//go:build js && wasm
// +build js,wasm

package main

import (
	"fmt"
	"syscall/js"
)

// verifySHA256 verifies that the SHA256 hash of the input data matches the provided expected hash.
func verifySHA256(this js.Value, args []js.Value) any {
	if len(args) < 2 {
		return js.ValueOf("invalid arguments: expected (data []uint8, expectedHash string)")
	}

	dataLen := args[0].Get("length").Int()
	data := make([]byte, dataLen)
	js.CopyBytesToGo(data, args[0])

	expectedHash := args[1].String()
	actualHash := computeSHA256(data)

	if actualHash == expectedHash {
		return js.ValueOf(true)
	}
	return js.ValueOf(fmt.Sprintf("hash mismatch: got %s, expected %s", actualHash, expectedHash))
}

// main initializes the WebAssembly module and exposes verifySHA256 to the JavaScript global scope.
func main() {
	c := make(chan struct{})
	fmt.Println("Software Verifier WASM Initialized")
	js.Global().Set("verifySHA256", js.FuncOf(verifySHA256))
	<-c
}