// wasmCompilation.js
// Created by Ada <ada@thingvellir.net> on 2026-03-28
// SPDX-License-Identifier: Apache-2.0
"use strict";

/*
(module
  (import "host" "memory" (memory 1))
  (import "host" "log" (func $log (param i32 i32)))

  (data (i32.const 0) "Hello, world!")

  (func (export "logTest")
        (call $log (i32.const 0) (i32.const 13)))

  (func (export "square") (param $n i32) (result i32)
        (i32.mul (local.get $n) (local.get $n))))
*/
const moduleData = Uint8Array.from([
    0x00, 0x61, 0x73, 0x6D, 0x01, 0x00, 0x00, 0x00,
    0x01, 0x0E, 0x03, 0x60, 0x02, 0x7F, 0x7F, 0x00,
    0x60, 0x00, 0x00, 0x60, 0x01, 0x7F, 0x01, 0x7F,
    0x02, 0x1B, 0x02, 0x04, 0x68, 0x6F, 0x73, 0x74,
    0x06, 0x6D, 0x65, 0x6D, 0x6F, 0x72, 0x79, 0x02,
    0x00, 0x01, 0x04, 0x68, 0x6F, 0x73, 0x74, 0x03,
    0x6C, 0x6F, 0x67, 0x00, 0x00, 0x03, 0x03, 0x02,
    0x01, 0x02, 0x07, 0x14, 0x02, 0x07, 0x6C, 0x6F,
    0x67, 0x54, 0x65, 0x73, 0x74, 0x00, 0x01, 0x06,
    0x73, 0x71, 0x75, 0x61, 0x72, 0x65, 0x00, 0x02,
    0x0A, 0x12, 0x02, 0x08, 0x00, 0x41, 0x00, 0x41,
    0x0D, 0x10, 0x00, 0x0B, 0x07, 0x00, 0x20, 0x00,
    0x20, 0x00, 0x6C, 0x0B, 0x0B, 0x13, 0x01, 0x00,
    0x41, 0x00, 0x0B, 0x0D, 0x48, 0x65, 0x6C, 0x6C,
    0x6F, 0x2C, 0x20, 0x77, 0x6F, 0x72, 0x6C, 0x64,
    0x21,
]);

let memory = new WebAssembly.Memory({ initial: 1 });

console.debug("WebAssembly.instantiate");

WebAssembly.instantiate(moduleData, {
    host: {
        memory,
        log: (ptr, length) => {
            // NOTE: We don't have an equivalent to the Web's TextDecoder class,
            // so we'll cheat a little and just assume each byte is ASCII
            let slice = new Uint8Array(memory.buffer, ptr, length);
            const str = String.fromCodePoint(...slice);

            console.log(`WASM: "${str}"`);
        },
    }
}).then(({ instance }) => {
    console.debug("WASM module successfully instantiated");

    console.info("square(4) =", instance.exports.square(4));
    instance.exports.logTest();
});