#include "core/ui/ui_config.hpp"

#include <iostream>
#include <string>
#include <string_view>
#include <unordered_map>

#include "core/resources/resource_helper.hpp"
#include "external/fkyaml_node.hpp"
#include "utils/defaults.hpp"
#include "utils/easing.hpp"

namespace {

    // Lector de camp amb fallback: si la clau existeix al node, escriu a
    // `dst` el valor convertit; si no, deixa `dst` com estava (que al
    // constructor ja hem inicialitzat amb Defaults::UI).
    template <typename T>
    void readField(const fkyaml::node& node, const char* key, T& dst) {
        if (node.contains(key)) { dst = node[key].get_value<T>(); }
    }

    // Variant per a Uint8 — fkyaml no serialitza a Uint8 directament, cal
    // passar per int i encaixar al rang 0..255 (valors fora de rang es
    // trunquen i s'avisen).
    void readColorIndex(const fkyaml::node& node, const char* key, Uint8& dst) {
        if (!node.contains(key)) { return; }
        const int VALUE = node[key].get_value<int>();
        if (VALUE < 0 || VALUE > 255) {
            std::cerr << "UiConfig: índex '" << key << "'=" << VALUE << " fora de rang 0..255 — ignorat\n";
            return;
        }
        dst = static_cast<Uint8>(VALUE);
    }

    // Registre de corbes disponibles. Afegir-ne una nova és només una
    // entrada ací: la llegeix `UiConfig::curveByName` i queda exposada al
    // YAML pel seu nom. No hi ha fallback mut: si el nom no hi és, l'api
    // retorna linear i avisa per stderr perquè l'error no passi en silenci.
    auto curveRegistry() -> const std::unordered_map<std::string_view, UiConfig::CurveFn>& {
        static const std::unordered_map<std::string_view, UiConfig::CurveFn> REGISTRY = {
            {"linear", &Easing::linear},
            {"outQuad", &Easing::outQuad},
            {"inQuad", &Easing::inQuad},
            {"inOutQuad", &Easing::inOutQuad},
            {"outCubic", &Easing::outCubic},
            {"inCubic", &Easing::inCubic},
        };
        return REGISTRY;
    }

    void readCurve(const fkyaml::node& node, const char* key, UiConfig::CurveFn& dst) {
        if (!node.contains(key)) { return; }
        const auto NAME = node[key].get_value<std::string>();
        dst = UiConfig::curveByName(NAME);
    }

    void readFont(const fkyaml::node& node, const char* key, UiConfig::Font& dst) {
        if (!node.contains(key)) { return; }
        const auto& f = node[key];
        readField(f, "name", dst.name);
        readField(f, "gif", dst.gif);
        readField(f, "fnt", dst.fnt);
        readField(f, "kerning", dst.kerning);
    }

}  // namespace

UiConfig::UiConfig()
    : render_info_text_(Defaults::UI::RENDER_INFO_TEXT),
      render_info_shadow_(Defaults::UI::RENDER_INFO_SHADOW),
      canvas_bg_(Defaults::UI::CANVAS_BG),
      notification_text_(Defaults::UI::NOTIFICATION_TEXT),
      notification_bg_(Defaults::UI::NOTIFICATION_BG),
      exit_text_(Defaults::UI::EXIT_TEXT),
      exit_bg_(Defaults::UI::EXIT_BG),
      menu_bg_(Defaults::UI::MENU_BG),
      menu_border_(Defaults::UI::MENU_BORDER),
      menu_title_(Defaults::UI::MENU_TITLE),
      menu_label_(Defaults::UI::MENU_LABEL),
      menu_value_(Defaults::UI::MENU_VALUE),
      menu_cursor_(Defaults::UI::MENU_CURSOR),
      menu_disabled_(Defaults::UI::MENU_DISABLED),
      hud_bg_(Defaults::UI::HUD_BG),
      hud_label_(Defaults::UI::HUD_LABEL),
      hud_value_(Defaults::UI::HUD_VALUE),
      hud_flash_(Defaults::UI::HUD_FLASH),
      room_text_(Defaults::UI::ROOM_TEXT),
      room_text_outline_(Defaults::UI::ROOM_TEXT_OUTLINE),
      notification_ms_(Defaults::UI::NOTIFICATION_TIME_MS),
      exit_ms_(Defaults::UI::EXIT_TIME_MS),
      hud_entry_ms_(Defaults::UI::HUD_ENTRY_MS),
      hud_flash_ms_(Defaults::UI::HUD_FLASH_MS),
      hud_shake_ms_(Defaults::UI::HUD_SHAKE_MS),
      pause_enter_ms_(Defaults::UI::PAUSE_ENTER_MS),
      pause_exit_ms_(Defaults::UI::PAUSE_EXIT_MS),
      pause_enter_curve_(curveByName(Defaults::UI::PAUSE_ENTER_CURVE)),
      pause_exit_curve_(curveByName(Defaults::UI::PAUSE_EXIT_CURVE)),
      menu_select_sound_(Defaults::UI::MENU_SELECT_SOUND),
      menu_accept_sound_(Defaults::UI::MENU_ACCEPT_SOUND),
      hud_font_{.name = Defaults::UI::Font::HUD_NAME, .gif = Defaults::UI::Font::HUD_GIF, .fnt = Defaults::UI::Font::HUD_FNT, .kerning = Defaults::UI::Font::HUD_KERNING},
      placeholder_font_{.name = Defaults::UI::Font::PLACEHOLDER_NAME, .gif = Defaults::UI::Font::PLACEHOLDER_GIF, .fnt = Defaults::UI::Font::PLACEHOLDER_FNT, .kerning = Defaults::UI::Font::PLACEHOLDER_KERNING},
      room_text_font_{.name = Defaults::UI::Font::ROOM_TEXT_NAME, .gif = Defaults::UI::Font::ROOM_TEXT_GIF, .fnt = Defaults::UI::Font::ROOM_TEXT_FNT, .kerning = Defaults::UI::Font::ROOM_TEXT_KERNING},
      menu_title_font_{.name = Defaults::UI::Font::MENU_TITLE_NAME, .gif = Defaults::UI::Font::MENU_TITLE_GIF, .fnt = Defaults::UI::Font::MENU_TITLE_FNT, .kerning = Defaults::UI::Font::MENU_TITLE_KERNING},
      menu_items_font_{.name = Defaults::UI::Font::MENU_ITEMS_NAME, .gif = Defaults::UI::Font::MENU_ITEMS_GIF, .fnt = Defaults::UI::Font::MENU_ITEMS_FNT, .kerning = Defaults::UI::Font::MENU_ITEMS_KERNING},
      notifier_{
          .padding_h = Defaults::UI::Notifier::PADDING_H,
          .padding_top = Defaults::UI::Notifier::PADDING_TOP,
          .padding_bottom = Defaults::UI::Notifier::PADDING_BOTTOM,
          .line_gap = Defaults::UI::Notifier::LINE_GAP,
          .margin_top = Defaults::UI::Notifier::MARGIN_TOP,
          .border_px = Defaults::UI::Notifier::BORDER_PX,
          .slide_ms = Defaults::UI::Notifier::SLIDE_MS,
          .slide_in_curve = curveByName(Defaults::UI::Notifier::SLIDE_IN_CURVE),
          .slide_out_curve = curveByName(Defaults::UI::Notifier::SLIDE_OUT_CURVE),
      } {
}

auto UiConfig::get() -> UiConfig& {
    static UiConfig instance_;
    return instance_;
}

auto UiConfig::curveByName(const std::string& name) -> CurveFn {
    const auto& reg = curveRegistry();
    const auto IT = reg.find(name);
    if (IT == reg.end()) {
        std::cerr << "UiConfig: corba '" << name << "' desconeguda — s'usa linear\n";
        return &Easing::linear;
    }
    return IT->second;
}

void UiConfig::load(const std::string& file_path) {
    auto bytes = Resource::Helper::loadFile(file_path);
    if (bytes.empty()) {
        std::cerr << "UiConfig: no s'ha pogut obrir " << file_path << " — s'usaran els defaults compilats\n";
        return;
    }

    try {
        const auto* begin = reinterpret_cast<const char*>(bytes.data());
        const auto* end = begin + bytes.size();
        auto yaml = fkyaml::node::deserialize(begin, end);

        if (yaml.contains("colors")) {
            const auto& c = yaml["colors"];
            readColorIndex(c, "render_info_text", render_info_text_);
            readColorIndex(c, "render_info_shadow", render_info_shadow_);
            readColorIndex(c, "canvas_bg", canvas_bg_);
            readColorIndex(c, "notification_text", notification_text_);
            readColorIndex(c, "notification_bg", notification_bg_);
            readColorIndex(c, "exit_text", exit_text_);
            readColorIndex(c, "exit_bg", exit_bg_);
            readColorIndex(c, "menu_bg", menu_bg_);
            readColorIndex(c, "menu_border", menu_border_);
            readColorIndex(c, "menu_title", menu_title_);
            readColorIndex(c, "menu_label", menu_label_);
            readColorIndex(c, "menu_value", menu_value_);
            readColorIndex(c, "menu_cursor", menu_cursor_);
            readColorIndex(c, "menu_disabled", menu_disabled_);
            readColorIndex(c, "hud_bg", hud_bg_);
            readColorIndex(c, "hud_label", hud_label_);
            readColorIndex(c, "hud_value", hud_value_);
            readColorIndex(c, "hud_flash", hud_flash_);
            readColorIndex(c, "room_text", room_text_);
            readColorIndex(c, "room_text_outline", room_text_outline_);
        }

        if (yaml.contains("timings")) {
            const auto& t = yaml["timings"];
            readField(t, "notification_ms", notification_ms_);
            readField(t, "exit_ms", exit_ms_);
        }

        if (yaml.contains("fonts")) {
            const auto& f = yaml["fonts"];
            readFont(f, "hud", hud_font_);
            readFont(f, "placeholder", placeholder_font_);
            readFont(f, "room_text", room_text_font_);
            readFont(f, "menu_title", menu_title_font_);
            readFont(f, "menu_items", menu_items_font_);
        }

        if (yaml.contains("hud")) {
            const auto& h = yaml["hud"];
            readField(h, "bg_enabled", hud_bg_enabled_);
            readField(h, "entry_ms", hud_entry_ms_);
            readField(h, "flash_ms", hud_flash_ms_);
            readField(h, "shake_ms", hud_shake_ms_);
        }

        if (yaml.contains("pause")) {
            const auto& p = yaml["pause"];
            readField(p, "enter_ms", pause_enter_ms_);
            readField(p, "exit_ms", pause_exit_ms_);
            readCurve(p, "enter_curve", pause_enter_curve_);
            readCurve(p, "exit_curve", pause_exit_curve_);
        }

        if (yaml.contains("sounds")) {
            const auto& s = yaml["sounds"];
            readField(s, "menu_select", menu_select_sound_);
            readField(s, "menu_accept", menu_accept_sound_);
        }

        if (yaml.contains("notifier")) {
            const auto& n = yaml["notifier"];
            readField(n, "padding_h", notifier_.padding_h);
            readField(n, "padding_top", notifier_.padding_top);
            readField(n, "padding_bottom", notifier_.padding_bottom);
            readField(n, "line_gap", notifier_.line_gap);
            readField(n, "margin_top", notifier_.margin_top);
            readField(n, "border_px", notifier_.border_px);
            readField(n, "slide_ms", notifier_.slide_ms);
            readCurve(n, "slide_in_curve", notifier_.slide_in_curve);
            readCurve(n, "slide_out_curve", notifier_.slide_out_curve);
        }

        std::cout << "UiConfig: carregat des de " << file_path << '\n';
    } catch (const std::exception& e) {
        std::cerr << "UiConfig: error parsejant " << file_path << ": " << e.what() << '\n';
    }
}