package memory

import (
	"context"
	"sync"

	"git.threesix.ai/jordan/slate-v3-1770514618/services/preferences-api/internal/domain"
	"git.threesix.ai/jordan/slate-v3-1770514618/services/preferences-api/internal/port"
)

var _ port.PreferencesRepository = (*PreferencesRepository)(nil)

// PreferencesRepository is a thread-safe in-memory implementation of port.PreferencesRepository.
type PreferencesRepository struct {
	mu    sync.RWMutex
	prefs map[domain.UserID]*domain.Preferences
}

// NewPreferencesRepository creates a new in-memory preferences repository.
func NewPreferencesRepository() *PreferencesRepository {
	return &PreferencesRepository{
		prefs: make(map[domain.UserID]*domain.Preferences),
	}
}

// Get returns preferences for a user.
// Returns domain.ErrPreferencesNotFound if not found.
func (r *PreferencesRepository) Get(_ context.Context, userID domain.UserID) (*domain.Preferences, error) {
	r.mu.RLock()
	defer r.mu.RUnlock()

	p, ok := r.prefs[userID]
	if !ok {
		return nil, domain.ErrPreferencesNotFound
	}
	cp := *p
	cp.Notifications = p.Notifications
	return &cp, nil
}

// Upsert stores preferences for a user (insert or replace).
func (r *PreferencesRepository) Upsert(_ context.Context, userID domain.UserID, prefs *domain.Preferences) error {
	r.mu.Lock()
	defer r.mu.Unlock()

	cp := *prefs
	cp.Notifications = prefs.Notifications
	r.prefs[userID] = &cp
	return nil
}