cgp-serde 0.1.0-alpha

use core::fmt::Display;

use cgp::prelude::*;
use serde::ser::SerializeMap;

use crate::alloc::string::ToString;
use crate::components::{CanSerializeValue, ValueSerializer, ValueSerializerComponent};
use crate::types::SerializeWithContext;

#[cgp_new_provider]
impl<Context, Value> ValueSerializer<Context, Value> for SerializeFields
where
    Value: HasFields,
    Value::Fields: FieldsSerializer<Context, Value>,
{
    fn serialize<S>(context: &Context, value: &Value, serializer: S) -> Result<S::Ok, S::Error>
    where
        S: serde::Serializer,
    {
        let s = serializer.serialize_map(None)?;
        Value::Fields::serialize_fields(context, value, s)
    }
}

trait FieldsSerializer<Context, Value> {
    fn serialize_fields<S>(
        context: &Context,
        value: &Value,
        serializer: S,
    ) -> Result<S::Ok, S::Error>
    where
        S: SerializeMap;
}

impl<Context, Value, Tag, FieldValue, Rest> FieldsSerializer<Context, Value>
    for Cons<Field<Tag, FieldValue>, Rest>
where
    Tag: Default + Display,
    Value: HasField<Tag, Value = FieldValue>,
    Context: CanSerializeValue<FieldValue>,
    Rest: FieldsSerializer<Context, Value>,
{
    fn serialize_fields<S>(
        context: &Context,
        value: &Value,
        mut serializer: S,
    ) -> Result<S::Ok, S::Error>
    where
        S: SerializeMap,
    {
        let tag = Tag::default().to_string();
        let field_value = value.get_field(PhantomData);
        serializer.serialize_entry(
            &tag,
            &SerializeWithContext {
                context,
                value: field_value,
            },
        )?;
        Rest::serialize_fields(context, value, serializer)
    }
}

impl<Context, Value> FieldsSerializer<Context, Value> for Nil {
    fn serialize_fields<S>(
        _context: &Context,
        _value: &Value,
        serializer: S,
    ) -> Result<S::Ok, S::Error>
    where
        S: SerializeMap,
    {
        serializer.end()
    }
}