import ServientWrapper from "./servient-wrapper"

export default class ServientManager {
    private servientWrappers: { [key: string]: ServientWrapper } = {}
    private static instance: ServientManager
    public static getInstance(): ServientManager {
        if (!ServientManager.instance) {
            ServientManager.instance = new ServientManager()
        }
        return ServientManager.instance
    }
    private constructor() {
        console.debug("[debug] ServientManager constructor called.")
    }
    public createServientWrapper(id: string, bindingType: string, params: any): ServientWrapper {
        console.debug("[debug] createServientWrapper. ", id, bindingType, params)
        this.servientWrappers[id] = new ServientWrapper(bindingType, params)
        return this.servientWrappers[id]
    }
    public existServienetWrapper(id: string) {
        if (this.servientWrappers[id]) {
            return true
        }
        return false
    }
    public async removeServientWrapper(id: string) {
        console.debug("[debug] removeServientWrapper. id: " + id)
        await this.endServient(id)
        delete this.servientWrappers[id]
    }

    private async endServient(id: string) {
        return new Promise<void>(async (resolve, reject) => {
            console.debug("[debug] endServient called. id: " + id)
            const servientWrapper = this.servientWrappers[id]
            const timeoutId = setTimeout(() => {
                console.warn("[warn] timeout happend while servient ending. id: " + id)
                resolve()
            }, 10000) // If it does not end after 10 seconds, it is considered to be finished.
            try {
                await servientWrapper.endServient()
                console.debug("[debug] servient ended. id: " + id)
                clearTimeout(timeoutId)
                resolve()
            } catch (err) {
                console.debug("[debug] failed to end servient. id: " + id + " error: " + err.toString())
                clearTimeout(timeoutId)
                reject(err)
            }
        })
    }

    public getThing(id: string, thingName: string) {
        const servientWrapper = this.servientWrappers[id]
        return servientWrapper?.getThing(thingName)
    }
}