package kis

import (
	"context"
	"errors"
	"fmt"
	"kis-flow/log"
	"sync"
)

var _poolOnce sync.Once

//  kisPool 用于管理全部的Function和Flow配置的池子
type kisPool struct {
	fnRouter funcRouter   // 全部的Function管理路由
	fnLock   sync.RWMutex // fnRouter 锁

	flowRouter flowRouter   // 全部的flow对象
	flowLock   sync.RWMutex // flowRouter 锁
}

// 单例
var _pool *kisPool

// Pool 单例构造
func Pool() *kisPool {
	_poolOnce.Do(func() {
		//创建kisPool对象
		_pool = new(kisPool)

		// fnRouter初始化
		_pool.fnRouter = make(funcRouter)

		// flowRouter初始化
		_pool.flowRouter = make(flowRouter)
	})

	return _pool
}

func (pool *kisPool) AddFlow(name string, flow Flow) {
	pool.flowLock.Lock()
	defer pool.flowLock.Unlock()

	if _, ok := pool.flowRouter[name]; !ok {
		pool.flowRouter[name] = flow
	} else {
		errString := fmt.Sprintf("Pool AddFlow Repeat FlowName=%s\n", name)
		panic(errString)
	}

	log.Logger().InfoF("Add FlowRouter FlowName=%s\n", name)
}

func (pool *kisPool) GetFlow(name string) Flow {
	pool.flowLock.RLock()
	defer pool.flowLock.RUnlock()

	if flow, ok := pool.flowRouter[name]; ok {
		return flow
	} else {
		return nil
	}
}

// FaaS 注册 Function 计算业务逻辑, 通过Function Name 索引及注册
func (pool *kisPool) FaaS(fnName string, f FaaS) {
	pool.fnLock.Lock()
	defer pool.fnLock.Unlock()

	if _, ok := pool.fnRouter[fnName]; !ok {
		pool.fnRouter[fnName] = f
	} else {
		errString := fmt.Sprintf("KisPoll FaaS Repeat FuncName=%s", fnName)
		panic(errString)
	}

	log.Logger().InfoF("Add KisPool FuncName=%s", fnName)
}

// CallFunction 调度 Function
func (pool *kisPool) CallFunction(ctx context.Context, fnName string, flow Flow) error {

	if f, ok := pool.fnRouter[fnName]; ok {
		return f(ctx, flow)
	}

	log.Logger().ErrorFX(ctx, "FuncName: %s Can not find in KisPool, Not Added.\n", fnName)

	return errors.New("FuncName: " + fnName + " Can not find in NsPool, Not Added.")
}