package metacache

import (
	"context"
	"sync"
	"time"

	"gitlink.org.cn/cloudream/common/pkgs/logger"
	stgglb "gitlink.org.cn/cloudream/jcs-pub/common/globals"
	corrpc "gitlink.org.cn/cloudream/jcs-pub/common/pkgs/rpc/coordinator"
	cortypes "gitlink.org.cn/cloudream/jcs-pub/coordinator/types"
)

func (m *MetaCacheHost) AddConnectivity() *Connectivity {
	cache := &Connectivity{
		entries: make(map[cortypes.HubID]*ConnectivityEntry),
	}

	m.caches = append(m.caches, cache)
	return cache
}

type Connectivity struct {
	lock    sync.RWMutex
	entries map[cortypes.HubID]*ConnectivityEntry
}

func (c *Connectivity) Get(from cortypes.HubID, to cortypes.HubID) *time.Duration {
	for i := 0; i < 2; i++ {
		c.lock.RLock()
		entry, ok := c.entries[from]
		if ok {
			con, ok := entry.To[to]
			if ok {
				c.lock.RUnlock()

				if con.Latency == nil {
					return nil
				}
				l := time.Millisecond * time.Duration(*con.Latency)
				return &l
			}
		}
		c.lock.RUnlock()

		c.load(from)
	}

	return nil
}

func (c *Connectivity) ClearOutdated() {
	c.lock.Lock()
	defer c.lock.Unlock()

	for hubID, entry := range c.entries {
		if time.Since(entry.UpdateTime) > time.Minute*5 {
			delete(c.entries, hubID)
		}
	}
}

func (c *Connectivity) load(hubID cortypes.HubID) {
	coorCli := stgglb.CoordinatorRPCPool.Get()

	defer coorCli.Release()

	get, cerr := coorCli.GetHubConnectivities(context.Background(), corrpc.ReqGetHubConnectivities([]cortypes.HubID{hubID}))
	if cerr != nil {
		logger.Warnf("get hub connectivities: %v", cerr)
		return
	}

	c.lock.Lock()
	defer c.lock.Unlock()

	ce := &ConnectivityEntry{
		From:       hubID,
		To:         make(map[cortypes.HubID]cortypes.HubConnectivity),
		UpdateTime: time.Now(),
	}

	for _, conn := range get.Connectivities {
		ce.To[conn.ToHubID] = conn
	}

	c.entries[hubID] = ce
}

type ConnectivityEntry struct {
	From       cortypes.HubID
	To         map[cortypes.HubID]cortypes.HubConnectivity
	UpdateTime time.Time
}