bindings-chasm-wasip1

import at.released.weh.bindings.chasm.exception.ProcExitException
import at.released.weh.bindings.chasm.wasip1.ChasmWasiPreview1Builder
import at.released.weh.host.EmbedderHost
import io.github.charlietap.chasm.embedding.instance
import io.github.charlietap.chasm.embedding.invoke
import io.github.charlietap.chasm.embedding.module
import io.github.charlietap.chasm.embedding.shapes.Import
import io.github.charlietap.chasm.embedding.shapes.Store
import io.github.charlietap.chasm.embedding.shapes.flatMap
import io.github.charlietap.chasm.embedding.shapes.fold
import io.github.charlietap.chasm.embedding.store

// Create Host and run code
EmbedderHost {
    fileSystem {
        addPreopenedDirectory(".", "/data")
    }
}.use {
    executeCode(it, wasmBinary)
}

fun executeCode(embedderHost: EmbedderHost, wasmBinary: ByteArray): Int {
    val store: Store = store()

    // Prepare WASI host imports
    val wasiImports: List<Import> = ChasmWasiPreview1Builder(store) {
        host = embedderHost
    }.build()

    // Instantiate the WebAssembly module
    val instance = module(wasmBinary)
        .flatMap { module -> instance(store, module, wasiImports) }
        .fold(
            onSuccess = { it },
            onError = { error("Can node instantiate WebAssembly binary: $it") },
        )

    // Execute code
    try {
        invoke(store, instance, "_start").fold(
            onSuccess = { it },
            onError = { error("main() failed") },
        )
    } catch (pre: ProcExitException) {
        return pre.exitCode
    }
    return 0
}