using System.Collections;

namespace Flee.Parsing
{

    /**
     * An abstract parse tree node. This class is inherited by all
     * nodes in the parse tree, i.e. by the token and production
     * classes.
     */
    internal abstract class Node
    {
        private Node _parent;
        private ArrayList _values;

        internal virtual bool IsHidden()
        {
            return false;
        }

        public abstract int Id
        {
            get;
        }

        public virtual int GetId()
        {
            return Id;
        }

        public abstract string Name
        {
            get;
        }

        public virtual string GetName()
        {
            return Name;
        }

        public virtual int StartLine
        {
            get
            {
                for (int i = 0; i < Count; i++)
                {
                    var line = this[i].StartLine;
                    if (line >= 0)
                    {
                        return line;
                    }
                }
                return -1;
            }
        }

        public virtual int GetStartLine()
        {
            return StartLine;
        }

        public virtual int StartColumn
        {
            get
            {
                for (int i = 0; i < Count; i++)
                {
                    var col = this[i].StartColumn;
                    if (col >= 0)
                    {
                        return col;
                    }
                }
                return -1;
            }
        }

        public virtual int GetStartColumn()
        {
            return StartColumn;
        }

        public virtual int EndLine
        {
            get
            {
                for (int i = Count - 1; i >= 0; i--)
                {
                    var line = this[i].EndLine;
                    if (line >= 0)
                    {
                        return line;
                    }
                }
                return -1;
            }
        }

        public virtual int GetEndLine()
        {
            return EndLine;
        }

        public virtual int EndColumn
        {
            get
            {
                int col;

                for (int i = Count - 1; i >= 0; i--)
                {
                    col = this[i].EndColumn;
                    if (col >= 0)
                    {
                        return col;
                    }
                }
                return -1;
            }
        }

        public virtual int GetEndColumn()
        {
            return EndColumn;
        }

        public Node Parent => _parent;

        public Node GetParent()
        {
            return Parent;
        }

        internal void SetParent(Node parent)
        {
            this._parent = parent;
        }

        public virtual int Count => 0;

        public virtual int GetChildCount()
        {
            return Count;
        }

        public int GetDescendantCount()
        {
            int count = 0;

            for (int i = 0; i < Count; i++)
            {
                count += 1 + this[i].GetDescendantCount();
            }
            return count;
        }

        public virtual Node this[int index] => null;

        public virtual Node GetChildAt(int index)
        {
            return this[index];
        }

        public ArrayList Values
        {
            get
            {
                if (_values == null)
                {
                    _values = new ArrayList();
                }
                return _values;
            }
            set
            {
                this._values = value;
            }
        }

        public int GetValueCount()
        {
            if (_values == null)
            {
                return 0;
            }
            else
            {
                return _values.Count;
            }
        }

        public object GetValue(int pos)
        {
            return Values[pos];
        }

        public ArrayList GetAllValues()
        {
            return _values;
        }

        
        public void AddValue(object value)
        {
            if (value != null)
            {
                Values.Add(value);
            }
        }

        public void AddValues(ArrayList values)
        {
            if (values != null)
            {
                Values.AddRange(values);
            }
        }

        public void RemoveAllValues()
        {
            _values = null;
        }

        public void PrintTo(TextWriter output)
        {
            PrintTo(output, "");
            output.Flush();
        }

        private void PrintTo(TextWriter output, string indent)
        {
            output.WriteLine(indent + ToString());
            indent = indent + "  ";
            for (int i = 0; i < Count; i++)
            {
                this[i].PrintTo(output, indent);
            }
        }
    }
}