using Microsoft.Playwright;

namespace JobTrackerApi.Services;

public sealed record CvPdfArtifact(string FileName, string StoragePath, byte[] Bytes);

public interface ICvPdfExporter
{
    Task<CvPdfArtifact> ExportAsync(TailoredCvRenderResult renderResult, CancellationToken cancellationToken);
}

public sealed class PlaywrightCvPdfExporter : ICvPdfExporter
{
    private readonly AppPaths _paths;
    private readonly ILogger<PlaywrightCvPdfExporter> _logger;

    public PlaywrightCvPdfExporter(AppPaths paths, ILogger<PlaywrightCvPdfExporter> logger)
    {
        _paths = paths;
        _logger = logger;
    }

    public async Task<CvPdfArtifact> ExportAsync(TailoredCvRenderResult renderResult, CancellationToken cancellationToken)
    {
        var now = DateTimeOffset.UtcNow;
        var folder = Path.Combine(_paths.CvExportsRoot, now.ToString("yyyyMMdd"));
        Directory.CreateDirectory(folder);
        var fileName = string.IsNullOrWhiteSpace(renderResult.SuggestedFileName)
            ? $"tailored-cv-{now:yyyyMMddHHmmss}.pdf"
            : renderResult.SuggestedFileName;
        var storagePath = Path.Combine(folder, fileName);

        try
        {
            using var playwright = await Playwright.CreateAsync();
            await using var browser = await playwright.Chromium.LaunchAsync(new BrowserTypeLaunchOptions
            {
                Headless = true,
            });
            var page = await browser.NewPageAsync();
            await page.SetContentAsync(renderResult.Html, new PageSetContentOptions
            {
                WaitUntil = WaitUntilState.Load,
            });
            var bytes = await page.PdfAsync(new PagePdfOptions
            {
                Format = "A4",
                PrintBackground = true,
                Margin = new()
                {
                    Top = "0",
                    Right = "0",
                    Bottom = "0",
                    Left = "0",
                }
            });
            await File.WriteAllBytesAsync(storagePath, bytes, cancellationToken);
            return new CvPdfArtifact(fileName, storagePath, bytes);
        }
        catch (Exception ex)
        {
            _logger.LogError(ex, "Failed to export CV PDF to {Path}", storagePath);
            throw new InvalidOperationException("CV PDF export is unavailable. Ensure Chromium is installed for Playwright on this machine.", ex);
        }
    }
}