use serde::de::{self, IgnoredAny};

use crate::{
    error::{Ensure, SemanticError},
    from_str,
    value::{JsoncValue, MapImpl},
};

use super::deserializer::ValueDeserializer;

pub struct ValueMapDeserializer<'de, I, F> {
    iter: Box<dyn Iterator<Item = (&'de String, &'de JsoncValue<I, F>)> + 'de>,
    next: Option<&'de JsoncValue<I, F>>,
}

impl<'de, I, F> ValueMapDeserializer<'de, I, F>
where
    I: num::ToPrimitive,
    F: num::ToPrimitive,
{
    pub fn new(map: &'de MapImpl<String, JsoncValue<I, F>>) -> Self {
        ValueMapDeserializer { iter: Box::new(map.iter()), next: None }
    }
}

impl<'de, I, F> de::MapAccess<'de> for ValueMapDeserializer<'de, I, F>
where
    I: num::ToPrimitive,
    F: num::ToPrimitive,
{
    type Error = crate::Error;

    fn next_key_seed<K>(&mut self, seed: K) -> Result<Option<K::Value>, Self::Error>
    where
        K: de::DeserializeSeed<'de>,
    {
        self.iter.next().map_or(Ok(None), |(k, v)| {
            self.next = Some(v);
            seed.deserialize(ValueMapKeyDeserializer::new(k)).map(Some)
        })
    }

    fn next_value_seed<V>(&mut self, seed: V) -> Result<V::Value, Self::Error>
    where
        V: de::DeserializeSeed<'de>,
    {
        self.next.take().map(|v| seed.deserialize(ValueDeserializer::new(v))).ok_or(Ensure::NextValue)?
    }

    fn size_hint(&self) -> Option<usize> {
        self.iter.size_hint().1
    }
}

pub struct ValueMapKeyDeserializer<'de> {
    key: &'de str,
}

impl<'de> ValueMapKeyDeserializer<'de> {
    pub fn new(key: &'de str) -> Self {
        ValueMapKeyDeserializer { key }
    }
}

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

    fn deserialize_any<V>(self, visitor: V) -> Result<V::Value, Self::Error>
    where
        V: de::Visitor<'de>,
    {
        self.deserialize_str(visitor)
    }

    fn deserialize_bool<V>(self, visitor: V) -> Result<V::Value, Self::Error>
    where
        V: de::Visitor<'de>,
    {
        visitor.visit_bool(from_str(self.key)?)
    }

    fn deserialize_i8<V>(self, visitor: V) -> Result<V::Value, Self::Error>
    where
        V: de::Visitor<'de>,
    {
        visitor.visit_i8(from_str(self.key)?)
    }

    fn deserialize_i16<V>(self, visitor: V) -> Result<V::Value, Self::Error>
    where
        V: de::Visitor<'de>,
    {
        visitor.visit_i16(from_str(self.key)?)
    }

    fn deserialize_i32<V>(self, visitor: V) -> Result<V::Value, Self::Error>
    where
        V: de::Visitor<'de>,
    {
        visitor.visit_i32(from_str(self.key)?)
    }

    fn deserialize_i64<V>(self, visitor: V) -> Result<V::Value, Self::Error>
    where
        V: de::Visitor<'de>,
    {
        visitor.visit_i64(from_str(self.key)?)
    }

    fn deserialize_u8<V>(self, visitor: V) -> Result<V::Value, Self::Error>
    where
        V: de::Visitor<'de>,
    {
        visitor.visit_u8(from_str(self.key)?)
    }

    fn deserialize_u16<V>(self, visitor: V) -> Result<V::Value, Self::Error>
    where
        V: de::Visitor<'de>,
    {
        visitor.visit_u16(from_str(self.key)?)
    }

    fn deserialize_u32<V>(self, visitor: V) -> Result<V::Value, Self::Error>
    where
        V: de::Visitor<'de>,
    {
        visitor.visit_u32(from_str(self.key)?)
    }

    fn deserialize_u64<V>(self, visitor: V) -> Result<V::Value, Self::Error>
    where
        V: de::Visitor<'de>,
    {
        visitor.visit_u64(from_str(self.key)?)
    }

    fn deserialize_f32<V>(self, visitor: V) -> Result<V::Value, Self::Error>
    where
        V: de::Visitor<'de>,
    {
        visitor.visit_f32(from_str(self.key)?)
    }

    fn deserialize_f64<V>(self, visitor: V) -> Result<V::Value, Self::Error>
    where
        V: de::Visitor<'de>,
    {
        visitor.visit_f64(from_str(self.key)?)
    }

    fn deserialize_char<V>(self, visitor: V) -> Result<V::Value, Self::Error>
    where
        V: de::Visitor<'de>,
    {
        visitor.visit_char(from_str(self.key)?)
    }

    fn deserialize_str<V>(self, visitor: V) -> Result<V::Value, Self::Error>
    where
        V: de::Visitor<'de>,
    {
        visitor.visit_borrowed_str(self.key)
    }

    fn deserialize_string<V>(self, visitor: V) -> Result<V::Value, Self::Error>
    where
        V: de::Visitor<'de>,
    {
        visitor.visit_borrowed_str(self.key)
    }

    fn deserialize_bytes<V>(self, visitor: V) -> Result<V::Value, Self::Error>
    where
        V: de::Visitor<'de>,
    {
        visitor.visit_bytes(self.key.as_bytes())
    }

    fn deserialize_byte_buf<V>(self, visitor: V) -> Result<V::Value, Self::Error>
    where
        V: de::Visitor<'de>,
    {
        visitor.visit_byte_buf(self.key.as_bytes().to_vec())
    }

    fn deserialize_option<V>(self, visitor: V) -> Result<V::Value, Self::Error>
    where
        V: de::Visitor<'de>,
    {
        // Map key cannot be null
        visitor.visit_some(self)
    }

    fn deserialize_unit<V>(self, visitor: V) -> Result<V::Value, Self::Error>
    where
        V: de::Visitor<'de>,
    {
        visitor.visit_unit()
    }

    fn deserialize_unit_struct<V>(self, _name: &'static str, visitor: V) -> Result<V::Value, Self::Error>
    where
        V: de::Visitor<'de>,
    {
        self.deserialize_unit(visitor)
    }

    fn deserialize_newtype_struct<V>(self, _name: &'static str, _visitor: V) -> Result<V::Value, Self::Error>
    where
        V: de::Visitor<'de>,
    {
        Err(SemanticError::AnyMapKey)?
    }

    fn deserialize_seq<V>(self, _visitor: V) -> Result<V::Value, Self::Error>
    where
        V: de::Visitor<'de>,
    {
        Err(SemanticError::AnyMapKey)?
    }

    fn deserialize_tuple<V>(self, _len: usize, _visitor: V) -> Result<V::Value, Self::Error>
    where
        V: de::Visitor<'de>,
    {
        Err(SemanticError::AnyMapKey)?
    }

    fn deserialize_tuple_struct<V>(self, _name: &'static str, _len: usize, _visitor: V) -> Result<V::Value, Self::Error>
    where
        V: de::Visitor<'de>,
    {
        Err(SemanticError::AnyMapKey)?
    }

    fn deserialize_map<V>(self, _visitor: V) -> Result<V::Value, Self::Error>
    where
        V: de::Visitor<'de>,
    {
        Err(SemanticError::AnyMapKey)?
    }

    fn deserialize_struct<V>(
        self,
        _name: &'static str,
        _fields: &'static [&'static str],
        _visitor: V,
    ) -> Result<V::Value, Self::Error>
    where
        V: de::Visitor<'de>,
    {
        Err(SemanticError::AnyMapKey)?
    }

    fn deserialize_enum<V>(
        self,
        _name: &'static str,
        _variants: &'static [&'static str],
        _visitor: V,
    ) -> Result<V::Value, Self::Error>
    where
        V: de::Visitor<'de>,
    {
        Err(SemanticError::AnyMapKey)?
    }

    fn deserialize_identifier<V>(self, visitor: V) -> Result<V::Value, Self::Error>
    where
        V: de::Visitor<'de>,
    {
        self.deserialize_str(visitor)
    }

    fn deserialize_ignored_any<V>(self, visitor: V) -> Result<V::Value, Self::Error>
    where
        V: de::Visitor<'de>,
    {
        let _ = self.deserialize_any(IgnoredAny)?;
        visitor.visit_unit()
    }
}