// Virtual address / IP pressure system.
// Lets a connection claim a human-friendly alias (short code, number, IP-style address).

export class IPPressure {
    constructor(mwse) {
        this.mwse        = mwse;
        this.APNumber    = undefined;
        this.APShortCode = undefined;
        this.APIPAddress = undefined;
    }

    async allocAPIPAddress() {
        const { status, ip } = await this.mwse.EventPooling.request({ type: 'alloc/APIPAddress' });
        if (status === 'success') { this.APIPAddress = ip; return ip; }
        throw new Error('Error allocating virtual IP address');
    }

    async allocAPNumber() {
        const { status, number } = await this.mwse.EventPooling.request({ type: 'alloc/APNumber' });
        if (status === 'success') { this.APNumber = number; return number; }
        throw new Error('Error allocating virtual number');
    }

    async allocAPShortCode() {
        const { status, code } = await this.mwse.EventPooling.request({ type: 'alloc/APShortCode' });
        if (status === 'success') { this.APShortCode = code; return code; }
        throw new Error('Error allocating virtual short code');
    }

    async reallocAPIPAddress() {
        const { status, ip } = await this.mwse.EventPooling.request({ type: 'realloc/APIPAddress' });
        if (status === 'success') { this.APIPAddress = ip; return ip; }
        throw new Error('Error reallocating virtual IP address');
    }

    async reallocAPNumber() {
        const { status, number } = await this.mwse.EventPooling.request({ type: 'realloc/APNumber' });
        if (status === 'success') { this.APNumber = number; return number; }
        throw new Error('Error reallocating virtual number');
    }

    async reallocAPShortCode() {
        const { status, code } = await this.mwse.EventPooling.request({ type: 'realloc/APShortCode' });
        if (status === 'success') { this.APShortCode = code; return code; }
        throw new Error('Error reallocating virtual short code');
    }

    async releaseAPIPAddress() {
        const { status } = await this.mwse.EventPooling.request({ type: 'release/APIPAddress' });
        if (status === 'success') { this.APIPAddress = undefined; return; }
        throw new Error('Error releasing virtual IP address');
    }

    async releaseAPNumber() {
        const { status } = await this.mwse.EventPooling.request({ type: 'release/APNumber' });
        if (status === 'success') { this.APNumber = undefined; return; }
        throw new Error('Error releasing virtual number');
    }

    async releaseAPShortCode() {
        const { status } = await this.mwse.EventPooling.request({ type: 'release/APShortCode' });
        if (status === 'success') { this.APShortCode = undefined; return; }
        throw new Error('Error releasing virtual short code');
    }

    async queryAPIPAddress(ip) {
        const { status, socket } = await this.mwse.EventPooling.request({
            type: 'whois/APIPAddress', whois: ip
        });
        return status === 'success' ? socket : null;
    }

    async queryAPNumber(number) {
        const { status, socket } = await this.mwse.EventPooling.request({
            type: 'whois/APNumber', whois: number
        });
        return status === 'success' ? socket : null;
    }

    async queryAPShortCode(code) {
        const { status, socket } = await this.mwse.EventPooling.request({
            type: 'whois/APShortCode', whois: code
        });
        return status === 'success' ? socket : null;
    }

    // ---- Sub-network (#40) -----------------------------------------------

    // Claim a /24 virtual sub-network (10.A.B.0/24).
    // The caller becomes the subnet owner. Members can then call allocSubNetIP().
    async allocSubNet() {
        const { status, prefix } = await this.mwse.EventPooling.request({ type: 'alloc/APSubNet' });
        if (status === 'success') { this.APSubNet = prefix; return prefix; }
        throw new Error('Error allocating sub-network');
    }

    async releaseSubNet() {
        const { status } = await this.mwse.EventPooling.request({ type: 'release/APSubNet' });
        if (status === 'success') { this.APSubNet = undefined; this.APSubNetIP = undefined; return; }
        throw new Error('Error releasing sub-network');
    }

    // Allocate a host IP within an existing subnet.
    // prefix: the "10.A.B" string returned by allocSubNet().
    async allocSubNetIP(prefix) {
        const { status, ip } = await this.mwse.EventPooling.request({
            type: 'alloc/APSubNetIP', prefix
        });
        if (status === 'success') { this.APSubNetIP = ip; return ip; }
        throw new Error('Error allocating sub-network IP');
    }

    async releaseSubNetIP() {
        const { status } = await this.mwse.EventPooling.request({ type: 'release/APSubNetIP' });
        if (status === 'success') { this.APSubNetIP = undefined; return; }
        throw new Error('Error releasing sub-network IP');
    }

    // Look up which socket holds a given IP within a subnet.
    async querySubNetIP(prefix, ip) {
        const { status, socket } = await this.mwse.EventPooling.request({
            type: 'whois/APSubNetIP', prefix, whois: ip
        });
        return status === 'success' ? socket : null;
    }
}