using Tesses.WebServer;
using Scriban;
using System.Web;
using YoutubeExplode.Search;
using System.Collections.Concurrent;
using System.Security.Cryptography;
using Newtonsoft.Json;


namespace Tesses.YouTubeDownloader2025Companion;

public class SearchResultHandler : IEventable {
    private class SearchResultObj(IAsyncEnumerator<YoutubeExplode.Common.Batch<ISearchResult>> e,bool isDialog) {
        public long expires = Program.NowEpoch + (3600*6);

        public IAsyncEnumerator<YoutubeExplode.Common.Batch<ISearchResult>> enumerator = e;

        public bool isDialog = isDialog;
    }
    private ConcurrentDictionary<string,SearchResultObj> ents=new ConcurrentDictionary<string, SearchResultObj>();

    public SearchResultHandler()
    {

    }
    
    private class SearchResult(string tytdUrl, string title, string id)
    {
        public string Url => HttpUtility.HtmlAttributeEncode($"{tytdUrl.TrimEnd('/')}/watch?v={id}");

        public string Imgurl => HttpUtility.HtmlAttributeEncode($"/api/v1/video-thumbnail?v={id}");

        public string Title => HttpUtility.HtmlEncode(title);

        public string Dialogok => HttpUtility.HtmlAttributeEncode($"searchDialogSubmit('{HttpUtility.JavaScriptStringEncode(id)}')");

        public string Addbtnjson => HttpUtility.HtmlAttributeEncode(JsonConvert.SerializeObject(new{type="add",value=id}));
    }
    public async Task<string> SearchAsync(string query,bool isDialog)
    {
        var obj = Program.YouTubeClient.Search.GetResultBatchesAsync(query, YoutubeExplode.Search.SearchFilter.Video);
        SearchResultObj ro = new SearchResultObj(obj.GetAsyncEnumerator(),isDialog);
        string id = RandomNumberGenerator.GetHexString(32);
        while(!ents.TryAdd(id,ro))
        {
            id = RandomNumberGenerator.GetHexString(32);
        }

        
        return await MoreAsync(id,ro);
    }

    private static ReloadingScript results_component = new ReloadingScript("wwwroot/components/search-results.sbnhtml");
    private static ReloadingScript results_dialog_component = new ReloadingScript("wwwroot/components/search-results-dialog.sbnhtml");
      
    private async Task<string> MoreAsync(string id,SearchResultObj o)
    {
        if(o.expires <= Program.NowEpoch)
        {
            return """<div class="row"><div class="max"></div><div class="min"><h1>The search has expired</h1></div><div class="max"></div></div>""";
        }
        if(await o.enumerator.MoveNextAsync())
        {

            var tytd = Program.Config ?? new AuthConfig();
            List<SearchResult> results = new List<SearchResult>();
            foreach(var ent in o.enumerator.Current.Items)
                if(ent is VideoSearchResult item)
                    results.Add(new SearchResult(tytd.TYTDUrl, item.Title, item.Id));
            
            return o.isDialog ? results_dialog_component.Render(new{results, moreurl = HttpUtility.HtmlAttributeEncode($"/search_more?id={id}")}) : results_component.Render(new {
                results, moreurl = HttpUtility.HtmlAttributeEncode($"/search_more?id={id}")
            });
        }
        return """<div class="row"><div class="max"></div><div class="min"><h1>There are no more results</h1></div><div class="max"></div></div>""";
    }
    

    public async Task<string> MoreAsync(string id)
    {
        if(ents.TryGetValue(id, out var v))
        {
            return await MoreAsync(id,v);
        }
        return """<div class="row"><div class="max"></div><div class="min"><h1>There are no more results</h1></div><div class="max"></div></div>""";
    }

    public async Task EventAsync()
    {
        try { 
        List<string> expired = new List<string>();
        var time = Program.NowEpoch;
        foreach(var item in ents)
        {
            if(item.Value.expires <= time)
                expired.Add(item.Key);
        }
        foreach(var expire in expired)
            ents.Remove(expire,out var e);
        }catch{

        }

        await Task.CompletedTask;
    }
}

public static partial class Components {
    public static async Task<string> SearchMoreAsync(ServerContext ctx)
    {
        if(ctx.QueryParams.TryGetFirst("id",out var id))
        {
            return await Program.SearchResultHandler.MoreAsync(id);
        }
        return """<div class="row"><div class="max"></div><div class="min"><h1>No continuation id provided</h1></div><div class="max"></div></div>""";
    
    }
}

public static partial class Pages {


    private static ReloadingScript search_page = new ReloadingScript("wwwroot/pages/search.sbnhtml");
    
    public static async Task<string> SearchAsync(ServerContext ctx)
    {
        string q="";
        string body = "";
        if(ctx.QueryParams.TryGetFirst("q",out q))
        {

            body = await Program.SearchResultHandler.SearchAsync(q,false);
        }

        return Components.Shell($"Search {q}",search_page.Render(new {body,q = HttpUtility.HtmlAttributeEncode(q)}),Program.DefaultLinks(1));
    }
    public static async Task<string> SearchDialogAsync(ServerContext ctx)
    {
        string q="";
        string body = "";
        if(ctx.QueryParams.TryGetFirst("q",out q))
        {

            body = await Program.SearchResultHandler.SearchAsync(q,true);
        }

        return body;
    }
}