package sdk

import (
	"context"
	"encoding/json"
)

type Encoder[T any] interface {
	Get(ctx context.Context, key string) (val T, ok bool, meta StateMetadata, err error)
	Set(ctx context.Context, key string, val T) error
}

var _ Encoder[struct{}] = (*JSONStateEncoder[struct{}])(nil)

func NewJSONStateEncoder[T any](ctx ExecutionContext) *JSONStateEncoder[T] {
	return &JSONStateEncoder[T]{
		Context: ctx,
	}
}

type JSONStateEncoder[T any] struct {
	Context ExecutionContext
}

func (j JSONStateEncoder[T]) Get(ctx context.Context, key string) (val T, ok bool, meta StateMetadata, err error) {
	var data []byte

	data, meta, err = j.Context.GetState(ctx, key)
	if err != nil {
		return val, false, StateMetadata{}, err
	}

	if len(data) == 0 {
		return val, false, meta, nil
	}

	if err := json.Unmarshal(data, &val); err != nil {
		return val, false, StateMetadata{}, err
	}

	return val, true, meta, nil
}

func (j JSONStateEncoder[T]) Set(ctx context.Context, key string, val T) error {
	data, err := json.Marshal(val)
	if err != nil {
		return err
	}

	return j.Context.SetState(ctx, key, data)
}