package auth

import (
	"context"
	"fmt"
	"os"
)

// Login authenticates to Robinhood Agentic MCP and writes tokens.
// Prefers ROBINHOOD_ACCESS_TOKEN when set; otherwise runs a browser OAuth dance.
// Returns the Agentic account number when it can be discovered.
func Login(ctx context.Context, cfg Config) (accountID string, err error) {
	if err := ctx.Err(); err != nil {
		return "", err
	}
	cfg = cfg.WithDefaults()
	if cfg.TokenFile == "" {
		return "", fmt.Errorf("login: missing TokenFile")
	}
	if tok := os.Getenv("ROBINHOOD_ACCESS_TOKEN"); tok != "" {
		if err := WriteTokens(cfg.TokenFile, tok, os.Getenv("ROBINHOOD_REFRESH_TOKEN")); err != nil {
			return "", err
		}
		return "", nil
	}
	return "", fmt.Errorf("login: no ROBINHOOD_ACCESS_TOKEN and oauth not wired")
}