using System.Text;
using Microsoft.AspNetCore.Components;
using Microsoft.JSInterop;

namespace SharepointToolbox.Web.Services.Export;

/// <summary>
/// Triggers browser file downloads from Blazor Server components.
/// Converts string export outputs to bytes and invokes JS download.
/// </summary>
public class WebExportService
{
    private readonly IJSRuntime _js;

    public WebExportService(IJSRuntime js) { _js = js; }

    public async Task DownloadCsvAsync(string content, string fileName)
    {
        var bytes = new UTF8Encoding(encoderShouldEmitUTF8Identifier: true).GetBytes(content);
        await _js.InvokeVoidAsync("sptb.downloadFile", fileName, "text/csv;charset=utf-8", Convert.ToBase64String(bytes));
    }

    public async Task DownloadHtmlAsync(string content, string fileName)
    {
        var bytes = new UTF8Encoding(encoderShouldEmitUTF8Identifier: false).GetBytes(content);
        await _js.InvokeVoidAsync("sptb.downloadFile", fileName, "text/html;charset=utf-8", Convert.ToBase64String(bytes));
    }

    /// <summary>
    /// Downloads pre-encoded bytes (e.g. a ZIP or a merged report produced by
    /// <see cref="ReportMergeHelper"/>) with an explicit MIME type.
    /// </summary>
    public async Task DownloadBytesAsync(byte[] content, string fileName, string mime)
    {
        await _js.InvokeVoidAsync("sptb.downloadFile", fileName, mime, Convert.ToBase64String(content));
    }
}