// A lot of this logic is a re-implementation or copy of serde_json::Value
use crate::Error;
use crate::ObjectHasher;
use crate::{cow::Cow, ErrorType};
use crate::{
    prelude::*,
    serde::value::shared::MapKeyDeserializer,
    value::borrowed::{Object, Value},
};
use serde_ext::{
    de::{
        self, Deserialize, DeserializeSeed, Deserializer, EnumAccess, IntoDeserializer, MapAccess,
        SeqAccess, VariantAccess, Visitor,
    },
    forward_to_deserialize_any,
};
use std::fmt;

impl<'de> de::Deserializer<'de> for Value<'de> {
    type Error = Error;

    // Look at the input data to decide what Serde data model type to
    // deserialize as. Not all data formats are able to support this operation.
    // Formats that support `deserialize_any` are known as self-describing.
    fn deserialize_any<V>(self, visitor: V) -> Result<V::Value, Error>
    where
        V: Visitor<'de>,
    {
        match self {
            Value::Static(StaticNode::Null) => visitor.visit_unit(),
            Value::Static(StaticNode::Bool(b)) => visitor.visit_bool(b),
            Value::Static(StaticNode::I64(n)) => visitor.visit_i64(n),
            #[cfg(feature = "128bit")]
            Value::Static(StaticNode::I128(n)) => visitor.visit_i128(n),
            Value::Static(StaticNode::U64(n)) => visitor.visit_u64(n),
            #[cfg(feature = "128bit")]
            Value::Static(StaticNode::U128(n)) => visitor.visit_u128(n),
            Value::Static(StaticNode::F64(n)) => visitor.visit_f64(n),
            #[cfg(feature = "beef")]
            Value::String(s) => {
                if s.is_borrowed() {
                    visitor.visit_borrowed_str(s.unwrap_borrowed())
                } else {
                    visitor.visit_string(s.into_owned())
                }
            }
            #[cfg(not(feature = "beef"))]
            Value::String(s) => match s {
                Cow::Borrowed(s) => visitor.visit_borrowed_str(s),
                Cow::Owned(s) => visitor.visit_string(s),
            },

            Value::Array(a) => visitor.visit_seq(Array(a.into_iter())),
            Value::Object(o) => visitor.visit_map(ObjectAccess::new(o.into_iter())),
        }
    }

    #[cfg_attr(not(feature = "no-inline"), inline)]
    fn deserialize_option<V>(self, visitor: V) -> Result<V::Value, Error>
    where
        V: Visitor<'de>,
    {
        if self == Value::Static(StaticNode::Null) {
            visitor.visit_unit()
        } else {
            visitor.visit_some(self)
        }
    }

    #[cfg_attr(not(feature = "no-inline"), inline)]
    fn deserialize_enum<V>(
        self,
        _name: &str,
        _variants: &'static [&'static str],
        visitor: V,
    ) -> Result<V::Value, Error>
    where
        V: Visitor<'de>,
    {
        let (variant, value) = match self {
            Value::Object(value) => {
                let mut iter = value.into_iter();
                let (variant, value) = match iter.next() {
                    Some(v) => v,
                    None => {
                        return Err(crate::Deserializer::error(ErrorType::Eof));
                    }
                };
                // enums are encoded in json as maps with a single key:value pair
                if iter.next().is_some() {
                    return Err(crate::Deserializer::error(ErrorType::TrailingData));
                }
                (variant, Some(value))
            }
            Value::String(variant) => (variant, None),
            other => {
                return Err(crate::Deserializer::error(ErrorType::Unexpected(
                    Some(ValueType::Object),
                    Some(other.value_type()),
                )));
            }
        };

        visitor.visit_enum(EnumDeserializer { variant, value })
    }

    #[cfg_attr(not(feature = "no-inline"), inline)]
    fn deserialize_newtype_struct<V>(
        self,
        _name: &'static str,
        visitor: V,
    ) -> Result<V::Value, Error>
    where
        V: Visitor<'de>,
    {
        visitor.visit_newtype_struct(self)
    }

    #[cfg_attr(not(feature = "no-inline"), inline)]
    fn deserialize_struct<V>(
        self,
        _name: &'static str,
        _fields: &'static [&'static str],
        visitor: V,
    ) -> Result<V::Value, Error>
    where
        V: Visitor<'de>,
    {
        match self {
            // Give the visitor access to each element of the sequence.
            Value::Array(a) => visitor.visit_seq(Array(a.into_iter())),
            Value::Object(o) => visitor.visit_map(ObjectAccess::new(o.into_iter())),
            other => Err(crate::Deserializer::error(ErrorType::Unexpected(
                Some(ValueType::Object),
                Some(other.value_type()),
            ))),
        }
    }

    forward_to_deserialize_any! {
        bool i8 i16 i32 i64 i128 u8 u16 u32 u64 u128 f32 f64 char str string
            bytes byte_buf unit unit_struct seq tuple
            tuple_struct map identifier ignored_any
    }
}

struct Array<'de>(std::vec::IntoIter<Value<'de>>);

// `SeqAccess` is provided to the `Visitor` to give it the ability to iterate
// through elements of the sequence.
impl<'de> SeqAccess<'de> for Array<'de> {
    type Error = Error;

    fn next_element_seed<T>(&mut self, seed: T) -> Result<Option<T::Value>, Self::Error>
    where
        T: DeserializeSeed<'de>,
    {
        self.0
            .next()
            .map_or(Ok(None), |v| seed.deserialize(v).map(Some))
    }
}

struct ArrayRef<'de>(std::slice::Iter<'de, Value<'de>>);

// `SeqAccess` is provided to the `Visitor` to give it the ability to iterate
// through elements of the sequence.
impl<'de> SeqAccess<'de> for ArrayRef<'de> {
    type Error = Error;

    fn next_element_seed<T>(&mut self, seed: T) -> Result<Option<T::Value>, Self::Error>
    where
        T: DeserializeSeed<'de>,
    {
        self.0
            .next()
            .map_or(Ok(None), |v| seed.deserialize(v).map(Some))
    }
}

struct ObjectAccess<'de, const N: usize = 32> {
    i: halfbrown::IntoIter<Cow<'de, str>, Value<'de>, N>,
    v: Option<Value<'de>>,
}

impl<'de, const N: usize> ObjectAccess<'de, N> {
    fn new(i: halfbrown::IntoIter<Cow<'de, str>, Value<'de>, N>) -> Self {
        Self { i, v: None }
    }
}

// `MapAccess` is provided to the `Visitor` to give it the ability to iterate
// through entries of the map.
impl<'de> MapAccess<'de> for ObjectAccess<'de> {
    type Error = Error;

    fn next_key_seed<K>(&mut self, seed: K) -> Result<Option<K::Value>, Self::Error>
    where
        K: DeserializeSeed<'de>,
    {
        if let Some((k, v)) = self.i.next() {
            self.v = Some(v);
            seed.deserialize(Value::String(k)).map(Some)
        } else {
            Ok(None)
        }
    }

    fn next_value_seed<V>(&mut self, seed: V) -> Result<V::Value, Self::Error>
    where
        V: DeserializeSeed<'de>,
    {
        match self.v.take() {
            Some(v) => seed.deserialize(v),
            None => Err(crate::Deserializer::error(ErrorType::Eof)),
        }
    }
}

struct ObjectRefAccess<'de> {
    i: halfbrown::Iter<'de, Cow<'de, str>, Value<'de>>,
    v: Option<&'de Value<'de>>,
}
impl<'de> ObjectRefAccess<'de> {
    fn new(i: halfbrown::Iter<'de, Cow<'de, str>, Value<'de>>) -> Self {
        Self { i, v: None }
    }
}

// `MapAccess` is provided to the `Visitor` to give it the ability to iterate
// through entries of the map.
impl<'de> MapAccess<'de> for ObjectRefAccess<'de> {
    type Error = Error;

    fn next_key_seed<K>(&mut self, seed: K) -> Result<Option<K::Value>, Self::Error>
    where
        K: DeserializeSeed<'de>,
    {
        if let Some((k, v)) = self.i.next() {
            self.v = Some(v);
            let s: &str = k;
            seed.deserialize(MapKeyDeserializer::borrowed(s)).map(Some)
        } else {
            Ok(None)
        }
    }

    fn next_value_seed<V>(&mut self, seed: V) -> Result<V::Value, Self::Error>
    where
        V: DeserializeSeed<'de>,
    {
        match self.v.take() {
            Some(v) => seed.deserialize(v),
            None => Err(crate::Deserializer::error(ErrorType::Eof)),
        }
    }
}

impl<'de> Deserialize<'de> for Value<'de> {
    fn deserialize<D>(deserializer: D) -> Result<Value<'de>, D::Error>
    where
        D: Deserializer<'de>,
    {
        deserializer.deserialize_any(ValueVisitor)
    }
}

struct ValueVisitor;

impl<'de> Visitor<'de> for ValueVisitor {
    type Value = Value<'de>;

    fn expecting(&self, formatter: &mut fmt::Formatter) -> fmt::Result {
        formatter.write_str("an JSONesque value")
    }

    /****************** unit ******************/
    #[cfg_attr(not(feature = "no-inline"), inline)]
    fn visit_unit<E>(self) -> Result<Self::Value, E> {
        Ok(Value::Static(StaticNode::Null))
    }

    /****************** bool ******************/
    #[cfg_attr(not(feature = "no-inline"), inline)]
    fn visit_bool<E>(self, value: bool) -> Result<Self::Value, E> {
        Ok(Value::Static(StaticNode::Bool(value)))
    }

    /****************** Option ******************/
    #[cfg_attr(not(feature = "no-inline"), inline)]
    fn visit_none<E>(self) -> Result<Self::Value, E> {
        Ok(Value::Static(StaticNode::Null))
    }

    #[cfg_attr(not(feature = "no-inline"), inline)]
    fn visit_some<D>(self, deserializer: D) -> Result<Self::Value, D::Error>
    where
        D: Deserializer<'de>,
    {
        deserializer.deserialize_any(self)
    }

    /****************** enum ******************/
    /*
    fn visit_enum<A>(self, data: A) -> Result<Self::Value, A::Error> where
        A: EnumAccess<'de>,
    {
    }
     */

    /****************** i64 ******************/
    #[cfg_attr(not(feature = "no-inline"), inline)]
    fn visit_i8<E>(self, value: i8) -> Result<Self::Value, E>
    where
        E: de::Error,
    {
        Ok(Value::Static(StaticNode::I64(i64::from(value))))
    }

    #[cfg_attr(not(feature = "no-inline"), inline)]
    fn visit_i16<E>(self, value: i16) -> Result<Self::Value, E>
    where
        E: de::Error,
    {
        Ok(Value::Static(StaticNode::I64(i64::from(value))))
    }

    #[cfg_attr(not(feature = "no-inline"), inline)]
    fn visit_i32<E>(self, value: i32) -> Result<Self::Value, E>
    where
        E: de::Error,
    {
        Ok(Value::Static(StaticNode::I64(i64::from(value))))
    }

    #[cfg_attr(not(feature = "no-inline"), inline)]
    fn visit_i64<E>(self, value: i64) -> Result<Self::Value, E>
    where
        E: de::Error,
    {
        Ok(Value::Static(StaticNode::I64(value)))
    }

    #[cfg(feature = "128bit")]
    #[cfg_attr(not(feature = "no-inline"), inline)]
    fn visit_i128<E>(self, value: i128) -> Result<Self::Value, E>
    where
        E: de::Error,
    {
        Ok(Value::Static(StaticNode::I128(value)))
    }

    /****************** u64 ******************/

    #[cfg_attr(not(feature = "no-inline"), inline)]
    fn visit_u8<E>(self, value: u8) -> Result<Self::Value, E>
    where
        E: de::Error,
    {
        Ok(Value::Static(StaticNode::U64(u64::from(value))))
    }

    #[cfg_attr(not(feature = "no-inline"), inline)]
    fn visit_u16<E>(self, value: u16) -> Result<Self::Value, E>
    where
        E: de::Error,
    {
        Ok(Value::Static(StaticNode::U64(u64::from(value))))
    }

    #[cfg_attr(not(feature = "no-inline"), inline)]
    fn visit_u32<E>(self, value: u32) -> Result<Self::Value, E>
    where
        E: de::Error,
    {
        Ok(Value::Static(StaticNode::U64(u64::from(value))))
    }

    #[cfg_attr(not(feature = "no-inline"), inline)]
    fn visit_u64<E>(self, value: u64) -> Result<Self::Value, E>
    where
        E: de::Error,
    {
        Ok(Value::Static(StaticNode::U64(value)))
    }

    #[cfg(feature = "128bit")]
    #[cfg_attr(not(feature = "no-inline"), inline)]
    fn visit_u128<E>(self, value: u128) -> Result<Self::Value, E>
    where
        E: de::Error,
    {
        Ok(Value::Static(StaticNode::U128(value)))
    }

    /****************** f64 ******************/

    #[cfg_attr(not(feature = "no-inline"), inline)]
    fn visit_f32<E>(self, value: f32) -> Result<Self::Value, E>
    where
        E: de::Error,
    {
        Ok(Value::Static(StaticNode::F64(f64::from(value))))
    }

    #[cfg_attr(not(feature = "no-inline"), inline)]
    fn visit_f64<E>(self, value: f64) -> Result<Self::Value, E>
    where
        E: de::Error,
    {
        Ok(Value::Static(StaticNode::F64(value)))
    }

    /****************** stringy stuff ******************/
    #[cfg_attr(not(feature = "no-inline"), inline)]
    fn visit_char<E>(self, value: char) -> Result<Self::Value, E>
    where
        E: de::Error,
    {
        Ok(Value::from(value.to_string()))
    }

    #[cfg_attr(not(feature = "no-inline"), inline)]
    fn visit_borrowed_str<E>(self, value: &'de str) -> Result<Self::Value, E>
    where
        E: de::Error,
    {
        Ok(Value::from(value))
    }

    #[cfg_attr(not(feature = "no-inline"), inline)]
    fn visit_str<E>(self, value: &str) -> Result<Self::Value, E>
    where
        E: de::Error,
    {
        Ok(Value::String(value.to_owned().into()))
    }

    #[cfg_attr(not(feature = "no-inline"), inline)]
    fn visit_string<E>(self, value: String) -> Result<Self::Value, E>
    where
        E: de::Error,
    {
        Ok(Value::String(value.into()))
    }

    /****************** byte stuff ******************/

    /*
    #[cfg_attr(not(feature = "no-inline"), inline)]
    fn visit_borrowed_bytes<E>(self, value: &'de [u8]) -> Result<Self::Value, E>
    where
        E: de::Error,
    {
        Ok(Value::String(value))
    }

    #[cfg_attr(not(feature = "no-inline"), inline)]
    fn visit_str<E>(self, value: &[u8]) -> Result<Self::Value, E>
    where
    'a: 'de
        E: de::Error,
    {
      Ok(Value::String(value))
    }

    #[cfg_attr(not(feature = "no-inline"), inline)]
    fn visit_string<E>(self, value: Vec<u8>) -> Result<Self::Value, E>
    where
        E: de::Error,
    {
      Ok(Value::String(&value))
    }
     */
    /****************** nexted stuff ******************/
    #[cfg_attr(not(feature = "no-inline"), inline)]
    fn visit_map<A>(self, mut map: A) -> Result<Self::Value, A::Error>
    where
        A: MapAccess<'de>,
    {
        let size = map.size_hint().unwrap_or_default();

        let mut m = Object::with_capacity_and_hasher(size, ObjectHasher::default());
        while let Some(k) = map.next_key::<&str>()? {
            let v = map.next_value()?;
            m.insert(k.into(), v);
        }
        Ok(Value::from(m))
    }

    #[cfg_attr(not(feature = "no-inline"), inline)]
    fn visit_seq<A>(self, mut seq: A) -> Result<Self::Value, A::Error>
    where
        A: SeqAccess<'de>,
    {
        let size = seq.size_hint().unwrap_or_default();

        let mut v = Vec::with_capacity(size);
        while let Some(e) = seq.next_element()? {
            v.push(e);
        }
        Ok(Value::Array(v))
    }
}

struct EnumDeserializer<'de> {
    variant: Cow<'de, str>,
    value: Option<Value<'de>>,
}

impl<'de> EnumAccess<'de> for EnumDeserializer<'de> {
    type Error = Error;
    type Variant = VariantDeserializer<'de>;

    fn variant_seed<V>(self, seed: V) -> Result<(V::Value, VariantDeserializer<'de>), Error>
    where
        V: DeserializeSeed<'de>,
    {
        let variant = self.variant.into_deserializer();
        let visitor = VariantDeserializer { value: self.value };
        seed.deserialize(variant).map(|v| (v, visitor))
    }
}

impl<'de> IntoDeserializer<'de, Error> for Value<'de> {
    type Deserializer = Self;

    fn into_deserializer(self) -> Self::Deserializer {
        self
    }
}

struct VariantDeserializer<'de> {
    value: Option<Value<'de>>,
}

impl<'de> VariantAccess<'de> for VariantDeserializer<'de> {
    type Error = Error;

    fn unit_variant(self) -> Result<(), Error> {
        match self.value {
            Some(value) => Deserialize::deserialize(value),
            None => Ok(()),
        }
    }

    fn newtype_variant_seed<T>(self, seed: T) -> Result<T::Value, Error>
    where
        T: DeserializeSeed<'de>,
    {
        match self.value {
            Some(value) => seed.deserialize(value),
            None => Err(crate::Deserializer::error(ErrorType::Unexpected(
                Some(ValueType::Object),
                None,
            ))),
        }
    }

    fn tuple_variant<V>(self, _len: usize, visitor: V) -> Result<V::Value, Error>
    where
        V: Visitor<'de>,
    {
        match self.value {
            Some(Value::Array(v)) => {
                if v.is_empty() {
                    visitor.visit_unit()
                } else {
                    visitor.visit_seq(Array(v.into_iter()))
                }
            }
            Some(other) => Err(crate::Deserializer::error(ErrorType::Unexpected(
                Some(ValueType::Array),
                Some(other.value_type()),
            ))),
            None => Err(crate::Deserializer::error(ErrorType::Unexpected(
                Some(ValueType::Array),
                None,
            ))),
        }
    }

    fn struct_variant<V>(
        self,
        _fields: &'static [&'static str],
        visitor: V,
    ) -> Result<V::Value, Error>
    where
        V: Visitor<'de>,
    {
        match self.value {
            Some(Value::Object(o)) => visitor.visit_map(ObjectAccess::new(o.into_iter())),
            Some(other) => Err(crate::Deserializer::error(ErrorType::Unexpected(
                Some(ValueType::Object),
                Some(other.value_type()),
            ))),
            None => Err(crate::Deserializer::error(ErrorType::Unexpected(
                Some(ValueType::Object),
                None,
            ))),
        }
    }
}

impl<'de> de::Deserializer<'de> for &'de Value<'de> {
    type Error = Error;

    // Look at the input data to decide what Serde data model type to
    // deserialize as. Not all data formats are able to support this operation.
    // Formats that support `deserialize_any` are known as self-describing.
    fn deserialize_any<V>(self, visitor: V) -> Result<V::Value, Error>
    where
        V: Visitor<'de>,
    {
        match self {
            Value::Static(StaticNode::Null) => visitor.visit_unit(),
            Value::Static(StaticNode::Bool(b)) => visitor.visit_bool(*b),
            Value::Static(StaticNode::I64(n)) => visitor.visit_i64(*n),
            #[cfg(feature = "128bit")]
            Value::Static(StaticNode::I128(n)) => visitor.visit_i128(*n),
            Value::Static(StaticNode::U64(n)) => visitor.visit_u64(*n),
            #[cfg(feature = "128bit")]
            Value::Static(StaticNode::U128(n)) => visitor.visit_u128(*n),
            Value::Static(StaticNode::F64(n)) => visitor.visit_f64(*n),
            Value::String(s) => visitor.visit_borrowed_str(s),
            Value::Array(a) => visitor.visit_seq(ArrayRef(a.as_slice().iter())),
            Value::Object(o) => visitor.visit_map(ObjectRefAccess::new(o.iter())),
        }
    }

    #[cfg_attr(not(feature = "no-inline"), inline)]
    fn deserialize_option<V>(self, visitor: V) -> Result<V::Value, Error>
    where
        V: Visitor<'de>,
    {
        if self == &Value::Static(StaticNode::Null) {
            visitor.visit_unit()
        } else {
            visitor.visit_some(self)
        }
    }
    #[cfg_attr(not(feature = "no-inline"), inline)]
    fn deserialize_newtype_struct<V>(
        self,
        _name: &'static str,
        visitor: V,
    ) -> Result<V::Value, Error>
    where
        V: Visitor<'de>,
    {
        visitor.visit_newtype_struct(self)
    }

    #[cfg_attr(not(feature = "no-inline"), inline)]
    fn deserialize_struct<V>(
        self,
        _name: &'static str,
        _fields: &'static [&'static str],
        visitor: V,
    ) -> Result<V::Value, Error>
    where
        V: Visitor<'de>,
    {
        match self {
            // Give the visitor access to each element of the sequence.
            Value::Array(a) => visitor.visit_seq(ArrayRef(a.as_slice().iter())),
            Value::Object(o) => visitor.visit_map(ObjectRefAccess::new(o.iter())),
            other => Err(crate::Deserializer::error(ErrorType::Unexpected(
                Some(ValueType::Object),
                Some(other.value_type()),
            ))),
        }
    }

    #[cfg_attr(not(feature = "no-inline"), inline)]
    fn deserialize_enum<V>(
        self,
        _name: &str,
        _variants: &'static [&'static str],
        visitor: V,
    ) -> Result<V::Value, Error>
    where
        V: Visitor<'de>,
    {
        let (variant, value) = match self {
            Value::Object(value) => {
                let mut iter = value.iter();
                let (variant, value) = match iter.next() {
                    Some(v) => v,
                    None => {
                        return Err(crate::Deserializer::error(ErrorType::Eof));
                    }
                };
                // enums are encoded in json as maps with a single key:value pair
                if iter.next().is_some() {
                    return Err(crate::Deserializer::error(ErrorType::TrailingData));
                }
                (variant, Some(value))
            }
            Value::String(variant) => (variant, None),
            other => {
                return Err(crate::Deserializer::error(ErrorType::Unexpected(
                    Some(ValueType::Object),
                    Some(other.value_type()),
                )));
            }
        };

        visitor.visit_enum(EnumRefDeserializer { variant, value })
    }

    forward_to_deserialize_any! {
        bool i8 i16 i32 i64 i128 u8 u16 u32 u64 u128 f32 f64 char str string
            bytes byte_buf unit unit_struct seq tuple
            tuple_struct map identifier ignored_any
    }
}

struct EnumRefDeserializer<'de> {
    variant: &'de Cow<'de, str>,
    value: Option<&'de Value<'de>>,
}

impl<'de> EnumAccess<'de> for EnumRefDeserializer<'de> {
    type Error = Error;
    type Variant = VariantRefDeserializer<'de>;

    #[cfg(feature = "beef")]
    fn variant_seed<V>(self, seed: V) -> Result<(V::Value, Self::Variant), Error>
    where
        V: DeserializeSeed<'de>,
    {
        let variant = self.variant.into_deserializer();
        let visitor = VariantRefDeserializer { value: self.value };
        seed.deserialize(variant).map(|v| (v, visitor))
    }
    #[cfg(not(feature = "beef"))]
    fn variant_seed<V>(self, seed: V) -> Result<(V::Value, Self::Variant), Error>
    where
        V: DeserializeSeed<'de>,
    {
        let var: &str = self.variant;
        let variant = var.into_deserializer();
        let visitor = VariantRefDeserializer { value: self.value };
        seed.deserialize(variant).map(|v| (v, visitor))
    }
}
struct VariantRefDeserializer<'de> {
    value: Option<&'de Value<'de>>,
}

impl<'de> VariantAccess<'de> for VariantRefDeserializer<'de> {
    type Error = Error;

    fn unit_variant(self) -> Result<(), Error> {
        match self.value {
            Some(value) => Deserialize::deserialize(value),
            None => Ok(()),
        }
    }

    fn newtype_variant_seed<T>(self, seed: T) -> Result<T::Value, Error>
    where
        T: DeserializeSeed<'de>,
    {
        match self.value {
            Some(value) => seed.deserialize(value),
            None => Err(crate::Deserializer::error(ErrorType::Unexpected(
                Some(ValueType::Object),
                None,
            ))),
        }
    }

    fn tuple_variant<V>(self, _len: usize, visitor: V) -> Result<V::Value, Error>
    where
        V: Visitor<'de>,
    {
        match self.value {
            Some(Value::Array(v)) => {
                if v.is_empty() {
                    visitor.visit_unit()
                } else {
                    visitor.visit_seq(ArrayRef(v.as_slice().iter()))
                }
            }
            Some(other) => Err(crate::Deserializer::error(ErrorType::Unexpected(
                Some(ValueType::Array),
                Some(other.value_type()),
            ))),
            None => Err(crate::Deserializer::error(ErrorType::Unexpected(
                Some(ValueType::Array),
                None,
            ))),
        }
    }

    fn struct_variant<V>(
        self,
        _fields: &'static [&'static str],
        visitor: V,
    ) -> Result<V::Value, Error>
    where
        V: Visitor<'de>,
    {
        match self.value {
            Some(Value::Object(o)) => visitor.visit_map(ObjectRefAccess::new(o.iter())),
            Some(other) => Err(crate::Deserializer::error(ErrorType::Unexpected(
                Some(ValueType::Object),
                Some(other.value_type()),
            ))),
            None => Err(crate::Deserializer::error(ErrorType::Unexpected(
                Some(ValueType::Object),
                None,
            ))),
        }
    }
}

#[cfg(test)]
mod test {
    use serde::Deserialize;

    use crate::{borrowed, json, prelude::*};

    #[test]
    fn option_field_absent_owned() {
        #[derive(serde::Deserialize, Debug)]
        pub struct Person {
            pub name: String,
            pub middle_name: Option<String>,
            pub friends: Vec<String>,
        }
        let mut raw_json = r#"{"name":"bob","friends":[]}"#.to_string();
        let result: Result<Person, _> =
            crate::to_borrowed_value(unsafe { raw_json.as_bytes_mut() })
                .and_then(super::super::from_value);
        assert!(result.is_ok());
    }
    #[test]
    fn option_field_present_owned() {
        #[derive(serde::Deserialize, Debug)]
        pub struct Point {
            pub x: u64,
            pub y: u64,
        }
        #[derive(serde::Deserialize, Debug)]
        pub struct Person {
            pub name: String,
            pub middle_name: Option<String>,
            pub friends: Vec<String>,
            pub pos: Point,
        }

        let mut raw_json =
            r#"{"name":"bob","middle_name": "frank", "friends":[], "pos":[0,1]}"#.to_string();
        let result: Result<Person, _> =
            crate::to_borrowed_value(unsafe { raw_json.as_bytes_mut() })
                .and_then(super::super::from_value);
        assert!(result.is_ok());
    }

    #[test]
    fn deserialize() {
        use halfbrown::{hashmap, HashMap};
        #[derive(serde::Deserialize, Debug, PartialEq, Eq)]
        #[serde(rename_all = "lowercase")]
        pub enum Rotate {
            Left,
            Right,
            Up,
            Down,
        }
        #[derive(serde::Deserialize, Debug, PartialEq)]
        pub struct Point {
            pub x: i64,
            pub y: i64,
            pub z: f64,
            pub rotate: Rotate,
        }
        #[derive(serde::Deserialize, Debug, PartialEq)]
        pub struct Person {
            pub name: String,
            pub middle_name: Option<String>,
            pub friends: Vec<String>,
            pub pos: Point,
            pub age: u64,
        }
        #[derive(serde::Deserialize, Debug, PartialEq, Eq)]
        pub struct TestStruct {
            pub key: HashMap<String, String>,
            pub vec: Vec<Vec<Option<u8>>>,
        }

        let mut raw_json =
            r#"{"name":"bob","middle_name": "frank", "friends":[], "pos": [-1, 2, -3.25, "up"], "age": 123}"#.to_string();
        let value =
            crate::to_borrowed_value(unsafe { raw_json.as_bytes_mut() }).expect("to_owned_value");
        let result: Person = super::super::from_refvalue(&value).expect("from_refvalue");
        let expected = Person {
            name: "bob".to_string(),
            middle_name: Some("frank".to_string()),
            friends: Vec::new(),
            pos: Point {
                x: -1,
                y: 2,
                z: -3.25_f64,
                rotate: Rotate::Up,
            },
            age: 123,
        };
        assert_eq!(result, expected);

        let mut raw_json = r#"{"key":{"subkey": "value"}, "vec":[[null], [1]]}"#.to_string();
        let value =
            crate::to_borrowed_value(unsafe { raw_json.as_bytes_mut() }).expect("to_owned_value");
        let result: TestStruct = super::super::from_refvalue(&value).expect("from_refvalue");
        let expected = TestStruct {
            key: hashmap!("subkey".to_string() => "value".to_string()),
            vec: vec![vec![None], vec![Some(1)]],
        };
        assert_eq!(result, expected);
    }

    #[cfg(feature = "128bit")]
    #[test]
    fn deserialize_128bit() {
        let value = i64::MIN as i128 - 1;
        let int128 = crate::BorrowedValue::Static(crate::StaticNode::I128(value));
        let res: i128 = super::super::from_refvalue(&int128).expect("from_refvalue");
        assert_eq!(value, res);

        let value = u64::MAX as u128;
        let int128 = crate::BorrowedValue::Static(crate::StaticNode::U128(value));
        let res: u128 = super::super::from_refvalue(&int128).expect("from_refvalue");
        assert_eq!(value, res);
    }

    #[test]
    fn variant() {
        struct NameAndConfig<'v> {
            name: String,
            config: Option<borrowed::Value<'v>>,
        }
        impl<'v> serde::Deserialize<'v> for NameAndConfig<'v> {
            fn deserialize<D>(deserializer: D) -> std::result::Result<Self, D::Error>
            where
                D: serde::Deserializer<'v>,
            {
                #[derive(Deserialize)]
                // This is ugly but it's needed for `serde::Deserialize` to not explode on lifetimes
                // An error like this is otherwise produced:
                //     error: lifetime may not live long enough
                //     --> src/serde/value/borrowed/de.rs:960:25
                //      |
                //  953 |                 #[derive(Deserialize)]
                //      |                          ----------- lifetime `'de` defined here
                //  ...
                //  956 |                 enum Variants<'v> {
                //      |                               -- lifetime `'v` defined here
                //  ...
                //  960 |                         config: Option<borrowed::Value<'v>>,
                //      |                         ^^^^^^ requires that `'de` must outlive `'v`
                //      |
                //      = help: consider adding the following bound: `'de: 'v`

                //  error: lifetime may not live long enough
                //     --> src/serde/value/borrowed/de.rs:960:25
                //      |
                //  953 |                 #[derive(Deserialize)]
                //      |                          ----------- lifetime `'de` defined here
                //  ...
                //  956 |                 enum Variants<'v> {
                //      |                               -- lifetime `'v` defined here
                //  ...
                //  960 |                         config: Option<borrowed::Value<'v>>,
                //      |                         ^^^^^^ requires that `'v` must outlive `'de`
                //      |
                //      = help: consider adding the following bound: `'v: 'de`
                #[serde(bound(deserialize = "'de: 'v, 'v: 'de"), untagged)]
                enum Variants<'v> {
                    Name(String),
                    NameAndConfig {
                        name: String,
                        config: Option<borrowed::Value<'v>>,
                    },
                }

                let var = Variants::deserialize(deserializer)?;

                match var {
                    Variants::Name(name) => Ok(NameAndConfig { name, config: None }),
                    Variants::NameAndConfig { name, config } => Ok(NameAndConfig { name, config }),
                }
            }
        }

        let v = json!({"name": "name", "config": 42});
        let nac = NameAndConfig::deserialize(v).expect("could structurize two element struct");
        assert_eq!(nac.name, "name");
        assert_eq!(nac.config.as_u8(), Some(42));
        let v = json!({"name": "name"});
        let nac = NameAndConfig::deserialize(v).expect("could structurize one element struct");
        assert_eq!(nac.name, "name");
        assert_eq!(nac.config, None);
        let v = json!("name");
        let nac = NameAndConfig::deserialize(v).expect("could structurize string");
        assert_eq!(nac.name, "name");
        assert_eq!(nac.config, None);
    }
}