@inherits FeedbackComponent<MediaGrabberOptions, MediaGrabberDownloadResult>
@using LANCommander.Server.Services.Abstractions
@using LANCommander.Server.Services.Models
@using LANCommander.SDK.Enums
@inject IMediaGrabberService MediaGrabberService
@inject IMessageService MessageService
@inject ILogger<MediaGrabberDialog> Logger

<GridRow Justify="RowJustify.SpaceBetween">
    <GridCol Span="12">
        <Flex Gap="FlexGap.Small">
            <Search @bind-Value="Search" OnSearch="(x) => GetResults(Type, x)" DefaultValue="@Search" />
            <Select Value="_selectedProvider"
                    ValueChanged="OnProviderChanged"
                    DataSource="_availableProviders"
                    TItem="string"
                    TItemValue="string"
                    Style="min-width: 180px;" />
        </Flex>
    </GridCol>
    <GridCol Span="6"></GridCol>
    <GridCol Span="6">
        <Slider TValue="double" @bind-Value="Size" DefaultValue="200" Min="50" Max="400" />
    </GridCol>
</GridRow>

@if (_preview != null)
{
    <div class="media-grabber-preview">
        <div class="media-grabber-preview__player">
            @if (IsYouTubeUrl(_preview.SourceUrl))
            {
                <iframe src="@GetYouTubeEmbedUrl(_preview.SourceUrl)"
                        frameborder="0"
                        allow="accelerometer; autoplay; clipboard-write; encrypted-media; gyroscope; picture-in-picture"
                        allowfullscreen />
            }
            else
            {
                <video src="@_preview.SourceUrl" controls autoplay />
            }
        </div>
        <button class="media-grabber-preview__close" @onclick="() => _preview = null" title="Close preview">
            <Icon Type="@IconType.Outline.Close" />
        </button>
    </div>
}

@if (Loading && !_groupedResults.Any())
{
    <Spin Spinning="true">
        <div style="min-height: 120px"></div>
    </Spin>
}

@foreach (var grabberGroup in _groupedResults)
{
    <div class="media-grabber-group">
        <div class="media-grabber-group-header">
            <div class="media-grabber-group-title">
                <h2>@grabberGroup.Group</h2>
                <span class="media-grabber-group-source">via @grabberGroup.GrabberName</span>
            </div>
            @if (MultiSelect && grabberGroup.Results.Any())
            {
                <Button Size="ButtonSize.Small" OnClick="() => ToggleSelectAll(grabberGroup)">
                    @(AllSelected(grabberGroup) ? "Deselect all" : "Select all")
                </Button>
            }
        </div>

        @if (Type == MediaType.Video)
        {
            <div class="media-picker">
                <div class="media-picker-items">
                    @foreach (var result in grabberGroup.Results)
                    {
                        var id = Guid.NewGuid();

                        <div class="media-picker-item" data-type="video" style="width: @(Size)px">
                            @if (MultiSelect)
                            {
                                <input type="checkbox" id="media-picker-item-@id" checked="@(_selectedKeys.Contains(result.UniqueKey))" @onchange="() => OnResultSelected(result)" />
                            }
                            else
                            {
                                <input type="radio" id="media-picker-item-@id" checked="@(Media == result)" name="SelectedResult" @onchange="() => OnResultSelected(result)" />
                            }
                            <label for="media-picker-item-@id" @ondblclick="() => OnResultPicked(result)"></label>
                            <img src="@result.ThumbnailUrl" />
                            <button class="media-picker-play" @onclick="() => PreviewVideo(result)" @onclick:stopPropagation="true" title="Preview"></button>
                        </div>
                    }
                </div>
            </div>
        }
        else
        {
            <ImagePicker Size="Size" MultiSelect="MultiSelect" SelectedValues="_selectedKeys" SelectedValuesChanged="OnMultiImageSelectionChanged" Images="@grabberGroup.Results.ToDictionary(r => r.UniqueKey, r => r.ThumbnailUrl)" ValueChanged="OnImageSelected" OnPicked="OnImagePicked" />
        }

        @if (CanLoadMore(grabberGroup))
        {
            <div class="media-grabber-load-more">
                <Button Size="ButtonSize.Small"
                        Loading="@(_loadingGroupId == GroupId(grabberGroup))"
                        Disabled="@(_loadingGroupId != null)"
                        OnClick="() => LoadMoreGroup(grabberGroup)">
                    Load more
                </Button>
            </div>
        }
    </div>
}

@if (Loading && _groupedResults.Any())
{
    <div class="media-grabber-loading-more">
        <Spin Spinning="true" Size="SpinSize.Small" />
    </div>
}

@if (!_groupedResults.Any() && !Loading)
{
    <Empty Description="@($"No results for \"{Search}\"")" />
}

@if (_isDownloading)
{
    <div style="position: absolute; inset: 0; background: rgba(0,0,0,0.75); display: flex; flex-direction: column; align-items: center; justify-content: center; z-index: 10; gap: 12px; border-radius: 8px;">
        <Spin Spinning="true" />
        <span>@_downloadStatus</span>
        <div style="width: 60%;">
            <Progress Percent="_downloadPercent" Size="ProgressSize.Small" Status="@ProgressStatus.Active" />
        </div>
    </div>
}

@code {
    [Parameter] public string Search { get; set; }
    [Parameter] public MediaType Type { get; set; }

    MediaGrabberResult Media { get; set; }
    MediaGrabberResult _preview { get; set; }

    bool MultiSelect { get; set; }
    HashSet<string> _selectedKeys = new();

    double Size { get; set; } = 200;
    bool Loading { get; set; } = true;
    bool _isDownloading;
    double _downloadPercent;
    string _downloadStatus = "Downloading...";

    CancellationTokenSource _searchCts;
    List<MediaGrabberResult> _allResults = new();
    List<GroupedResults> _groupedResults = new();
    HashSet<string> _seenKeys = new();

    HashSet<string> _pagingProviders = new();
    Dictionary<string, int> _groupPages = new();
    HashSet<string> _exhaustedGroups = new();
    string _loadingGroupId;

    string _selectedProvider = string.Empty;
    string[] _availableProviders = [];

    protected override async Task OnFirstAfterRenderAsync()
    {
        Type = Options.Type;
        Search = Options.Search;
        MultiSelect = Options.MultiSelect;

        _availableProviders = new[] { "All" }.Concat(MediaGrabberService.GetGrabberNames()).ToArray();
        _selectedProvider = _availableProviders.First();
        _pagingProviders = MediaGrabberService.GetPagingGrabberNames().ToHashSet();

        await GetResults(Type, Search);
    }

    private async Task OnProviderChanged(string provider)
    {
        _selectedProvider = provider;

        if (!string.IsNullOrWhiteSpace(Search))
            await GetResults(Type, Search);
    }

    private async Task GetResults(MediaType type, string search)
    {
        _searchCts?.Cancel();
        _searchCts = new CancellationTokenSource();
        var token = _searchCts.Token;

        try
        {
            Loading = true;
            _preview = null;
            _allResults.Clear();
            _groupedResults.Clear();
            _seenKeys.Clear();
            _selectedKeys.Clear();
            _groupPages.Clear();
            _exhaustedGroups.Clear();
            _loadingGroupId = null;
            await InvokeAsync(StateHasChanged);

            if (String.IsNullOrWhiteSpace(search))
                return;

            var grabberName = _selectedProvider == "All" ? null : _selectedProvider;

            await StreamResults(type, search, grabberName, 0, null, token);

            Loading = false;
            await InvokeAsync(StateHasChanged);
        }
        catch (OperationCanceledException) { }
        catch (Exception ex)
        {
            MessageService.Error("An unknown error occurred when trying to get media results");
            Logger.LogError(ex, "An unknown error occurred when trying to get media results");

            Loading = false;
        }
    }

    private string GroupId(GroupedResults group) => $"{group.GrabberName}|{group.Group}";

    private bool CanLoadMore(GroupedResults group) =>
        !Loading
        && group.Results.Any()
        && _pagingProviders.Contains(group.GrabberName)
        && !_exhaustedGroups.Contains(GroupId(group));

    private async Task LoadMoreGroup(GroupedResults group)
    {
        if (Loading || _loadingGroupId != null || String.IsNullOrWhiteSpace(Search))
            return;

        var groupId = GroupId(group);
        _searchCts ??= new CancellationTokenSource();
        var token = _searchCts.Token;

        try
        {
            _loadingGroupId = groupId;
            await InvokeAsync(StateHasChanged);

            var nextPage = _groupPages.GetValueOrDefault(groupId) + 1;
            _groupPages[groupId] = nextPage;

            // Only query the provider this group came from, and keep only this game's results.
            var added = await StreamResults(Type, Search, group.GrabberName, nextPage, group.Group, token);

            if (added == 0)
                _exhaustedGroups.Add(groupId);

            _loadingGroupId = null;
            await InvokeAsync(StateHasChanged);
        }
        catch (OperationCanceledException) { }
        catch (Exception ex)
        {
            _loadingGroupId = null;
            MessageService.Error("An unknown error occurred when trying to get more media results");
            Logger.LogError(ex, "An unknown error occurred when trying to get more media results");
        }
    }

    private async Task<int> StreamResults(MediaType type, string search, string? grabberName, int page, string? onlyGroup, CancellationToken token)
    {
        var added = 0;

        await foreach (var batch in MediaGrabberService.SearchStreamAsync(type, search, grabberName, page, token))
        {
            if (token.IsCancellationRequested)
                break;

            foreach (var result in batch)
            {
                if (onlyGroup != null && result.Group != onlyGroup)
                    continue;

                result.UniqueKey = $"{result.GrabberName}:{result.Id}";

                if (!_seenKeys.Add(result.UniqueKey))
                    continue;

                _allResults.Add(result);
                added++;
            }

            RebuildGroups();
            await InvokeAsync(StateHasChanged);
        }

        return added;
    }

    private void RebuildGroups()
    {
        _groupedResults = _allResults
            .GroupBy(r => new { r.GrabberName, r.Group })
            .Select(g => new GroupedResults
            {
                GrabberName = g.Key.GrabberName,
                Group = g.Key.Group,
                Results = g.DistinctBy(r => r.Id).ToList()
            })
            .ToList();
    }

    private void OnResultSelected(MediaGrabberResult result)
    {
        Media = result;

        if (MultiSelect)
        {
            if (!_selectedKeys.Add(result.UniqueKey))
                _selectedKeys.Remove(result.UniqueKey);
        }
    }

    private bool AllSelected(GroupedResults group) =>
        group.Results.Count > 0 && group.Results.All(r => _selectedKeys.Contains(r.UniqueKey));

    private async Task ToggleSelectAll(GroupedResults group)
    {
        var keys = group.Results.Select(r => r.UniqueKey).ToList();

        if (keys.All(_selectedKeys.Contains))
        {
            foreach (var key in keys)
                _selectedKeys.Remove(key);
        }
        else
        {
            foreach (var key in keys)
                _selectedKeys.Add(key);
        }

        await InvokeAsync(StateHasChanged);
    }

    private async Task OnResultPicked(MediaGrabberResult result)
    {
        Media = result;
        await DownloadAndClose();
    }

    private void OnImageSelected(string uniqueKey)
    {
        Media = _allResults.FirstOrDefault(r => r.UniqueKey == uniqueKey);
    }

    private void OnMultiImageSelectionChanged(HashSet<string> selectedKeys)
    {
        _selectedKeys = selectedKeys;
    }

    private async Task OnImagePicked(string uniqueKey)
    {
        if (MultiSelect)
        {
            if (!_selectedKeys.Add(uniqueKey))
                _selectedKeys.Remove(uniqueKey);

            await InvokeAsync(StateHasChanged);
        }
        else
        {
            OnImageSelected(uniqueKey);
            await DownloadAndClose();
        }
    }

    private void PreviewVideo(MediaGrabberResult result)
    {
        _preview = _preview?.Id == result.Id ? null : result;
    }

    private static bool IsYouTubeUrl(string url) =>
        url.Contains("youtube.com/") || url.Contains("youtu.be/");

    private static string GetYouTubeEmbedUrl(string url)
    {
        var uri = new Uri(url);
        var query = System.Web.HttpUtility.ParseQueryString(uri.Query);
        var videoId = query["v"] ?? uri.Segments.LastOrDefault();
        return $"https://www.youtube.com/embed/{videoId}?autoplay=1";
    }

    public override async Task OnFeedbackOkAsync(ModalClosingEventArgs args)
    {
        args.Cancel = true;
        await DownloadAndClose();
    }

    public override async Task OnFeedbackCancelAsync(ModalClosingEventArgs args)
    {
        _preview = null;
        await base.OnFeedbackCancelAsync(args);
    }

    private async Task DownloadAndClose()
    {
        if (MultiSelect)
        {
            await DownloadMultipleAndClose();
            return;
        }

        if (Media == null)
            return;

        _preview = null;
        _isDownloading = true;
        _downloadPercent = 0;
        _downloadStatus = "Downloading...";
        await InvokeAsync(StateHasChanged);

        try
        {
            var progress = new Progress<MediaDownloadProgress>(p =>
            {
                _downloadPercent = p.Percent ?? 0;
                _downloadStatus = p.Status ?? "Downloading...";
                InvokeAsync(StateHasChanged);
            });

            var download = await MediaGrabberService.DownloadAsync(Media, progress);

            var result = new MediaGrabberDownloadResult
            {
                Result = Media,
                Download = download
            };

            await base.OkCancelRefWithResult!.OnOk(result);
            await CloseFeedbackAsync();
        }
        catch (Exception ex)
        {
            _isDownloading = false;
            await InvokeAsync(StateHasChanged);
            MessageService.Error("Download failed. Please try again.");
            Logger.LogError(ex, "Failed to download media");
        }
    }

    private async Task DownloadMultipleAndClose()
    {
        var selectedResults = _allResults.Where(r => _selectedKeys.Contains(r.UniqueKey)).ToList();

        if (!selectedResults.Any())
            return;

        _preview = null;
        _isDownloading = true;
        _downloadPercent = 0;
        await InvokeAsync(StateHasChanged);

        try
        {
            var downloadResult = new MediaGrabberDownloadResult();

            for (int i = 0; i < selectedResults.Count; i++)
            {
                var selected = selectedResults[i];
                _downloadStatus = $"Downloading {i + 1} of {selectedResults.Count}...";
                _downloadPercent = 0;
                await InvokeAsync(StateHasChanged);

                var progress = new Progress<MediaDownloadProgress>(p =>
                {
                    _downloadPercent = p.Percent ?? 0;
                    InvokeAsync(StateHasChanged);
                });

                var download = await MediaGrabberService.DownloadAsync(selected, progress);

                downloadResult.Results.Add(new MediaGrabberDownloadResultEntry
                {
                    Result = selected,
                    Download = download
                });
            }

            await base.OkCancelRefWithResult!.OnOk(downloadResult);
            await CloseFeedbackAsync();
        }
        catch (Exception ex)
        {
            _isDownloading = false;
            await InvokeAsync(StateHasChanged);
            MessageService.Error("Download failed. Please try again.");
            Logger.LogError(ex, "Failed to download media");
        }
    }

    private class GroupedResults
    {
        public string GrabberName { get; set; }
        public string Group { get; set; }
        public List<MediaGrabberResult> Results { get; set; }
    }
}