initial commit

backend/app/services/reschedule.py

@@ -0,0 +1,114 @@
+from __future__ import annotations
+
+from datetime import date, timedelta
+
+from fastapi import HTTPException
+
+
+def _add(d: date, days: int) -> date:
+    return d + timedelta(days=days)
+
+
+def _step(d: date, weekdays: list[int], direction: int) -> date:
+    selected = set(weekdays)
+    cursor = _add(d, direction)
+    for _ in range(28):
+        if cursor.weekday() in selected:
+            return cursor
+        cursor = _add(cursor, direction)
+    raise HTTPException(400, "Не удалось найти тренировочный день")
+
+
+def _on_or_after(d: date, weekdays: list[int]) -> date:
+    if d.weekday() in set(weekdays):
+        return d
+    return _step(_add(d, -1), weekdays, 1)
+
+
+def _order(week: int, day_index: int) -> int:
+    return week * 10 + day_index
+
+
+def _next_training(after: date, weekdays: list[int], taken: set[date]) -> date:
+    value = _step(after, weekdays, 1)
+    while value in taken:
+        value = _step(value, weekdays, 1)
+    return value
+
+
+def _place(desired: date, previous: date | None, weekdays: list[int], taken: set[date]) -> date:
+    value = desired
+    if previous is not None and value <= previous:
+        value = _next_training(previous, weekdays, taken)
+    while value in taken:
+        value = _next_training(value, weekdays, taken)
+    return value
+
+
+def plan_move(workouts: list, moved_id: int, new_date: date, weekdays: list[int]) -> dict[int, date]:
+    moved = next((w for w in workouts if w.id == moved_id), None)
+    if moved is None:
+        raise HTTPException(404, "Тренировка не найдена")
+    if moved.status == "completed":
+        raise HTTPException(400, "Выполненную тренировку переносить нельзя")
+    if new_date < date.today():
+        raise HTTPException(400, "В закрытый период переносить нельзя")
+
+    sorted_items = sorted(workouts, key=lambda w: (_order(w.week_number, w.day_index), w.id))
+    completed = [w for w in sorted_items if w.status == "completed"]
+    if any(w.scheduled_date == new_date for w in completed):
+        raise HTTPException(400, "На эту дату уже есть выполненная тренировка")
+
+    moved_order = _order(moved.week_number, moved.day_index)
+    earlier = [w for w in completed if _order(w.week_number, w.day_index) < moved_order]
+    later = [w for w in completed if _order(w.week_number, w.day_index) > moved_order]
+    if earlier and new_date <= earlier[-1].scheduled_date:
+        raise HTTPException(400, "Дата должна быть позже уже выполненной тренировки")
+    if later and new_date >= later[0].scheduled_date:
+        raise HTTPException(400, "Дата должна быть раньше уже выполненной следующей тренировки")
+
+    taken = {w.scheduled_date for w in completed}
+    assigned: dict[int, date] = {}
+    index = 0
+    while index < len(sorted_items):
+        if sorted_items[index].status == "completed":
+            index += 1
+            continue
+        start = index
+        while index < len(sorted_items) and sorted_items[index].status != "completed":
+            index += 1
+        segment = sorted_items[start:index]
+        prev_anchor = sorted_items[start - 1] if start > 0 else None
+        next_anchor = sorted_items[index] if index < len(sorted_items) else None
+        proposed = sorted(new_date if item.id == moved_id else item.scheduled_date for item in segment)
+        dates: list[date] = []
+        for raw in proposed:
+            value = _place(raw, dates[-1] if dates else None, weekdays, taken)
+            if prev_anchor is not None and value <= prev_anchor.scheduled_date:
+                raise HTTPException(400, "Дата должна быть позже уже выполненной тренировки")
+            if next_anchor is not None and value >= next_anchor.scheduled_date:
+                raise HTTPException(400, "Дата должна быть раньше уже выполненной следующей тренировки")
+            dates.append(value)
+            taken.add(value)
+        for item, value in zip(segment, dates):
+            assigned[item.id] = value
+
+    return assigned
+
+
+def plan_weekday_change(workouts: list, weekdays: list[int], start_from: date) -> dict[int, date]:
+    open_items = sorted(
+        (w for w in workouts if w.status != "completed"),
+        key=lambda w: _order(w.week_number, w.day_index),
+    )
+    taken = {w.scheduled_date for w in workouts if w.status == "completed"}
+    assigned: dict[int, date] = {}
+    cursor = start_from
+    for item in open_items:
+        date_value = _on_or_after(cursor, weekdays)
+        while date_value in taken:
+            date_value = _step(date_value, weekdays, 1)
+        assigned[item.id] = date_value
+        taken.add(date_value)
+        cursor = _add(date_value, 1)
+    return assigned