/*!
 * chartjs-adapter-date-fns v3.0.0 - Lightweight date adapter for Chart.js
 * Uses native Date parsing (no external dependencies)
 */
(function() {
  'use strict';
  const FORMATS = {
    datetime: 'MMM d, yyyy, h:mm:ss a',
    millisecond: 'h:mm:ss.SSS a',
    second: 'h:mm:ss a',
    minute: 'h:mm a',
    hour: 'ha',
    day: 'MMM d',
    week: 'PP',
    month: 'MMM yyyy',
    quarter: "'Q'Q - yyyy",
    year: 'yyyy'
  };

  function formatDate(date, fmt) {
    const d = new Date(date);
    if (isNaN(d.getTime())) return '';
    const h = d.getHours();
    const m = d.getMinutes();
    const s = d.getSeconds();
    const ms = d.getMilliseconds();
    const months = ['Jan','Feb','Mar','Apr','May','Jun','Jul','Aug','Sep','Oct','Nov','Dec'];
    const ampm = h >= 12 ? 'PM' : 'AM';
    const h12 = h % 12 || 12;

    switch(fmt) {
      case 'h:mm:ss.SSS a':
        return `${h12}:${String(m).padStart(2,'0')}:${String(s).padStart(2,'0')}.${String(ms).padStart(3,'0')} ${ampm}`;
      case 'h:mm:ss a':
        return `${h12}:${String(m).padStart(2,'0')}:${String(s).padStart(2,'0')} ${ampm}`;
      case 'h:mm a':
        return `${h12}:${String(m).padStart(2,'0')} ${ampm}`;
      case 'ha':
        return `${h12}${ampm}`;
      case 'MMM d':
        return `${months[d.getMonth()]} ${d.getDate()}`;
      case 'MMM yyyy':
        return `${months[d.getMonth()]} ${d.getFullYear()}`;
      case 'yyyy':
        return `${d.getFullYear()}`;
      default:
        return `${months[d.getMonth()]} ${d.getDate()}, ${d.getFullYear()}, ${h12}:${String(m).padStart(2,'0')}:${String(s).padStart(2,'0')} ${ampm}`;
    }
  }

  const UNITS = ['millisecond','second','minute','hour','day','week','month','quarter','year'];
  const UNIT_MS = {
    millisecond: 1,
    second: 1000,
    minute: 60000,
    hour: 3600000,
    day: 86400000,
    week: 604800000,
    month: 2592000000,
    quarter: 7776000000,
    year: 31536000000
  };

  if (typeof Chart !== 'undefined' && Chart._adapters && Chart._adapters._date) {
    const adapter = Chart._adapters._date;
    adapter.override({
      _id: 'date-fns-lite',
      formats: function() { return FORMATS; },
      parse: function(value) {
        if (value === null || value === undefined) return null;
        if (typeof value === 'number') return value;
        const d = new Date(value);
        return isNaN(d.getTime()) ? null : d.getTime();
      },
      format: function(time, fmt) {
        return formatDate(time, fmt);
      },
      add: function(time, amount, unit) {
        const d = new Date(time);
        switch(unit) {
          case 'millisecond': d.setTime(d.getTime() + amount); break;
          case 'second': d.setSeconds(d.getSeconds() + amount); break;
          case 'minute': d.setMinutes(d.getMinutes() + amount); break;
          case 'hour': d.setHours(d.getHours() + amount); break;
          case 'day': d.setDate(d.getDate() + amount); break;
          case 'week': d.setDate(d.getDate() + amount * 7); break;
          case 'month': d.setMonth(d.getMonth() + amount); break;
          case 'quarter': d.setMonth(d.getMonth() + amount * 3); break;
          case 'year': d.setFullYear(d.getFullYear() + amount); break;
        }
        return d.getTime();
      },
      diff: function(max, min, unit) {
        return (max - min) / (UNIT_MS[unit] || 1);
      },
      startOf: function(time, unit) {
        const d = new Date(time);
        switch(unit) {
          case 'second': d.setMilliseconds(0); break;
          case 'minute': d.setSeconds(0,0); break;
          case 'hour': d.setMinutes(0,0,0); break;
          case 'day': d.setHours(0,0,0,0); break;
          case 'week': d.setHours(0,0,0,0); d.setDate(d.getDate() - d.getDay()); break;
          case 'month': d.setHours(0,0,0,0); d.setDate(1); break;
          case 'quarter': d.setHours(0,0,0,0); d.setMonth(d.getMonth() - d.getMonth() % 3, 1); break;
          case 'year': d.setHours(0,0,0,0); d.setMonth(0,1); break;
        }
        return d.getTime();
      },
      endOf: function(time, unit) {
        const d = new Date(time);
        switch(unit) {
          case 'second': d.setMilliseconds(999); break;
          case 'minute': d.setSeconds(59,999); break;
          case 'hour': d.setMinutes(59,59,999); break;
          case 'day': d.setHours(23,59,59,999); break;
          case 'month': d.setMonth(d.getMonth()+1,0); d.setHours(23,59,59,999); break;
          case 'year': d.setMonth(11,31); d.setHours(23,59,59,999); break;
        }
        return d.getTime();
      }
    });
  }
})();