#pragma once

#include <string>
#include <vector>
#include <art.h>
#include <sparsepp.h>
#include <store.h>
#include <topster.h>
#include <json.hpp>
#include <field.h>

class Collection {
private:
    // Using a $ prefix so that these meta keys stay above record entries in a lexicographically ordered KV store
    static constexpr const char* COLLECTION_META_PREFIX = "$CM";
    static constexpr const char* DOC_ID_PREFIX = "$DI";
    static constexpr const char* COLLECTION_NEXT_SEQ_PREFIX = "$CS";
    static constexpr const char* SEQ_ID_PREFIX = "$SI";

    std::string name;

    uint32_t collection_id;

    // Auto incrementing record ID used internally for indexing - not exposed to the client
    uint32_t next_seq_id;

    spp::sparse_hash_map<std::string, field> schema;

    std::vector<std::string> rank_fields;

    Store* store;

    spp::sparse_hash_map<std::string, art_tree*> index_map;

    spp::sparse_hash_map<uint32_t, int64_t> primary_rank_scores;

    spp::sparse_hash_map<uint32_t, int64_t> secondary_rank_scores;

    std::string get_doc_id_key(std::string doc_id);

    std::string get_seq_id_key(uint32_t seq_id);

    static inline std::vector<art_leaf *> next_suggestion(const std::vector<std::vector<art_leaf *>> &token_leaves,
                                                          long long int n);
    void log_leaves(const int cost, const std::string &token, const std::vector<art_leaf *> &leaves) const;

    void search(std::string & query, const std::string & field, const int num_typos, const size_t num_results,
                Topster<100> & topster, size_t & num_found, const token_ordering token_order = FREQUENCY,
                const bool prefix = false);

    void search_candidates(int & token_rank, std::vector<std::vector<art_leaf*>> & token_leaves, Topster<100> & topster,
                           size_t & total_results, size_t & num_found, const size_t & max_results);

    void index_string_field(const std::string & text, const uint32_t score, art_tree *t, uint32_t seq_id) const;

    void index_string_array_field(const std::vector<std::string> & strings, const uint32_t score, art_tree *t, uint32_t seq_id) const;

    void index_int32_field(const int32_t value, uint32_t score, art_tree *t, uint32_t seq_id) const;

    void index_int64_field(const int64_t value, uint32_t score, art_tree *t, uint32_t seq_id) const;

    void index_int32_array_field(const std::vector<int32_t> & values, const uint32_t score, art_tree *t, uint32_t seq_id) const;

    void index_int64_array_field(const std::vector<int64_t> & values, const uint32_t score, art_tree *t, uint32_t seq_id) const;

public:
    Collection() = delete;

    Collection(const std::string name, const uint32_t collection_id, const uint32_t next_seq_id, Store *store,
               const std::vector<field> & search_fields, const std::vector<std::string> rank_fields);

    ~Collection();

    static std::string get_next_seq_id_key(std::string collection_name);

    static std::string get_meta_key(std::string collection_name);

    std::string get_seq_id_prefix();

    uint32_t get_collection_id();

    uint32_t get_next_seq_id();

    uint32_t doc_id_to_seq_id(std::string doc_id);

    std::vector<std::string> get_rank_fields();

    spp::sparse_hash_map<std::string, field> get_schema();

    std::string add(std::string json_str);

    nlohmann::json search(std::string query, const std::vector<std::string> fields, const std::vector<filter> filters,
                          const int num_typos, const size_t num_results, const token_ordering token_order = FREQUENCY,
                          const bool prefix = false);

    void remove(std::string id);

    void score_results(Topster<100> &topster, const int & token_rank, const std::vector<art_leaf *> &query_suggestion,
                       const uint32_t *result_ids, const size_t result_size) const;

    enum {MAX_SEARCH_TOKENS = 20};
    enum {MAX_RESULTS = 100};

    void index_in_memory(const nlohmann::json &document, uint32_t seq_id);
};