// Package analyze turns fetched market data + news into an investment-advice
// report via Claude, using one of two interchangeable modes: "subscription"
// (shells out to the `claude` CLI, billed against a Claude Pro/Max
// subscription) or "api" (calls the Messages API directly, billed per token).
package analyze

import (
	"context"
	"fmt"

	"github.com/ytshih/stonks/internal/config"
)

// Analyzer sends a prompt to Claude and returns the response text.
type Analyzer interface {
	Analyze(ctx context.Context, prompt string) (string, error)
}

// Constructor builds an Analyzer from the analyzer config block.
type Constructor func(cfg config.AnalyzerConfig) (Analyzer, error)

var registry = map[string]Constructor{}

// Register makes an analyzer constructor available under mode. Called from
// each mode implementation's init().
func Register(mode string, ctor Constructor) {
	if _, exists := registry[mode]; exists {
		panic(fmt.Sprintf("analyze: constructor already registered for mode %q", mode))
	}
	registry[mode] = ctor
}

// Build looks up the constructor for cfg.Mode and invokes it.
func Build(cfg config.AnalyzerConfig) (Analyzer, error) {
	ctor, ok := registry[cfg.Mode]
	if !ok {
		return nil, fmt.Errorf("analyze: no analyzer registered for mode %q", cfg.Mode)
	}
	return ctor(cfg)
}