import type { SourceRCONCommandRequest } from "../api/types";

const maxChatBytes = 1024;
const maxCommandBytes = 4000;
const steamID64 = /^[0-9]{17}$/;

export interface SourceRCONChatDraft {
  chatType: number;
  message: string;
  targetSteamId?: string;
}

export function sourceRCONChatRequest(serverInstanceId: string, draft: SourceRCONChatDraft, sequence = Date.now()): SourceRCONCommandRequest {
  const message = validateSourceRCONText(draft.message, maxChatBytes, "聊天内容");
  if (!Number.isInteger(draft.chatType) || draft.chatType < 0 || draft.chatType > 7) {
    throw new Error("聊天类型必须在 0 到 7 之间。");
  }
  const targetSteamId = draft.targetSteamId?.trim() ?? "";
  if (targetSteamId && !steamID64.test(targetSteamId)) {
    throw new Error("目标 SteamID64 必须为 17 位数字。");
  }
  return {
    kind: "chat",
    chatType: draft.chatType,
    message,
    targetSteamId: targetSteamId || undefined,
    idempotencyKey: sourceRCONIdempotencyKey("chat", serverInstanceId, sequence)
  };
}

export function sourceRCONRawCommandRequest(serverInstanceId: string, command: string, sequence = Date.now()): SourceRCONCommandRequest {
  return {
    kind: "command",
    command: validateSourceRCONText(command, maxCommandBytes, "原始指令"),
    idempotencyKey: sourceRCONIdempotencyKey("command", serverInstanceId, sequence)
  };
}

function validateSourceRCONText(value: string, maxBytes: number, label: string): string {
  const normalized = value.trim();
  if (!normalized || new TextEncoder().encode(normalized).byteLength > maxBytes || /[\u0000\r\n]/.test(normalized)) {
    throw new Error(`${label}必须是受限的单行文本。`);
  }
  return normalized;
}

function sourceRCONIdempotencyKey(kind: "chat" | "command", serverInstanceId: string, sequence: number): string {
  return `web:source-rcon:${kind}:${serverInstanceId.trim()}:${Math.max(0, Math.floor(sequence))}`;
}