//! Inputs are the actual contents sent to a target for each exeuction.

pub mod bytes;
pub use bytes::BytesInput;

pub mod encoded;
pub use encoded::*;

pub mod gramatron;
pub use gramatron::*;

pub mod generalized;
pub use generalized::*;

#[cfg(feature = "nautilus")]
pub mod nautilus;
use alloc::{
    boxed::Box,
    string::{String, ToString},
    vec::Vec,
};
use core::{clone::Clone, fmt::Debug, marker::PhantomData};
#[cfg(feature = "std")]
use std::{fs::File, hash::Hash, io::Read, path::Path};

#[cfg(feature = "nautilus")]
pub use nautilus::*;
use serde::{Deserialize, Serialize};

#[cfg(feature = "std")]
use crate::bolts::fs::write_file_atomic;
use crate::{bolts::ownedref::OwnedSlice, Error};

/// An input for the target
#[cfg(not(feature = "std"))]
pub trait Input: Clone + Serialize + serde::de::DeserializeOwned + Debug {
    /// Write this input to the file
    fn to_file<P>(&self, _path: P) -> Result<(), Error> {
        Err(Error::not_implemented("Not supported in no_std"))
    }

    /// Write this input to the file
    fn from_file<P>(_path: P) -> Result<Self, Error> {
        Err(Error::not_implemented("Not supprted in no_std"))
    }

    /// Generate a name for this input
    fn generate_name(&self, idx: usize) -> String;

    /// An hook executed if the input is stored as `Testcase`
    fn wrapped_as_testcase(&mut self) {}
}

/// An input for the target
#[cfg(feature = "std")]
pub trait Input: Clone + Serialize + serde::de::DeserializeOwned + Debug {
    /// Write this input to the file
    fn to_file<P>(&self, path: P) -> Result<(), Error>
    where
        P: AsRef<Path>,
    {
        write_file_atomic(path, &postcard::to_allocvec(self)?)
    }

    /// Load the content of this input from a file
    fn from_file<P>(path: P) -> Result<Self, Error>
    where
        P: AsRef<Path>,
    {
        let mut file = File::open(path)?;
        let mut bytes: Vec<u8> = vec![];
        file.read_to_end(&mut bytes)?;
        Ok(postcard::from_bytes(&bytes)?)
    }

    /// Generate a name for this input
    fn generate_name(&self, idx: usize) -> String;

    /// An hook executed if the input is stored as `Testcase`
    fn wrapped_as_testcase(&mut self) {}
}

/// Convert between two input types with a state
pub trait InputConverter: Debug {
    /// Source type
    type From: Input;
    /// Destination type
    type To: Input;

    /// Convert the src type to the dest
    fn convert(&mut self, input: Self::From) -> Result<Self::To, Error>;
}

/// `None` type to satisfy the type infearence in an `Option`
#[macro_export]
macro_rules! none_input_converter {
    () => {
        None::<$crate::inputs::ClosureInputConverter<_, _>>
    };
}

/// An input for tests, mainly. There is no real use much else.
#[derive(Copy, Clone, Serialize, Deserialize, Debug, Hash)]
pub struct NopInput {}
impl Input for NopInput {
    fn generate_name(&self, _idx: usize) -> String {
        "nop-input".to_string()
    }
}
impl HasTargetBytes for NopInput {
    fn target_bytes(&self) -> OwnedSlice<u8> {
        OwnedSlice::from(vec![0])
    }
}

// TODO change this to fn target_bytes(&self, buffer: &mut Vec<u8>) -> &[u8];
/// Can be represented with a vector of bytes.
/// This representation is not necessarily deserializable.
/// Instead, it can be used as bytes input for a target
pub trait HasTargetBytes {
    /// Target bytes, that can be written to a target
    fn target_bytes(&self) -> OwnedSlice<u8>;
}

/// Contains an internal bytes Vector
pub trait HasBytesVec {
    /// The internal bytes map
    fn bytes(&self) -> &[u8];
    /// The internal bytes map (as mutable borrow)
    fn bytes_mut(&mut self) -> &mut Vec<u8>;
}

/// Defines the input type shared across traits of the type.
/// Needed for consistency across HasCorpus/HasSolutions and friends.
pub trait UsesInput {
    /// Type which will be used throughout this state.
    type Input: Input;
}

#[derive(Debug)]
/// Basic `InputConverter` with just one type that is not converting
pub struct NopInputConverter<I> {
    phantom: PhantomData<I>,
}

impl<I> Default for NopInputConverter<I> {
    fn default() -> Self {
        Self {
            phantom: PhantomData,
        }
    }
}

impl<I> InputConverter for NopInputConverter<I>
where
    I: Input,
{
    type From = I;
    type To = I;

    fn convert(&mut self, input: Self::From) -> Result<Self::To, Error> {
        Ok(input)
    }
}

/// `InputConverter` that uses a closure to convert
pub struct ClosureInputConverter<F, T>
where
    F: Input,
    T: Input,
{
    convert_cb: Box<dyn FnMut(F) -> Result<T, Error>>,
}

impl<F, T> Debug for ClosureInputConverter<F, T>
where
    F: Input,
    T: Input,
{
    fn fmt(&self, f: &mut core::fmt::Formatter<'_>) -> core::fmt::Result {
        f.debug_struct("ClosureInputConverter")
            .finish_non_exhaustive()
    }
}

impl<F, T> ClosureInputConverter<F, T>
where
    F: Input,
    T: Input,
{
    /// Create a new converter using two closures, use None to forbid the conversion or the conversion back
    #[must_use]
    pub fn new(convert_cb: Box<dyn FnMut(F) -> Result<T, Error>>) -> Self {
        Self { convert_cb }
    }
}

impl<F, T> InputConverter for ClosureInputConverter<F, T>
where
    F: Input,
    T: Input,
{
    type From = F;
    type To = T;

    fn convert(&mut self, input: Self::From) -> Result<Self::To, Error> {
        (self.convert_cb)(input)
    }
}