#region license
// This file is part of Vocaluxe.
// 
// Vocaluxe is free software: you can redistribute it and/or modify
// it under the terms of the GNU General Public License as published by
// the Free Software Foundation, either version 3 of the License, or
// (at your option) any later version.
// 
// Vocaluxe is distributed in the hope that it will be useful,
// but WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
// GNU General Public License for more details.
// 
// You should have received a copy of the GNU General Public License
// along with Vocaluxe. If not, see <http://www.gnu.org/licenses/>.
#endregion

using System;
using System.Collections.Generic;
using System.Xml.XPath;

namespace VocaluxeLib
{
    public class CXMLReader
    {
        private readonly XPathNavigator _Navigator;
        private readonly String _FilePath;

        public string FilePath
        {
            get { return _FilePath; }
        }

        //Private method. Use OpenFile factory method to get an instance
        private CXMLReader(string uri)
        {
            _FilePath = uri;
            var xmlDoc = new XPathDocument(uri);
            _Navigator = xmlDoc.CreateNavigator();
        }

        public XPathNavigator Navigator
        {
            get { return _Navigator; }
        }

        public static CXMLReader OpenFile(string fileName)
        {
            try
            {
                return new CXMLReader(fileName);
            }
            catch (Exception e)
            {
                CBase.Log.LogError("Can't open XML file: " + fileName + ": " + e.Message);
                return null;
            }
        }

        public bool TryGetEnumValue<T>(string xPath, ref T value)
            where T : struct
        {
            string val;
            if (GetValue(xPath, out val, Enum.GetName(typeof(T), value)))
                return CHelper.TryParse(val, out value, true);
            return false;
        }

        public bool TryGetIntValue(string xPath, ref int value)
        {
            string val;
            if (GetValue(xPath, out val, value.ToString()))
                return int.TryParse(val, out value);
            return false;
        }

        public bool TryGetIntValueRange(string xPath, ref int value, int min = 0, int max = 100)
        {
            bool result = TryGetIntValue(xPath, ref value);
            if (result)
                value = value.Clamp(min, max);
            return result;
        }

        public bool TryGetFloatValue(string xPath, ref float value)
        {
            string val;
            return GetValue(xPath, out val, value.ToString()) && CHelper.TryParse(val, out value);
        }

        public bool TryGetColorFromRGBA(string xPath, ref SColorF value)
        {
            bool result = true;
            result &= TryGetFloatValue(xPath + "/R", ref value.R);
            result &= TryGetFloatValue(xPath + "/G", ref value.G);
            result &= TryGetFloatValue(xPath + "/B", ref value.B);
            result &= TryGetFloatValue(xPath + "/A", ref value.A);
            if (result)
            {
                value.R = value.R.Clamp(0f, 1f);
                value.G = value.G.Clamp(0f, 1f);
                value.B = value.B.Clamp(0f, 1f);
                value.A = value.A.Clamp(0f, 1f);
            }
            return result;
        }

        public bool GetValue(string xPath, out string value, string defaultValue = "")
        {
            int resultCt = 0;
            string val = string.Empty;

            _Navigator.MoveToRoot();
            XPathNodeIterator iterator = _Navigator.Select(xPath);

            while (iterator.MoveNext())
            {
                val = iterator.Current.Value;
                resultCt++;
            }

            if (resultCt != 1)
            {
                value = defaultValue;
                return false;
            }
            value = val;
            return true;
        }

        public List<string> GetNames(string xPath)
        {
            var values = new List<string>();

            _Navigator.MoveToRoot();
            XPathNodeIterator iterator = _Navigator.Select(xPath);
            while (iterator.MoveNext())
                values.Add(iterator.Current.LocalName);

            return values;
        }

        public IEnumerable<string> GetAttributes(string xPath, string attribute)
        {
            var values = new List<string>();

            _Navigator.MoveToRoot();
            XPathNodeIterator iterator = _Navigator.Select(xPath);
            while (iterator.MoveNext())
                values.Add(iterator.Current.GetAttribute(attribute, ""));

            return values;
        }

        public bool GetValues(string xPath, ref List<string> values)
        {
            _Navigator.MoveToRoot();
            XPathNodeIterator iterator = _Navigator.Select(xPath);
            while (iterator.MoveNext())
                values.Add(iterator.Current.Value);

            return true;
        }

        public bool ItemExists(string xPath)
        {
            _Navigator.MoveToRoot();

            return _Navigator.Select(xPath).MoveNext();
        }
    }
}