@using Microsoft.AspNetCore.Components.Web
@using Microsoft.EntityFrameworkCore
@using OpenArchival.Blazor.AdminPages
@using OpenArchival.DataAccess
@using OpenArchival.Blazor.CustomComponents
@using MudExRichTextEditor
@using MudBlazor
@using System.Text

@page "/admin/blogedit"
@page "/admin/blogedit/{Id}"
@layout AdminPages.AdminControlPanelLayout;

<MudText Typo="Typo.h6">Create a Blog Post</MudText>
<MudDivider></MudDivider>
<MudTextField Placeholder="Title" T="string" @bind-Value=@BlogPostModel.Title></MudTextField>

<MudExRichTextEdit @ref="@_contentEditor"
                   ReadOnly="false"
                   Height="444"
                   Class="m-2 mt-4"
                   Placeholder="Edit html"
                   ValueHtmlBehavior="MudExRichTextEditor.Types.GetHtmlBehavior.SemanticHtml"
                   @bind-Value="BlogPostModel.Content">
    @((MarkupString)BlogPostModel.Content)
</MudExRichTextEdit>

<ChipContainer T="BlogPostTag" @ref="@_tagsChipContainer" @bind-Items="BlogPostModel.Tags">
        <InputContent>
            <MudAutocomplete T="string"
                             Placeholder="Add Tags..."
                             @bind-Text=_tagsInputValue
                             OnKeyDown="HandleTagsEnter"
                             >
            </MudAutocomplete>
        </InputContent>
    </ChipContainer>

<MudGrid Justify="Justify.FlexEnd" Class="mr-4 pt-8">
    <MudButton StartIcon="@Icons.Material.Filled.Publish" Color=Color.Primary Variant=Variant.Filled OnClick="OnPublishBlogPost">Publish</MudButton>
</MudGrid>

@inject IDbContextFactory<ApplicationDbContext> ContextFactory;
@inject ISnackbar Snackbar;
@inject NavigationManager NavigationManager;

@*OnKeyDown="@(ev => HandleChipContainerEnter<string>(ev, _tagsChipContainer, _tagsInputValue, () => _tagsInputValue = string.Empty))"*@
@code {
    [Parameter]
    public int Id { get; set; }

    public List<string> StringTags { get; set; } = [];
    public BlogPost BlogPostModel { get; set; } = new();

    private MudExRichTextEdit _contentEditor = default!;

    private string _tagsInputValue = "";
    private ChipContainer<BlogPostTag> _tagsChipContainer = default!;

    protected override void OnParametersSet()
    {
        if (Id != 0)
        {
            using var context = ContextFactory.CreateDbContext();

            BlogPost? existingPost = context.BlogPosts.Include(p => p.Tags).Where(p => p.Id == Id).FirstOrDefault();

            if (existingPost is null)
            {
                NavigationManager.NavigateTo($"blog-not-found/{System.Web.HttpUtility.UrlEncode($"No blog with id {Id} exists in the database!")}");
                return;
            }

            BlogPostModel = existingPost;
        }
        base.OnParametersSet();
    }

    private async Task DeDuplicatePostTags(BlogPost post, ApplicationDbContext context)
    {
        List<BlogPostTag> finalTags = [];
        foreach (BlogPostTag tag in post.Tags)
        {
            var existing = await context.BlogPostTags.Where(t => t.Name == tag.Name).FirstOrDefaultAsync();
            if (existing is not null)
            {
                finalTags.Add(existing);
            } 
            else
            {
                context.BlogPostTags.Add(tag);
                finalTags.Add(tag);
            }
        }

        post.Tags = finalTags;
    }

    private void BuildBlogSearchIndex(BlogPost post)
    {
        var tagsSb = new StringBuilder();
        var allSb = new StringBuilder();

        allSb.Append($"{post.Title} ");
        allSb.Append($"{post.Content} ");

        foreach (BlogPostTag tag in post.Tags)
        {
            tagsSb.Append($"{tag.Name} ");
            allSb.Append($"{tag.Name} ");
        }

        post.AllSearchString = allSb.ToString();
        post.TagsSearchString = tagsSb.ToString();
    }

    private async Task OnPublishBlogPost(Microsoft.AspNetCore.Components.Web.MouseEventArgs args)
    {
        if (string.IsNullOrEmpty(BlogPostModel.Content))
        {
            Snackbar.Add("Content is required in the blog post, write something.", Severity.Warning);
            return;
        }

        if (string.IsNullOrEmpty(BlogPostModel.Title))
        {
            Snackbar.Add("A post title is required", Severity.Warning);
            return;
        }

        await using var context = await ContextFactory.CreateDbContextAsync();
        BlogPostModel.ModifiedTime = DateTime.UtcNow;

        // Blog post does not exist in database
        if (BlogPostModel.Id == 0)
        {
            BlogPostModel.CreationTime = DateTime.UtcNow;

            // Loop through the tags and de-duplicate any of them
            await DeDuplicatePostTags(BlogPostModel, context);

            BuildBlogSearchIndex(BlogPostModel);

            context.BlogPosts.Add(BlogPostModel);
        } 
        else
        {
            // Blog post exists in database

            // Find the existing post so we can update it

            BlogPost? existing = await context.BlogPosts.Include(p=>p.Tags).FirstOrDefaultAsync(p => p.Id == BlogPostModel.Id);
            if (existing is null)
            {
                Snackbar.Add($"Unable to find a post with id {BlogPostModel.Id} in the database, cannot update post!", Severity.Error);
                return;
            }

            // De-duplicate tags
            await DeDuplicatePostTags(BlogPostModel, context);

            // Copy over the values we want
            existing.Title = BlogPostModel.Title;
            existing.Content = BlogPostModel.Content;
            existing.ModifiedTime = BlogPostModel.ModifiedTime;

            existing.Tags.Clear();
            foreach (var tag in BlogPostModel.Tags)
            {
                existing.Tags.Add(tag);
            }

            BuildBlogSearchIndex(existing);
        }

        await context.SaveChangesAsync();

        Snackbar.Add("Changes saved!", Severity.Success);

        // Reset the model
        BlogPostModel = new();

        StateHasChanged();
    }

    public void HandleTagsEnter(KeyboardEventArgs args)
    {
        if (args.Key == "Enter")
        {
            var newTag = new BlogPostTag() { Name = _tagsInputValue };
            _tagsInputValue = "";

            BlogPostModel.Tags.Add(newTag);

            StateHasChanged();    
        }
    }
}