//This is Concedo's shitty adapter for adding python bindings for llama

//Considerations:
//Don't want to use pybind11 due to dependencies on MSVCC
//ZERO or MINIMAL changes as possible to main.cpp - do not move their function declarations here!
//Leave main.cpp UNTOUCHED, We want to be able to update the repo and pull any changes automatically.
//No dynamic memory allocation! Setup structs with FIXED (known) shapes and sizes for ALL output fields
//Python will ALWAYS provide the memory, we just write to it.

#include "main.cpp"
#include "extra.h"

extern "C" {

    struct load_model_inputs
    {
        const int threads;
        const int max_context_length;
        const int batch_size;
        const char * model_filename;
        const int n_parts_overwrite = -1;
    };
    struct generation_inputs
    {
        const int seed;                
        const char * prompt;
        const int max_length;
        const float temperature;
        const int top_k;
        const float top_p;
        const float rep_pen;
        const int rep_pen_range;
        const bool reset_state = true; //determines if we can continue off the previous prompt state
    };
    struct generation_outputs
    {
        int status = -1;
        char text[16384]; //16kb should be enough for any response
    };

    gpt_params api_params;
    gpt_vocab api_vocab;
    llama_model api_model;    
    int api_n_past = 0;
    gpt_vocab::id old_embd_id = -1;
    std::vector<float> api_logits;
    std::vector<gpt_vocab::id> last_n_tokens;
    size_t mem_per_token = 0;
    bool legacy_format = false;

    bool load_model(const load_model_inputs inputs)
    {
        api_params.n_threads = inputs.threads;
        api_params.n_ctx = inputs.max_context_length;
        api_params.n_batch = inputs.batch_size;
        api_params.model = inputs.model_filename;

        int n_parts_overwrite =  inputs.n_parts_overwrite;

        int loadresult = llama_model_load(api_params.model, api_model, api_vocab, api_params.n_ctx, GGML_TYPE_F16, n_parts_overwrite);
        if (!loadresult) {  
            fprintf(stderr, "%s: failed to load model from '%s'\n", __func__, api_params.model.c_str());
            return false;
        }
        legacy_format = (loadresult==2?true:false);
        if(legacy_format)
        {
            printf("\n---\nWarning: Your model is using an OUTDATED format. Please reconvert it for better results!\n");
        }

        return true;
    }

    generation_outputs generate(const generation_inputs inputs, generation_outputs & output)
    {
        api_params.prompt = inputs.prompt;
        api_params.seed = inputs.seed;
        api_params.n_predict = inputs.max_length;
        api_params.top_k = inputs.top_k;
        api_params.top_p = inputs.top_p;
        api_params.temp = inputs.temperature;
        api_params.repeat_last_n = inputs.rep_pen_range;
        api_params.repeat_penalty = inputs.rep_pen;

        bool reset_state = inputs.reset_state;
        if(api_n_past==0)
        {
            reset_state = true;
        }
      
        if(api_params.repeat_last_n<1)
        {
            api_params.repeat_last_n = 1;
        }
        if(api_params.top_k<1)
        {
            api_params.top_k = 300; //to disable top_k we actually need to increase this value to a very high number
        }
        if (api_params.seed < 0)
        {
            api_params.seed = time(NULL);
        }

        //display usage
        // std::string tst = " ";
        // char * tst2 = (char*)tst.c_str();
        // gpt_print_usage(1,&tst2,api_params);
        
        if(reset_state)
        {
            api_params.prompt.insert(0, 1, ' ');
        }
        // tokenize the prompt
        std::vector<gpt_vocab::id> embd_inp;
        if(legacy_format)
        {
            embd_inp = ::legacy_llama_tokenize(api_vocab, api_params.prompt, true);
        }else{
            embd_inp = ::llama_tokenize(api_vocab, api_params.prompt, true);
        }
         
        //api_params.n_predict = std::min(api_params.n_predict, api_model.hparams.n_ctx - (int)embd_inp.size());
        //truncate to front of the prompt if its too long
        if (embd_inp.size() + api_params.n_predict > api_model.hparams.n_ctx) {
            int offset = embd_inp.size() - api_model.hparams.n_ctx + api_params.n_predict;
            embd_inp = std::vector<gpt_vocab::id>(embd_inp.begin() + offset, embd_inp.end());
        }
        std::vector<gpt_vocab::id> embd;
        
        int last_n_size = api_params.repeat_last_n;
        last_n_tokens.resize(last_n_size);
        if(reset_state)
        {
            llama_eval(api_model, api_params.n_threads, 0, {0, 1, 2, 3}, api_logits, mem_per_token);
            std::fill(last_n_tokens.begin(), last_n_tokens.end(), 0);
            api_n_past = 0;
        }else{
            //strip out the reset token (1) at the start of the embedding
            if(embd_inp.size()>0)
            {
                embd_inp.erase(embd_inp.begin());
            }
            if(old_embd_id!=-1)
            {
                embd.push_back(old_embd_id);
            }
        }
        
        int remaining_tokens = api_params.n_predict;
        int input_consumed = 0;
        std::mt19937 api_rng(api_params.seed);
        std::string concat_output = "";        
       
        printf("\nProcessing: ");
        while (remaining_tokens > 0)
        {
            gpt_vocab::id id = 0;
            // predict
            if (embd.size() > 0)
            {
                // for (auto i: embd) {                    
                //     std::cout << i << ',';
                // }
                //printf("\nnp:%d embd:%d mem:%d",api_n_past,embd.size(),mem_per_token);
                printf("|");
                if (!llama_eval(api_model, api_params.n_threads, api_n_past, embd, api_logits, mem_per_token))
                {
                    fprintf(stderr, "Failed to predict\n");
                    snprintf(output.text, sizeof(output.text), "%s", "");
                    output.status = 0;
                    return output;
                }
            }

            api_n_past += embd.size();
            embd.clear();            
            if (embd_inp.size() <= input_consumed)
            {
                // out of user input, sample next token
                const float top_k = api_params.top_k;
                const float top_p = api_params.top_p;
                const float temp = api_params.temp;
                const float repeat_penalty = api_params.repeat_penalty;
                const int n_vocab = api_model.hparams.n_vocab;
                
                {
                    // set the logit of the eos token (2) to zero to avoid sampling it
                    api_logits[api_logits.size() - n_vocab + EOS_TOKEN_ID] = 0;
                    //set logits of opening square bracket to zero.
                    api_logits[api_logits.size() - n_vocab + 518] = 0;
                    api_logits[api_logits.size() - n_vocab + 29961] = 0;


                    id = llama_sample_top_p_top_k(api_vocab, api_logits.data() + (api_logits.size() - n_vocab), last_n_tokens, repeat_penalty, top_k, top_p, temp, api_rng);

                    last_n_tokens.erase(last_n_tokens.begin());
                    last_n_tokens.push_back(id);
                }

                // add it to the context
                old_embd_id = id;
                embd.push_back(id);

                // decrement remaining sampling budget
                --remaining_tokens;
                //printf("\nid:%d word:%s\n",id,api_vocab.id_to_token[id].c_str());
                concat_output += api_vocab.id_to_token[id].c_str();
            }
            else
            {
                // some user input remains from prompt or interaction, forward it to processing
                while (embd_inp.size() > input_consumed)
                {
                    old_embd_id = embd_inp[input_consumed];
                    embd.push_back(embd_inp[input_consumed]);
                    last_n_tokens.erase(last_n_tokens.begin());
                    last_n_tokens.push_back(embd_inp[input_consumed]);
                    ++input_consumed;
                    if (embd.size() > api_params.n_batch)
                    {
                        break;
                    }
                }
            }
            
        }

        //printf("output: %s",concat_output.c_str());
        output.status = 1;
        snprintf(output.text, sizeof(output.text), "%s", concat_output.c_str());
        return output;
    }
}