package core

import (
	"fmt"
	"strings"
	"sync"
)

type connection struct {
	locker  sync.Mutex
	alias   string
	tags    []string
	onClose map[string]func()
}

func (rc *connection) addTag(name, val string) {
	rc.locker.Lock()
	defer rc.locker.Unlock()

	prefix := name + "="
	for i, tag := range rc.tags {
		if strings.HasPrefix(tag, prefix) {
			rc.tags[i] = prefix + val
			return
		}
	}
	rc.tags = append(rc.tags, prefix+val)
}

func (rc *connection) removeTag(name string, val string) {
	rc.locker.Lock()
	defer rc.locker.Unlock()

	whole := fmt.Sprintf("%s=%s", name, val)
	for i, tag := range rc.tags {
		if tag == whole {
			if i == 0 && len(rc.tags) == 1 {
				rc.tags = nil
			} else {
				lastidx := len(rc.tags) - 1
				if i < lastidx {
					rc.tags[i] = rc.tags[lastidx]
				}
				rc.tags = rc.tags[:lastidx]
			}
			return
		}
	}
}

func (rc *connection) registOnCloseFunc(name string, f func()) {
	rc.locker.Lock()
	defer rc.locker.Unlock()

	if rc.onClose == nil {
		f()
		return
	}
	rc.onClose[name] = f
}

func (rc *connection) hasOnCloseFunc(name string) bool {
	rc.locker.Lock()
	defer rc.locker.Unlock()

	if rc.onClose == nil {
		return false
	}

	_, ok := rc.onClose[name]
	return ok
}

func (rc *connection) unregistOnCloseFunc(name string) (out func()) {
	rc.locker.Lock()
	defer rc.locker.Unlock()

	if rc.onClose == nil {
		return
	}
	out = rc.onClose[name]
	delete(rc.onClose, name)
	return
}

func (rc *connection) cleanup() {
	rc.locker.Lock()
	defer rc.locker.Unlock()

	cp := rc.onClose
	rc.onClose = nil
	go func() {
		for _, f := range cp {
			f()
		}
	}()
}