"""4-week schedule calendar routes.

Displays a calendar view showing which workout day maps to which date.
"""

from datetime import date, timedelta

import structlog
from fastapi import APIRouter, Depends, Request
from fastapi.responses import HTMLResponse
from sqlmodel import Session

from app.database import get_db_session
from app.models.user import User
from app.services.exercise_service import ExerciseService
from app.services.workout_session_service import WorkoutSessionService
from app.utils.auth import require_active_profile

logger = structlog.get_logger(__name__)

router = APIRouter(prefix="/schedule", tags=["schedule"])


@router.get("", response_class=HTMLResponse)
async def schedule_view(
    request: Request,
    session: Session = Depends(get_db_session),
    profile: User = Depends(require_active_profile),
):
    """Render the 4-week schedule calendar.

    Shows a 4-week grid where each training day is mapped to a
    calendar date. Days with completed sessions are highlighted.
    """
    exercise_service = ExerciseService(session)
    workout_days = exercise_service.list_workout_days()

    # Build 4-week calendar starting from Monday of current week
    today = date.today()
    monday = today - timedelta(days=today.weekday())

    weeks = []
    completed_dates = set()

    # Get completed sessions for highlighting
    ws_service = WorkoutSessionService(session)
    sessions_list = ws_service.list_sessions(
        user_id=profile.id, limit=100,
    )
    completed_dates = {ws.date for ws in sessions_list}

    # 4 workout days per week, 4 weeks
    for week_num in range(4):
        week_start = monday + timedelta(weeks=week_num)
        week_data = {
            "week_number": week_num + 1,
            "days": [],
        }
        for day_offset, workout_day in enumerate(workout_days):
            training_date = week_start + timedelta(days=day_offset)
            is_today = training_date == today
            is_completed = training_date in completed_dates

            week_data["days"].append({
                "workout_day": workout_day,
                "date": training_date,
                "is_today": is_today,
                "is_completed": is_completed,
            })
        weeks.append(week_data)

    templates = request.app.state.templates
    return templates.TemplateResponse("pages/schedule.html", {
        "request": request,
        "weeks": weeks,
        "active_profile": profile,
    })