import { access, readFile } from 'node:fs/promises'
import { createHash } from 'node:crypto'
import { resolve, isAbsolute } from 'node:path'

const root = resolve(new URL('..', import.meta.url).pathname)
const sdkRoot = process.env.FREECAD_WASM_SDK_DIR ? resolve(root, process.env.FREECAD_WASM_SDK_DIR) : ''
const required = (value, name) => {
  if (typeof value !== 'string' || !value.trim()) throw new Error(`FreeCAD WASM SDK manifest requires ${name}.`)
  return value.trim()
}
const exists = async (path) => access(path).then(() => true).catch(() => false)
const sha256 = async (path) => createHash('sha256').update(await readFile(path)).digest('hex')
const fail = (message) => { throw new Error(`FreeCAD WASM naming SDK: ${message}`) }

if (!sdkRoot) {
  console.log(JSON.stringify({ status: 'sdk-not-configured', availability: 'unavailable', systemExact: false, reason: 'FREECAD_WASM_SDK_DIR is not configured; the shipped Worker remains OCCT-only.' }, null, 2))
  process.exit(0)
}

const manifestPath = resolve(sdkRoot, 'manifest.json')
if (!await exists(manifestPath)) fail(`missing manifest: ${manifestPath}`)
let manifest
try { manifest = JSON.parse(await readFile(manifestPath, 'utf8')) } catch (error) { fail(`manifest is not valid JSON: ${error instanceof Error ? error.message : String(error)}`) }
if (manifest.schemaVersion !== 1) fail(`unsupported manifest schema ${String(manifest.schemaVersion)}.`)
if (required(manifest.freecadVersion, 'freecadVersion') !== '1.1.1') fail('freecadVersion must be 1.1.1.')
if (required(manifest.sourceCommit, 'sourceCommit') !== '0108fd4b4850cc46e625b60e53cea7a7bbe69f8d') fail('sourceCommit is not the locked FreeCAD commit.')
if (required(manifest.emscriptenVersion, 'emscriptenVersion') !== '3.1.69') fail('emscriptenVersion must be 3.1.69.')
if (required(manifest.qtTarget, 'qtTarget') !== 'wasm32-emscripten' || required(manifest.pythonTarget, 'pythonTarget') !== 'wasm32-emscripten') fail('Qt and Python must both be wasm32-emscripten targets.')
const includeDirs = Array.isArray(manifest.includeDirs) ? manifest.includeDirs : fail('includeDirs must be an array.')
const resolvedIncludeDirs = includeDirs.map((includeDir) => isAbsolute(includeDir) ? includeDir : resolve(sdkRoot, includeDir))
const libraries = Array.isArray(manifest.libraries) ? manifest.libraries : fail('libraries must be an array.')
const libraryNames = new Set(libraries.map((library) => library?.name))
for (const name of ['FreeCADBase', 'FreeCADApp', 'Part', 'QtCore', 'Python']) if (!libraryNames.has(name)) fail(`libraries must include ${name}.`)
const namingBridge = manifest.namingBridge && typeof manifest.namingBridge === 'object' ? manifest.namingBridge : fail('namingBridge is required.')
const bridgePath = required(namingBridge.source, 'namingBridge.source')
const bridge = isAbsolute(bridgePath) ? bridgePath : resolve(sdkRoot, bridgePath)
if (!await exists(bridge)) fail(`missing naming bridge source: ${bridge}`)
if (!Array.isArray(namingBridge.exports) || !['freecadNamingAbiVersion', 'freecadNamingCapabilitiesJson', 'freecadNamingEvidenceJson'].every((name) => namingBridge.exports.includes(name))) fail('namingBridge.exports must declare all three versioned ABI callbacks.')
for (const path of resolvedIncludeDirs) {
  if (!await exists(path)) fail(`missing include directory: ${path}`)
}
for (const library of libraries) {
  if (!library || typeof library !== 'object') fail('libraries entries must be objects.')
  const name = required(library.name, 'libraries[].name')
  const pathValue = required(library.path, `libraries[${name}].path`)
  const path = isAbsolute(pathValue) ? pathValue : resolve(sdkRoot, pathValue)
  if (!path.endsWith('.a')) fail(`library ${name} must be a static .a archive.`)
  if (!await exists(path)) fail(`missing static library ${name}: ${path}`)
  if ((await readFile(path)).byteLength === 0) fail(`static library ${name} is empty.`)
  if (typeof library.sha256 !== 'string' || !/^[a-f0-9]{64}$/.test(library.sha256)) fail(`library ${name} requires a lowercase SHA-256.`)
  const actualHash = await sha256(path)
  if (actualHash !== library.sha256) fail(`library ${name} hash mismatch: expected ${library.sha256}, got ${actualHash}.`)
}
for (const header of ['App/StringHasher.h', 'App/MappedName.h', 'App/ElementMap.h']) {
  if (!(await Promise.all(resolvedIncludeDirs.map((includeDir) => exists(resolve(includeDir, header))))).some(Boolean)) fail(`missing locked FreeCAD private header in includeDirs: ${header}`)
}
const bridgeSha = await sha256(bridge)
if (typeof namingBridge.sha256 !== 'string' || !/^[a-f0-9]{64}$/.test(namingBridge.sha256)) fail('namingBridge.sha256 requires a lowercase SHA-256.')
if (namingBridge.sha256 !== bridgeSha) fail(`naming bridge hash mismatch: expected ${namingBridge.sha256}, got ${bridgeSha}.`)
console.log(JSON.stringify({ status: 'sdk-ready', availability: 'available', systemExact: false, sdkRoot, freecadVersion: manifest.freecadVersion, sourceCommit: manifest.sourceCommit, emscriptenVersion: manifest.emscriptenVersion, includeDirs, libraries: libraries.map(({ name, path, sha256 }) => ({ name, path, sha256 })), namingBridge: { source: bridgePath, sha256: bridgeSha, exports: [...namingBridge.exports] } }, null, 2))