seabored 0.1.0

use crate::types::CborIntegerValue;
use parsio::{Read, Write};

// Lil hack to pass over the serde fence
thread_local! {
    pub(crate) static TAG: std::cell::Cell<Option<u64>> = const { std::cell::Cell::new(None) };
}

mod serde_de;
mod serde_ser;

pub struct Deserializer<'de, R: Read<'de>> {
    reader: R,
    _marker: std::marker::PhantomData<&'de ()>,
}

impl<'de, R: Read<'de>> Deserializer<'de, R> {
    #[inline]
    pub fn new(reader: R) -> Self {
        Self {
            reader,
            _marker: Default::default(),
        }
    }

    #[inline]
    pub fn into_inner(self) -> R {
        self.reader
    }
}

pub struct Serializer<W: Write> {
    pub(crate) writer: W,
}

impl<W: Write> Serializer<W> {
    pub fn new(writer: W) -> Self {
        Self { writer }
    }

    pub fn into_inner(self) -> W {
        self.writer
    }
}

#[inline(always)]
/// Read a serde-enabled data structure from a slice
pub fn from_slice<'de, T: ::serde_core::Deserialize<'de>>(
    buf: &'de [u8],
) -> Result<T, crate::error::SeaboredDeError> {
    from_reader(buf)
}

#[inline(always)]
/// Read a serde-enabled data structure from a type that implements our [`io::Read`] trait
// You might want to use the [`io::StdReader`] adapter if you need that
pub fn from_reader<'de, T: ::serde_core::Deserialize<'de>, R: Read<'de>>(
    reader: R,
) -> Result<T, crate::error::SeaboredDeError> {
    let mut deserializer = Deserializer::new(reader);
    ::serde_core::Deserialize::deserialize(&mut deserializer)
}

#[inline(always)]
/// Serialize a data structure to a Writer that implements our [`io::Write`] trait
/// You might want to use the [`io::StdWriter`] adapter if you need that
pub fn to_writer<W: Write, T: ::serde_core::Serialize>(
    writer: &mut W,
    value: &T,
) -> Result<usize, crate::error::SeaboredSerError> {
    let mut serializer = Serializer::new(writer);
    value.serialize(&mut serializer)
}

#[inline(always)]
/// Serialize a data structure to a Vec
pub fn to_vec<T: ::serde_core::Serialize>(
    value: &T,
) -> Result<Vec<u8>, crate::error::SeaboredSerError> {
    let mut buf = vec![];
    let written = to_writer(&mut buf, value)?;
    debug_assert_eq!(written, buf.len());
    Ok(buf)
}

/// Wrapper for Tagged CBOR values
/// This makes sure the tag is used when deserializing and emitted when serializing
///
/// ## Example (serde)
/// ```rust,ignore
/// const MY_TAG: u64 = 123456789;
///
/// #[derive(serde::Serialize, serde::Deserialize)]
/// struct MyStruct<'a> {
///     thing: seabored::serde::Tagged<'a, { MY_TAG }, &'a str>,
/// }
/// ```
pub struct Tagged<'a, const TAG: u64, V: 'a> {
    inner: V,
    _marker: std::marker::PhantomData<&'a ()>,
}

#[derive(Debug)]
pub(crate) struct DynamicTaggedValue<'a> {
    pub(crate) tag: CborIntegerValue,
    pub(crate) value: std::borrow::Cow<'a, crate::Value<'a>>,
}

pub(crate) const DYN_TAGGED_TYP_NAME: &str = "seabored::serde::DynamicTaggedValue";

impl<'de> ::serde_core::Deserialize<'de> for DynamicTaggedValue<'de> {
    fn deserialize<D>(deserializer: D) -> Result<Self, D::Error>
    where
        D: ::serde_core::Deserializer<'de>,
    {
        struct DynamicTaggedValueVisitor;

        impl<'de> ::serde_core::de::Visitor<'de> for DynamicTaggedValueVisitor {
            type Value = DynamicTaggedValue<'de>;

            fn expecting(&self, formatter: &mut std::fmt::Formatter) -> std::fmt::Result {
                write!(formatter, "A Dynamically tagged CBOR Value")
            }

            fn visit_newtype_struct<D>(self, deserializer: D) -> Result<Self::Value, D::Error>
            where
                D: ::serde_core::Deserializer<'de>,
            {
                use ::serde_core::Deserialize as _;
                let tag = crate::serde::TAG.get().expect("This should never happen");
                let value = crate::Value::deserialize(deserializer)?;
                Ok(DynamicTaggedValue {
                    tag: tag.into(),
                    value: std::borrow::Cow::Owned(value),
                })
            }
        }

        deserializer.deserialize_newtype_struct(DYN_TAGGED_TYP_NAME, DynamicTaggedValueVisitor)
    }
}

impl<'a> ::serde_core::Serialize for DynamicTaggedValue<'a> {
    fn serialize<S>(&self, serializer: S) -> Result<S::Ok, S::Error>
    where
        S: ::serde_core::Serializer,
    {
        serializer.serialize_newtype_struct(DYN_TAGGED_TYP_NAME, self)
    }
}

/// Internal only: Parses the tag value from the "seabored::serde::Tagged<'life, TAG, V>" form
/// Returns `None` if non-matching
///
/// ## Warning
/// Can panic if fed anything else than our own internals, hence the visibility of this fn
#[inline(always)]
pub(crate) fn parse_tag_from_typ(typ: &str) -> Option<u64> {
    const TAGGED_VALUE_TYP_ROOT_NAME: &str = "seabored::serde::Tagged";
    // Split at the generics boundary to get (`seabored::serde::Tagged`, `'life, TAG, V>`)
    let (tname, targs) = typ.split_once('<')?;
    if tname != TAGGED_VALUE_TYP_ROOT_NAME {
        return None;
    }

    let (_, targs) = targs.split_once(',').unwrap(); // SAFETY: Lifetime is always present in the type, skip over lifetime
    let (tag_str, _) = targs.split_once(',').unwrap(); // SAFETY: const TAG: u64 is next
    let tag_str = tag_str.trim();
    Some(if tag_str == "u64::MAX" {
        u64::MAX
    } else {
        tag_str.parse().unwrap() // SAFETY: Tag cannot be anything else than u64
    })
}

impl<'a, const TAG: u64, V: ::serde_core::Serialize + 'a> ::serde_core::Serialize
    for Tagged<'a, TAG, V>
{
    #[inline(always)]
    fn serialize<S>(&self, serializer: S) -> Result<S::Ok, S::Error>
    where
        S: ::serde_core::Serializer,
    {
        serializer.serialize_newtype_struct(std::any::type_name::<Self>(), &self.inner)
    }
}

impl<'a, 'de: 'a, const TAG: u64, V: ::serde_core::Deserialize<'de> + 'a>
    ::serde_core::Deserialize<'de> for Tagged<'a, TAG, V>
{
    #[inline(always)]
    fn deserialize<D>(deserializer: D) -> Result<Self, D::Error>
    where
        D: ::serde_core::Deserializer<'de>,
    {
        struct TaggedValueVisitor<'a, 'de: 'a, const TAG: u64, V: ::serde_core::Deserialize<'de>>(
            std::marker::PhantomData<(&'a V, &'de ())>,
        );

        impl<'a, 'de: 'a, const TAG: u64, V: ::serde_core::Deserialize<'de>>
            ::serde_core::de::Visitor<'de> for TaggedValueVisitor<'a, 'de, TAG, V>
        {
            type Value = Tagged<'a, TAG, V>;

            fn expecting(&self, formatter: &mut std::fmt::Formatter) -> std::fmt::Result {
                write!(formatter, "A CBOR Tagged Value")
            }

            fn visit_newtype_struct<D>(self, deserializer: D) -> Result<Self::Value, D::Error>
            where
                D: ::serde_core::Deserializer<'de>,
            {
                let inner = V::deserialize(deserializer)?;
                Ok(inner.into())
            }
        }

        deserializer.deserialize_newtype_struct(
            std::any::type_name::<Self>(),
            TaggedValueVisitor::<'a, 'de, TAG, V>(Default::default()),
        )
    }
}

impl<'a, const TAG: u64, V: 'a> From<V> for Tagged<'a, TAG, V> {
    #[inline(always)]
    fn from(inner: V) -> Self {
        Self {
            inner,
            _marker: Default::default(),
        }
    }
}

impl<'a, const TAG: u64, V: 'a> std::fmt::Debug for Tagged<'a, TAG, V>
where
    V: std::fmt::Debug,
{
    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
        f.debug_struct("Tagged")
            .field("TAG", &TAG)
            .field("inner", &self.inner)
            .finish()
    }
}

impl<'a, const TAG: u64, V: 'a> PartialEq for Tagged<'a, TAG, V>
where
    V: PartialEq,
{
    #[inline(always)]
    fn eq(&self, other: &Self) -> bool {
        self.inner.eq(&other.inner)
    }
}

impl<'a, const TAG: u64, V: 'a> Tagged<'a, TAG, V> {
    #[inline(always)]
    pub fn into_inner(self) -> V {
        self.inner
    }
}

/// Much like the [`TaggedValue`] wrapper, this is a wrapper around SimpleValues, since they need to be treated a tad differently
#[derive(Debug, Clone, Copy, PartialEq, Eq)]
#[repr(transparent)]
pub struct SimpleValue(pub u8);

impl SimpleValue {
    pub(crate) const TYP_NAME: &'static str = "seabored::serde::SimpleValue";
}

impl ::serde_core::Serialize for SimpleValue {
    fn serialize<S>(&self, serializer: S) -> Result<S::Ok, S::Error>
    where
        S: ::serde_core::Serializer,
    {
        serializer.serialize_newtype_struct(Self::TYP_NAME, self)
    }
}

impl<'de> ::serde_core::Deserialize<'de> for SimpleValue {
    fn deserialize<D>(deserializer: D) -> Result<Self, D::Error>
    where
        D: ::serde_core::Deserializer<'de>,
    {
        struct SimpleValueVisitor;
        impl<'de> ::serde_core::de::Visitor<'de> for SimpleValueVisitor {
            type Value = SimpleValue;

            fn expecting(&self, formatter: &mut std::fmt::Formatter) -> std::fmt::Result {
                write!(formatter, "A CBOR SimpleValue")
            }

            fn visit_newtype_struct<D>(self, deserializer: D) -> Result<Self::Value, D::Error>
            where
                D: ::serde_core::Deserializer<'de>,
            {
                use ::serde_core::Deserialize as _;
                Ok(SimpleValue(u8::deserialize(deserializer)?))
            }
        }

        deserializer.deserialize_newtype_struct(Self::TYP_NAME, SimpleValueVisitor)
    }
}

#[cfg(test)]
mod tests {
    use crate::{
        Value,
        serde::{SimpleValue, Tagged},
    };

    struct Repo;
    impl Repo {
        pub const TV: u64 = 99999;
    }

    #[derive(Debug, PartialEq, Eq, serde::Serialize, serde::Deserialize)]
    struct SubTest<'a> {
        sub: (),
        #[serde(with = "serde_bytes")]
        data: &'a [u8],
    }

    #[derive(Debug, PartialEq, Eq, serde::Serialize, serde::Deserialize)]
    enum Mune {
        Nothing,
        Whatever { id: u32 },
    }

    const TEST_CONST: u64 = 9999999;
    #[derive(Debug, PartialEq, serde::Serialize, serde::Deserialize)]
    struct Test<'a> {
        v1: bool,
        v2: String,
        v3: (),
        v4: Option<u64>,
        #[serde(with = "serde_bytes")]
        v5: Vec<u8>,
        // No serde_bytes
        v5_a: Vec<u8>,
        v6: f32,
        v6_f64: f64,
        v7: Option<i64>,
        v7_pos: Option<i64>,
        #[serde(borrow)]
        v8: Tagged<'a, { Repo::TV }, bool>,
        #[serde(borrow)]
        v9: Tagged<'a, 12u64, std::borrow::Cow<'a, serde_bytes::Bytes>>,
        v10: SimpleValue,
        #[serde(borrow)]
        v11: Tagged<'a, { TEST_CONST }, bool>,
        #[serde(borrow)]
        v12: Tagged<'a, { u64::MAX }, ()>,
        #[serde(borrow)]
        v13: Tagged<'a, 69, Option<u64>>, // nice
        v14: Option<()>,
        v15: Tagged<'a, 420, Value<'a>>, // blaze it
        v16: Value<'a>,
        #[serde(with = "serde_bytes")]
        v17: [u8; 32],
        // No serde_bytes
        v17_a: [u8; 32],
        data: SubTest<'a>,
        mune1: Mune,
        mune2: Mune,
        u8max: u8,
        u16max: u16,
        u32max: u32,
        u64max: u64,
        biguint: u128,
        i8min: i8,
        i16min: i16,
        i32min: i32,
        i64min: i64,
        bigsint: i128,
    }

    impl Default for Test<'_> {
        fn default() -> Self {
            Test {
                v1: false,
                v2: "Here is a test!".into(),
                v3: (),
                v4: None,
                v5: vec![1, 2, 3, 4, 5, 6],
                v5_a: vec![1, 2, 3, 4, 5, 6],
                v6: std::f32::consts::PI,
                v6_f64: f64::MAX,
                v7: Some(-100),
                v7_pos: Some(100),
                v8: false.into(),
                v9: Tagged::from(std::borrow::Cow::Owned(vec![7, 8, 9].into())),
                v10: SimpleValue(59),
                v11: true.into(),
                v12: ().into(),
                v13: Some(64).into(),
                v14: Some(()),
                v15: Tagged::from(Value::Bool(false)),
                v16: Value::Tagged(((u32::MAX as u64).into(), Box::new(Value::Bool(true)))),
                v17: [0x00; 32],
                v17_a: [0x00; 32],
                data: SubTest {
                    sub: (),
                    data: &[1, 43, 35, 64],
                },
                mune1: Mune::Nothing,
                mune2: Mune::Whatever { id: 100 },
                u8max: u8::MAX,
                u16max: u16::MAX,
                u32max: u32::MAX,
                u64max: u64::MAX,
                biguint: u128::MAX,
                i8min: i8::MIN,
                i16min: i16::MIN,
                i32min: i32::MIN,
                i64min: i64::MIN,
                bigsint: i128::MIN,
            }
        }
    }

    #[wasm_bindgen_test::wasm_bindgen_test(unsupported = test)]
    fn can_roundtrip() {
        use pretty_assertions::assert_eq;
        let value = Test::default();

        let mut buf = vec![];
        super::to_writer(&mut buf, &value).unwrap();
        let value2 = super::from_slice::<Test>(&buf).unwrap();
        assert_eq!(value, value2);
    }
}