"use strict";

/**
 * Windows 服务器采集器
 *
 * 采集指标：
 *   - cpu_usage      CPU 使用率（%）
 *   - memory_usage   内存使用率（%）
 *   - disk_usage     磁盘使用率（%）
 *   - process_count  进程数
 *   - uptime         运行时间
 *   - service_status 关键服务状态
 *
 * 实现说明：
 *   使用 PowerShell Base64 EncodedCommand 方式执行，与 NetMesh System Manager 一致。
 *   传入 exec 函数执行远程命令（由调度器注入）。
 */

const BaseAdapter = require("./baseAdapter.cjs");

class WindowsServerAdapter extends BaseAdapter {
  constructor(connectionInfo, options = {}) {
    super(connectionInfo, options);
    this.adapterName = "windows_server";
    if (options.execFn) {
      this.execute = options.execFn;
    }
  }

  getSupportedMetrics() {
    return [
      "cpu_usage",
      "memory_usage",
      "disk_usage",
      "process_count",
      "uptime",
      "service_status",
    ];
  }

  async collectMetrics() {
    const metrics = {};
    const raw = {};
    const DEBUG = process.env.INSPECTION_DEBUG === "1";

    // 1. CPU + 内存 + 运行时间（快速，独立执行）
    try {
      const script = this._buildFastStatsScript();
      const cmd = this._buildPowerShellCmd(script);
      if (DEBUG) console.log("[WinAdapter] 执行命令:", cmd);
      raw.stats = await this.execute(cmd);
      if (DEBUG) console.log("[WinAdapter] 原始输出:", raw.stats);
      const parsed = this._parseStats(raw.stats);
      if (DEBUG) console.log("[WinAdapter] 解析结果:", parsed);
      Object.assign(metrics, parsed);
    } catch (e) {
      raw.stats_error = e.message;
      if (DEBUG) console.error("[WinAdapter] 采集失败:", e.message);
    }

    // 2. 磁盘使用率（较慢，单独执行，超时放宽到 30s）
    try {
      const diskScript = this._buildDiskScript();
      const diskCmd = this._buildPowerShellCmd(diskScript);
      if (DEBUG) console.log("[WinAdapter] 磁盘命令:", diskCmd);
      raw.disk = await this.execute(diskCmd);
      if (DEBUG) console.log("[WinAdapter] 磁盘原始输出:", raw.disk);
      metrics.disk_usage = this._parseDisk(raw.disk);
    } catch (e) {
      raw.disk_error = e.message;
      if (DEBUG) console.error("[WinAdapter] 磁盘采集失败:", e.message);
    }

    // 3. 关键服务状态
    try {
      const serviceScript = this._buildServiceScript();
      const cmd = this._buildPowerShellCmd(serviceScript);
      if (DEBUG) console.log("[WinAdapter] 服务命令:", cmd);
      raw.services = await this.execute(cmd);
      if (DEBUG) console.log("[WinAdapter] 服务原始输出:", raw.services);
      metrics.service_status = this._parseServices(raw.services);
    } catch (e) {
      metrics.service_status = [];
      raw.services_error = e.message;
      if (DEBUG) console.error("[WinAdapter] 服务采集失败:", e.message);
    }

    return metrics;
  }

  /**
   * 快速统计：CPU + 内存（使用更快的 WMI 查询）
   */
  _buildFastStatsScript() {
    return `
try { $cpu = (Get-WmiObject Win32_Processor).LoadPercentage; if (-not $cpu) { $cpu = 0 } } catch { $cpu = 0 }
try { $os = Get-WmiObject Win32_OperatingSystem; $total = [math]::Round($os.TotalVisibleMemorySize/1MB,0); $free = [math]::Round($os.FreePhysicalMemory/1MB,0); $usage = if ($total -gt 0) { [math]::Round(($total-$free)/$total*100,1) } else { 0 } } catch { $total = 0; $usage = 0; $free = 0 }
@{ cpu = $cpu; mem_usage = $usage; mem_total = $total; mem_free = $free } | ConvertTo-Json -Compress
`.trim();
  }

  /** 磁盘使用率（只查 C: 盘） */
  _buildDiskScript() {
    return `
try {
  $disk = Get-WmiObject Win32_LogicalDisk -Filter "DeviceID='C:'"
  if ($disk -and $disk.Size -gt 0) {
    $s = [math]::Round($disk.Size/1GB,1); $f = [math]::Round($disk.FreeSpace/1GB,1); $u = [math]::Round(($disk.Size-$disk.FreeSpace)/$disk.Size*100,1)
    @{ d='C:'; s=$s; f=$f; u=$u } | ConvertTo-Json -Compress
  } else { 'null' }
} catch { 'null' }
`.trim();
  }

  _parseDisk(stdout) {
    try {
      const json = this._extractJson(stdout);
      if (!json || json === "null" || json === null) return [];
      return [{
        drive: json.d || "C:",
        size_gb: json.s || 0,
        free_gb: json.f || 0,
        usage_percent: json.u || 0,
      }];
    } catch {
      return [];
    }
  }

  /**
   * 构建 PowerShell 命令：UTF-16LE Base64 编码 + -EncodedCommand
   * Node.js Buffer.from(str, "utf16le") 是最可靠的编码方式
   */
  _buildPowerShellCmd(script) {
    // 用 Node.js 原生 Buffer 进行 UTF-16LE 编码，再转 Base64
    // UTF-16LE 编码（不带 BOM），然后 Base64
    const utf16le = Buffer.from(script, "utf16le");
    const encoded = utf16le.toString("base64");
    return `powershell -NoProfile -NonInteractive -EncodedCommand ${encoded}`;
  }

  _buildServiceScript() {
    return `
$ErrorActionPreference = 'SilentlyContinue'

# 关键服务
$services = @(
  "wuauserv",     # Windows Update
  "Spooler",      # Print Spooler
  "TermService",  # Remote Desktop
  "DHCP",         # DHCP Client
  "DNScache"      # DNS Client
)

$results = foreach ($svc in $services) {
  $s = Get-Service -Name $svc -ErrorAction SilentlyContinue
  if ($s) {
    [PSCustomObject]@{
      name = $s.Name
      display_name = $s.DisplayName
      status = $s.Status.ToString()
      start_type = $s.StartType.ToString()
    }
  }
}

$results | ConvertTo-Json -Depth 3
`.trim();
  }

  _parseStats(stdout) {
    try {
      const json = this._extractJson(stdout);
      if (!json) return {};

      const result = {};
      if (json.cpu !== undefined) result.cpu_usage = json.cpu;
      if (json.mem_usage !== undefined) result.memory_usage = json.mem_usage;
      if (json.mem_total !== undefined && json.mem_total > 0) {
        result.memory = {
          total_mb: json.mem_total,
          used_mb: Math.round((json.mem_usage / 100) * json.mem_total),
        };
      }

      return result;
    } catch (e) {
      return {};
    }
  }

  _parseServices(stdout) {
    try {
      const json = this._extractJson(stdout);
      if (!json) return [];
      return Array.isArray(json) ? json : [json];
    } catch (e) {
      return [];
    }
  }

  /**
   * 从 PowerShell 输出中提取 JSON（可能有多余的警告/文本）
   */
  _extractJson(text) {
    if (!text) return null;
    const start = text.indexOf("{");
    const startArr = text.indexOf("[");
    const realStart = startArr === -1 ? start : (start === -1 ? startArr : Math.min(start, startArr));
    if (realStart === -1) return null;

    let depth = 0;
    let end = -1;
    const open = text[realStart];
    const close = open === "{" ? "}" : "]";

    for (let i = realStart; i < text.length; i++) {
      if (text[i] === open) depth++;
      else if (text[i] === close) {
        depth--;
        if (depth === 0) {
          end = i;
          break;
        }
      }
    }

    if (end === -1) return null;
    try {
      return JSON.parse(text.substring(realStart, end + 1));
    } catch (e) {
      return null;
    }
  }
}

module.exports = WindowsServerAdapter;