type TaskEntity<T extends any> = () => Promise<T>

class SuperTask<T extends any> {
    private runningCount = 0
    private taskList: Array<TaskEntity<T>> = []

    constructor(private runCount = 0) {

    }

    addTask(task: TaskEntity<T>) {
        this.taskList.push(task)
        this.run()
    }

    private run() {
        if (this.runningCount < this.runCount) {
            if (this.taskList.length > 0) {
                const task = this.taskList.shift()!
                this.runningCount++
                task().then(res => console.log(res)).finally(() => {
                    this.runningCount--
                    this.run()
                })
            }
        }

    }
}
const timeOut = (time: number, content: string): Promise<string> => {
    return new Promise(resolve => {
        setTimeout(() => {
            resolve(content)
        }, time)
    })
}



const superTask = new SuperTask(3)
superTask.addTask(() => timeOut(3000, '3000'))
superTask.addTask(() => timeOut(1000, '1000'))
superTask.addTask(() => timeOut(2000, '2000'))
superTask.addTask(() => timeOut(4000, '4000'))
superTask.addTask(() => timeOut(1000, '1000'))