import { EventHandler } from "./definitions"

interface PlayerEventRegistrar {
    registrations : Function[]
}

interface PlayerEventRegistrationMap {
    [name : string] : PlayerEventRegistrar
}

export class EventRegistrar {

    private eventRegistrations : PlayerEventRegistrationMap = {}

    public bindToChannel(channel : Channel.MessagingChannel) {
        for (let name of Object.keys(this.eventRegistrations))
            channel.bind(name, (txn, params) => this.fire(name, params))
    }

    public registerTypes(names : string[]) {
        for (let name of names)
            this.eventRegistrations[name] = { registrations: [] }
    }

    public fire<T>(name : string, event : T) {
        this.eventRegistrations[name].registrations.forEach(x => x(event))
    }

    public addListener<T>(name : string, handler : EventHandler<T>) {
        if (!this.eventRegistrations[name]) {
            console.warn(`PeerTube: addEventListener(): The event '${name}' is not supported`)
            return false
        }

        this.eventRegistrations[name].registrations.push(handler)
        return true
    }

    public removeListener<T>(name : string, handler : EventHandler<T>) {
        if (!this.eventRegistrations[name])
            return false

        this.eventRegistrations[name].registrations = 
            this.eventRegistrations[name].registrations.filter(x => x === handler)
        
        return true
    }
}