use cranelift_codegen::settings;
use cranelift_codegen::settings::Configurable;
use faerie::Artifact;
use wasmtime_runtime;

/// Emits a module that has been emitted with the `WasmRuntime` runtime
/// implementation to a native object file.
pub fn emit_module<'module>(
    obj: &mut Artifact,
    compilation: &wasmtime_runtime::Compilation<'module>,
    relocations: &wasmtime_runtime::Relocations,
) -> Result<(), String> {
    debug_assert!(
        compilation.module.start_func.is_none()
            || compilation.module.start_func.unwrap() >= compilation.module.imported_funcs.len(),
        "imported start functions not supported yet"
    );

    let mut shared_builder = settings::builder();
    shared_builder
        .enable("enable_verifier")
        .expect("Missing enable_verifier setting");

    for (i, function_relocs) in relocations.iter().enumerate() {
        assert!(function_relocs.is_empty(), "relocations not supported yet");
        let body = &compilation.functions[i];
        let func_index = compilation.module.imported_funcs.len() + i;
        let string_name = format!("wasm_function[{}]", func_index);

        obj.define(string_name, body.clone())
            .map_err(|err| format!("{}", err))?;
    }

    Ok(())
}