src/utils/weeklyCalendar.ts

import { Activity } from "../types/heatmap";

export const aggregateToWeeklyData = (dailyData: Activity[]): Activity[] => {
  if (!dailyData || dailyData.length === 0) return [];

  const weeklyData: Activity[] = [];
  let currentWeekStart: Date | null = null;
  let currentWeekCount = 0;
  let currentWeekLevel = 0;

  for (const dayActivity of dailyData) {
    const date = new Date(dayActivity.date);
    const dayOfWeek = date.getDay(); // 0 = Sunday, 1 = Monday, etc.

    // If it's Sunday or we don't have a current week, start a new week
    if (dayOfWeek === 0 || currentWeekStart === null) {
      // Save the previous week if it exists
      if (currentWeekStart !== null) {
        weeklyData.push({
          date: currentWeekStart.toISOString().split('T')[0],
          count: currentWeekCount,
          level: currentWeekLevel,
        });
      }

      // Start new week
      currentWeekStart = new Date(date);
      currentWeekCount = dayActivity.count;
      currentWeekLevel = dayActivity.level;
    } else {
      // Add to current week
      currentWeekCount += dayActivity.count;
      // Use the maximum level for the week
      currentWeekLevel = Math.max(currentWeekLevel, dayActivity.level);
    }
  }

  // Don't forget the last week
  if (currentWeekStart !== null) {
    weeklyData.push({
      date: currentWeekStart.toISOString().split('T')[0],
      count: currentWeekCount,
      level: currentWeekLevel,
    });
  }

  return weeklyData;
};

export const getWeekDateRange = (weekStartDate: string): string => {
  const startDate = new Date(weekStartDate);
  const endDate = new Date(startDate);
  endDate.setDate(startDate.getDate() + 6);

  const formatDate = (date: Date) => {
    return date.toLocaleDateString('en-US', { 
      month: 'short', 
      day: 'numeric' 
    });
  };

  return `${formatDate(startDate)} - ${formatDate(endDate)}`;
};