using DirectShowLib;
using System;
using System.Collections;
using System.IO;
using System.Runtime.InteropServices;

// Code of MediaPortal (www.team-mediaportal.com)

namespace WPFMediaKit.DirectShow.MediaPlayers;

public static class DirectShowUtil
{
    private static readonly ILog log = LogManager.GetLogger(typeof(DirectShowUtil));

    public static IBaseFilter AddFilterToGraph(IGraphBuilder graphBuilder, FilterName filterName, string baseDir, Guid clsid)
    {
        if (String.IsNullOrEmpty(filterName.Name))
            return null;

        try
        {
            IBaseFilter NewFilter = null;

            // use local lib
            if (!String.IsNullOrEmpty(filterName.Filename) && filterName.CLSID != Guid.Empty)
            {
                if (filterName.Name == "System AsyncFileSource")
                {
                    NewFilter = (IBaseFilter)(new AsyncReader());
                }
                else
                {
                    string dllPath = Path.Combine(baseDir, filterName.Filename);
                    NewFilter = FilterFromFile.LoadFilterFromDll(dllPath, filterName.CLSID,
                          !Path.IsPathRooted(dllPath));
                }
            }

            // or try load from system
            if (NewFilter == null)
            {
                foreach (Filter filter in Filters.LegacyFilters)
                {
                    if (String.Compare(filter.Name, filterName.Name, true) == 0 &&
                        (clsid == Guid.Empty || filter.CLSID == clsid))
                    {
                        NewFilter = (IBaseFilter)Marshal.BindToMoniker(filter.MonikerString);
                    }
                }
            }

            int hr = graphBuilder.AddFilter(NewFilter, filterName.Name);
            if (hr < 0)
            {
                log.Error("Unable to add filter: {0} to graph", filterName.Name);
                NewFilter = null;
            }
            else
            {
                log.Debug("Added filter: {0} to graph", filterName.Name);
            }

            if (NewFilter == null)
            {
                log.Error("Failed filter: {0} not found", filterName.Name);
            }

            return NewFilter;
        }
        catch (Exception ex)
        {
            log.Error(ex, "Error adding filter: {0} to graph", filterName.Name);
            return null;
        }
    }

    public static bool DisconnectAllPins(IGraphBuilder graphBuilder, IBaseFilter filter)
    {
        IEnumPins pinEnum;
        int hr = filter.EnumPins(out pinEnum);
        if (hr != 0 || pinEnum == null)
        {
            return false;
        }
        FilterInfo info;
        filter.QueryFilterInfo(out info);

        Marshal.ReleaseComObject(info.pGraph);
        bool allDisconnected = true;
        for (; ; )
        {
            IPin[] pins = new IPin[1];
            IntPtr fetched = IntPtr.Zero;
            hr = pinEnum.Next(1, pins, fetched);
            if (hr != 0 || fetched == IntPtr.Zero)
            {
                break;
            }
            PinInfo pinInfo;
            pins[0].QueryPinInfo(out pinInfo);
            DsUtils.FreePinInfo(pinInfo);
            if (pinInfo.dir == PinDirection.Output)
            {
                if (!DisconnectPin(graphBuilder, pins[0]))
                {
                    allDisconnected = false;
                }
            }
            Marshal.ReleaseComObject(pins[0]);
        }
        Marshal.ReleaseComObject(pinEnum);
        return allDisconnected;
    }

    public static bool DisconnectPin(IGraphBuilder graphBuilder, IPin pin)
    {
        IPin other;
        int hr = pin.ConnectedTo(out other);
        bool allDisconnected = true;
        PinInfo info;
        pin.QueryPinInfo(out info);
        DsUtils.FreePinInfo(info);

        if (hr == 0 && other != null)
        {
            other.QueryPinInfo(out info);
            if (!DisconnectAllPins(graphBuilder, info.filter))
            {
                allDisconnected = false;
            }
            hr = pin.Disconnect();
            if (hr != 0)
            {
                allDisconnected = false;
            }
            hr = other.Disconnect();
            if (hr != 0)
            {
                allDisconnected = false;
            }
            DsUtils.FreePinInfo(info);
            Marshal.ReleaseComObject(other);
        }
        else
        {
        }
        return allDisconnected;
    }

    public static void RemoveFilters(IGraphBuilder graphBuilder)
    {
        RemoveFilters(graphBuilder, string.Empty);
    }

    public static void RemoveFilters(IGraphBuilder graphBuilder, string filterName)
    {
        if (graphBuilder == null)
        {
            return;
        }

        int hr = 0;
        IEnumFilters enumFilters = null;
        ArrayList filtersArray = new ArrayList();

        try
        {
            hr = graphBuilder.EnumFilters(out enumFilters);
            DsError.ThrowExceptionForHR(hr);

            IBaseFilter[] filters = new IBaseFilter[1];
            IntPtr fetched = IntPtr.Zero;

            while (enumFilters.Next(filters.Length, filters, fetched) == 0)
            {
                filtersArray.Add(filters[0]);
            }

            foreach (IBaseFilter filter in filtersArray)
            {
                FilterInfo info;
                filter.QueryFilterInfo(out info);
                Marshal.ReleaseComObject(info.pGraph);

                try
                {
                    if (!String.IsNullOrEmpty(filterName))
                    {
                        if (String.Equals(info.achName, filterName))
                        {
                            DisconnectAllPins(graphBuilder, filter);
                            hr = graphBuilder.RemoveFilter(filter);
                            DsError.ThrowExceptionForHR(hr);
                            Marshal.ReleaseComObject(filter);
                            log.Debug("Remove filter from graph: {0}", info.achName);
                        }
                    }
                    else
                    {
                        DisconnectAllPins(graphBuilder, filter);
                        hr = graphBuilder.RemoveFilter(filter);
                        DsError.ThrowExceptionForHR(hr);
                        int i = Marshal.ReleaseComObject(filter);
                        log.Debug(string.Format("Remove filter from graph: {0} {1}", info.achName, i));
                    }
                }
                catch (Exception ex)
                {
                    log.Error(ex, "Remove of filter failed with code (HR): {0}, explanation: {1}", info.achName, hr.ToString());
                }
            }
        }
        catch (Exception)
        {
            return;
        }
        finally
        {
            if (enumFilters != null)
            {
                Marshal.ReleaseComObject(enumFilters);
            }
        }
    }
}