package main

import (
	"sort"
	"sync"
)

// TargetInfo holds the display name and gRPC address of one collector target.
type TargetInfo struct {
	Name string // collector --source value, falls back to addr until first snapshot
	Addr string // configured gRPC address
}

// TargetRegistry tracks addr → display name for all configured collectors.
// Names default to the addr and are updated to the collector's --source value
// when the first snapshot arrives.
type TargetRegistry struct {
	mu    sync.RWMutex
	names map[string]string // addr → current name
}

func NewTargetRegistry(addrs []string) *TargetRegistry {
	names := make(map[string]string, len(addrs))
	for _, a := range addrs {
		names[a] = a // default until first snapshot
	}
	return &TargetRegistry{names: names}
}

// SetName updates the display name for addr (called when a snapshot arrives).
func (r *TargetRegistry) SetName(addr, name string) {
	r.mu.Lock()
	r.names[addr] = name
	r.mu.Unlock()
}

// Targets returns all registered targets sorted by addr.
func (r *TargetRegistry) Targets() []TargetInfo {
	r.mu.RLock()
	defer r.mu.RUnlock()
	out := make([]TargetInfo, 0, len(r.names))
	for addr, name := range r.names {
		out = append(out, TargetInfo{Name: name, Addr: addr})
	}
	sort.Slice(out, func(i, j int) bool { return out[i].Addr < out[j].Addr })
	return out
}