#include "core/rendering/animatedsprite.h"

#include <iostream>  // for cout
#include <sstream>   // for basic_stringstream

#include "core/rendering/texture.h"          // for Texture
#include "core/resources/resource_helper.h"  // for loadFile (pack + filesystem fallback)

namespace {

    // Normalitza CRLF: fitxers .ani amb terminadors de Windows fan que
    // line == "[animation]" no faci match i el parser entri en bucle
    // infinit / no carregui cap animació.
    void stripCr(std::string &s) {
        if (!s.empty() && s.back() == '\r') {
            s.pop_back();
        }
    }

    void parseFramesList(const std::string &value, Animation &buffer, int frame_width, int frame_height, int frames_per_row, int max_tiles) {
        std::stringstream ss(value);
        std::string tmp;
        SDL_Rect rect = {0, 0, frame_width, frame_height};
        while (getline(ss, tmp, ',')) {
            const int NUM_TILE = std::stoi(tmp) > max_tiles ? 0 : std::stoi(tmp);
            rect.x = (NUM_TILE % frames_per_row) * frame_width;
            rect.y = (NUM_TILE / frames_per_row) * frame_height;
            buffer.frames.push_back(rect);
        }
    }

    void parseAnimationField(const std::string &line, int pos, Animation &buffer, int frame_width, int frame_height, int frames_per_row, int max_tiles, const std::string &filename) {
        const std::string KEY = line.substr(0, pos);
        const std::string VALUE = line.substr(pos + 1, line.length());
        if (KEY == "name") {
            buffer.name = VALUE;
        } else if (KEY == "speed") {
            buffer.speed = std::stoi(VALUE);
            // Time-based: el valor del .ani s'expressa en "ticks per frame
            // d'animació" (assumint 60 Hz). El camp `speed` (int) es manté per al
            // fallback frame-based; el nou `step_duration_s` (float) és el que
            // gasta animate(dt).
            buffer.step_duration_s = static_cast<float>(buffer.speed) / 60.0F;
        } else if (KEY == "loop") {
            buffer.loop = std::stoi(VALUE);
        } else if (KEY == "frames") {
            parseFramesList(VALUE, buffer, frame_width, frame_height, frames_per_row, max_tiles);
        } else {
            std::cout << "Warning: file " << filename.c_str() << "\n, unknown parameter \"" << KEY.c_str() << "\"" << '\n';
        }
    }

    auto parseAnimationBlock(std::istream &file, int frame_width, int frame_height, int frames_per_row, int max_tiles, const std::string &filename) -> Animation {
        Animation buffer;
        buffer.speed = 0;
        buffer.step_duration_s = 0.0F;
        buffer.loop = -1;
        buffer.counter = 0;
        buffer.current_frame = 0;
        buffer.completed = false;
        buffer.time_accumulator_s = 0.0F;

        std::string line;
        do {
            if (!std::getline(file, line)) {
                break;
            }
            stripCr(line);
            int pos = line.find('=');
            if (pos != (int)std::string::npos) {
                parseAnimationField(line, pos, buffer, frame_width, frame_height, frames_per_row, max_tiles, filename);
            }
        } while (line != "[/animation]");

        return buffer;
    }

    void parseGlobalField(const std::string &line, int pos, int &frames_per_row, int &frame_width, int &frame_height, int &max_tiles, const Texture *texture, const std::string &filename) {
        const std::string KEY = line.substr(0, pos);
        const std::string VALUE = line.substr(pos + 1, line.length());
        if (KEY == "framesPerRow") {
            frames_per_row = std::stoi(VALUE);
        } else if (KEY == "frameWidth") {
            frame_width = std::stoi(VALUE);
        } else if (KEY == "frameHeight") {
            frame_height = std::stoi(VALUE);
        } else {
            std::cout << "Warning: file " << filename.c_str() << "\n, unknown parameter \"" << KEY.c_str() << "\"" << '\n';
        }

        if (frames_per_row == 0 && frame_width > 0) {
            frames_per_row = texture->getWidth() / frame_width;
        }
        if (max_tiles == 0 && frame_width > 0 && frame_height > 0) {
            const int W = texture->getWidth() / frame_width;
            const int H = texture->getHeight() / frame_height;
            max_tiles = W * H;
        }
    }

}  // namespace

// Parser compartido: lee un istream con el formato .ani
static auto parseAnimationStream(std::istream &file, Texture *texture, const std::string &filename, bool verbose) -> AnimatedSpriteData {
    AnimatedSpriteData as;
    as.texture = texture;
    int frames_per_row = 0;
    int frame_width = 0;
    int frame_height = 0;
    int max_tiles = 0;
    std::string line;

    if (verbose) {
        std::cout << "Animation loaded: " << filename << '\n';
    }

    while (std::getline(file, line)) {
        stripCr(line);
        if (line == "[animation]") {
            as.animations.push_back(parseAnimationBlock(file, frame_width, frame_height, frames_per_row, max_tiles, filename));
        } else {
            int pos = line.find('=');
            if (pos != (int)std::string::npos) {
                parseGlobalField(line, pos, frames_per_row, frame_width, frame_height, max_tiles, texture, filename);
            }
        }
    }

    return as;
}

// Carga la animación desde un fichero (vía ResourceHelper: pack si està inicialitzat, filesystem si no)
auto loadAnimationFromFile(Texture *texture, const std::string &file_path, bool verbose) -> AnimatedSpriteData {
    const std::string FILE_NAME = file_path.substr(file_path.find_last_of("\\/") + 1);
    auto bytes = ResourceHelper::loadFile(file_path);
    if (bytes.empty()) {
        if (verbose) {
            std::cout << "Warning: Unable to open " << FILE_NAME.c_str() << " file" << '\n';
        }
        AnimatedSpriteData as;
        as.texture = texture;
        return as;
    }
    return loadAnimationFromMemory(texture, bytes, FILE_NAME, verbose);
}

// Carga la animación desde bytes en memoria
auto loadAnimationFromMemory(Texture *texture, const std::vector<uint8_t> &bytes, const std::string &name_for_logs, bool verbose) -> AnimatedSpriteData {
    if (bytes.empty()) {
        AnimatedSpriteData as;
        as.texture = texture;
        return as;
    }
    std::string content(reinterpret_cast<const char *>(bytes.data()), bytes.size());
    std::stringstream ss(content);
    return parseAnimationStream(ss, texture, name_for_logs, verbose);
}

// Constructor
AnimatedSprite::AnimatedSprite(Texture *texture, SDL_Renderer *renderer, const std::string &file, const std::vector<std::string> *buffer)
    : current_animation_(0) {
    // Copia los punteros
    setTexture(texture);
    setRenderer(renderer);

    // Carga las animaciones
    if (!file.empty()) {
        AnimatedSpriteData as = loadAnimationFromFile(texture, file);

        // Copia los datos de las animaciones
        animation_.insert(animation_.end(), as.animations.begin(), as.animations.end());
    }

    else if (buffer != nullptr) {
        loadFromVector(buffer);
    }
}

// Constructor
AnimatedSprite::AnimatedSprite(SDL_Renderer *renderer, AnimatedSpriteData *data)
    : current_animation_(0) {
    // Copia los punteros
    setTexture(data->texture);
    setRenderer(renderer);

    // Copia los datos de las animaciones
    this->animation_.insert(this->animation_.end(), data->animations.begin(), data->animations.end());
}

// Destructor
AnimatedSprite::~AnimatedSprite() {
    for (auto &a : animation_) {
        a.frames.clear();
    }
    animation_.clear();
}

// Obtiene el indice de la animación a partir del nombre
auto AnimatedSprite::getIndex(const std::string &name) -> int {
    int index = -1;

    for (const auto &a : animation_) {
        index++;
        if (a.name == name) {
            return index;
        }
    }

    std::cout << "** Warning: could not find \"" << name.c_str() << "\" animation" << '\n';

    return -1;
}

// Avança l'acumulador i calcula el frame actual a partir de `step_duration_s`.
void AnimatedSprite::animate(float dt_s) {
    Animation &anim = animation_[current_animation_];
    if (!enabled_ || anim.step_duration_s <= 0.0F) {
        return;
    }

    anim.time_accumulator_s += dt_s;
    anim.current_frame = static_cast<int>(anim.time_accumulator_s / anim.step_duration_s);

    if (anim.current_frame >= (int)anim.frames.size()) {
        if (anim.loop == -1) {
            anim.current_frame = anim.frames.size();
            anim.completed = true;
        } else {
            anim.time_accumulator_s = 0.0F;
            anim.current_frame = anim.loop;
        }
    } else {
        setSpriteClip(anim.frames[anim.current_frame]);
    }
}

// Obtiene el numero de frames de la animación actual
auto AnimatedSprite::getNumFrames() -> int {
    return (int)animation_[current_animation_].frames.size();
}

// Establece el frame actual de la animación
void AnimatedSprite::setCurrentFrame(int num) {
    // Descarta valores fuera de rango
    if (num >= (int)animation_[current_animation_].frames.size()) {
        num = 0;
    }

    // Cambia el valor de la variable
    animation_[current_animation_].current_frame = num;
    animation_[current_animation_].counter = 0;

    // Escoge el frame correspondiente de la animación
    setSpriteClip(animation_[current_animation_].frames[animation_[current_animation_].current_frame]);
}

// Establece el valor del contador
void AnimatedSprite::setAnimationCounter(const std::string &name, int num) {
    animation_[getIndex(name)].counter = num;
}

// Establece la velocidad de una animación
void AnimatedSprite::setAnimationSpeed(const std::string &name, int speed) {
    animation_[getIndex(name)].counter = speed;
}

// Establece la velocidad de una animación
void AnimatedSprite::setAnimationSpeed(int index, int speed) {
    animation_[index].counter = speed;
}

// Establece si la animación se reproduce en bucle
void AnimatedSprite::setAnimationLoop(const std::string &name, int loop) {
    animation_[getIndex(name)].loop = loop;
}

// Establece si la animación se reproduce en bucle
void AnimatedSprite::setAnimationLoop(int index, int loop) {
    animation_[index].loop = loop;
}

// Establece el valor de la variable
void AnimatedSprite::setAnimationCompleted(const std::string &name, bool value) {
    animation_[getIndex(name)].completed = value;
}

// OLD - Establece el valor de la variable
void AnimatedSprite::setAnimationCompleted(int index, bool value) {
    animation_[index].completed = value;
}

// Comprueba si ha terminado la animación
auto AnimatedSprite::animationIsCompleted() -> bool {
    return animation_[current_animation_].completed;
}

// Devuelve el rectangulo de una animación y frame concreto
auto AnimatedSprite::getAnimationClip(const std::string &name, Uint8 index) -> SDL_Rect {
    return animation_[getIndex(name)].frames[index];
}

// Devuelve el rectangulo de una animación y frame concreto
auto AnimatedSprite::getAnimationClip(int index_a, Uint8 index_f) -> SDL_Rect {
    return animation_[index_a].frames[index_f];
}

// Carga la animación desde un vector (reutiliza parseAnimationStream via stringstream)
auto AnimatedSprite::loadFromVector(const std::vector<std::string> *source) -> bool {
    std::stringstream ss;
    for (const auto &line : *source) {
        ss << line << '\n';
    }
    AnimatedSpriteData as = parseAnimationStream(ss, texture_, "", false);
    animation_.insert(animation_.end(), as.animations.begin(), as.animations.end());

    // El primer frame lleva frame_width/frame_height en .w/.h — los usamos como rect por defecto
    if (!as.animations.empty() && !as.animations.front().frames.empty()) {
        const auto &first = as.animations.front().frames.front();
        setRect({0, 0, first.w, first.h});
    }

    return true;
}

// Establece la animacion actual
void AnimatedSprite::setCurrentAnimation(const std::string &name) {
    const int NEW_ANIMATION = getIndex(name);
    if (current_animation_ != NEW_ANIMATION) {
        current_animation_ = NEW_ANIMATION;
        animation_[current_animation_].current_frame = 0;
        animation_[current_animation_].counter = 0;
        animation_[current_animation_].completed = false;
    }
}

// Establece la animacion actual
void AnimatedSprite::setCurrentAnimation(int index) {
    const int NEW_ANIMATION = index;
    if (current_animation_ != NEW_ANIMATION) {
        current_animation_ = NEW_ANIMATION;
        animation_[current_animation_].current_frame = 0;
        animation_[current_animation_].counter = 0;
        animation_[current_animation_].completed = false;
    }
}

// animate(dt) + MovingSprite::update(dt) (move + rotació)
void AnimatedSprite::update(float dt_s) {
    animate(dt_s);
    MovingSprite::update(dt_s);
}

// Establece el rectangulo para un frame de una animación
void AnimatedSprite::setAnimationFrames(Uint8 index_animation, Uint8 /*index_frame*/, int x, int y, int w, int h) {
    animation_[index_animation].frames.push_back({x, y, w, h});
}

// OLD - Establece el contador para todas las animaciones
void AnimatedSprite::setAnimationCounter(int value) {
    for (auto &a : animation_) {
        a.counter = value;
    }
}

// Reinicia la animación
void AnimatedSprite::resetAnimation() {
    animation_[current_animation_].current_frame = 0;
    animation_[current_animation_].counter = 0;
    animation_[current_animation_].completed = false;
}