#include "core/resources/skin_manager.hpp"

#include <algorithm>
#include <iostream>
#include <utility>

#include "core/resources/resource_helper.h"
#include "core/resources/resource_loader.h"
#include "external/fkyaml_node.hpp"

SkinManager *SkinManager::instance = nullptr;

void SkinManager::init(const std::string &executable_path, const std::string &asset_prefix) {
    if (instance == nullptr) {
        instance = new SkinManager(executable_path, asset_prefix);
        instance->scan();
    }
}

void SkinManager::destroy() {
    delete instance;
    instance = nullptr;
}

auto SkinManager::get() -> SkinManager * {
    return instance;
}

SkinManager::SkinManager(std::string executable_path, std::string asset_prefix)
    : executable_path_(std::move(executable_path)),
      asset_prefix_(std::move(asset_prefix)) {
}

void SkinManager::scan() {
    skins_.clear();

    // ResourceLoader enumera tant entries del pack com fitxers de
    // `data/` en mode fallback. Les claus retornades són relatives a
    // `data/` (ex: "skins/classic/skin.yaml"). Buscar manifests
    // amb aquest patró és més robust que `std::filesystem` perquè
    // funciona igual a release (pack) que a dev (filesystem).
    const auto ALL = ResourceLoader::getInstance().getAvailableResources();

    const std::string PREFIX = "skins/";
    const std::string SUFFIX = "/skin.yaml";

    for (const auto &key : ALL) {
        if (!key.starts_with(PREFIX) || !key.ends_with(SUFFIX)) { continue; }
        const std::string ID = key.substr(PREFIX.size(), key.size() - PREFIX.size() - SUFFIX.size());
        if (ID.find('/') != std::string::npos) { continue; }  // només top-level dins skins/

        // ResourceHelper espera un path que contingui "data/" — el construïm
        // amb la convenció habitual del projecte.
        const std::string FULL_PATH = executable_path_ + asset_prefix_ + "/data/" + key;
        auto bytes = ResourceHelper::loadFile(FULL_PATH);
        if (bytes.empty()) {
            std::cerr << "SkinManager: cannot read manifest " << FULL_PATH << '\n';
            continue;
        }

        SkinInfo info;
        info.id = ID;
        info.display_name = ID;
        info.gfx_dir = "gfx";

        try {
            const std::string CONTENT(reinterpret_cast<const char *>(bytes.data()), bytes.size());
            auto yaml = fkyaml::node::deserialize(CONTENT);
            if (yaml.contains("display_name")) {
                info.display_name = yaml["display_name"].get_value<std::string>();
            }
            if (yaml.contains("gfx_dir")) {
                info.gfx_dir = yaml["gfx_dir"].get_value<std::string>();
            }
        } catch (const fkyaml::exception &e) {
            std::cerr << "SkinManager: bad manifest " << FULL_PATH << ": " << e.what() << '\n';
            continue;
        }

        skins_.push_back(std::move(info));
    }

    // Ordre alfabètic estable: garanteix que next/prev són deterministes.
    std::ranges::sort(skins_, [](const SkinInfo &a, const SkinInfo &b) { return a.id < b.id; });
}

auto SkinManager::exists(const std::string &id) const -> bool {
    return std::ranges::any_of(skins_, [&](const SkinInfo &s) { return s.id == id; });
}

auto SkinManager::currentDisplayName() const -> std::string {
    return displayNameOf(current_id_);
}

auto SkinManager::displayNameOf(const std::string &id) const -> std::string {
    const auto IT = std::ranges::find_if(skins_, [&](const SkinInfo &s) { return s.id == id; });
    return (IT != skins_.end()) ? IT->display_name : id;
}

void SkinManager::setCurrent(const std::string &id) {
    if (exists(id)) {
        current_id_ = id;
    }
}

auto SkinManager::gfxDirOf(const std::string &id) const -> std::string {
    const auto IT = std::ranges::find_if(skins_, [&](const SkinInfo &s) { return s.id == id; });
    return (IT != skins_.end()) ? IT->gfx_dir : std::string("gfx");
}

auto SkinManager::gfxPath(const std::string &basename) const -> std::string {
    return asset_prefix_ + "/data/skins/" + current_id_ + "/" + gfxDirOf(current_id_) + "/" + basename;
}

auto SkinManager::nextSkinId() const -> std::string {
    if (skins_.empty()) { return current_id_; }
    for (size_t i = 0; i < skins_.size(); ++i) {
        if (skins_[i].id == current_id_) {
            return skins_[(i + 1) % skins_.size()].id;
        }
    }
    return skins_.front().id;
}

auto SkinManager::prevSkinId() const -> std::string {
    if (skins_.empty()) { return current_id_; }
    for (size_t i = 0; i < skins_.size(); ++i) {
        if (skins_[i].id == current_id_) {
            return skins_[(i + skins_.size() - 1) % skins_.size()].id;
        }
    }
    return skins_.front().id;
}