package utils

type ParamsManager interface {
	Add(k, v string) ParamsManager
	Del(k string) ParamsManager
	Get(k string) (string, bool)
	Map() map[string]string
}

type ParamsChainManager interface {
	ParamsManager
	SetPrev(ParamsChainManager)
	NewNext() ParamsChainManager
}

// SimpleParamsManager 单点参数管理器
type SimpleParamsManager map[string]string

func (pm SimpleParamsManager) Add(k, v string) ParamsManager {
	pm[k] = v
	return pm
}

func (pm SimpleParamsManager) Del(k string) ParamsManager {
	delete(pm, k)
	return pm
}

func (pm SimpleParamsManager) Get(k string) (string, bool) {
	v, e := pm[k]
	return v, e
}

func (pm SimpleParamsManager) Map() map[string]string {
	return pm
}

// SimpleParamsChainManager 链式参数管理器
type SimpleParamsChainManager struct {
	val  map[string]string
	prev ParamsManager
}

func (pm *SimpleParamsChainManager) Del(k string) ParamsManager {
	delete(pm.val, k)
	return pm
}

func (pm *SimpleParamsChainManager) Add(k, v string) ParamsManager {
	pm.val[k] = v
	return pm
}

func (pm *SimpleParamsChainManager) Get(k string) (string, bool) {
	var (
		v string
		e bool
	)
	if pm.val != nil {
		v, e = pm.val[k]
	}
	if !e && pm.prev != nil {
		v, e = pm.prev.Get(k)
	}
	return v, e
}

func (pm *SimpleParamsChainManager) Map() map[string]string {
	return pm.val
}

func (pm *SimpleParamsChainManager) SetPrev(prev ParamsChainManager) {
	pm.prev = prev
}

func (pm *SimpleParamsChainManager) NewNext() ParamsChainManager {
	return &SimpleParamsChainManager{
		prev: pm,
		val:  map[string]string{},
	}
}

/**
函数相关
*/

func NewSimpleChainParamsManager() *SimpleParamsChainManager {
	return &SimpleParamsChainManager{
		prev: nil,
		val:  map[string]string{},
	}
}

func NewSimpleParamManager() SimpleParamsManager {
	return SimpleParamsManager{}
}

func ConvertSimpleParamsChainManager(pm ParamsManager) *SimpleParamsChainManager {
	return &SimpleParamsChainManager{
		prev: pm,
		val:  map[string]string{},
	}
}