Files
Finlytic/FinlyticFundamentals/Services/HtmlFallbackScraper.cs
T

305 lines
14 KiB
C#

using System;
using System.Collections.Generic;
using System.Globalization;
using System.Text.RegularExpressions;
using System.Threading;
using System.Threading.Tasks;
using FinlyticFundamentals.Entities;
using Microsoft.Extensions.Logging;
using Microsoft.Playwright;
namespace FinlyticFundamentals.Services;
public interface IHtmlFallbackScraper
{
Task<ScrapedFundamentalsData?> ScrapeFallbackAsync(string isin, string ticker, CancellationToken cancellationToken = default);
}
/// <summary>
/// Fallback scraper using Playwright (headless Chromium) to scrape Yahoo Finance pages
/// for alternative ticker symbols (e.g., APC.SG) whose data is not available via the API.
/// Targets stable data-testid selectors from the rendered Yahoo Finance SPA.
/// </summary>
public class HtmlFallbackScraper : IHtmlFallbackScraper, IAsyncDisposable
{
private readonly ILogger<HtmlFallbackScraper> _logger;
private IPlaywright? _playwright;
private IBrowser? _browser;
private readonly SemaphoreSlim _browserLock = new(1, 1);
public HtmlFallbackScraper(ILogger<HtmlFallbackScraper> logger)
{
_logger = logger;
}
public async Task<ScrapedFundamentalsData?> ScrapeFallbackAsync(
string isin,
string ticker,
CancellationToken cancellationToken = default)
{
_logger.LogInformation(
"[YahooFallbackScraper] Executing Playwright Fallback Scrape for ticker '{Ticker}' (ISIN: {Isin})...",
ticker, isin);
try
{
var browser = await GetOrInitBrowserAsync(cancellationToken);
var fundamentals = new AssetFundamentalsEntity
{
Isin = isin,
PrimaryTicker = ticker,
LastUpdatedAt = DateTime.UtcNow,
LastStaticUpdatedAt = DateTime.UtcNow
};
var tickerData = new TickerFundamentalsEntity
{
Ticker = ticker,
Isin = isin,
LastUpdatedAt = DateTime.UtcNow
};
fundamentals.CompanyName = ticker;
// Share context for both pages so we only have to accept cookies once
await using (var ctx = await browser.NewContextAsync(BuildContextOptions()))
{
// ── 1. Key Statistics Page ─────────────────────────────────────
var statsUrl = $"https://finance.yahoo.com/quote/{Uri.EscapeDataString(ticker)}/key-statistics/";
_logger.LogInformation("[YahooFallbackScraper] Navigating to stats page: {Url}", statsUrl);
var statsPage = await ctx.NewPageAsync();
try
{
await statsPage.GotoAsync(statsUrl, new PageGotoOptions
{
WaitUntil = WaitUntilState.DOMContentLoaded,
Timeout = 45_000
});
await HandleConsentAsync(statsPage);
// Wait for the statistics section to be visible
await statsPage.WaitForSelectorAsync(
"section[data-testid='qsp-statistics'], section[data-testid='stats-highlight']",
new PageWaitForSelectorOptions { Timeout = 20_000 });
// --- Valuation Measures Table ---
var valuationRows = await statsPage.QuerySelectorAllAsync(
"section[data-testid='qsp-statistics'] table tbody tr");
foreach (var row in valuationRows)
{
var cells = await row.QuerySelectorAllAsync("td");
if (cells.Count < 2) continue;
var label = (await cells[0].InnerTextAsync()).Trim();
var value = (await cells[1].InnerTextAsync()).Trim();
if (string.IsNullOrWhiteSpace(value) || value == "N/A" || value == "--") continue;
switch (NormalizeLabel(label))
{
case "market cap": tickerData.MarketCapitalization = ParseSuffixNumber(value) ?? 0m; break;
case "enterprise value": tickerData.EnterpriseValue = ParseSuffixNumber(value) ?? 0m; break;
case "trailing p/e": tickerData.PeRatioTrailing = ParseDecimal(value); break;
case "forward p/e": tickerData.PeRatioForward = ParseDecimal(value); break;
case "peg ratio (5yr expected)": tickerData.PegRatio = ParseDecimal(value); break;
case "price/sales": tickerData.PsRatio = ParseDecimal(value); break;
case "price/book": tickerData.PbRatio = ParseDecimal(value); break;
case "enterprise value/revenue": tickerData.EvToRevenue = ParseDecimal(value); break;
case "enterprise value/ebitda": tickerData.EvToEbitda = ParseDecimal(value); break;
}
}
// --- Financial Highlight Cards ---
var highlightRows = await statsPage.QuerySelectorAllAsync(
"div[data-testid='stats-highlight'] section[data-testid='card-container'] table tr");
foreach (var row in highlightRows)
{
var cells = await row.QuerySelectorAllAsync("td");
if (cells.Count < 2) continue;
var label = (await cells[0].InnerTextAsync()).Trim();
var value = (await cells[1].InnerTextAsync()).Trim();
if (string.IsNullOrWhiteSpace(value) || value == "N/A" || value == "--") continue;
switch (NormalizeLabel(label))
{
case "profit margin": tickerData.NetProfitMargin = ParsePercent(value); break;
case "operating margin": tickerData.OperatingMargin = ParsePercent(value); break;
case "return on assets": tickerData.ReturnOnAssets = ParsePercent(value); break;
case "return on equity": tickerData.ReturnOnEquity = ParsePercent(value); break;
case "current ratio": tickerData.CurrentRatio = ParseDecimal(value); break;
case "quick ratio": tickerData.QuickRatio = ParseDecimal(value); break;
case "total debt/equity": tickerData.DebtToEquity = ParseDecimal(value); break;
case "52 week high": tickerData.FiftyTwoWeekHigh = ParseDecimal(value) ?? 0m; break;
case "52 week low": tickerData.FiftyTwoWeekLow = ParseDecimal(value) ?? 0m; break;
case "forward annual dividend yield":
case "trailing annual dividend yield":
tickerData.DividendYield ??= ParsePercent(value); break;
case "payout ratio": tickerData.PayoutRatio = ParsePercent(value); break;
}
}
_logger.LogInformation(
"[YahooFallbackScraper] Stats parsed for '{Ticker}': MarketCap={MarketCap}, EV={EV}, TrailingPE={PE}, ForwardPE={FPE}",
ticker, tickerData.MarketCapitalization, tickerData.EnterpriseValue,
tickerData.PeRatioTrailing, tickerData.PeRatioForward);
}
catch (TimeoutException tex)
{
_logger.LogWarning(tex,
"[YahooFallbackScraper] Timeout waiting for stats page selectors for ticker '{Ticker}'. Page may not have loaded.", ticker);
}
finally
{
await statsPage.CloseAsync();
}
}
// ── 2. Guard: no meaningful data ──────────────────────────────
if (tickerData.MarketCapitalization == 0)
{
_logger.LogWarning(
"[YahooFallbackScraper] Playwright scrape for '{Ticker}' produced no meaningful data (MarketCap=0). Returning NULL.",
ticker);
return null;
}
_logger.LogInformation(
"[YahooFallbackScraper] Playwright Fallback Scrape complete for '{Ticker}'. MarketCap={MarketCap}",
ticker, tickerData.MarketCapitalization);
return new ScrapedFundamentalsData(
fundamentals,
tickerData,
new List<CompanyExecutiveEntity>(),
new List<FinancialStatementEntity>(),
new List<ForwardEstimateEntity>()
);
}
catch (Exception ex)
{
_logger.LogError(ex,
"[YahooFallbackScraper] Error during Playwright Fallback Scrape for ticker '{Ticker}' (ISIN: {Isin})",
ticker, isin);
return null;
}
}
// ── Browser Lifecycle ──────────────────────────────────────────────────
private async Task<IBrowser> GetOrInitBrowserAsync(CancellationToken cancellationToken = default)
{
if (_browser != null) return _browser;
await _browserLock.WaitAsync(cancellationToken);
try
{
if (_browser != null) return _browser;
_playwright = await Playwright.CreateAsync();
_browser = await _playwright.Chromium.LaunchAsync(new BrowserTypeLaunchOptions
{
Headless = true,
Args = new[] { "--no-sandbox", "--disable-dev-shm-usage" }
});
_logger.LogInformation("[YahooFallbackScraper] Playwright Chromium browser initialized.");
return _browser;
}
finally
{
_browserLock.Release();
}
}
private static BrowserNewContextOptions BuildContextOptions() => new()
{
UserAgent = "Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/122.0.0.0 Safari/537.36",
ViewportSize = new ViewportSize { Width = 1280, Height = 900 },
Locale = "en-US",
ExtraHTTPHeaders = new Dictionary<string, string>
{
["Accept-Language"] = "en-US,en;q=0.9"
}
};
public async ValueTask DisposeAsync()
{
if (_browser != null) await _browser.CloseAsync();
_playwright?.Dispose();
}
// ── Parse Helpers ─────────────────────────────────────────────────────
private async Task HandleConsentAsync(IPage page)
{
try
{
if (page.Url.Contains("consent.yahoo.com"))
{
_logger.LogInformation("[YahooFallbackScraper] Redirected to consent page. Attempting to accept cookies...");
var agreeBtn = page.Locator("button[name='agree'], button.accept-all, button[value='agree']");
if (await agreeBtn.CountAsync() > 0)
{
await agreeBtn.First.ClickAsync();
await page.WaitForNavigationAsync(new PageWaitForNavigationOptions { WaitUntil = WaitUntilState.DOMContentLoaded, Timeout = 20_000 });
_logger.LogInformation("[YahooFallbackScraper] Cookie consent accepted. Navigated back to: {Url}", page.Url);
}
else
{
_logger.LogWarning("[YahooFallbackScraper] On consent page but could not find the 'agree' button.");
}
}
}
catch (Exception ex)
{
_logger.LogWarning(ex, "[YahooFallbackScraper] Error while handling cookie consent.");
}
}
/// <summary>Lowercases, strips trailing digits, common Yahoo qualifiers like (ttm), (mrq), and extra spaces.</summary>
private static string NormalizeLabel(string label)
{
label = label.ToLowerInvariant();
label = Regex.Replace(label, @"\s*\d+\s*$", ""); // trailing superscripts
label = label.Replace("(ttm)", "").Replace("(mrq)", "").Replace("(fye)", ""); // remove date qualifiers
label = Regex.Replace(label, @"\s+", " "); // collapse spaces
return label.Trim();
}
private static decimal? ParseDecimal(string? input)
{
if (string.IsNullOrWhiteSpace(input) || input == "N/A" || input == "--" || input == "-") return null;
input = Regex.Replace(input, @"[^\d.-]", "");
return decimal.TryParse(input, NumberStyles.Any, CultureInfo.InvariantCulture, out var val) ? val : null;
}
private static decimal? ParsePercent(string? input)
{
var val = ParseDecimal(input);
if (!val.HasValue) return null;
return val.Value > 1m ? val.Value / 100m : val.Value;
}
private static decimal? ParseSuffixNumber(string? input)
{
if (string.IsNullOrWhiteSpace(input) || input == "N/A" || input == "--" || input == "-") return null;
input = input.Trim();
decimal multiplier = input.EndsWith("T", StringComparison.OrdinalIgnoreCase) ? 1_000_000_000_000m
: input.EndsWith("B", StringComparison.OrdinalIgnoreCase) ? 1_000_000_000m
: input.EndsWith("M", StringComparison.OrdinalIgnoreCase) ? 1_000_000m
: input.EndsWith("K", StringComparison.OrdinalIgnoreCase) ? 1_000m
: 1m;
var numPart = Regex.Replace(input, @"[^\d.-]", "");
var val = ParseDecimal(numPart);
return val.HasValue ? val.Value * multiplier : null;
}
}