@using Generic.Media.Components
@using Microsoft.AspNetCore.Components.Forms
@using System.Collections.Generic
@using System.Linq
@using System.Net.Http.Json
@using System.Net.Http.Headers
@using Blazored.LocalStorage
@inject IHttpClientFactory HttpClientFactory
@inject ILocalStorageService LocalStorage

@if (SingleUploadMode && _items.Count == 1)
{
    // Auto-select first item in single mode if not selected
    // Done in OnInitialized or after upload
}

<div class="flex flex-col gap-6 w-full">

    <!-- Section 1: Cropper / Viewer (Always Available) -->
    <div class="w-full">
        <ImageCropper @ref="_cropper" Item="@_selectedItem" OnCropSaved="@OnCropSaved" OnCancel="@OnCropCancel"
            AspectRatio="@AspectRatio" TargetWidth="@TargetWidth" TargetHeight="@TargetHeight"
            AiApiKey="@AiModelApiKey" />
    </div>

    <!-- Section 2: Dropzone & List -->
    <div class="w-full">
        <div class="mb-4">
            <MediaDropZone OnFileDropped="@HandleFileDrop" CompactMode="@(_items.Any())" />
        </div>

        @if (_items.Any())
        {
            <SortableMediaList Items="@_items" OnRemove="@RemoveItem" OnSort="@UpdateOrder"
                OnEdit="@((item) => SelectItem(item))" />
        }

        @if (!SingleUploadMode && _items.Count < MaxItems)
        {
            <div class="mt-4">
                <ExternalLinkInput OnLinkAdded="@HandleLinkAdded" />
            </div>
        }
    </div>
</div>

@code {
    [Parameter] public List<string> InitialUrls { get; set; } = new();
    [Parameter] public EventCallback<List<string>> OnChange { get; set; }
    [Parameter] public int MaxItems { get; set; } = 10;

    // Config Parameters
    [Parameter] public double? AspectRatio { get; set; }
    [Parameter] public int? TargetWidth { get; set; }
    [Parameter] public int? TargetHeight { get; set; }
    [Parameter] public bool SingleUploadMode { get; set; }
    [Parameter] public string? AiModelApiKey { get; set; }
    [Parameter] public string CdnBaseUrl { get; set; } = "http://localhost:2003/";

    private List<MediaItemModel> _items = new();
    private List<string> _deletedUrls = new();
    private ImageCropper? _cropper;
    private MediaItemModel? _selectedItem;

    protected override void OnInitialized()
    {
        if (SingleUploadMode) MaxItems = 1;

        if (InitialUrls != null)
        {
            foreach (var url in InitialUrls)
            {
                _items.Add(new MediaItemModel
                {
                    Url = url,
                    Type = DetectMediaType(url),
                    Order = _items.Count
                });
            }
            // Auto Select first item
            if (_items.Any()) _selectedItem = _items.First();
        }
    }

    // Called after render to ensure cropper updates with initially selected item if needed
    protected override async Task OnAfterRenderAsync(bool firstRender)
    {
        if (firstRender && _selectedItem != null && _cropper != null)
        {
            await _cropper.OpenAsync(_selectedItem);
        }
    }

    private async Task HandleFileDrop(InputFileChangeEventArgs e)
    {
        var files = e.GetMultipleFiles(SingleUploadMode ? 1 : 20); // 20 as arbitrary max for batch

        if (SingleUploadMode && files.Count > 0)
        {
            // Clear existing for single mode
            var allItems = _items.ToList();
            foreach (var item in allItems) RemoveItem(item);
        }

        MediaItemModel? lastAdded = null;

        foreach (var file in files)
        {
            if (_items.Count >= MaxItems) break;

            var newItem = new MediaItemModel
            {
                File = file,
                Type = file.ContentType.StartsWith("video") ? MediaType.Video : MediaType.Image,
                IsLocal = true,
                Order = _items.Count
            };

            _items.Add(newItem);
            lastAdded = newItem;

            // Generate Preview for Images
            if (newItem.Type == MediaType.Image)
            {
                // Read async to avoid blocking UI?
                // Fire and forget task to load preview
                _ = LoadPreviewAsync(newItem);
            }
        }

        // Auto select the last added item to show in cropper
        if (lastAdded != null && lastAdded.Type == MediaType.Image)
        {
            await SelectItem(lastAdded);
        }
    }

    private async Task LoadPreviewAsync(MediaItemModel item)
    {
        try
        {
            if (item.File == null) return;
            var maxFileSize = 10L * 1024 * 1024; // 10MB
            var buffer = new byte[item.File.Size];
            await item.File.OpenReadStream(maxFileSize).ReadAsync(buffer);
            var base64 = Convert.ToBase64String(buffer);
            item.PreviewUrl = $"data:{item.File.ContentType};base64,{base64}";
            // If this item is currently selected, trigger update
            if (_selectedItem == item)
            {
                await SelectItem(item);
            }
            StateHasChanged();
        }
        catch (Exception ex)
        {
            Console.WriteLine($"Failed to load preview: {ex.Message}");
        }
    }

    private void HandleLinkAdded(string url)
    {
        if (_items.Count >= MaxItems) return;
        if (SingleUploadMode && _items.Count > 0)
        {
            var allItems = _items.ToList();
            foreach (var item in allItems) RemoveItem(item);
        }

        var newItem = new MediaItemModel
        {
            Url = url,
            Type = DetectMediaType(url),
            Order = _items.Count
        };

        _items.Add(newItem);
        if (newItem.Type == MediaType.Image) _ = SelectItem(newItem);
    }

    private void RemoveItem(MediaItemModel item)
    {
        _items.Remove(item);
        if (_selectedItem == item)
        {
            _selectedItem = null;
            // Clear cropper?
            if (_cropper != null)
            {
                // We can't really "clear" it easily without a Clear method,
                // but passing null to something that expects it might work.
                // For now, re-render will pass Item=null to ImageCropper
            }
        }

        // Track deletion if it was a remote URL
        if (!string.IsNullOrEmpty(item.Url) && !item.IsLocal)
        {
            _deletedUrls.Add(item.Url);
        }

        Reindex();
    }

    private async Task SelectItem(MediaItemModel item)
    {
        _selectedItem = item;
        if (item.Type == MediaType.Image && _cropper != null)
        {
            await _cropper.OpenAsync(item);
        }
        StateHasChanged();
    }

    private void OnCropSaved(MediaItemModel item)
    {
        // Item is modified by reference
        // Force refresh list to show new thumb
        StateHasChanged();
    }

    private void OnCropCancel()
    {
        // Do nothing
    }

    private void UpdateOrder(List<MediaItemModel> sortedItems)
    {
        _items = sortedItems;
        Reindex();
    }

    private void Reindex()
    {
        for (int i = 0; i < _items.Count; i++)
        {
            _items[i].Order = i;
        }
    }

    private MediaType DetectMediaType(string url)
    {
        if (string.IsNullOrWhiteSpace(url)) return MediaType.Image;
        if (url.Contains("youtube.com") || url.Contains("youtu.be")) return MediaType.YouTube;
        if (url.Contains("vimeo.com")) return MediaType.Vimeo;
        if (url.EndsWith(".mp4") || url.EndsWith(".webm")) return MediaType.Video;
        return MediaType.Image;
    }

    public class UploadResult
    {
        public List<string> FinalUrls { get; set; } = new();
        public List<string> DeletedUrls { get; set; } = new();
    }

    public async Task<UploadResult> ProcessUploadsAsync()
    {
        var result = new UploadResult();
        result.DeletedUrls = new List<string>(_deletedUrls);

        var client = HttpClientFactory.CreateClient("CDN");
        var token = await LocalStorage.GetItemAsync<string>("authToken");
        if (!string.IsNullOrEmpty(token))
        {
            client.DefaultRequestHeaders.Authorization = new AuthenticationHeaderValue("Bearer", token);
        }

        foreach (var item in _items)
        {
            if (item.IsLocal)
            {
                // Handle Local File Upload
                try
                {
                    using var content = new MultipartFormDataContent();

                    if (!string.IsNullOrEmpty(item.PreviewUrl) && item.PreviewUrl.StartsWith("data:"))
                    {
                        // Cropped or preview base64
                        var base64Data = item.PreviewUrl.Split(',')[1];
                        var bytes = Convert.FromBase64String(base64Data);
                        var byteContent = new ByteArrayContent(bytes);
                        byteContent.Headers.ContentType = new MediaTypeHeaderValue("image/webp");
                        content.Add(byteContent, "file", "image.webp");
                    }
                    else if (item.File != null)
                    {
                        // Original file
                        var fileContent = new StreamContent(item.File.OpenReadStream(10 * 1024 * 1024));
                        fileContent.Headers.ContentType = new MediaTypeHeaderValue(item.File.ContentType);
                        content.Add(fileContent, "file", item.File.Name);
                    }
                    else
                    {
                        continue;
                    }

                    var response = await client.PostAsync("files/upload", content);
                    if (response.IsSuccessStatusCode)
                    {
                        var uploadRes = await response.Content.ReadFromJsonAsync<UploadResponse>();
                        if (uploadRes != null && (!string.IsNullOrEmpty(uploadRes.Path) || !string.IsNullOrEmpty(uploadRes.Url)))
                        {
                            var fullUrl = !string.IsNullOrEmpty(uploadRes.Url)
                            ? uploadRes.Url
                            : $"{CdnBaseUrl.TrimEnd('/')}/{uploadRes.Path?.TrimStart('/')}";

                            result.FinalUrls.Add(fullUrl);
                            item.Url = fullUrl;
                            item.IsLocal = false;
                        }
                    }
                    else
                    {
                        var errorMsg = await response.Content.ReadAsStringAsync();
                        throw new Exception($"Upload failed with status {response.StatusCode}: {errorMsg}");
                    }
                }
                catch (Exception ex)
                {
                    Console.WriteLine($"Upload Error: {ex.Message}");
                    throw; // Re-throw to block save in parent
                }
            }
            else if (!string.IsNullOrEmpty(item.Url))
            {
                result.FinalUrls.Add(item.Url);
            }
        }

        return result;
    }

    public void Clear()
    {
        _items.Clear();
        _deletedUrls.Clear();
        _selectedItem = null;
        StateHasChanged();
    }

    private class UploadResponse
    {
        public string? Path { get; set; }
        public string? Url { get; set; }
    }
}