import { spawnSync } from 'child_process'
import { existsSync, readFileSync } from 'fs'
import type { OutputChunk, RolldownPlugin } from 'rolldown'

export default function hermesCPlugin({
    after,
    before,
    flags,
}: {
    flags?: string[]
    before?: (v: string) => void
    after?: (v: string) => void
} = {}): RolldownPlugin {
    const paths = {
        win32: 'win64-bin/hermesc.exe',
        darwin: 'osx-bin/hermesc',
        linux: 'linux64-bin/hermesc',
    }

    if (!(process.platform in paths))
        throw new Error(`Unsupported platform: ${process.platform}`)

    const sdksDir = './node_modules/hermes-compiler/hermesc'
    const binPath = `${sdksDir}/${paths[process.platform as keyof typeof paths]}`

    if (!existsSync(binPath))
        throw new Error(
            `Hermes compiler not found at ${binPath}. Please ensure you have react-native installed.`,
        )

    const ver = JSON.parse(
        readFileSync(`${sdksDir}/../package.json`).toString(),
    ).version

    return {
        name: 'hermesc',
        generateBundle(_, bundle) {
            if (before) before(ver)

            const file = bundle['revenge.js'] as OutputChunk
            if (!file) throw new Error('No code to compile')

            const argList = ['-emit-binary', ...(flags ?? [])]

            const cmd =
                // TODO: Move away from Bun: https://github.com/oven-sh/bun/issues/25498
                typeof Bun !== 'undefined'
                    ? (() => {
                          const cmd = Bun.spawnSync([binPath, ...argList], {
                              // @ts-expect-error: Works but types are incorrect
                              stdio: [new Blob([file.code]), 'pipe'],
                          })

                          return {
                              status: cmd.exitCode,
                              stdout: cmd.stdout,
                              stderr: cmd.stderr,
                          }
                      })()
                    : spawnSync(binPath, argList, {
                          stdio: ['pipe', 'pipe'],
                          input: file.code,
                      })

            if (cmd.status !== 0) {
                if (cmd.stderr.length)
                    throw new Error(
                        `Got error from hermesc: ${cmd.stderr.toString()}`,
                    )
                else throw new Error(`hermesc exited with code: ${cmd.status}`)
            }

            const buf = cmd.stdout
            if (!buf.length)
                throw new Error(
                    `No output from hermesc. Probably a compilation error.\nTry running the command manually: ${binPath} ${argList.join(' ')}`,
                )

            this.emitFile({
                type: 'asset',
                fileName: `${file.fileName.split('.')[0]!}.bundle`,
                source: buf,
            })

            if (after) after(ver)
        },
    }
}