import {
    SpeechSynthesisCmd,
    SpeechSynthesisReg,
    SRV_SPEECH_SYNTHESIS,
} from "../jdom/constants"
import { Packet } from "../jdom/packet"
import { JDRegisterServer } from "../jdom/servers/registerserver"
import { JDServiceServer } from "../jdom/servers/serviceserver"

export class SpeechSynthesisServer extends JDServiceServer {
    readonly enabled: JDRegisterServer<[boolean]>
    readonly pitch: JDRegisterServer<[number]>
    readonly rate: JDRegisterServer<[number]>
    readonly lang: JDRegisterServer<[string]>
    readonly volume: JDRegisterServer<[number]>

    readonly synthesis: SpeechSynthesis

    constructor() {
        super(SRV_SPEECH_SYNTHESIS)

        this.synthesis = typeof self !== "undefined" && window.speechSynthesis

        this.enabled = this.addRegister<[boolean]>(SpeechSynthesisReg.Enabled, [
            !this.synthesis?.paused,
        ])
        this.pitch = this.addRegister<[number]>(SpeechSynthesisReg.Pitch, [1])
        this.rate = this.addRegister<[number]>(SpeechSynthesisReg.Rate, [1])
        this.lang = this.addRegister<[string]>(SpeechSynthesisReg.Lang, [""])
        this.volume = this.addRegister<[number]>(SpeechSynthesisReg.Volume, [
            0.5,
        ])

        this.addCommand(SpeechSynthesisCmd.Speak, this.handleSpeak.bind(this))
        this.addCommand(SpeechSynthesisCmd.Cancel, this.handleCancel.bind(this))
    }

    private handleSpeak(pkt: Packet) {
        const [text] = pkt.jdunpack("s")
        if (!this.synthesis || !text) return

        const [pitch] = this.pitch.values()
        const [rate] = this.pitch.values()
        const [lang] = this.lang.values()
        const [volume] = this.volume.values()

        const utterance = new SpeechSynthesisUtterance(text)
        utterance.pitch = pitch
        utterance.rate = rate
        utterance.lang = lang
        utterance.volume = volume

        this.synthesis.speak(utterance)
    }

    private handleCancel(pkt: Packet) {
        this.synthesis?.cancel()
    }
}