// Build-Protokolle je Projekt: upload-data/preview-logs/<projectId>/<runFile>, maskiert, letzte 5
import crypto from 'node:crypto'
import fs from 'node:fs/promises'
import path from 'node:path'
import { config } from '../config.js'
import { maskLog } from './previewEnv.js'

const KEEP = 5
const MAX_LINES = 300
const PROJECT_RE = /^[A-Za-z0-9][A-Za-z0-9._-]{0,35}$/
const FILE_RE = /^\d{4}-\d{2}-\d{2}T\d{2}-\d{2}-\d{2}-\d{3}Z-[0-9a-f]{6}\.log$/

const projectDir = (projectId) => {
  if (!PROJECT_RE.test(String(projectId || '')) || String(projectId).includes('..')) {
    throw new Error('Ungültige Projekt-ID')
  }
  return path.join(config.previewRunner.logDir, projectId)
}

export async function saveRunLog(projectId, lines, env) {
  const dir = projectDir(projectId)
  await fs.mkdir(dir, { recursive: true })
  const stamp = new Date().toISOString().replace(/[:.]/g, '-')
  const runFile = `${stamp}-${crypto.randomBytes(3).toString('hex')}.log`
  const text = maskLog((Array.isArray(lines) ? lines : []).slice(-MAX_LINES).join('\n'), env)
  await fs.writeFile(path.join(dir, runFile), text + '\n', 'utf8')
  const all = (await fs.readdir(dir)).filter((f) => FILE_RE.test(f)).sort()
  for (const old of all.slice(0, Math.max(0, all.length - KEEP))) {
    await fs.rm(path.join(dir, old), { force: true })
  }
  return runFile
}

export const isRunFile = (name) => FILE_RE.test(String(name || ''))

// Neueste zuerst
export async function listRunLogs(projectId) {
  let files
  try { files = await fs.readdir(projectDir(projectId)) } catch { return [] }
  return files
    .filter((f) => FILE_RE.test(f))
    .sort()
    .reverse()
    .map((runFile) => ({
      runFile,
      at: runFile.slice(0, 24).replace(/^(.{13})-(.{2})-(.{2})-/, '$1:$2:$3.'),
    }))
}

export async function readRunLog(projectId, runFile) {
  if (!FILE_RE.test(String(runFile || ''))) return null
  try {
    return await fs.readFile(path.join(projectDir(projectId), runFile), 'utf8')
  } catch {
    return null
  }
}