package store

import "sync"

// DeviceID is a typed device identifier.
// Using a named type (instead of plain string) makes call sites clearer
// and prevents accidentally mixing unrelated string values.
type DeviceID string

// Store holds in-memory fleet metrics for known devices.
type Store struct {
	known map[DeviceID]struct{}

	// mu protects the heartbeats/uploads maps (insert/lookup of entries only).
	// Each per-device history has its own mutex for mutations.
	mu         sync.Mutex
	heartbeats map[DeviceID]*heartbeatHistory
	uploads    map[DeviceID]*uploadHistory
}

// New creates a Store seeded with the given known device IDs.
func New(known []DeviceID) *Store {
	m := make(map[DeviceID]struct{}, len(known))
	for _, id := range known {
		m[id] = struct{}{}
	}
	return &Store{
		known:      m,
		heartbeats: make(map[DeviceID]*heartbeatHistory),
		uploads:    make(map[DeviceID]*uploadHistory),
	}
}

// Known reports whether deviceID was present in the startup device list.
func (s *Store) Known(deviceID DeviceID) bool {
	_, ok := s.known[deviceID]
	return ok
}