feat(stats): optimize dashboard data loading with internal ui endpoints

app/api/ui_data.py

@@ -0,0 +1,120 @@
+from __future__ import annotations
+
+from datetime import datetime
+
+from fastapi import APIRouter, Depends, Path
+from fastapi.responses import JSONResponse
+
+from app.api.dto.tasks import ErrorDTO, TaskBoardDTO, TaskBoardItemDTO, TaskDetailsDTO
+from app.api.tasks import get_task_or_error, get_task_repository
+from app.storage import JsonFileTaskRepository, StoredTask
+
+
+router = APIRouter(prefix="/ui_data", tags=["ui_data"])
+
+
+def get_task_status(task: StoredTask) -> str:
+    if task.done_at is not None:
+        return "done"
+    if task.started_at is not None:
+        return "in_progress"
+    return "backlog"
+
+
+def format_duration(task: StoredTask) -> str:
+    if task.started_at is None or task.done_at is None:
+        return "—"
+
+    delta = task.done_at - task.started_at
+    total_seconds = int(delta.total_seconds())
+    hours, remainder = divmod(total_seconds, 3600)
+    minutes, seconds = divmod(remainder, 60)
+    return f"{hours}h {minutes}m {seconds}s"
+
+
+def to_board_item_dto(task: StoredTask) -> TaskBoardItemDTO:
+    status = get_task_status(task)
+    display_date_label: str
+    display_date_value: datetime | None
+
+    if status == "backlog":
+        display_date_label = "Created"
+        display_date_value = task.created_at
+    elif status == "in_progress":
+        display_date_label = "Started"
+        display_date_value = task.started_at
+    else:
+        display_date_label = "Done"
+        display_date_value = task.done_at
+
+    return TaskBoardItemDTO(
+        id=task.id,
+        title=task.title,
+        status=status,
+        display_date_label=display_date_label,
+        display_date_value=display_date_value,
+    )
+
+
+def to_task_details_dto(task: StoredTask) -> TaskDetailsDTO:
+    return TaskDetailsDTO(
+        id=task.id,
+        title=task.title,
+        status=get_task_status(task),
+        created_at=task.created_at,
+        started_at=task.started_at,
+        done_at=task.done_at,
+        cycle_time=format_duration(task),
+    )
+
+
+@router.get(
+    "/stats/board",
+    response_model=TaskBoardDTO,
+    responses={
+        400: {"model": ErrorDTO},
+    },
+    include_in_schema=False,
+)
+def stats_board(
+    repo: JsonFileTaskRepository = Depends(get_task_repository),
+) -> TaskBoardDTO:
+    tasks = repo.list_tasks()
+    backlog_tasks: list[TaskBoardItemDTO] = []
+    in_progress_tasks: list[TaskBoardItemDTO] = []
+    done_tasks: list[TaskBoardItemDTO] = []
+
+    for task in tasks:
+        item = to_board_item_dto(task)
+        if item.status == "backlog":
+            backlog_tasks.append(item)
+        elif item.status == "in_progress":
+            in_progress_tasks.append(item)
+        else:
+            done_tasks.append(item)
+
+    return TaskBoardDTO(
+        backlog_tasks=backlog_tasks,
+        in_progress_tasks=in_progress_tasks,
+        done_tasks=done_tasks,
+    )
+
+
+@router.get(
+    "/tasks/{task_id}",
+    response_model=TaskDetailsDTO,
+    responses={
+        400: {"model": ErrorDTO},
+        404: {"model": ErrorDTO},
+    },
+    include_in_schema=False,
+)
+def task_details(
+    task_id: str = Path(...),
+    repo: JsonFileTaskRepository = Depends(get_task_repository),
+) -> TaskDetailsDTO | JSONResponse:
+    task, error = get_task_or_error(repo=repo, task_id=task_id)
+    if error is not None:
+        return error
+
+    return to_task_details_dto(task)