use weave::attempt;

use spellbook::components::Array;

#[cfg(feature="convert_sigils")]
use sigils::{Zero, Number, Real, Trig};

#[cfg(feature="convert_sigils")]
use sigils::vector::{Vector, Vector2, Vector3, Vector4};

#[cfg(feature="convert_sigils")]
use sigils::quaternion::Quaternion;

use crate::byte_sized::{ByteSized, get_byte_size_of_string};
use crate::conversion_error::ConversionError;
use crate::converter::Converter;
use crate::endian::{BigEndian, LittleEndian, PlatformEndian, NetworkEndian};
use crate::endian::Endianess;



// From and Into are not used because we need to also
// know the endianess to use for converting.
/// A type that can be converted to and from bytes.
pub trait Transmutable: Sized
{
   /// Transmute an array of bytes in the
   /// platform's endian to this type.
   fn from_bytes(buffer: &[u8]) -> Result<Self, ConversionError>
   {
      Self::from_endian_bytes(buffer, Endianess::Platform)
   }

   /// Transmute an array of bytes in the
   /// given endian to this type.
   fn from_endian_bytes(buffer: &[u8], endianess: Endianess)
      -> Result<Self, ConversionError>;


   /// Transmute this type to an array of bytes in
   /// the Platform's endian.
   fn to_bytes(self) -> Array<u8>
   {
      self.as_endian_bytes(Endianess::Platform)
   }

   /// Transmute this type to an array of bytes in
   /// the desired endian.
   fn to_endian_bytes(self, endianess: Endianess) -> Array<u8>
   {
      self.as_endian_bytes(endianess)
   }


   /// Transmute this type to an array of bytes in
   /// the Platform's endian.
   fn as_bytes(&self) -> Array<u8>
   {
      self.as_endian_bytes(Endianess::Platform)
   }

   /// Transmute this type to an array of bytes in
   /// the desired endian.
   fn as_endian_bytes(&self, endianess: Endianess) -> Array<u8>;


   /// Get the current size of this Transmutable in bytes.
   fn determine_byte_size(&self) -> usize;
}



/// Handles the repetative endianess matching
/// for the primitive number types when converting
/// a number to bytes.
macro_rules! handle_endianess_to_bytes
{
   ($val: ident, $endianess: ident, $func: ident) =>
   {
      {
         match $endianess
         {
            Endianess::Big =>
            {
               BigEndian::$func(*$val)
            }

            Endianess::Little =>
            {
               LittleEndian::$func(*$val)
            }

            Endianess::Platform =>
            {
               PlatformEndian::$func(*$val)
            }

            Endianess::Network =>
            {
               NetworkEndian::$func(*$val)
            }
         }
      }
   }
}

/// Handles the repetative endianess matching
/// for the primitive number types when converting
/// a number from bytes.
macro_rules! handle_endianess_from_bytes
{
   ($buffer: ident, $endianess: ident, $func: ident) =>
   {
      match $endianess
      {
         Endianess::Big =>
         {
            BigEndian::$func(&$buffer)
         }

         Endianess::Little =>
         {
            LittleEndian::$func(&$buffer)
         }

         Endianess::Platform =>
         {
            PlatformEndian::$func(&$buffer)
         }

         Endianess::Network =>
         {
            NetworkEndian::$func(&$buffer)
         }
      }
   }
}



impl Transmutable for u8
{
   #[allow(unused_variables)]
   fn from_endian_bytes(buffer: &[u8], endianess: Endianess)
      -> Result<Self, ConversionError>
   {
      // Just return the byte from the buffer.
      // A single byte has no endian form.
      check_length!(buffer >= u8::BYTES);
      Ok(buffer[0])
   }

   #[allow(unused_variables)]
   fn as_endian_bytes(&self, endianess: Endianess) -> Array<u8>
   {
      let mut bytes: Array<u8>;

      bytes = Array::with_capacity(1usize);
      bytes.insert_element(*self);

      bytes
   }

   fn determine_byte_size(&self) -> usize
   {
      u8::BYTES
   }
}

impl Transmutable for u16
{
   fn from_endian_bytes(buffer: &[u8], endianess: Endianess)
      -> Result<Self, ConversionError>
   {
      // Convert the given bytes to this type and return it.
      handle_endianess_from_bytes!(buffer, endianess, bytes_to_u16)
   }

   fn as_endian_bytes(&self, endianess: Endianess) -> Array<u8>
   {
      // Return the Endianess conversion.
      handle_endianess_to_bytes!(self, endianess, u16_to_bytes)
   }

   fn determine_byte_size(&self) -> usize
   {
      u16::BYTES
   }
}

impl Transmutable for u32
{
   fn from_endian_bytes(buffer: &[u8], endianess: Endianess)
      -> Result<Self, ConversionError>
   {
      // Convert the given bytes to this type and return it.
      handle_endianess_from_bytes!(buffer, endianess, bytes_to_u32)
   }

   fn as_endian_bytes(&self, endianess: Endianess) -> Array<u8>
   {
      // Convert this to bytes and add it to the buffer.
      handle_endianess_to_bytes!(self, endianess, u32_to_bytes)
   }

   fn determine_byte_size(&self) -> usize
   {
      u32::BYTES
   }
}

impl Transmutable for u64
{
   fn from_endian_bytes(buffer: &[u8], endianess: Endianess)
      -> Result<Self, ConversionError>
   {
      // Convert the given bytes to this type and return it.
      handle_endianess_from_bytes!(buffer, endianess, bytes_to_u64)
   }

   fn as_endian_bytes(&self, endianess: Endianess) -> Array<u8>
   {
      // Convert this to bytes and add it to the buffer.
      handle_endianess_to_bytes!(self, endianess, u64_to_bytes)
   }

   fn determine_byte_size(&self) -> usize
   {
      u64::BYTES
   }
}

impl Transmutable for usize
{
   fn from_endian_bytes(buffer: &[u8], endianess: Endianess)
      -> Result<Self, ConversionError>
   {
      // Convert the given bytes to this type and return it.
      handle_endianess_from_bytes!(buffer, endianess, bytes_to_usize)
   }

   fn as_endian_bytes(&self, endianess: Endianess) -> Array<u8>
   {
      // Convert this to bytes and add it to the buffer.
      handle_endianess_to_bytes!(self, endianess, usize_to_bytes)
   }

   fn determine_byte_size(&self) -> usize
   {
      usize::BYTES
   }
}

impl Transmutable for i8
{
   #[allow(unused_variables)]
   fn from_endian_bytes(buffer: &[u8], endianess: Endianess)
      -> Result<Self, ConversionError>
   {
      check_length!(buffer >= i8::BYTES);

      Ok(buffer[0] as i8)
   }

   #[allow(unused_variables)]
   fn as_endian_bytes(&self, endianess: Endianess) -> Array<u8>
   {
      let mut bytes: Array<u8>;

      bytes = Array::with_capacity(1usize);
      bytes.insert_element(*self as u8);

      bytes
   }

   fn determine_byte_size(&self) -> usize
   {
      i8::BYTES
   }
}

impl Transmutable for i16
{
   fn from_endian_bytes(buffer: &[u8], endianess: Endianess)
      -> Result<Self, ConversionError>
   {
      // Convert the given bytes to this type and return it.
      handle_endianess_from_bytes!(buffer, endianess, bytes_to_i16)
   }

   fn as_endian_bytes(&self, endianess: Endianess) -> Array<u8>
   {
      // Convert this to bytes and add it to the buffer.
      handle_endianess_to_bytes!(self, endianess, i16_to_bytes)
   }

   fn determine_byte_size(&self) -> usize
   {
      i16::BYTES
   }
}

impl Transmutable for i32
{
   fn from_endian_bytes(buffer: &[u8], endianess: Endianess)
      -> Result<Self, ConversionError>
   {
      // Convert the given bytes to this type and return it.
      handle_endianess_from_bytes!(buffer, endianess, bytes_to_i32)
   }

   fn as_endian_bytes(&self, endianess: Endianess) -> Array<u8>
   {
      // Convert this to bytes and add it to the buffer.
      handle_endianess_to_bytes!(self, endianess, i32_to_bytes)
   }

   fn determine_byte_size(&self) -> usize
   {
      i32::BYTES
   }
}

impl Transmutable for i64
{
   fn from_endian_bytes(buffer: &[u8], endianess: Endianess)
      -> Result<Self, ConversionError>
   {
      // Convert the given bytes to this type and return it.
      handle_endianess_from_bytes!(buffer, endianess, bytes_to_i64)
   }

   fn as_endian_bytes(&self, endianess: Endianess) -> Array<u8>
   {
      // Convert this to bytes and add it to the buffer.
      handle_endianess_to_bytes!(self, endianess, i64_to_bytes)
   }

   fn determine_byte_size(&self) -> usize
   {
      i64::BYTES
   }
}

impl Transmutable for isize
{
   fn from_endian_bytes(buffer: &[u8], endianess: Endianess)
      -> Result<Self, ConversionError>
   {
      // Convert the given bytes to this type and return it.
      handle_endianess_from_bytes!(buffer, endianess, bytes_to_isize)
   }

   fn as_endian_bytes(&self, endianess: Endianess) -> Array<u8>
   {
      // Convert this to bytes and add it to the buffer.
      handle_endianess_to_bytes!(self, endianess, isize_to_bytes)
   }

   fn determine_byte_size(&self) -> usize
   {
      isize::BYTES
   }
}

impl Transmutable for f32
{
   fn from_endian_bytes(buffer: &[u8], endianess: Endianess)
      -> Result<Self, ConversionError>
   {
      // Convert the given bytes to this type and return it.
      handle_endianess_from_bytes!(buffer, endianess, bytes_to_f32)
   }

   fn as_endian_bytes(&self, endianess: Endianess) -> Array<u8>
   {
      // Convert this to bytes and add it to the buffer.
      handle_endianess_to_bytes!(self, endianess, f32_to_bytes)
   }

   fn determine_byte_size(&self) -> usize
   {
      f32::BYTES
   }
}

impl Transmutable for f64
{
   fn from_endian_bytes(buffer: &[u8], endianess: Endianess)
      -> Result<Self, ConversionError>
   {
      // Convert the given bytes to this type and return it.
      handle_endianess_from_bytes!(buffer, endianess, bytes_to_f64)
   }

   fn as_endian_bytes(&self, endianess: Endianess) -> Array<u8>
   {
      // Convert this to bytes and add it to the buffer.
      handle_endianess_to_bytes!(self, endianess, f64_to_bytes)
   }

   fn determine_byte_size(&self) -> usize
   {
      f64::BYTES
   }
}

impl Transmutable for String
{
   fn from_endian_bytes(buffer: &[u8], endianess: Endianess)
      -> Result<Self, ConversionError>
   {
      // Convert the given bytes to this type and return it.
      handle_endianess_from_bytes!(buffer, endianess, bytes_to_string)
   }

   fn as_endian_bytes(&self, endianess: Endianess) -> Array<u8>
   {
      // Convert this to bytes and add it to the buffer.
      // We are not using the macro because *String is a str.
      match endianess
      {
         Endianess::Big =>
         {
            BigEndian::string_to_bytes(self.clone())
         }

         Endianess::Little =>
         {
            LittleEndian::string_to_bytes(self.clone())
         }

         Endianess::Platform =>
         {
            PlatformEndian::string_to_bytes(self.clone())
         }

         Endianess::Network =>
         {
            NetworkEndian::string_to_bytes(self.clone())
         }
      }
   }

   fn determine_byte_size(&self) -> usize
   {
      get_byte_size_of_string(self)
   }
}

#[cfg(feature="convert_sigils")]
impl<T> Transmutable for Vector2<T> where T: Number + ByteSized + Transmutable
{
   fn from_endian_bytes(buffer: &[u8], endianess: Endianess)
      -> Result<Self, ConversionError>
   {
      let num_bytes: usize;
      let mut vec: Vector2<T>;

      // Determine the number of bytes requires to
      // represent a Vector2.
      vec = Vector2::<T>::zero();
      num_bytes = vec.determine_byte_size();

      // Make sure that there is enough data to read
      // the bytes for this type.
      check_length!(buffer >= num_bytes);

      // Convert the given bytes to this type and return it.
      vec.x = attempt!(T::from_endian_bytes(&buffer[0..T::BYTES],
                                        endianess));
      vec.y = attempt!(T::from_endian_bytes(&buffer[T::BYTES..num_bytes],
                                        endianess));
      Ok(vec)
   }

   fn as_endian_bytes(&self, endianess: Endianess) -> Array<u8>
   {
      let num_bytes: usize;
      let mut buffer: Array<u8>;

      // Determine the number of bytes requires to
      // represent a Vector2.
      num_bytes = T::BYTES * self.get_size() as usize;

      // Make sure that there is enough space to store
      // the bytes from this type.
      buffer = Array::with_capacity(num_bytes);

      // Convert this to bytes and add it to the buffer.
      buffer.append(&mut self.x.as_endian_bytes(endianess));
      buffer.append(&mut self.y.as_endian_bytes(endianess));

      // Return the byte buffer.
      buffer
   }

   fn determine_byte_size(&self) -> usize
   {
      T::BYTES * self.get_size() as usize
   }
}

#[cfg(feature="convert_sigils")]
impl<T> Transmutable for Vector3<T> where T: Number + ByteSized + Transmutable
{
   fn from_endian_bytes(buffer: &[u8], endianess: Endianess)
      -> Result<Self, ConversionError>
   {
      let num_bytes: usize;
      let mut vec: Vector3<T>;

      // Determine the number of bytes requires to
      // represent a Vector3.
      vec = Vector3::<T>::zero();
      num_bytes = vec.determine_byte_size();

      check_length!(buffer >= num_bytes);

      // Convert the given bytes to this type and return it.
      vec.x = attempt!(T::from_endian_bytes(&buffer[0..T::BYTES],
                                        endianess));
      vec.y = attempt!(T::from_endian_bytes(&buffer[T::BYTES..(T::BYTES * 2)],
                                        endianess));
      vec.z = attempt!(T::from_endian_bytes(&buffer[(T::BYTES * 2)..num_bytes],
                                        endianess));
      Ok(vec)
   }

   fn as_endian_bytes(&self, endianess: Endianess) -> Array<u8>
   {
      let num_bytes: usize;
      let mut buffer: Array<u8>;

      // Determine the number of bytes requires to
      // represent a Vector3.
      num_bytes = T::BYTES * self.get_size() as usize;

      // Make sure that there is enough space to store
      // the bytes from this type.
      buffer = Array::with_capacity(num_bytes);

      // Convert this to bytes and add it to the buffer.
      buffer.append(&mut self.x.as_endian_bytes(endianess));
      buffer.append(&mut self.y.as_endian_bytes(endianess));
      buffer.append(&mut self.z.as_endian_bytes(endianess));

      // Return the byte buffer.
      buffer
   }

   fn determine_byte_size(&self) -> usize
   {
      T::BYTES * self.get_size() as usize
   }
}

#[cfg(feature="convert_sigils")]
impl<T> Transmutable for Vector4<T> where T: Number + ByteSized + Transmutable
{
   fn from_endian_bytes(buffer: &[u8], endianess: Endianess)
      -> Result<Self, ConversionError>
   {
      let num_bytes: usize;
      let mut vec: Vector4<T>;

      // Determine the number of bytes requires to
      // represent a Vector4.
      vec = Vector4::<T>::zero();
      num_bytes = vec.determine_byte_size();

      check_length!(buffer >= num_bytes);

      // Convert the given bytes to this type and return it.
      vec.x = attempt!(T::from_endian_bytes(&buffer[0..T::BYTES],
                                        endianess));
      vec.y = attempt!(T::from_endian_bytes(&buffer[T::BYTES..(T::BYTES * 2)],
                                        endianess));
      vec.z = attempt!(T::from_endian_bytes(&buffer[(T::BYTES*2)..(T::BYTES*3)],
                                        endianess));
      vec.w = attempt!(T::from_endian_bytes(&buffer[(T::BYTES * 3)..num_bytes],
                                        endianess));
      Ok(vec)
   }

   fn as_endian_bytes(&self, endianess: Endianess) -> Array<u8>
   {
      let num_bytes: usize;
      let mut buffer: Array<u8>;

      // Determine the number of bytes requires to
      // represent a Vector4.
      num_bytes = T::BYTES * self.get_size() as usize;

      // Make sure that there is enough space to store
      // the bytes from this type.
      buffer = Array::with_capacity(num_bytes);

      // Convert this to bytes and add it to the buffer.
      buffer.append(&mut self.x.as_endian_bytes(endianess));
      buffer.append(&mut self.y.as_endian_bytes(endianess));
      buffer.append(&mut self.z.as_endian_bytes(endianess));
      buffer.append(&mut self.w.as_endian_bytes(endianess));

      // Return the byte buffer.
      buffer
   }

   fn determine_byte_size(&self) -> usize
   {
      T::BYTES * self.get_size() as usize
   }
}

#[cfg(feature="convert_sigils")]
impl<T> Transmutable for Quaternion<T>
   where T: Real + Trig + ByteSized + Transmutable
{
   fn from_endian_bytes(buffer: &[u8], endianess: Endianess)
      -> Result<Self, ConversionError>
   {
      let num_bytes: usize;
      let mut quat: Quaternion<T>;

      // Determine the number of bytes requires to
      // represent a Quaternion.
      quat = Quaternion::<T>::zero();
      num_bytes = quat.determine_byte_size();

      // Make sure that there is enough data to read
      // the bytes for this type.
      check_length!(buffer >= num_bytes);

      // Convert the given bytes to this type and return it.
      quat.scalar = attempt!(T::from_endian_bytes(&buffer[0..T::BYTES],
                                              endianess));
      quat.vector =
         attempt!(Vector3::<T>::from_endian_bytes(&buffer[T::BYTES..num_bytes],
                                              endianess));
      Ok(quat)
   }

   fn as_endian_bytes(&self, endianess: Endianess) -> Array<u8>
   {
      let num_bytes: usize;
      let mut buffer: Array<u8>;

      // Determine the number of bytes requires to
      // represent a Quaternion.
      num_bytes = T::BYTES * 4usize;

      // Make sure that there is enough space to store
      // the bytes from this type.
      buffer = Array::with_capacity(num_bytes);

      // Convert this to bytes and add it to the buffer.
      buffer.append(&mut self.scalar.as_endian_bytes(endianess));
      buffer.append(&mut self.vector.as_endian_bytes(endianess));

      // Return the byte buffer.
      buffer
   }

   fn determine_byte_size(&self) -> usize
   {
      T::BYTES * 4usize
   }
}