feat: done vibing

internal/fetch/fetcher.go

@@ -0,0 +1,75 @@
+// Package fetch defines the pluggable data-source interface and its
+// implementations (yfinance-equivalent prices, Finnhub, RSS news).
+package fetch
+
+import (
+	"context"
+	"fmt"
+	"time"
+
+	"github.com/ytshih/stonks/internal/config"
+)
+
+// Quote is a single point-in-time price observation for one symbol.
+type Quote struct {
+	Symbol        string // ticker as passed to the fetcher, e.g. "AAPL", "BTC-USD", "GC=F"
+	Label         string // human-friendly name, e.g. "Apple Inc."
+	Price         float64
+	ChangePercent float64 // percent change over the source's default window (usually 1 day)
+	Currency      string
+	Source        string // which fetcher produced this, e.g. "yfinance", "finnhub"
+}
+
+// NewsItem is a single headline/article.
+type NewsItem struct {
+	Title     string
+	Source    string // publication or fetcher name
+	URL       string
+	Published time.Time
+	Summary   string
+}
+
+// Result is what one fetcher call returns. The orchestrator merges Results
+// from every configured fetcher before handing them to the analyzer.
+type Result struct {
+	Quotes []Quote
+	News   []NewsItem
+}
+
+// Merge appends other's quotes and news onto r.
+func (r *Result) Merge(other Result) {
+	r.Quotes = append(r.Quotes, other.Quotes...)
+	r.News = append(r.News, other.News...)
+}
+
+// Fetcher fetches market data and/or news for the given targets.
+// Implementations should return a partial Result plus an error when only
+// some data could be retrieved, rather than nothing at all — the caller
+// decides whether a partial result is still worth reporting.
+type Fetcher interface {
+	Name() string
+	Fetch(ctx context.Context, targets config.Targets) (Result, error)
+}
+
+// Constructor builds a Fetcher from its PluginConfig (name + params).
+type Constructor func(cfg config.PluginConfig) (Fetcher, error)
+
+var registry = map[string]Constructor{}
+
+// Register makes a fetcher constructor available under name. Called from
+// each fetcher implementation's init().
+func Register(name string, ctor Constructor) {
+	if _, exists := registry[name]; exists {
+		panic(fmt.Sprintf("fetch: constructor already registered for %q", name))
+	}
+	registry[name] = ctor
+}
+
+// Build looks up the constructor for cfg.Name and invokes it.
+func Build(cfg config.PluginConfig) (Fetcher, error) {
+	ctor, ok := registry[cfg.Name]
+	if !ok {
+		return nil, fmt.Errorf("fetch: no fetcher registered for %q", cfg.Name)
+	}
+	return ctor(cfg)
+}