use crate::Error;

use alloc::borrow::ToOwned;

use alloc::vec::Vec;

use const_interpreter_loop::run_const_span;

use function_ref::FunctionRef;

use value_stack::Stack;

use crate::core::reader::types::{FuncType, ResultType};

use crate::execution::assert_validated::UnwrapValidatedExt;

use crate::execution::hooks::{EmptyHookSet, HookSet};

use crate::execution::store::Store;

use crate::execution::value::Value;

use crate::value::InteropValueList;

use crate::{Result as CustomResult, RuntimeError, ValidationInfo};

pub(crate) mod assert_validated;

pub mod const_interpreter_loop;

pub mod function_ref;

pub mod hooks;

mod interpreter_loop;

pub(crate) mod linear_memory;

pub(crate) mod locals;

pub mod registry;

pub mod store;

pub mod value;

pub mod value_stack;

/// The default module name if a [RuntimeInstance] was created using [RuntimeInstance::new].

pub const DEFAULT_MODULE: &str = "__interpreter_default__";

#[derive(Debug)]

pub struct RuntimeInstance<'b, H = EmptyHookSet>

where

    H: HookSet + core::fmt::Debug,

{

    pub hook_set: H,

    pub store: Store<'b>,

}

impl Default for RuntimeInstance<'_, EmptyHookSet> {

    fn default() -> Self {

        Self::new()

    }

}

impl<'b> RuntimeInstance<'b, EmptyHookSet> {

    pub fn new() -> Self {

        Self::new_with_hooks(EmptyHookSet)

    }

    pub fn new_with_default_module(validation_info: &'_ ValidationInfo<'b>) -> CustomResult<Self> {

        let mut instance = Self::new_with_hooks(EmptyHookSet);

        instance.add_module(DEFAULT_MODULE, validation_info)
?0
;

        Ok(instance)

    }

    pub fn new_named(

        module_name: &str,

        validation_info: &'_ ValidationInfo<'b>,

        // store: &mut Store,

    ) -> CustomResult<Self> {

        let mut instance = Self::new_with_hooks(EmptyHookSet);

        instance.add_module(module_name, validation_info)
?0
;

        Ok(instance)

    }

}

impl<'b, H> RuntimeInstance<'b, H>

where

    H: HookSet + core::fmt::Debug,

{

    pub fn add_module(

        &mut self,

        module_name: &str,

        validation_info: &'_ ValidationInfo<'b>,

    ) -> CustomResult<()> {

        self.store.add_module(module_name, validation_info)

    }

    pub fn new_with_hooks(

        hook_set: H,

        // store: &mut Store,

    ) -> Self {

        RuntimeInstance {

            hook_set,

            store: Store::default(),

        }

    }

    pub fn get_function_by_name(

        &self,

        module_name: &str,

        function_name: &str,

    ) -> Result<FunctionRef, RuntimeError> {

        FunctionRef::new_from_name(module_name, function_name, &self.store)

            .map_err(|_| 
RuntimeError::FunctionNotFound0
)

    }

    pub fn get_function_by_index(

        &self,

        module_addr: usize,

        function_idx: usize,

    ) -> Result<FunctionRef, RuntimeError> {

        let module_inst = self

            .store

            .modules

            .get(module_addr)

            .ok_or(RuntimeError::ModuleNotFound)
?0
;

        let func_addr = *module_inst

            .func_addrs

            .get(function_idx)

            .ok_or(RuntimeError::FunctionNotFound)
?0
;

        Ok(FunctionRef { func_addr })

    }

    /// Invokes a function with the given parameters of type `Param`, and return types of type `Returns`.

    pub fn invoke_typed<Params: InteropValueList, Returns: InteropValueList>(

        &mut self,

        function_ref: &FunctionRef,

        params: Params,

        // store: &mut Store,

    ) -> Result<Returns, RuntimeError> {

        let FunctionRef { func_addr } = *function_ref;

        self.store

            .invoke(func_addr, params.into_values())

            .map(|values| 
Returns::from_values(values.into_iter())6.18k
)

    }

    /// Invokes a function with the given parameters. The return types depend on the function signature.

    pub fn invoke(

        &mut self,

        function_ref: &FunctionRef,

        params: Vec<Value>,

    ) -> Result<Vec<Value>, RuntimeError> {

        let FunctionRef { func_addr } = *function_ref;

        self.store.invoke(func_addr, params)

    }

    /// Adds a host function under module namespace `module_name` with name `name`.

    /// roughly similar to `func_alloc` in <https://webassembly.github.io/spec/core/appendix/embedding.html#functions>

    /// except the host function is made visible to other modules through these names.

    pub fn add_host_function_typed<Params: InteropValueList, Returns: InteropValueList>(

        &mut self,

        module_name: &str,

        name: &str,

        host_func: fn(Vec<Value>) -> Vec<Value>,

    ) -> Result<FunctionRef, Error> {

        let host_func_ty = FuncType {

            params: ResultType {

                valtypes: Vec::from(Params::TYS),

            },

            returns: ResultType {

                valtypes: Vec::from(Returns::TYS),

            },

        };

        self.add_host_function(module_name, name, host_func_ty, host_func)

    }

    pub fn add_host_function(

        &mut self,

        module_name: &str,

        name: &str,

        host_func_ty: FuncType,

        host_func: fn(Vec<Value>) -> Vec<Value>,

    ) -> Result<FunctionRef, Error> {

        let func_addr = self.store.alloc_host_func(host_func_ty, host_func);

        self.store.registry.register(

            module_name.to_owned().into(),

            name.to_owned().into(),

            store::ExternVal::Func(func_addr),

        )
?0
;

        Ok(FunctionRef { func_addr })

    }

}

/// Helper function to quickly construct host functions without worrying about wasm to Rust

/// type conversion.

/// # Example

/// ```

/// use wasm::{validate, RuntimeInstance, host_function_wrapper, Value};

/// fn my_wrapped_host_func(params: Vec<Value>) -> Vec<Value> {

///     host_function_wrapper(params, |(x, y): (u32, i32)| -> u32 {

///         x + (y as u32)

///  })

/// }

/// fn main() {

///     let mut instance = RuntimeInstance::new();

///     let foo_bar = instance.add_host_function_typed::<(u32,i32),u32>("foo", "bar", my_wrapped_host_func).unwrap();

/// }

/// ```

pub fn host_function_wrapper<Params: InteropValueList, Results: InteropValueList>(

    params: Vec<Value>,

    f: impl FnOnce(Params) -> Results,

) -> Vec<Value> {

    let params = Params::from_values(params.into_iter());

    let results = f(params);

    results.into_values()

}