import { SettingsCmd, SettingsEvent, SRV_SETTINGS } from "../jdom/constants"
import { jdpack } from "../jdom/pack"
import { Packet } from "../jdom/packet"
import { OutPipe } from "../jdom/pipes"
import { JDServiceServer } from "../jdom/servers/serviceserver"
import { Setting } from "../jdom/setting"
import { fromHex, toHex } from "../jdom/utils"

export class SettingsServer extends JDServiceServer {
    private settings: Record<string, string>

    constructor(readonly store?: Setting) {
        super(SRV_SETTINGS)

        this.addCommand(SettingsCmd.Get, this.handleGet.bind(this))
        this.addCommand(SettingsCmd.Set, this.handleSet.bind(this))
        this.addCommand(SettingsCmd.Delete, this.handleDelete.bind(this))
        this.addCommand(SettingsCmd.ListKeys, this.handleListKeys.bind(this))
        this.addCommand(SettingsCmd.List, this.handleList.bind(this))
        this.addCommand(SettingsCmd.Clear, this.handleClear.bind(this))

        this.settings = this.read()
    }

    private getPayload(key: string) {
        const value = this.settings[key]
        const secret = /^$/.test(key)

        let payload: Uint8Array
        if (value === undefined) {
            payload = new Uint8Array(0)
        } else if (secret) {
            const payload = new Uint8Array(1)
            payload[0] = 0
        } else {
            payload = fromHex(value)
        }

        return payload
    }

    private async handleGet(pkt: Packet) {
        const [key] = pkt.jdunpack<[string]>("s")
        const payload = this.getPayload(key)
        const resp = Packet.jdpacked<[string, Uint8Array]>(
            SettingsCmd.Get,
            "z b",
            [key, payload],
        )
        await this.sendPacketAsync(resp)
    }

    private async handleSet(pkt: Packet) {
        const [key, value] = pkt.jdunpack<[string, Uint8Array]>("z b")
        this.settings[key] = toHex(value)
        await this.save()
    }

    private async handleDelete(pkt: Packet) {
        const [key] = pkt.jdunpack<[string]>("s")
        delete this.settings[key]
        await this.save()
    }

    private async handleListKeys(pkt: Packet) {
        const pipe = OutPipe.from(this.device.bus, pkt, true)
        await pipe.respondForEach(Object.keys(this.settings), k =>
            jdpack<[string]>("s", [k]),
        )
    }

    private async handleList(pkt: Packet) {
        const pipe = OutPipe.from(this.device.bus, pkt, true)
        await pipe.respondForEach(Object.keys(this.settings), k => {
            const payload = this.getPayload(k)
            return jdpack<[string, Uint8Array]>("z b", [k, payload])
        })
    }

    private handleClear() {
        this.settings = {}
        this.save()
    }

    private read(): Record<string, string> {
        if (!this.store) return {}

        try {
            return JSON.parse(this.store.get() || "{}")
        } catch (e) {
            console.debug(e)
            return {}
        }
    }

    private async save() {
        this.store?.set(JSON.stringify(this.settings))
        await this.sendEvent(SettingsEvent.Change)
    }
}