#ifndef POKEMON_TABLE_H
#define POKEMON_TABLE_H

#include "pokemon.h"
#include <vector>
#include <unordered_map>
#include <memory>
#include <string>
#include <string_view>
#include <optional>

namespace PokEng {

// Forward declaration
struct PokemonSpecies;

/**
 * @brief A high-performance Pokemon data table that provides O(1) lookup by ID
 *
 * This class loads all Pokemon species data from JSON files and stores them
 * in a way that allows for extremely fast runtime access by Pokemon ID.
 * The table is designed to be loaded once at startup and then used throughout
 * the application's lifetime.
 */
class PokemonTable {
public:
    /**
     * @brief Default constructor
     *
     * Creates an empty Pokemon table. Use loadFromDataDirectory() or
     * loadFromFiles() to populate the table with data.
     */
    PokemonTable() = default;

    /**
     * @brief Destructor
     */
    ~PokemonTable() = default;

    // Delete copy operations to prevent accidental copies
    PokemonTable(const PokemonTable&) = delete;
    PokemonTable& operator=(const PokemonTable&) = delete;

    // Allow move operations
    PokemonTable(PokemonTable&&) = default;
    PokemonTable& operator=(PokemonTable&&) = default;

    /**
     * @brief Load Pokemon data from the standard data directory
     *
     * This method loads all Pokemon data from the JSON files in the
     * data/pokemon/ directory, parsing all generations.
     *
     * @return true if loading was successful, false otherwise
     */
    bool loadFromDataDirectory();

    /**
     * @brief Load Pokemon data from specific JSON files
     *
     * @param filePaths Vector of paths to JSON files containing Pokemon data
     * @return true if loading was successful, false otherwise
     */
    bool loadFromFiles(const std::vector<std::string>& filePaths);

    /**
     * @brief Get a Pokemon species by its ID
     *
     * This is the primary lookup method and provides O(1) access time.
     *
     * @param id The Pokemon ID (1-based, e.g., 1 = Bulbasaur)
     * @return Pointer to the PokemonSpecies if found, nullptr otherwise
     */
    const PokemonSpecies* getPokemon(uint16_t id) const;

    /**
     * @brief Get a Pokemon species by its name
     *
     * This method provides O(1) access time using an internal hash map.
     *
     * @param name The Pokemon name (case-sensitive)
     * @return Pointer to the PokemonSpecies if found, nullptr otherwise
     */
    const PokemonSpecies* getPokemonByName(std::string_view name) const;

    /**
     * @brief Check if a Pokemon ID exists in the table
     *
     * @param id The Pokemon ID to check
     * @return true if the Pokemon exists, false otherwise
     */
    bool hasPokemon(uint16_t id) const;

    /**
     * @brief Get the total number of Pokemon species in the table
     *
     * @return The number of Pokemon species loaded
     */
    size_t size() const;

    /**
     * @brief Check if the table is empty
     *
     * @return true if no Pokemon data has been loaded, false otherwise
     */
    bool empty() const;

    /**
     * @brief Get the highest Pokemon ID in the table
     *
     * @return The maximum Pokemon ID, or 0 if the table is empty
     */
    uint16_t getMaxId() const;

    /**
     * @brief Clear all data from the table
     */
    void clear();

    /**
     * @brief Get all Pokemon species (for iteration)
     *
     * @return A const reference to the internal vector of Pokemon species
     */
    const std::vector<PokemonSpecies>& getAllPokemon() const;

    /**
     * @brief Validate that the table contains valid data
     *
     * This method performs basic validation checks on the loaded data.
     *
     * @return true if the data appears valid, false otherwise
     */
    bool validate() const;

private:
    /**
     * @brief Parse a single Pokemon JSON file
     *
     * @param filePath Path to the JSON file to parse
     * @return true if parsing was successful, false otherwise
     */
    bool parsePokemonFile(const std::string& filePath);

    /**
     * @brief Parse a single Pokemon object from JSON
     *
     * @param pokemonJson The JSON value representing a Pokemon
     * @return The parsed PokemonSpecies object
     */
    PokemonSpecies parsePokemonJson(const void* pokemonJson);

    /**
     * @brief Parse base stats from JSON
     *
     * @param statsJson The JSON value containing the stats object
     * @return The parsed BaseStats object
     */
    BaseStats parseBaseStats(const void* statsJson);

    /**
     * @brief Parse Pokemon types from JSON
     *
     * @param typesJson The JSON array containing the types
     * @return The parsed PokemonTypes object
     */
    PokemonTypes parseTypes(const void* typesJson);

private:
    // Storage for Pokemon species - indexed by ID (1-based)
    // Index 0 is unused, index 1 = Bulbasaur, etc.
    std::vector<PokemonSpecies> m_pokemonSpecies;

    // Hash map for name-based lookups
    std::unordered_map<std::string, uint16_t> m_nameToIdMap;

    // Track the maximum ID for validation
    uint16_t m_maxId = 0;
};

/**
 * @brief Global Pokemon table instance
 *
 * This provides a convenient global access point to the Pokemon data.
 * The table should be initialized once at application startup.
 */
extern std::unique_ptr<PokemonTable> g_pokemonTable;

/**
 * @brief Initialize the global Pokemon table
 *
 * This function should be called once at application startup to load
 * all Pokemon data. It loads from the standard data directory.
 *
 * @return true if initialization was successful, false otherwise
 */
bool initializePokemonTable();

/**
 * @brief Shutdown the global Pokemon table
 *
 * This function should be called at application shutdown to clean up
 * the global Pokemon table resources.
 */
void shutdownPokemonTable();

} // namespace PokEng

#endif // POKEMON_TABLE_H