import type { PluginOption } from 'vite'
import * as path from 'path'
import * as fs from 'fs-extra'

export interface ElectronBytecodeOptions {
  entry?: string
  keepSource?: boolean
}

function shouldSkipBytecode(): boolean {
  const flag = String(process.env.SKIP_ELECTRON_BYTECODE ?? '').trim().toLowerCase()
  return flag === '1' || flag === 'true' || flag === 'yes'
}

function resolveElectronExecutable(): string | null {
  try {
    const electronPath = require('electron')
    if (typeof electronPath === 'string' && fs.pathExistsSync(electronPath)) {
      return electronPath
    }
  } catch (error) {
    console.warn('[vite-plugin-electron-encrypt] Skipping bytecode compilation because Electron is unavailable:', error)
    return null
  }

  console.warn('[vite-plugin-electron-encrypt] Skipping bytecode compilation because the Electron executable could not be resolved.')
  return null
}

export default function electronBytecode(options?: ElectronBytecodeOptions): PluginOption {
  return {
    name: 'vite-plugin-electron-encrypt',
    apply: 'build',
    async closeBundle() {
      if (process.env.NODE_ENV !== 'production') return
      if (shouldSkipBytecode()) {
        console.warn('[vite-plugin-electron-encrypt] Skipping bytecode compilation because SKIP_ELECTRON_BYTECODE is enabled.')
        return
      }

      const entryPath = path.resolve(process.cwd(), options?.entry || 'dist-electron/main/main.js');

      if (!fs.pathExistsSync(entryPath)) return

      const electronPath = resolveElectronExecutable()
      if (!electronPath) return

      const outputPath = entryPath.replace(/\.js$/, '.jsc')
      const backupPath = `${entryPath}.bak`
      const tempScriptPath = path.join(path.dirname(entryPath), '_compile.js')
      const { execFileSync } = require('child_process')
      
      fs.copyFileSync(entryPath, backupPath)

      try {
        // We must compile the bytecode using the ELECTRON executable, not the local Node.js.
        // Node.js and Electron use different V8 versions.
        // Run a small script inside Electron to compile the file
        const compileScript = `
          const bytenode = require('bytenode');
          bytenode.compileFile({ filename: ${JSON.stringify(entryPath)}, output: ${JSON.stringify(outputPath)} }).then(() => process.exit(0)).catch(e => { console.error(e); process.exit(1); });
        `;
        fs.writeFileSync(tempScriptPath, compileScript);
        
        execFileSync(electronPath, [tempScriptPath], { env: { ...process.env, ELECTRON_RUN_AS_NODE: '1' } });
      } catch (err) {
        console.error('Failed to compile bytecode with Electron:', err);
        fs.copyFileSync(backupPath, entryPath)
        throw err;
      } finally {
        if (fs.pathExistsSync(tempScriptPath)) {
          fs.unlinkSync(tempScriptPath)
        }
      }

      const stub = [
        "require('bytenode')",
        `require('./${path.basename(outputPath)}')`
      ].join("\n")
      fs.writeFileSync(entryPath, stub)
    }
  }
}