import {performance} from 'node:perf_hooks';
import type {Bot} from '@wp2508/mineflayer';
import {metadata, ResourceInfo} from '../resource_metrics.ts';

export interface NetworkInfo {
    available: boolean;
    received_bytes: number;
    sent_bytes: number;
    received_bytes_per_second: number | null;
    sent_bytes_per_second: number | null;
    interval_ms: number;
}

/** Totals include the first observed counters of every new socket. Unobserved old-socket tails are unknowable. */
export class NetworkCounter {
    private socket: object | undefined;
    private read = 0;
    private written = 0;
    private time: number | undefined;
    private received = 0;
    private sent = 0;
    sample(socket: {bytesRead?: number; bytesWritten?: number} | undefined, now: number): NetworkInfo {
        const read = socket?.bytesRead;
        const written = socket?.bytesWritten;
        const available = typeof read === 'number' && Number.isFinite(read) && read >= 0
            && typeof written === 'number' && Number.isFinite(written) && written >= 0;
        const elapsed = this.time === undefined ? 0 : now - this.time;
        const continuous = available && socket === this.socket && this.time !== undefined
            && read >= this.read && written >= this.written && elapsed > 0;
        const dr = available ? (socket === this.socket && read >= this.read ? read - this.read : read) : 0;
        const dw = available ? (socket === this.socket && written >= this.written ? written - this.written : written) : 0;
        this.received += dr;
        this.sent += dw;
        if (available) {
            this.socket = socket;
            this.read = read;
            this.written = written;
        }
        this.time = available ? now : undefined;
        return {available, received_bytes: this.received, sent_bytes: this.sent,
            received_bytes_per_second: continuous ? dr * 1000 / elapsed : null,
            sent_bytes_per_second: continuous ? dw * 1000 / elapsed : null, interval_ms: continuous ? elapsed : 0};
    }
}

export class init extends ResourceInfo<NetworkInfo> {
    readonly name = 'used_network';
    readonly i18n = metadata('机器人网络流量', '读取传输层套接字的字节计数，包含协议开销；'
        + '更换套接字后保留累计观察量，不包含旧套接字被替换前未观察到的尾部流量。', {
        available: ['计数是否可用', '套接字是否同时提供有效的接收和发送字节计数'],
        received_bytes: ['累计接收量', '累计观察到的接收流量，单位为字节'],
        sent_bytes: ['累计发送量', '累计观察到的发送流量，单位为字节'],
        received_bytes_per_second: ['接收速率', '接收流量速率，单位为字节每秒；缺少连续采样基线时为 null'],
        sent_bytes_per_second: ['发送速率', '发送流量速率，单位为字节每秒；缺少连续采样基线时为 null'],
        interval_ms: ['速率采样间隔', '通过单调时钟测得的实际速率采样间隔，单位为毫秒；缺少连续采样基线时为 0'],
    });
    constructor(bot: Bot) {
        const counter = new NetworkCounter();
        super(counter.sample(bot._client?.socket, performance.now()));
        this.start(1000, () => { this.publish(counter.sample(bot._client?.socket, performance.now())); });
    }
}