// Copyright (c) Microsoft Corporation. All rights reserved.
// Licensed under the MIT License.

#pragma once

#include <variant>

#include "bpe_kernels.h"
#include "ugm_kernels.hpp"
#include "tokenizer_jsconfig.hpp"
#include "bpe_streaming.hpp"
#include "c_api_utils.hpp"
#include "minja.hpp"

namespace ort_extensions {

class TokenizerImpl : public OrtxObjectImpl {
 public:
  TokenizerImpl();
  virtual ~TokenizerImpl();

 public:
  OrtxStatus Load(const std::string& tok_path);
  OrtxStatus Load(const OrtxTokenizerBlob& blob);

  OrtxStatus Tokenize(const std::vector<std::string_view>& input, std::vector<std::vector<extTokenId_t>>& t_ids) const {
    return BatchEncode(input, t_ids);
  }

  OrtxStatus Detokenize(const std::vector<span<extTokenId_t const>>& t_ids, std::vector<std::string>& t_text) const {
    return BatchDecode(t_ids, t_text);
  }

  OrtxStatus Token2Id(const std::string& token, extTokenId_t& id) const {
    id = std::visit([&](auto& tokenizer) { return tokenizer->GetTokenId(token); }, tokenizer_);
    return {};
  }

  OrtxStatus Id2Token(extTokenId_t id, std::string& token, std::unique_ptr<TokenizerDecodingState>& cache) const {
    TokenizerDecodingState* state_ptr = cache.get();
    OrtxStatus status = Id2Token(id, token, &state_ptr);
    if (status.IsOk()) {
      if (state_ptr != cache.get()) {
        cache.reset(state_ptr);
      }
    }

    return status;
  }

  OrtxStatus BatchEncode(const std::vector<std::string_view>& input,
                         std::vector<std::vector<extTokenId_t>>& t_ids) const;

  OrtxStatus BatchDecode(const std::vector<span<extTokenId_t const>>& t_ids, std::vector<std::string>& t_text) const;

  using MessageList = std::vector<std::unordered_map<std::string, std::string>>;
  std::string chat_template;
  mutable MessageList messages;

  std::string bos_token;
  std::string eos_token;
  std::vector<std::string> custom_tools;
  bool tools_in_user_message;
  std::string strftime_now;
  std::string date_string;
  std::vector<std::string> builtin_tools;

  OrtxStatus PhiVisionChatTemplate(std::string& output, bool add_generation_prompt) const;
  OrtxStatus Phi3ChatTemplate(std::string& output, bool add_generation_prompt) const;
  OrtxStatus Phi3_5ChatTemplate(std::string& output, bool add_generation_prompt) const;
  OrtxStatus Phi3SmallChatTemplate(std::string& output, bool add_generation_prompt) const;
  OrtxStatus Phi3MediumChatTemplate(std::string& output, bool add_generation_prompt) const;
  OrtxStatus Phi4ChatTemplate(std::string& output, bool add_generation_prompt) const;
  OrtxStatus Llama2ChatTemplate(std::string& output, bool add_generation_prompt) const;
  OrtxStatus Llama3ChatTemplate(std::string& output, bool add_generation_prompt) const;
  OrtxStatus Llama3_2ChatTemplate(std::string& output, bool add_generation_prompt) const;
  OrtxStatus Llama3_3ChatTemplate(std::string& output, bool add_generation_prompt) const;
  OrtxStatus DeepSeekChatTemplate(std::string& output, bool add_generation_prompt) const;
  OrtxStatus Gemma3ChatTemplate(std::string& output, bool add_generation_prompt) const;


  OrtxStatus Id2Token(extTokenId_t id, std::string& token, TokenizerDecodingState** state) const;
  OrtxStatus GetDecoderPromptIds(size_t batch_size, const char* lang, const char* task, int no_timestamps,
                                 std::vector<std::vector<extTokenId_t>>& t_ids) const;
  OrtxStatus ApplyChatTemplate(
    const char* template_str, const char* message, std::string& output, bool add_generation_prompt) const;

 private:
  OrtxStatus LoadTokenizer(const OrtxTokenizerBlob* blob = nullptr);
  OrtxStatus LoadChatTemplate();

  static MessageList ParseJson(const std::string& json_str);
  void InitializeChatParameters(
    const char* template_str = nullptr,
    const std::vector<std::string>& custom_tools_param = {},
    bool tools_in_user_message_param = true,
    const std::string& strftime_param = "",
    const std::string& date_str = "26 Jul 2024",
    const std::vector<std::string>& builtin_tools_param = {});

  OrtxStatus ApplyChatTemplate(
    const MessageList& messages,
    std::string& output,
    bool add_generation_prompt) const;

  using bpe_tokenizer_t = std::unique_ptr<JsonFastTokenizer>;
  using ugm_tokenizer_t = std::unique_ptr<SpmUgmTokenizer>;
  std::variant<bpe_tokenizer_t, ugm_tokenizer_t> tokenizer_;

  using bpe_decoder_t = std::unique_ptr<BpeStreamingDecoder>;
  using ugm_decoder_t = std::unique_ptr<SpmUgmDecoder>;
  std::variant<bpe_decoder_t, ugm_decoder_t> detokenizer_;

  std::shared_ptr<ort_extensions::TokenJsonConfig> tok_config_;
  std::shared_ptr<minja::TemplateNode> chat_template_root_;
};

}  // namespace ort_extensions
