slots": []} for slot in slots: if slot.start == time: slot.rowspan = TimeTable.rowspan(times, slot.start, slot.end) slot.colspan = slot.room_count row["slots"].append(slot) if row["slots"] or next_time is None: yield row @staticmethod def rowspan(times, start, end): return times.index(end) - times.index(start) def pairwise(iterable): a, b = itertools.tee(iterable) b.next() return itertools.izip_longest(a, b)