use std::ffi::CString;
use std::mem::{align_of, forget};

use wasmer::{Exports, Store};

use crate::dynamic_data::DynamicLibrary;
use crate::script_implementations::wasm::extern_ref::ExternRef;
use crate::script_implementations::wasm::script_resolver::WebAssemblyEnv;
use crate::static_data::{EffectParameter, StaticData};
use crate::StringKey;

mod dynamic_data;
mod static_data;

#[allow(unused_macros)]
macro_rules! register_func {
    ($exports: ident, $store: ident, $func: ident) => {
        $exports.insert(stringify!($func), Function::new_native($store, $func));
    };
}

macro_rules! register_func_with_env {
    ($exports: ident, $store: ident, $func: ident, $env: expr) => {
        $exports.insert(
            stringify!($func),
            wasmer::Function::new_native_with_env($store, $env.clone(), $func),
        );
    };
}

macro_rules! register {
    (
        $(
            fn $name:ident($($par:ident: $par_type:ty),*$(,)?) $(-> $return:ty)? $block:block
        )*
    ) => {
        pub(crate) fn register(exports: &mut crate::script_implementations::wasm::export_registry::Exports,
            store: &crate::script_implementations::wasm::export_registry::Store,
            env: crate::script_implementations::wasm::script_resolver::WebAssemblyEnv) {
        $(

            fn $name(
                $(
                $par: $par_type,
                )*
            ) $(-> $return)* $block
            crate::script_implementations::wasm::export_registry::register_func_with_env!(exports, store, $name, env);
        )*

        }
    };
}

pub(crate) use register;
pub(crate) use register_func_with_env;

pub(crate) fn register_webassembly_funcs(exports: &mut Exports, store: &Store, env: WebAssemblyEnv) {
    register_func_with_env!(exports, store, _print, env);
    register_func_with_env!(exports, store, _error, env);
    register_func_with_env!(exports, store, _vec_extern_ref_get_value, env);

    static_data::register(exports, store, env.clone());
    dynamic_data::register(exports, store, env.clone());

    register_func_with_env!(exports, store, string_key_get_hash, env);
    register_func_with_env!(exports, store, string_key_get_str, env);
    register_func_with_env!(exports, store, dynamic_library_get_static_data, env);
    register_func_with_env!(exports, store, effect_parameter_get_type, env);
    register_func_with_env!(exports, store, effect_parameter_as_bool, env);
    register_func_with_env!(exports, store, effect_parameter_as_int, env);
    register_func_with_env!(exports, store, effect_parameter_as_float, env);
    register_func_with_env!(exports, store, effect_parameter_as_string, env);
}

fn _print(env: &WebAssemblyEnv, p: u32, len: u32) {
    unsafe {
        let mem: *mut u8 = env.data().memory().data_ptr().offset(p as isize);
        let s = String::from_raw_parts(mem, len as usize, len as usize);
        println!("{}", s);
        forget(s);
    }
}

#[track_caller]
fn _error(env: &WebAssemblyEnv, message: u32, message_len: u32, file: u32, file_len: u32, line: u32, position: u32) {
    unsafe {
        let mem: *mut u8 = env.data().memory().data_ptr().offset(message as isize);
        let message_str = String::from_raw_parts(mem, message_len as usize, message_len as usize);
        let mem: *mut u8 = env.data().memory().data_ptr().offset(file as isize);
        let file_str = String::from_raw_parts(mem, file_len as usize, file_len as usize);
        panic!(
            "Error: {} in file {}, line: {}:{}",
            message_str, file_str, line, position
        );
    }
}

fn _vec_extern_ref_get_value(env: &WebAssemblyEnv, reference: u32, index: u32) -> u32 {
    env.data().get_extern_vec_ref_extern_ref(reference, index)
}

fn string_key_get_hash(env: &WebAssemblyEnv, string_key: ExternRef<StringKey>) -> u32 {
    string_key.value(env).unwrap().hash()
}

fn string_key_get_str(env: &WebAssemblyEnv, string_key: ExternRef<StringKey>) -> u32 {
    let string_key = string_key.value(env).unwrap().str();
    let wasm_string_ptr = env
        .data()
        .allocate_mem((string_key.len() + 1) as u32, align_of::<CString>() as u32);
    let mut wasm_string: Vec<u8> =
        unsafe { Vec::from_raw_parts(wasm_string_ptr.0, string_key.len() + 1, string_key.len() + 1) };
    wasm_string.resize(string_key.len() + 1, 0);
    string_key.as_bytes().clone_into(&mut wasm_string);
    wasm_string.insert(string_key.len(), 0 as u8);
    forget(wasm_string);
    wasm_string_ptr.1
}

fn dynamic_library_get_static_data(
    env: &WebAssemblyEnv,
    dynamic_lib: ExternRef<DynamicLibrary>,
) -> ExternRef<StaticData> {
    ExternRef::new(env.data().as_ref(), dynamic_lib.value(env).unwrap().static_data())
}

fn effect_parameter_get_type(env: &WebAssemblyEnv, parameter: ExternRef<EffectParameter>) -> u8 {
    let v = parameter.value(env).unwrap();
    match v {
        EffectParameter::Bool(_) => 1,
        EffectParameter::Int(_) => 2,
        EffectParameter::Float(_) => 3,
        EffectParameter::String(_) => 4,
    }
}

fn effect_parameter_as_bool(env: &WebAssemblyEnv, parameter: ExternRef<EffectParameter>) -> u8 {
    let v = parameter.value(env).unwrap();
    match v {
        EffectParameter::Bool(b) => {
            if *b {
                1
            } else {
                0
            }
        }
        _ => panic!("Unexpected parameter type!"),
    }
}

fn effect_parameter_as_int(env: &WebAssemblyEnv, parameter: ExternRef<EffectParameter>) -> i64 {
    let v = parameter.value(env).unwrap();
    match v {
        EffectParameter::Int(i) => *i,
        _ => panic!("Unexpected parameter type!"),
    }
}

fn effect_parameter_as_float(env: &WebAssemblyEnv, parameter: ExternRef<EffectParameter>) -> f32 {
    let v = parameter.value(env).unwrap();
    match v {
        EffectParameter::Float(f) => *f,
        _ => panic!("Unexpected parameter type!"),
    }
}

fn effect_parameter_as_string(env: &WebAssemblyEnv, parameter: ExternRef<EffectParameter>) -> ExternRef<StringKey> {
    let v = parameter.value(env).unwrap();
    match v {
        EffectParameter::String(s) => ExternRef::new(env.data().as_ref(), s),
        _ => panic!("Unexpected parameter type!"),
    }
}