/* global window, document, DWgetSelection, DWsetSelection, pasteText */

(function () {
  'use strict';

  var Luxtools = window.Luxtools || (window.Luxtools = {});
  var DateFix = Luxtools.DateFix || (Luxtools.DateFix = {});

  // Month name patterns for regex (English and German)
  var MONTH_PATTERN = '(?:jan|feb|m[aä]r|apr|ma[iy]|jun|jul|aug|sep|sept|okt|oct|nov|de[cz])[a-z]*\\.?';

  // Regex to find date candidates in text for "fix all" feature
  var CANDIDATE_REGEX = new RegExp(
    '\\b(?:' +
      '\\d{4}[-\\/.][\\d]{1,2}[-\\/.][\\d]{1,2}|' +                    // YYYY-MM-DD
      '\\d{1,2}[-\\/.][\\d]{1,2}[-\\/.][\\d]{4}|' +                    // DD-MM-YYYY
      MONTH_PATTERN + '\\s+\\d{1,2}(?:st|nd|rd|th)?[,]?\\s+\\d{4}|' +  // Month DD, YYYY
      '\\d{1,2}(?:st|nd|rd|th)?\\.?\\s+' + MONTH_PATTERN + '\\s+\\d{4}|' + // DD Month YYYY
      '\\d{4}\\s+' + MONTH_PATTERN + '\\s+\\d{1,2}' +                  // YYYY Month DD
    ')(?:[T\\s]+\\d{1,2}:\\d{2}(?::\\d{2})?(?:\\s*(?:am|pm))?)?\\b',
    'gi'
  );

  // Map month names (English and German) to month numbers (1-12)
  var MONTH_MAP = {
    'jan': 1, 'januar': 1, 'january': 1,
    'feb': 2, 'februar': 2, 'february': 2,
    'mar': 3, 'mär': 3, 'märz': 3, 'march': 3, 'maerz': 3,
    'apr': 4, 'april': 4,
    'may': 5, 'mai': 5,
    'jun': 6, 'juni': 6, 'june': 6,
    'jul': 7, 'juli': 7, 'july': 7,
    'aug': 8, 'august': 8,
    'sep': 9, 'sept': 9, 'september': 9,
    'oct': 10, 'okt': 10, 'oktober': 10, 'october': 10,
    'nov': 11, 'november': 11,
    'dec': 12, 'dez': 12, 'dezember': 12, 'december': 12
  };

  function pad2(n) {
    return n < 10 ? '0' + n : String(n);
  }

  /**
   * Look up a month name (English or German) and return its number (1-12).
   * Returns null if not found.
   */
  function parseMonthName(name) {
    if (!name) return null;
    var key = name.toLowerCase().replace(/\.$/, '');
    return MONTH_MAP[key] || null;
  }

  /**
   * Preprocess input to make it parseable by Date.
   * Handles formats Date.parse() doesn't understand natively.
   */
  function preprocess(input) {
    var s = input
      .replace(/^\s*[([{"'`]+|[)\]}",'`]+\s*$/g, '')  // strip surrounding brackets/quotes
      .replace(/\s*(Z|[+-]\d{2}:?\d{2})$/i, '')       // strip timezone
      .replace(/(\d)(st|nd|rd|th)\b/gi, '$1')         // strip ordinal suffixes
      .replace(/,/g, ' ')
      .replace(/\s+/g, ' ')
      .trim();

    // Handle month names (English and German) - convert to YYYY-MM-DD format
    // Pattern: DD Month YYYY or DD. Month YYYY
    var monthMatch = s.match(/^(\d{1,2})\.?\s+([a-zäö]+)\.?\s+(\d{4})(.*)$/i);
    if (monthMatch) {
      var day = parseInt(monthMatch[1], 10);
      var monthNum = parseMonthName(monthMatch[2]);
      var year = monthMatch[3];
      var rest = monthMatch[4] || '';
      if (monthNum) {
        return year + '-' + pad2(monthNum) + '-' + pad2(day) + rest;
      }
    }

    // Pattern: Month DD, YYYY
    monthMatch = s.match(/^([a-zäö]+)\.?\s+(\d{1,2})\s+(\d{4})(.*)$/i);
    if (monthMatch) {
      var monthNum = parseMonthName(monthMatch[1]);
      var day = parseInt(monthMatch[2], 10);
      var year = monthMatch[3];
      var rest = monthMatch[4] || '';
      if (monthNum) {
        return year + '-' + pad2(monthNum) + '-' + pad2(day) + rest;
      }
    }

    // Pattern: YYYY Month DD
    monthMatch = s.match(/^(\d{4})\s+([a-zäö]+)\.?\s+(\d{1,2})(.*)$/i);
    if (monthMatch) {
      var year = monthMatch[1];
      var monthNum = parseMonthName(monthMatch[2]);
      var day = parseInt(monthMatch[3], 10);
      var rest = monthMatch[4] || '';
      if (monthNum) {
        return year + '-' + pad2(monthNum) + '-' + pad2(day) + rest;
      }
    }

    // DD.MM.YYYY or DD/MM/YYYY -> rearrange to YYYY-MM-DD for Date
    var match = s.match(/^(\d{1,2})[-\/.](\d{1,2})[-\/.](\d{4})(.*)$/);
    if (match) {
      var a = parseInt(match[1], 10);
      var b = parseInt(match[2], 10);
      var year = match[3];
      var rest = match[4] || '';
      // Disambiguate: if first > 12, it must be day (DMY); else assume DMY
      var day = a > 12 ? a : (b > 12 ? b : a);
      var month = a > 12 ? b : (b > 12 ? a : b);
      s = year + '-' + pad2(month) + '-' + pad2(day) + rest;
    }

    return s;
  }

  /**
   * Try to parse a date/time string into a Date object.
   * Returns null if parsing fails or produces an invalid date.
   */
  function tryParse(input) {
    if (!input || typeof input !== 'string') return null;

    var preprocessed = preprocess(input);
    if (!preprocessed) return null;

    // Try native parsing
    var ts = Date.parse(preprocessed);
    if (!isNaN(ts)) return new Date(ts);

    // Fallback: replace dots/slashes with dashes and try again
    var normalized = preprocessed.replace(/[\/\.]/g, '-');
    ts = Date.parse(normalized);
    if (!isNaN(ts)) return new Date(ts);

    return null;
  }

  /**
   * Check if the original input contained a time component.
   */
  function hasTimeComponent(input) {
    return /\d{1,2}:\d{2}/.test(input);
  }

  /**
   * Format a Date object to YYYY-MM-DD or YYYY-MM-DD HH:MM:SS.
   */
  function formatDate(date, includeTime) {
    var out = date.getFullYear() + '-' + pad2(date.getMonth() + 1) + '-' + pad2(date.getDate());
    if (includeTime) {
      out += ' ' + pad2(date.getHours()) + ':' + pad2(date.getMinutes()) + ':' + pad2(date.getSeconds());
    }
    return out;
  }

  /**
   * Normalize a timestamp string to YYYY-MM-DD (or YYYY-MM-DD HH:MM:SS if time present).
   * Returns null if the input cannot be parsed as a valid date.
   */
  function normalizeTimestamp(input) {
    var date = tryParse(input);
    if (!date) return null;
    return formatDate(date, hasTimeComponent(input));
  }

  function getEditor(edid) {
    return document.getElementById(edid);
  }

  function fixSelection(edid) {
    if (typeof DWgetSelection !== 'function' || typeof pasteText !== 'function') return false;
    var textarea = getEditor(edid);
    if (!textarea) return false;

    var selection = DWgetSelection(textarea);
    var text = selection.getText();
    if (!text || !text.trim()) return false;

    var normalized = normalizeTimestamp(text);
    if (!normalized) return false;

    pasteText(selection, normalized, { nosel: true });
    return false;
  }

  function fixAll(edid) {
    var textarea = getEditor(edid);
    if (!textarea) return false;

    var selection = typeof DWgetSelection === 'function' ? DWgetSelection(textarea) : null;
    var original = textarea.value;
    var replaced = original.replace(CANDIDATE_REGEX, function (match) {
      var normalized = normalizeTimestamp(match);
      return normalized || match;
    });

    if (replaced !== original) {
      textarea.value = replaced;
      if (selection && typeof DWsetSelection === 'function') {
        selection.start = Math.min(selection.start, textarea.value.length);
        selection.end = Math.min(selection.end, textarea.value.length);
        DWsetSelection(selection);
      }
    }

    return false;
  }

  DateFix.normalize = normalizeTimestamp;
  DateFix.fixSelection = fixSelection;
  DateFix.fixAll = fixAll;

  // Toolbar button action handlers
  // DokuWiki toolbar looks for addBtnAction<Type> functions for custom button types.
  // The buttons are registered via PHP (TOOLBAR_DEFINE hook in action.php).
  window.addBtnActionLuxtoolsDatefix = function ($btn, props, edid) {
    $btn.on('click', function () {
      fixSelection(edid);
      return false;
    });
    return 'luxtools-datefix';
  };

  window.addBtnActionLuxtoolsDatefixAll = function ($btn, props, edid) {
    $btn.on('click', function () {
      fixAll(edid);
      return false;
    });
    return 'luxtools-datefix-all';
  };
})();