feat: done vibing

internal/fetch/yfinance.go

@@ -0,0 +1,157 @@
+package fetch
+
+import (
+	"context"
+	"encoding/json"
+	"fmt"
+	"net/http"
+	"net/url"
+	"sync"
+	"time"
+
+	"github.com/ytshih/stonks/internal/config"
+)
+
+func init() {
+	Register("yfinance", newYFinanceFetcher)
+}
+
+// Yahoo's older batch quote endpoint (/v6/finance/quote, used by the
+// unmaintained piquette/finance-go library) has since been locked behind
+// auth (401/404 without a session crumb). The per-symbol chart endpoint
+// below is still open and unauthenticated as of writing, and covers
+// crypto, equities, and futures alike via the same shape — so this fetcher
+// talks to it directly instead of depending on a library hitting a dead
+// endpoint.
+const yfinanceChartURLTemplate = "https://query1.finance.yahoo.com/v8/finance/chart/%s"
+
+// yfinanceFetcher fetches prices from Yahoo Finance's public chart API —
+// the same unofficial endpoint Python's yfinance scrapes. No API key
+// required, but it does require a browser-like User-Agent or Yahoo
+// returns 429.
+type yfinanceFetcher struct {
+	client *http.Client
+}
+
+func newYFinanceFetcher(cfg config.PluginConfig) (Fetcher, error) {
+	return &yfinanceFetcher{
+		client: &http.Client{Timeout: 10 * time.Second},
+	}, nil
+}
+
+func (f *yfinanceFetcher) Name() string { return "yfinance" }
+
+// yfinanceTask pairs the symbol used to query Yahoo (query) with the plain
+// symbol shown in the report and matched against config.Targets (display).
+// These differ for forex, where Yahoo requires a "=X" suffix (e.g.
+// "USDTWD=X") that config and the rest of the pipeline never see.
+type yfinanceTask struct {
+	query   string
+	display string
+}
+
+func (f *yfinanceFetcher) Fetch(ctx context.Context, targets config.Targets) (Result, error) {
+	tasks := make([]yfinanceTask, 0, len(targets.Crypto)+len(targets.Equities)+len(targets.Futures)+len(targets.Forex))
+	for _, s := range targets.Crypto {
+		tasks = append(tasks, yfinanceTask{query: s, display: s})
+	}
+	for _, s := range targets.Equities {
+		tasks = append(tasks, yfinanceTask{query: s, display: s})
+	}
+	for _, ticker := range targets.Futures {
+		tasks = append(tasks, yfinanceTask{query: ticker, display: ticker})
+	}
+	for _, s := range targets.Forex {
+		tasks = append(tasks, yfinanceTask{query: s + "=X", display: s})
+	}
+	if len(tasks) == 0 {
+		return Result{}, nil
+	}
+
+	type outcome struct {
+		quote Quote
+		err   error
+	}
+	outcomes := make([]outcome, len(tasks))
+
+	var wg sync.WaitGroup
+	for i, task := range tasks {
+		wg.Add(1)
+		go func(i int, task yfinanceTask) {
+			defer wg.Done()
+			q, err := f.fetchOne(ctx, task)
+			outcomes[i] = outcome{quote: q, err: err}
+		}(i, task)
+	}
+	wg.Wait()
+
+	var result Result
+	var errs []error
+	for i, o := range outcomes {
+		if o.err != nil {
+			errs = append(errs, fmt.Errorf("%s: %w", tasks[i].display, o.err))
+			continue
+		}
+		result.Quotes = append(result.Quotes, o.quote)
+	}
+
+	return result, joinErrs(errs)
+}
+
+type yfinanceChartResponse struct {
+	Chart struct {
+		Result []struct {
+			Meta struct {
+				Symbol                     string  `json:"symbol"`
+				Currency                   string  `json:"currency"`
+				RegularMarketPrice         float64 `json:"regularMarketPrice"`
+				RegularMarketChangePercent float64 `json:"regularMarketChangePercent"`
+			} `json:"meta"`
+		} `json:"result"`
+		Error *struct {
+			Description string `json:"description"`
+		} `json:"error"`
+	} `json:"chart"`
+}
+
+func (f *yfinanceFetcher) fetchOne(ctx context.Context, task yfinanceTask) (Quote, error) {
+	reqURL := fmt.Sprintf(yfinanceChartURLTemplate, url.PathEscape(task.query))
+
+	req, err := http.NewRequestWithContext(ctx, http.MethodGet, reqURL, nil)
+	if err != nil {
+		return Quote{}, err
+	}
+	// Yahoo returns 429 for requests with no browser-like User-Agent.
+	req.Header.Set("User-Agent", "Mozilla/5.0 (compatible; stonks/1.0)")
+
+	resp, err := f.client.Do(req)
+	if err != nil {
+		return Quote{}, err
+	}
+	defer resp.Body.Close()
+
+	if resp.StatusCode != http.StatusOK {
+		return Quote{}, fmt.Errorf("unexpected status %d", resp.StatusCode)
+	}
+
+	var parsed yfinanceChartResponse
+	if err := json.NewDecoder(resp.Body).Decode(&parsed); err != nil {
+		return Quote{}, fmt.Errorf("decode response: %w", err)
+	}
+	if parsed.Chart.Error != nil {
+		return Quote{}, fmt.Errorf("yahoo error: %s", parsed.Chart.Error.Description)
+	}
+	if len(parsed.Chart.Result) == 0 {
+		return Quote{}, fmt.Errorf("no data returned")
+	}
+
+	meta := parsed.Chart.Result[0].Meta
+	return Quote{
+		Symbol:        task.display,
+		Label:         task.display,
+		Price:         meta.RegularMarketPrice,
+		ChangePercent: meta.RegularMarketChangePercent,
+		Currency:      meta.Currency,
+		Source:        "yfinance",
+	}, nil
+}