/**
 * Audit logic: hot paths (filesystem, processes, drives, system, network, env) → Python FastAPI.
 * Windows-specific shell/registry work stays in Node.
 */
import * as path from 'node:path'
import * as os from 'node:os'
import { execFile, execFileSync, spawn } from 'node:child_process'
import { promisify } from 'node:util'
import { pyGet, pyPost } from './pythonBackend'

const execFileAsync = promisify(execFile)

export interface DriveInfo {
  letter: string
  mount: string
  label: string
  totalBytes: number
  freeBytes: number
  usedBytes: number
}

export interface DirEntry {
  name: string
  fullPath: string
  isDirectory: boolean
  sizeBytes: number
  mtimeMs: number
  error?: string
  sizeTruncated?: boolean
}

export interface ProcessRow {
  pid: number
  name: string
  memoryBytes: number
  cpuSeconds?: number
  commandLine?: string
}

export interface ServiceRow {
  name: string
  displayName: string
  state: string
  startType: string
}

export interface InstalledApp {
  name: string
  version: string
  publisher: string
  installLocation: string
  uninstallString: string
  estimatedSizeKb: number
}

export interface NetworkRow {
  name: string
  address: string
  family: string
  internal: boolean
  mac?: string
}

function resolveSafePath(input: string): string {
  const normalized = path.normalize(input)
  return path.resolve(normalized)
}

export async function getDrivesWin(): Promise<DriveInfo[]> {
  return pyGet<DriveInfo[]>('/api/drives')
}

export async function listDirectory(
  dirPath: string,
  options: { maxEntries?: number } = {}
): Promise<DirEntry[]> {
  const root = resolveSafePath(dirPath)
  return pyPost<DirEntry[]>('/api/list_dir', {
    path: root,
    max_entries: options.maxEntries ?? 800,
  })
}

export async function computeFolderSize(dirPath: string): Promise<{ bytes: number; files: number; truncated: boolean }> {
  return pyPost<{ bytes: number; files: number; truncated: boolean }>('/api/folder_size', {
    path: resolveSafePath(dirPath),
  })
}

export async function findLargeFiles(
  rootPath: string,
  minBytes: number,
  maxResults: number
): Promise<{ path: string; sizeBytes: number }[]> {
  return pyPost<{ path: string; sizeBytes: number }[]>('/api/large_files', {
    path: resolveSafePath(rootPath),
    min_bytes: minBytes,
    max_results: maxResults,
  })
}

export async function getProcessesWin(): Promise<ProcessRow[]> {
  return pyGet<ProcessRow[]>('/api/processes')
}

export async function getServicesWin(): Promise<ServiceRow[]> {
  const script = `
    Get-CimInstance Win32_Service | Select-Object Name,DisplayName,State,StartMode | ConvertTo-Json -Compress
  `
  try {
    const { stdout } = await execFileAsync(
      'powershell.exe',
      ['-NoProfile', '-NonInteractive', '-Command', script],
      { windowsHide: true, maxBuffer: 20 * 1024 * 1024, timeout: 120_000 }
    )
    const raw = JSON.parse(stdout.trim() || '[]')
    const arr = Array.isArray(raw) ? raw : [raw]
    return arr.map((s: Record<string, unknown>) => ({
      name: String(s.Name ?? ''),
      displayName: String(s.DisplayName ?? ''),
      state: String(s.State ?? ''),
      startType: String(s.StartMode ?? ''),
    }))
  } catch {
    return []
  }
}

export function getInstalledPrograms(): InstalledApp[] {
  const script = `
    $paths = @(
      'HKLM:\\Software\\Microsoft\\Windows\\CurrentVersion\\Uninstall\\*',
      'HKLM:\\Software\\WOW6432Node\\Microsoft\\Windows\\CurrentVersion\\Uninstall\\*',
      'HKCU:\\Software\\Microsoft\\Windows\\CurrentVersion\\Uninstall\\*'
    )
    Get-ItemProperty $paths -ErrorAction SilentlyContinue |
      Where-Object { $_.DisplayName } |
      Select-Object DisplayName, DisplayVersion, Publisher, InstallLocation, UninstallString, EstimatedSize |
      ConvertTo-Json -Compress -Depth 4
  `
  try {
    const stdout = execFileSync(
      'powershell.exe',
      ['-NoProfile', '-NonInteractive', '-Command', script],
      { encoding: 'utf8', windowsHide: true, maxBuffer: 50 * 1024 * 1024 }
    )
    const raw = JSON.parse(stdout.trim() || '[]')
    const arr = Array.isArray(raw) ? raw : [raw]
    const apps: InstalledApp[] = arr.map((r: Record<string, unknown>) => ({
      name: String(r.DisplayName ?? ''),
      version: String(r.DisplayVersion ?? ''),
      publisher: String(r.Publisher ?? ''),
      installLocation: String(r.InstallLocation ?? ''),
      uninstallString: String(r.UninstallString ?? ''),
      estimatedSizeKb: Number(r.EstimatedSize) || 0,
    }))
    const seen = new Set<string>()
    return apps
      .filter((a) => {
        const k = a.name.toLowerCase()
        if (!k || seen.has(k)) return false
        seen.add(k)
        return true
      })
      .sort((a, b) => a.name.localeCompare(b.name))
  } catch {
    return []
  }
}

export async function getSystemSnapshot() {
  return pyGet<{
    hostname: string
    platform: string
    release: string
    arch: string
    uptimeSec: number
    totalMem: number
    freeMem: number
    cpuModel: string
    cpuCount: number
    load1: number
    load5: number
    load15: number
    userInfo: string
    homedir: string
    tmpdir: string
  }>('/api/system')
}

export async function getNetworkInterfaces(): Promise<NetworkRow[]> {
  return pyGet<NetworkRow[]>('/api/network')
}

export async function getEnvSnapshot(keys?: string[]): Promise<Record<string, string>> {
  const all = await pyGet<Record<string, string>>('/api/env')
  if (!keys?.length) return all
  const out: Record<string, string> = {}
  for (const k of keys) {
    const v = all[k]
    if (v !== undefined) out[k] = v
  }
  return out
}

export async function getStartupFolders(): Promise<{ path: string; entries: DirEntry[] }[]> {
  const appData = process.env.APPDATA ?? path.join(os.homedir(), 'AppData', 'Roaming')
  const programData = process.env.PROGRAMDATA ?? 'C:\\ProgramData'
  const folders = [
    path.join(appData, 'Microsoft', 'Windows', 'Start Menu', 'Programs', 'Startup'),
    path.join(programData, 'Microsoft', 'Windows', 'Start Menu', 'Programs', 'StartUp'),
  ]
  const result: { path: string; entries: DirEntry[] }[] = []
  for (const f of folders) {
    const entries = await listDirectory(f, { maxEntries: 200 })
    result.push({ path: f, entries })
  }
  return result
}

export async function getTempAudit(): Promise<{ path: string; bytes: number; files: number; truncated: boolean }[]> {
  const dirs = [os.tmpdir(), path.join(os.tmpdir(), '..', 'Temp')].map((p) => path.normalize(p))
  const uniq = [...new Set(dirs)]
  const out: { path: string; bytes: number; files: number; truncated: boolean }[] = []
  for (const d of uniq) {
    try {
      const r = await computeFolderSize(d)
      out.push({ path: d, ...r })
    } catch {
      out.push({ path: d, bytes: 0, files: 0, truncated: false })
    }
  }
  return out
}

export async function getScheduledTasksSummary(): Promise<{ name: string; state: string }[]> {
  const script = `
    Get-ScheduledTask | Select-Object TaskName,State | ConvertTo-Json -Compress
  `
  try {
    const { stdout } = await execFileAsync(
      'powershell.exe',
      ['-NoProfile', '-NonInteractive', '-Command', script],
      { windowsHide: true, maxBuffer: 20 * 1024 * 1024, timeout: 120_000 }
    )
    const raw = JSON.parse(stdout.trim() || '[]')
    const arr = Array.isArray(raw) ? raw : [raw]
    return arr.map((t: Record<string, unknown>) => ({
      name: String(t.TaskName ?? ''),
      state: String(t.State ?? ''),
    }))
  } catch {
    return []
  }
}

export async function openPathInExplorer(p: string): Promise<void> {
  const resolved = resolveSafePath(p)
  await execFileAsync('explorer.exe', [resolved], { windowsHide: true })
}

export function killProcess(pid: number): Promise<void> {
  return new Promise((resolve, reject) => {
    const proc = spawn('taskkill', ['/PID', String(pid), '/F'], { windowsHide: true })
    proc.on('close', (code) => (code === 0 ? resolve() : reject(new Error(`taskkill exit ${code}`))))
    proc.on('error', reject)
  })
}

export async function getWindowsFeaturesSnippet(): Promise<string> {
  try {
    const { stdout } = await execFileAsync(
      'dism.exe',
      ['/Online', '/Get-Features', '/Format:Table'],
      { windowsHide: true, maxBuffer: 5 * 1024 * 1024, timeout: 60_000 }
    )
    return stdout.slice(0, 120_000)
  } catch (e) {
    return String((e as Error).message)
  }
}