package audit

import "strings"

type Tracker struct { windows map[string]*Window }

func NewTracker() *Tracker { return &Tracker{windows: make(map[string]*Window)} }

func (t *Tracker) Accept(frame Frame) string {
    if strings.TrimSpace(frame.Device) == "" { return "missing device" }
    window := t.windows[frame.Device]
    if window == nil { window = &Window{}; t.windows[frame.Device] = window }
    return window.Observe(frame.Sequence)
}

func (t *Tracker) Snapshot() map[string]Summary {
    result := make(map[string]Summary, len(t.windows))
    for device, window := range t.windows { result[device] = window.Summary }
    return result
}