import fs from 'node:fs'
import path from 'node:path'
import { spawnSync } from 'node:child_process'
import { fileURLToPath } from 'node:url'

const scriptDirectory = path.dirname(fileURLToPath(import.meta.url))
const pipelineDirectory = path.resolve(scriptDirectory, '..')
const workspace = path.resolve(pipelineDirectory, '..')
const manifestPath = path.join(pipelineDirectory, 'manifests', 'g01-background-candidates.json')
const reportPath = path.join(pipelineDirectory, 'generated', 'g01-background', 'build-report.json')
const manifest = JSON.parse(fs.readFileSync(manifestPath, 'utf8'))

if (manifest.schemaVersion !== 1 || manifest.page !== 'G01' || manifest.candidates?.length !== 4) {
  throw new Error('G01 background manifest must declare exactly four schema v1 candidates')
}

for (const candidate of manifest.candidates) {
  const source = path.resolve(workspace, candidate.master)
  const relative = path.relative(workspace, source)
  if (relative.startsWith('..') || path.isAbsolute(relative)) throw new Error(`${candidate.id} master escapes workspace`)
  if (!fs.existsSync(source)) throw new Error(`${candidate.id} master is missing: ${candidate.master}`)
}

const localPython = path.join(pipelineDirectory, '.venv', 'Scripts', 'python.exe')
const python = process.env.PYTHON || (fs.existsSync(localPython) ? localPython : 'python')
const result = spawnSync(
  python,
  [path.join(scriptDirectory, 'build_g01_backgrounds.py'), manifestPath, '--workspace', workspace, '--report', reportPath],
  { cwd: workspace, encoding: 'utf8', stdio: 'inherit' }
)

if (result.error) throw new Error(`无法启动 Python（${python}）：${result.error.message}`)
if (result.status !== 0) process.exit(result.status ?? 1)