@page "/media/playlists"
@using ErsatzTV.Application.MediaCollections
@using ErsatzTV.Application.Tree
@implements IDisposable
@inject ILogger<Playlists> Logger
@inject ISnackbar Snackbar
@inject IMediator Mediator
@inject IDialogService Dialog

<MudForm Style="max-height: 100%">
    <div class="d-flex flex-column" style="height: 100vh; overflow-x: auto">
        <MudContainer MaxWidth="MaxWidth.ExtraLarge" Class="pt-8">
            <MudText Typo="Typo.h5" Class="mb-2">Playlist Groups</MudText>
            <MudDivider Class="mb-6"/>
            <MudStack Row="true" Breakpoint="Breakpoint.SmAndDown" Class="form-field-stack gap-md-8 mb-5">
                <div class="d-flex">
                    <MudText>Playlist Group Name</MudText>
                </div>
                <MudTextField @bind-Value="_playlistGroupName" For="@(() => _playlistGroupName)"/>
            </MudStack>
            <MudStack Row="true" Breakpoint="Breakpoint.SmAndDown" Class="form-field-stack gap-md-8 mb-5">
                <div class="d-flex"></div>
                <MudButton Variant="Variant.Filled" Color="Color.Primary" OnClick="@(_ => AddPlaylistGroup())" StartIcon="@Icons.Material.Filled.Add">
                    Add Playlist Group
                </MudButton>
            </MudStack>
            <MudText Typo="Typo.h5" Class="mt-10 mb-2">Playlists</MudText>
            <MudDivider Class="mb-6"/>
            <MudStack Row="true" Breakpoint="Breakpoint.SmAndDown" Class="form-field-stack gap-md-8 mb-5">
                <div class="d-flex">
                    <MudText>Playlist Group</MudText>
                </div>
                <MudSelect @bind-Value="_selectedPlaylistGroup">
                    @foreach (PlaylistGroupViewModel playlistGroup in _playlistGroups)
                    {
                        <MudSelectItem Value="@playlistGroup">@playlistGroup.Name</MudSelectItem>
                    }
                </MudSelect>
            </MudStack>
            <MudStack Row="true" Breakpoint="Breakpoint.SmAndDown" Class="form-field-stack gap-md-8 mb-5">
                <div class="d-flex">
                    <MudText>Playlist Name</MudText>
                </div>
                <MudTextField @bind-Value="_playlistName" For="@(() => _playlistName)"/>
            </MudStack>
            <MudStack Row="true" Breakpoint="Breakpoint.SmAndDown" Class="form-field-stack gap-md-8 mb-5">
                <div class="d-flex"></div>
                <MudButton Variant="Variant.Filled" Color="Color.Primary" OnClick="@(_ => AddPlaylist())" StartIcon="@Icons.Material.Filled.Add">
                    Add Playlist
                </MudButton>
            </MudStack>
            <MudStack Row="true" Breakpoint="Breakpoint.SmAndDown" Class="form-field-stack gap-md-8 mb-5">
                <div class="d-flex"></div>
                <MudTreeView T="PlaylistTreeItemViewModel" Items="@_treeItems" Hover="true" Style="width: 100%">
                    <ItemTemplate Context="item">
                        <MudTreeViewItem T="PlaylistTreeItemViewModel" Items="@item.Value!.TreeItems" Icon="@item.Value.Icon" Value="@item.Value">
                            <BodyContent>
                                <div style="display: grid; grid-template-columns: 1fr auto; align-items: center; width: 100%">
                                    <MudGrid Justify="Justify.FlexStart">
                                        <MudItem xs="5">
                                            <MudText>@item.Value.Text</MudText>
                                        </MudItem>
                                        @if (!string.IsNullOrWhiteSpace(item.Value.EndText))
                                        {
                                            <MudItem xs="6">
                                                <MudText>@item.Value.EndText</MudText>
                                            </MudItem>
                                        }
                                    </MudGrid>
                                    <div style="justify-self: end;">
                                        @foreach (int playlistId in Optional(item.Value.PlaylistId))
                                        {
                                            <MudIconButton Icon="@Icons.Material.Filled.Edit" Size="Size.Medium" Color="Color.Inherit" Href="@($"media/playlists/{playlistId}")"/>
                                        }
                                        <MudIconButton Icon="@Icons.Material.Filled.Delete"
                                                       Size="Size.Medium"
                                                       Color="Color.Inherit"
                                                       Disabled="@item.Value.IsSystem"
                                                       OnClick="@(_ => DeleteItem(item.Value))"/>
                                    </div>
                                </div>
                            </BodyContent>
                        </MudTreeViewItem>
                    </ItemTemplate>
                </MudTreeView>
            </MudStack>
        </MudContainer>
    </div>
</MudForm>

@code {
    private CancellationTokenSource _cts;
    private readonly List<TreeItemData<PlaylistTreeItemViewModel>> _treeItems = [];
    private List<PlaylistGroupViewModel> _playlistGroups = [];
    private PlaylistGroupViewModel _selectedPlaylistGroup;
    private string _playlistGroupName;
    private string _playlistName;

    public void Dispose()
    {
        _cts?.Cancel();
        _cts?.Dispose();
    }

    protected override async Task OnParametersSetAsync()
    {
        _cts?.Cancel();
        _cts?.Dispose();
        _cts = new CancellationTokenSource();
        var token = _cts.Token;

        try
        {
            await ReloadPlaylistTree(token);
            await InvokeAsync(StateHasChanged);
        }
        catch (OperationCanceledException)
        {
            // do nothing
        }
    }

    private async Task ReloadPlaylistTree(CancellationToken cancellationToken)
    {
        _playlistGroups = await Mediator.Send(new GetAllPlaylistGroups(), cancellationToken);

        _treeItems.Clear();
        TreeViewModel tree = await Mediator.Send(new GetPlaylistTree(), cancellationToken);
        foreach (TreeGroupViewModel group in tree.Groups)
        {
            _treeItems.Add(new TreeItemData<PlaylistTreeItemViewModel> { Value = new PlaylistTreeItemViewModel(group) });
        }
    }

    private async Task AddPlaylistGroup()
    {
        if (!string.IsNullOrWhiteSpace(_playlistGroupName))
        {
            Either<BaseError, PlaylistGroupViewModel> result = await Mediator.Send(new CreatePlaylistGroup(_playlistGroupName), _cts.Token);

            foreach (BaseError error in result.LeftToSeq())
            {
                Snackbar.Add(error.Value, Severity.Error);
                Logger.LogError("Unexpected error adding playlist group: {Error}", error.Value);
            }

            foreach (PlaylistGroupViewModel _ in result.RightToSeq())
            {
                await ReloadPlaylistTree(_cts.Token);
                await InvokeAsync(StateHasChanged);
            }
        }
    }

    private async Task AddPlaylist()
    {
        if (_selectedPlaylistGroup is not null && !string.IsNullOrWhiteSpace(_playlistName))
        {
            Either<BaseError, PlaylistViewModel> result = await Mediator.Send(new CreatePlaylist(_selectedPlaylistGroup.Id, _playlistName), _cts.Token);

            foreach (BaseError error in result.LeftToSeq())
            {
                Snackbar.Add(error.Value, Severity.Error);
                Logger.LogError("Unexpected error adding playlist: {Error}", error.Value);
            }

            foreach (PlaylistViewModel playlist in result.RightToSeq())
            {
                foreach (PlaylistTreeItemViewModel item in _treeItems.Map(i => i.Value).Where(item => item.PlaylistGroupId == _selectedPlaylistGroup.Id))
                {
                    item.TreeItems.Add(new TreeItemData<PlaylistTreeItemViewModel> { Value = new PlaylistTreeItemViewModel(playlist) });
                }

                _playlistName = null;
                await InvokeAsync(StateHasChanged);
            }
        }
    }

    private async Task DeleteItem(PlaylistTreeItemViewModel treeItem)
    {
        foreach (int playlistGroupId in Optional(treeItem.PlaylistGroupId))
        {
            var parameters = new DialogParameters { { "EntityType", "playlist group" }, { "EntityName", treeItem.Text } };
            var options = new DialogOptions { CloseButton = true, MaxWidth = MaxWidth.ExtraSmall };

            IDialogReference dialog = await Dialog.ShowAsync<DeleteDialog>("Delete Playlist Group", parameters, options);
            DialogResult result = await dialog.Result;
            if (result is not null && !result.Canceled)
            {
                Option<BaseError> deleteResult = await Mediator.Send(new DeletePlaylistGroup(playlistGroupId), _cts.Token);
                foreach (BaseError error in deleteResult)
                {
                    Snackbar.Add(error.ToString(), Severity.Error);
                    return;
                }

                _treeItems.RemoveAll(i => i.Value?.PlaylistGroupId == playlistGroupId);
                if (_selectedPlaylistGroup?.Id == playlistGroupId)
                {
                    _selectedPlaylistGroup = null;
                }

                _playlistGroups = await Mediator.Send(new GetAllPlaylistGroups(), _cts.Token);
                await InvokeAsync(StateHasChanged);
            }
        }

        foreach (int playlistId in Optional(treeItem.PlaylistId))
        {
            var parameters = new DialogParameters { { "EntityType", "playlist" }, { "EntityName", treeItem.Text } };
            var options = new DialogOptions { CloseButton = true, MaxWidth = MaxWidth.ExtraSmall };

            IDialogReference dialog = await Dialog.ShowAsync<DeleteDialog>("Delete Playlist", parameters, options);
            DialogResult result = await dialog.Result;
            if (result is not null && !result.Canceled)
            {
                Option<BaseError> deleteResult = await Mediator.Send(new DeletePlaylist(playlistId), _cts.Token);
                foreach (BaseError error in deleteResult)
                {
                    Snackbar.Add(error.ToString(), Severity.Error);
                    return;
                }

                foreach (PlaylistTreeItemViewModel parent in _treeItems.Map(i => i.Value))
                {
                    parent.TreeItems.RemoveAll(i => i.Value == treeItem);
                }

                await InvokeAsync(StateHasChanged);
            }
        }
    }

}