use super::{to_value, Map, Value};
use crate::{ser::StringSerializer, Error, Number, Result};
use serde::ser;
use std::fmt::Display;

impl ser::Serialize for Value {
    fn serialize<S>(&self, serializer: S) -> Result<S::Ok, S::Error>
    where
        S: ser::Serializer,
    {
        match *self {
            Value::Null => serializer.serialize_unit(),
            Value::Bool(b) => serializer.serialize_bool(b),
            Value::Number(ref n) => n.serialize(serializer),
            Value::String(ref s) => serializer.serialize_str(s),
            Value::Array(ref v) => v.serialize(serializer),
            Value::Object(ref v) => v.serialize(serializer),
        }
    }
}

pub struct ValueSerializer;

impl ser::Serializer for ValueSerializer {
    type Ok = Value;
    type Error = Error;

    type SerializeSeq = SerializeSeq;
    type SerializeTuple = SerializeSeq;
    type SerializeTupleStruct = SerializeSeq;
    type SerializeTupleVariant = SerializeTupleVariant;
    type SerializeMap = SerializeMap;
    type SerializeStruct = SerializeMap;
    type SerializeStructVariant = SerializeStructVariant;

    serialize_self! { some newtype_struct }
    forward_to_serialize_seq! { tuple tuple_struct }

    fn serialize_bool(self, value: bool) -> Result<Self::Ok> {
        Ok(Value::Bool(value))
    }

    fn serialize_i8(self, value: i8) -> Result<Self::Ok> {
        self.serialize_i64(value as i64)
    }

    fn serialize_i16(self, value: i16) -> Result<Self::Ok> {
        self.serialize_i64(value as i64)
    }

    fn serialize_i32(self, value: i32) -> Result<Self::Ok> {
        self.serialize_i64(value as i64)
    }

    fn serialize_i64(self, value: i64) -> Result<Self::Ok> {
        Ok(Value::Number(value.into()))
    }

    fn serialize_u8(self, value: u8) -> Result<Self::Ok> {
        self.serialize_u64(value as u64)
    }

    fn serialize_u16(self, value: u16) -> Result<Self::Ok> {
        self.serialize_u64(value as u64)
    }

    fn serialize_u32(self, value: u32) -> Result<Self::Ok> {
        self.serialize_u64(value as u64)
    }

    fn serialize_u64(self, value: u64) -> Result<Self::Ok> {
        Ok(Value::Number(value.into()))
    }

    fn serialize_f32(self, value: f32) -> Result<Self::Ok> {
        self.serialize_f64(value as f64)
    }

    fn serialize_f64(self, value: f64) -> Result<Self::Ok> {
        Ok(Number::from_f64(value).map_or(Value::Null, Value::Number))
    }

    fn serialize_char(self, value: char) -> Result<Self::Ok> {
        Ok(Value::String(value.to_string()))
    }

    fn serialize_str(self, value: &str) -> Result<Self::Ok> {
        Ok(Value::String(value.to_owned()))
    }

    fn serialize_bytes(self, value: &[u8]) -> Result<Self::Ok> {
        let vec = value.iter().map(|&b| Value::Number(b.into())).collect();
        Ok(Value::Array(vec))
    }

    fn serialize_unit(self) -> Result<Self::Ok> {
        Ok(Value::Null)
    }

    fn serialize_unit_struct(self, _name: &'static str) -> Result<Self::Ok> {
        self.serialize_unit()
    }

    fn serialize_unit_variant(
        self,
        _name: &'static str,
        _variant_index: u32,
        variant: &'static str,
    ) -> Result<Self::Ok> {
        self.serialize_str(variant)
    }

    fn serialize_newtype_variant<T>(
        self,
        _name: &'static str,
        _variant_index: u32,
        variant: &'static str,
        value: &T,
    ) -> Result<Self::Ok>
    where
        T: ?Sized + ser::Serialize,
    {
        let mut object = Map::with_capacity(1);
        object.insert(variant.to_owned(), to_value(value)?);
        Ok(Value::Object(object))
    }

    fn serialize_none(self) -> Result<Self::Ok> {
        self.serialize_unit()
    }

    fn serialize_seq(self, len: Option<usize>) -> Result<Self::SerializeSeq> {
        Ok(SerializeSeq {
            vec: Vec::with_capacity(len.unwrap_or(0)),
        })
    }

    fn serialize_tuple_variant(
        self,
        _name: &'static str,
        _variant_index: u32,
        variant: &'static str,
        len: usize,
    ) -> Result<Self::SerializeTupleVariant> {
        Ok(SerializeTupleVariant {
            name: variant.to_owned(),
            vec: Vec::with_capacity(len),
        })
    }

    fn serialize_map(self, len: Option<usize>) -> Result<Self::SerializeMap> {
        Ok(SerializeMap {
            map: Map::with_capacity(len.unwrap_or(0)),
            next_key: None,
        })
    }

    fn serialize_struct(self, _name: &'static str, len: usize) -> Result<Self::SerializeStruct> {
        self.serialize_map(Some(len))
    }

    fn serialize_struct_variant(
        self,
        _name: &'static str,
        _variant_index: u32,
        variant: &'static str,
        len: usize,
    ) -> Result<Self::SerializeStructVariant> {
        Ok(SerializeStructVariant {
            name: variant.to_owned(),
            map: Map::with_capacity(len),
        })
    }

    fn collect_str<T>(self, value: &T) -> Result<Self::Ok>
    where
        T: ?Sized + Display,
    {
        Ok(Value::String(value.to_string()))
    }
}

pub struct SerializeSeq {
    vec: Vec<Value>,
}

impl ser::SerializeSeq for SerializeSeq {
    type Ok = Value;
    type Error = Error;

    fn serialize_element<T>(&mut self, value: &T) -> Result<()>
    where
        T: ?Sized + ser::Serialize,
    {
        self.vec.push(to_value(value)?);
        Ok(())
    }

    fn end(self) -> Result<Self::Ok> {
        Ok(Value::Array(self.vec))
    }
}

impl ser::SerializeTuple for SerializeSeq {
    impl_forward_to_serialize_seq!(serialize_element, Value);
}

impl ser::SerializeTupleStruct for SerializeSeq {
    impl_forward_to_serialize_seq!(serialize_field, Value);
}

pub struct SerializeTupleVariant {
    name: String,
    vec: Vec<Value>,
}

impl ser::SerializeTupleVariant for SerializeTupleVariant {
    type Ok = Value;
    type Error = Error;

    fn serialize_field<T>(&mut self, value: &T) -> Result<()>
    where
        T: ?Sized + ser::Serialize,
    {
        self.vec.push(to_value(value)?);
        Ok(())
    }

    fn end(self) -> Result<Self::Ok> {
        let mut object = Map::with_capacity(1);
        object.insert(self.name, self.vec.into());
        Ok(Value::Object(object))
    }
}

pub struct SerializeMap {
    map: Map<String, Value>,
    next_key: Option<String>,
}

impl ser::SerializeMap for SerializeMap {
    type Ok = Value;
    type Error = Error;

    fn serialize_key<T>(&mut self, key: &T) -> Result<()>
    where
        T: ?Sized + ser::Serialize,
    {
        self.next_key = Some(key.serialize(StringSerializer)?);
        Ok(())
    }

    fn serialize_value<T>(&mut self, value: &T) -> Result<()>
    where
        T: ?Sized + ser::Serialize,
    {
        let key = self.next_key.take();
        let key = key.expect("serialize_value called before serialize_key");
        self.map.insert(key, to_value(value)?);
        Ok(())
    }

    fn end(self) -> Result<Self::Ok> {
        Ok(Value::Object(self.map))
    }
}

impl ser::SerializeStruct for SerializeMap {
    type Ok = Value;
    type Error = Error;

    fn serialize_field<T>(&mut self, key: &'static str, value: &T) -> Result<()>
    where
        T: ?Sized + ser::Serialize,
    {
        ser::SerializeMap::serialize_entry(self, key, value)
    }

    fn end(self) -> Result<Self::Ok> {
        ser::SerializeMap::end(self)
    }
}

pub struct SerializeStructVariant {
    name: String,
    map: Map<String, Value>,
}

impl ser::SerializeStructVariant for SerializeStructVariant {
    type Ok = Value;
    type Error = Error;

    fn serialize_field<T>(&mut self, key: &'static str, value: &T) -> Result<()>
    where
        T: ?Sized + ser::Serialize,
    {
        self.map.insert(key.to_owned(), to_value(value)?);
        Ok(())
    }

    fn end(self) -> Result<Self::Ok> {
        let mut object = Map::with_capacity(1);
        object.insert(self.name, self.map.into());
        Ok(Value::Object(object))
    }
}