{
  function makeCommand(type, filters, parts) {
  
    const validParts = parts || [];
    // Extract pure description (without attributes)
    const description = validParts
      .filter(part => part.type === 'text')
      .map(part => part.value)
      .join(' ')
      .trim();
    
    // Collect all attributes
    const attributes = validParts
      .filter(part => part.type !== 'text')
      .filter(part => part !== null);
      
    const project = validParts
      .filter(part => part.type === 'project')
      .map(part => part.value)
      .join('')
      .trim();
      
    const tags = validParts
      .filter(part => part.type === 'tag')
      .map(part => part.value);
      
    
    // Store original parts for reconstruction
    const originalParts = validParts.filter(part => part !== null);
    let validFilters;
    if (!!filters) {
      validFilters = filters.flat();
    } else {
      validFilters = [];
    }
    
    return {
      type: type,
      description: description || [],
      attributes: attributes || [],
      filters: validFilters,
      project: project,	
      tags: JSON.stringify(tags),
      parts: parts || [],
      reconstruct: function() {
        const filterStr = this.filters.map(f => f.reconstruct()).join(',');
        const partsStr = this.parts.map(p => p.reconstruct()).join(' ');
        return [filterStr, this.type, partsStr].filter(Boolean).join(' ');
      }
    };
  }
}

Start = AddCommand / DoneCommand / ExplicitFilterCommand / ImplicitFilterCommand

// ADD COMMAND
AddCommand = "add" _ parts:(Part / _)+ EOF {
  return makeCommand('add', null, parts.filter(p => p !== null));
}

// DONE COMMAND
DoneCommand = filters:Filters _ "done" EOF {
  return makeCommand('done', filters, null);
}

ExplicitFilterCommand = filters:Filters _ "filter" _* moreFilters:Filters* EOF {
  return makeCommand('filter', [...filters, ...moreFilters], null);
}

ImplicitFilterCommand = filters:Filters+ EOF {
  return makeCommand('filter', filters, null);
}

Filters = first:Filter rest:(_ Filter)* {
  return [first, ...rest.map(r => r[1])];
}


IdRange = start:Integer "-" end:Integer {
  const ids = [];
  for (let i = start; i <= end; i++) {
    ids.push(i);
  }
  return ids;
}

SingleId = id:Integer {
  return [id];
}

Filter = IdFilter / Tag / Project / Priority / Due

IdFilter = first:(IdRange / SingleId) rest:("," (IdRange / SingleId))* trailing:"," ? {
  const ids = [first, ...rest.map(r => r[1])].flat();
  return {
    type: 'id',
    ids: ids,
    reconstruct: function() { return this.ids.join(','); }
  };
}

Part = Attribute / TextPart

TextPart = chars:Word {
  return {
    type: "text",
    value: chars,
    reconstruct: function() { return this.value; }
  };
}

Attribute = Due / Tag / Project / Priority

Due = "@" value:TimeValue {
  return { 
    type: "due", 
    value: value,
    reconstruct: function() { return `@${this.value}`; }
  };
}

Project = ("pro:" / "project:" / "+") value:Word {
  return { 
    type: "project", 
    value: value,
    reconstruct: function() { return `+${this.value}`; }
  };
}

Priority = "priority:" value:[HML] {
  return { 
    type: "priority", 
    value: value,
    reconstruct: function() { return `priority:${this.value}`; }
  };
}

Tag = "#" value:Word {
  return { 
    type: "tag", 
    value: value,
    reconstruct: function() { return `#${this.value}`; }
  };
}

Integer = digits:[0-9]+ {
  return parseInt(digits.join(''), 10);
}

TimeValue = chars:[0-9:]+ ("am" / "pm")? {
  return chars.join('') + (text() || '');
}

Word = chars:[a-zA-Z0-9_-]+ {
  return chars.join('');
}

_ = [ \t]+ {
  return null;
}

EOF = !.