// Package auth — context keys and helpers for authentication state.
//
// This file owns the symbols that other packages use to read/write the
// authenticated user from a request context. Previously these symbols
// lived in pkg/greet/ which was the wrong home (auth concern in greet
// package) ; moved here as part of the middleware design cleanup.
package auth

import (
	"context"

	"dance-lessons-coach/pkg/user"
)

// contextKey is unexported to prevent collisions with other packages
// using string keys (Go convention).
type contextKey string

// UserContextKey is the key under which the authenticated user is
// stored in the request context by AuthMiddleware.
const UserContextKey contextKey = "authenticatedUser"

// GetAuthenticatedUserFromContext extracts the authenticated user from
// the request context. Returns (nil, false) if no user is present
// (which is the case for unauthenticated requests AND for requests
// that failed silent fail-through ; cf. AuthMiddleware semantics).
func GetAuthenticatedUserFromContext(ctx context.Context) (*user.User, bool) {
	u, ok := ctx.Value(UserContextKey).(*user.User)
	return u, ok
}