use crate::dynamic_data::{EmptyScriptResolver, ScriptResolver};
use crate::ffi::{IdentifiablePointer, OwnedPtr};
use std::ptr::drop_in_place;

/// Instantiates a basic empty script resolver, that always returns None.
#[no_mangle]
extern "C" fn empty_script_resolver_new() -> IdentifiablePointer<Box<dyn ScriptResolver>> {
    let v: Box<dyn ScriptResolver> = Box::new(EmptyScriptResolver {
        identifier: Default::default(),
    });
    let id = v.value_identifier();
    let ptr = Box::into_raw(Box::new(v));
    IdentifiablePointer::new(ptr, id)
}

/// Drops a script resolver.
#[no_mangle]
extern "C" fn script_resolver_drop(ptr: OwnedPtr<Box<dyn ScriptResolver>>) {
    unsafe { drop_in_place(ptr) };
}

/// Foreign function interfaces for the Webassembly script resolver.
#[cfg(feature = "wasm")]
mod web_assembly_script_resolver {
    use crate::dynamic_data::ScriptResolver;
    use crate::ffi::{ExternPointer, IdentifiablePointer};
    use crate::script_implementations::wasm::script_resolver::WebAssemblyScriptResolver;

    /// Instantiates a new WebAssemblyScriptResolver.
    #[no_mangle]
    extern "C" fn webassembly_script_resolver_new() -> IdentifiablePointer<Box<dyn ScriptResolver>> {
        let v: Box<dyn ScriptResolver> = WebAssemblyScriptResolver::new();
        let id = v.value_identifier();
        let ptr = Box::into_raw(Box::new(v));
        IdentifiablePointer::new(ptr, id)
    }

    /// Load a compiled WASM module.
    #[no_mangle]
    extern "C" fn webassembly_script_resolver_load_wasm_from_bytes(
        mut ptr: ExternPointer<Box<WebAssemblyScriptResolver>>,
        arr: *const u8,
        len: usize,
    ) {
        unsafe { ptr.as_mut().load_wasm_from_bytes(std::slice::from_raw_parts(arr, len)) }
    }

    /// Tells the script resolver we're done loading wasm modules, and to finalize the resolver.
    #[no_mangle]
    extern "C" fn webassembly_script_resolver_finalize(mut ptr: ExternPointer<Box<WebAssemblyScriptResolver>>) {
        ptr.as_mut().finalize();
    }
}