#pragma once
#include <string_view>
#include <memory>
#include <string>
namespace drogon
{
class HttpMessageBody
{
  public:
    enum class BodyType
    {
        kNone = 0,
        kString,
        kStringView
    };
    BodyType bodyType()
    {
        return type_;
    }
    virtual const char *data() const
    {
        return nullptr;
    }
    virtual char *data()
    {
        return nullptr;
    }
    virtual size_t length() const
    {
        return 0;
    }
    virtual std::string_view getString() const = 0;
    virtual void append(const char * , size_t )
    {
    }
    virtual ~HttpMessageBody()
    {
    }
  protected:
    BodyType type_{BodyType::kNone};
};
class HttpMessageStringBody : public HttpMessageBody
{
  public:
    HttpMessageStringBody()
    {
        type_ = BodyType::kString;
    }
    HttpMessageStringBody(const std::string &body) : body_(body)
    {
        type_ = BodyType::kString;
    }
    HttpMessageStringBody(std::string &&body) : body_(std::move(body))
    {
        type_ = BodyType::kString;
    }
    const char *data() const override
    {
        return body_.data();
    }
    char *data() override
    {
        return const_cast<char *>(body_.data());
    }
    size_t length() const override
    {
        return body_.length();
    }
    std::string_view getString() const override
    {
        return std::string_view{body_.data(), body_.length()};
    }
    void append(const char *buf, size_t len) override
    {
        body_.append(buf, len);
    }
  private:
    std::string body_;
};
class HttpMessageStringViewBody : public HttpMessageBody
{
  public:
    HttpMessageStringViewBody(const char *buf, size_t len) : body_(buf, len)
    {
        type_ = BodyType::kStringView;
    }
    const char *data() const override
    {
        return body_.data();
    }
    char *data() override
    {
        return const_cast<char *>(body_.data());
    }
    size_t length() const override
    {
        return body_.length();
    }
    std::string_view getString() const override
    {
        return body_;
    }
  private:
    std::string_view body_;
};
}