-- Allow multiple check-in/out within a single duty schedule.
-- Preserves first check-in time & arrival/late status on subsequent re-check-ins.

CREATE OR REPLACE FUNCTION public.attendance_check_in(
  p_duty_id uuid,
  p_lat double precision,
  p_lng double precision
) RETURNS uuid
LANGUAGE plpgsql SECURITY DEFINER
AS $$
DECLARE
  v_schedule duty_schedules%ROWTYPE;
  v_log_id uuid;
  v_now timestamptz := now();
  v_status text;
BEGIN
  SELECT * INTO v_schedule FROM duty_schedules WHERE id = p_duty_id;
  IF NOT FOUND THEN
    RAISE EXCEPTION 'Duty schedule not found';
  END IF;
  IF v_schedule.user_id != auth.uid() THEN
    RAISE EXCEPTION 'Not your duty schedule';
  END IF;

  IF v_now < (v_schedule.start_time - interval '2 hours') THEN
    RAISE EXCEPTION 'Too early to check in (2-hour window)';
  END IF;
  IF v_now > v_schedule.end_time THEN
    RAISE EXCEPTION 'Duty has already ended';
  END IF;

  -- Determine status (used only when first check-in)
  IF v_now <= v_schedule.start_time THEN
    v_status := 'arrival';
  ELSE
    v_status := 'late';
  END IF;

  -- Insert a new attendance log row for each check-in
  INSERT INTO attendance_logs (user_id, duty_schedule_id, check_in_at, check_in_lat, check_in_lng)
  VALUES (auth.uid(), p_duty_id, v_now, p_lat, p_lng)
  RETURNING id INTO v_log_id;

  -- Only update duty schedule on first check-in (preserve original arrival status)
  UPDATE duty_schedules
  SET check_in_at   = COALESCE(check_in_at, v_now),
      check_in_location = ST_SetSRID(ST_MakePoint(p_lng, p_lat), 4326)::geography,
      status = CASE
                 WHEN check_in_at IS NULL THEN v_status::duty_status
                 ELSE status
               END
  WHERE id = p_duty_id;

  RETURN v_log_id;
END;
$$;

-- Also update duty_check_in for consistency
CREATE OR REPLACE FUNCTION public.duty_check_in(
  p_duty_id uuid,
  p_lat double precision,
  p_lng double precision
) RETURNS text
LANGUAGE plpgsql SECURITY DEFINER
AS $$
DECLARE
  v_schedule duty_schedules%ROWTYPE;
  v_now timestamptz := now();
  v_status text;
BEGIN
  SELECT * INTO v_schedule FROM duty_schedules WHERE id = p_duty_id;
  IF NOT FOUND THEN
    RAISE EXCEPTION 'Duty schedule not found';
  END IF;
  IF v_schedule.user_id != auth.uid() THEN
    RAISE EXCEPTION 'Not your duty schedule';
  END IF;

  IF v_now <= v_schedule.start_time THEN
    v_status := 'arrival';
  ELSE
    v_status := 'late';
  END IF;

  UPDATE duty_schedules
  SET check_in_at   = COALESCE(check_in_at, v_now),
      check_in_location = ST_SetSRID(ST_MakePoint(p_lng, p_lat), 4326)::geography,
      status = CASE
                 WHEN check_in_at IS NULL THEN v_status::duty_status
                 ELSE status
               END
  WHERE id = p_duty_id;

  -- Create attendance log entry
  INSERT INTO attendance_logs (user_id, duty_schedule_id, check_in_at, check_in_lat, check_in_lng)
  VALUES (auth.uid(), p_duty_id, v_now, p_lat, p_lng);

  RETURN v_status;
END;
$$;