package app

import (
	"strings"
	"time"
)

func (r *transportHealthRefresher) syncKnownClients(items []TransportClient) {
	r.mu.Lock()
	defer r.mu.Unlock()

	known := make(map[string]struct{}, len(items))
	for _, it := range items {
		id := strings.TrimSpace(it.ID)
		if id == "" {
			continue
		}
		known[id] = struct{}{}
		entry := r.entries[id]
		if entry == nil {
			entry = &transportHealthRefreshEntry{
				swr: newRefreshCoordinator(
					transportHealthFreshTTL,
					transportHealthBackoffMin,
					transportHealthBackoffMax,
				),
			}
			r.entries[id] = entry
		}
		if ts, ok := parseTransportHealthLastCheck(it); ok {
			entry.swr.setUpdatedAt(ts)
		}
	}

	for id := range r.entries {
		if _, ok := known[id]; !ok {
			delete(r.entries, id)
		}
	}
}

func (r *transportHealthRefresher) begin(item TransportClient, force bool, now time.Time) bool {
	id := strings.TrimSpace(item.ID)
	if id == "" {
		return false
	}

	r.mu.Lock()
	defer r.mu.Unlock()

	entry := r.entries[id]
	if entry == nil {
		entry = &transportHealthRefreshEntry{
			swr: newRefreshCoordinator(
				transportHealthFreshTTL,
				transportHealthBackoffMin,
				transportHealthBackoffMax,
			),
		}
		r.entries[id] = entry
	}
	if ts, ok := parseTransportHealthLastCheck(item); ok {
		entry.swr.setUpdatedAt(ts)
	}
	hasData := strings.TrimSpace(item.Health.LastCheck) != ""
	return entry.swr.beginRefresh(now, force, hasData)
}

func (r *transportHealthRefresher) finishSuccess(id string, now time.Time) {
	id = strings.TrimSpace(id)
	if id == "" {
		return
	}
	r.mu.Lock()
	defer r.mu.Unlock()
	entry := r.entries[id]
	if entry == nil {
		return
	}
	entry.swr.finishSuccess(now)
}

func (r *transportHealthRefresher) finishError(id, msg string, now time.Time) {
	id = strings.TrimSpace(id)
	if id == "" {
		return
	}
	r.mu.Lock()
	defer r.mu.Unlock()
	entry := r.entries[id]
	if entry == nil {
		return
	}
	entry.swr.finishError(msg, now)
}

func (r *transportHealthRefresher) acquire() {
	r.sem <- struct{}{}
}

func (r *transportHealthRefresher) release() {
	select {
	case <-r.sem:
	default:
	}
}

func parseTransportHealthLastCheck(item TransportClient) (time.Time, bool) {
	ts := strings.TrimSpace(item.Health.LastCheck)
	if ts == "" {
		return time.Time{}, false
	}
	t, err := time.Parse(time.RFC3339, ts)
	if err != nil {
		return time.Time{}, false
	}
	return t, true
}