import { access, mkdir } from 'node:fs/promises'
import { constants } from 'node:fs'
import { dirname, resolve } from 'node:path'
import { fileURLToPath } from 'node:url'
import { spawn } from 'node:child_process'

const here = dirname(fileURLToPath(import.meta.url))
const harnessRoot = resolve(here, '..')
const projectRoot = resolve(harnessRoot, '..')
const blendFile = resolve(projectRoot, 'blender_prototype', 'sanctification_card_material_prototype.blend')
const pythonScript = resolve(here, 'export_card_mesh.py')
const outputFile = resolve(harnessRoot, 'public', 'reference', 'card-mesh.glb')

const explicit = process.env.BLENDER_EXECUTABLE
const platformCandidates = process.platform === 'win32'
  ? [
      'C:\\Program Files\\Blender Foundation\\Blender 5.2\\blender.exe',
      'C:\\Program Files\\Blender Foundation\\Blender 5.1\\blender.exe',
      'C:\\Program Files\\Blender Foundation\\Blender 5.0\\blender.exe',
    ]
  : [
      '/usr/bin/blender',
      '/usr/local/bin/blender',
      '/snap/bin/blender',
    ]

async function exists(path) {
  try {
    await access(path, constants.X_OK)
    return true
  } catch {
    return false
  }
}

let blender = explicit
if (blender && !(await exists(blender))) {
  throw new Error(`BLENDER_EXECUTABLE does not exist or is not executable: ${blender}`)
}
if (!blender) {
  for (const candidate of platformCandidates) {
    if (await exists(candidate)) {
      blender = candidate
      break
    }
  }
}
if (!blender) blender = 'blender'

await mkdir(dirname(outputFile), { recursive: true })

const args = [
  '--background',
  blendFile,
  '--python',
  pythonScript,
  '--',
  '--output',
  outputFile,
]

console.log(`Exporting card mesh with ${blender}`)
const child = spawn(blender, args, { stdio: 'inherit', shell: false })
const exitCode = await new Promise((resolveExit, reject) => {
  child.once('error', reject)
  child.once('exit', (code) => resolveExit(code ?? 1))
})

if (exitCode !== 0) {
  throw new Error(`Blender export failed with exit code ${exitCode}`)
}

console.log(`Card mesh exported to ${outputFile}`)