#include "game/scenes/room_fsm.hpp"

#include <array>
#include <iostream>
#include <string_view>

#include "core/locale/locale.hpp"
#include "core/resources/resource_helper.hpp"
#include "external/fkyaml_node.hpp"

namespace {

    // Llegeix un sub-camp sencer d'un node YAML. Si manca, retorna el
    // fallback. Dissenyat per al consum puntual de `loadConfig`.
    auto readChildInt(const fkyaml::node& parent, const char* key, int fallback) -> int {
        if (!parent.contains(key)) { return fallback; }
        return parent[key].get_value<int>();
    }

}  // namespace

namespace RoomFsm {

    auto loadConfig(const std::string& yaml_path) -> Config {
        Config cfg{};
        cfg.text_enter_curve = UiConfig::curveByName("outCubic");
        cfg.text_exit_curve = UiConfig::curveByName("inCubic");

        auto bytes = Resource::Helper::loadFile(yaml_path);
        if (bytes.empty()) {
            std::cout << "RoomFsm: " << yaml_path << " absent — uso fallbacks compilats\n";
            return cfg;
        }
        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("room_intro")) {
            const auto& n = yaml["room_intro"];
            cfg.intro_fade_in_ms = readChildInt(n, "fade_in_ms", cfg.intro_fade_in_ms);
            cfg.intro_text_delay_ms = readChildInt(n, "text_delay_ms", cfg.intro_text_delay_ms);
            cfg.intro_text_enter_ms = readChildInt(n, "text_enter_ms", cfg.intro_text_enter_ms);
            cfg.intro_text_hold_ms = readChildInt(n, "text_hold_ms", cfg.intro_text_hold_ms);
            cfg.intro_text_exit_ms = readChildInt(n, "text_exit_ms", cfg.intro_text_exit_ms);
            cfg.player_spawn_delay_ms = readChildInt(n, "player_spawn_delay_ms", cfg.player_spawn_delay_ms);
            cfg.intro_text_line_gap_px = readChildInt(n, "line_gap_px", cfg.intro_text_line_gap_px);
        }
        if (yaml.contains("room_outro")) {
            const auto& n = yaml["room_outro"];
            cfg.outro_text_enter_ms = readChildInt(n, "text_enter_ms", cfg.outro_text_enter_ms);
            cfg.outro_text_hold_ms = readChildInt(n, "text_hold_ms", cfg.outro_text_hold_ms);
            cfg.outro_text_exit_ms = readChildInt(n, "text_exit_ms", cfg.outro_text_exit_ms);
            cfg.outro_fade_out_ms = readChildInt(n, "fade_out_ms", cfg.outro_fade_out_ms);
            cfg.outro_text_line_gap_px = readChildInt(n, "line_gap_px", cfg.outro_text_line_gap_px);
            cfg.outro_black_hold_ms = readChildInt(n, "black_hold_ms", cfg.outro_black_hold_ms);
        }
        if (yaml.contains("text")) {
            const auto& n = yaml["text"];
            if (n.contains("enter_curve")) {
                cfg.text_enter_curve = UiConfig::curveByName(n["enter_curve"].get_value<std::string>());
            }
            if (n.contains("exit_curve")) {
                cfg.text_exit_curve = UiConfig::curveByName(n["exit_curve"].get_value<std::string>());
            }
        }

        std::cout << "RoomFsm: timings carregats des de " << yaml_path
                  << " (intro fade " << cfg.intro_fade_in_ms
                  << "ms, outro fade " << cfg.outro_fade_out_ms << "ms)\n";
        return cfg;
    }

    auto advance(State current, Transition& t, const Config& cfg, int delta_ms) -> State {
        if (current == State::PLAYING) { return current; }

        t.elapsed_ms += delta_ms;

        if (current == State::ROOM_INTRO) {
            const std::array<int, 5> DURS = {
                cfg.intro_fade_in_ms,
                cfg.intro_text_delay_ms,
                cfg.intro_text_enter_ms,
                cfg.intro_text_hold_ms,
                cfg.intro_text_exit_ms,
            };
            while (t.phase < static_cast<int>(DURS.size()) && t.elapsed_ms >= DURS[t.phase]) {
                t.elapsed_ms -= DURS[t.phase];
                ++t.phase;
            }
            if (t.phase >= static_cast<int>(DURS.size())) { return State::PLAYING; }
            return current;
        }

        // ROOM_OUTRO
        const std::array<int, 5> DURS = {
            cfg.outro_text_enter_ms,
            cfg.outro_text_hold_ms,
            cfg.outro_text_exit_ms,
            cfg.outro_fade_out_ms,
            // Pausa final en negre, després del fade-out i abans del
            // canvi a INTRO. Si és 0 ms, el while-loop la consumeix
            // sense esperar — comportament idèntic a l'històric.
            cfg.outro_black_hold_ms,
        };
        while (t.phase < static_cast<int>(DURS.size()) && t.elapsed_ms >= DURS[t.phase]) {
            t.elapsed_ms -= DURS[t.phase];
            ++t.phase;
        }
        // Final de l'OUTRO → ROOM_INTRO de la sala SEGÜENT. La FSM no
        // sap quina és — només avisa del canvi d'estat. La GameScene,
        // dins `setState(ROOM_INTRO)` amb PREV=OUTRO, demana al
        // LevelManager el següent nivell i recarrega tilemap/entitats.
        if (t.phase >= static_cast<int>(DURS.size())) { return State::ROOM_INTRO; }
        return current;
    }

    namespace {
        // Substitueix la primera ocurrència de `placeholder` dins de `tpl`
        // pel valor d'`n` convertit a string. Utilitzat per les dues
        // formatadores d'INTRO; si la clau del Locale no porta el
        // placeholder (traducció buida o ja substituïda), retorna la
        // plantilla intacta.
        auto substitute(std::string tpl, std::string_view placeholder, int n) -> std::string {
            auto pos = tpl.find(placeholder);
            if (pos != std::string::npos) {
                tpl.replace(pos, placeholder.size(), std::to_string(n));
            }
            return tpl;
        }
    }  // namespace

    auto formatIntroPyramidLine(int pyramid) -> std::string {
        return substitute(Locale::get().text("game.room_intro_pyramid"), "{p}", pyramid);
    }

    auto formatIntroRoomLine(int room) -> std::string {
        return substitute(Locale::get().text("game.room_intro_room"), "{r}", room);
    }

    auto stateName(State s) -> const char* {
        switch (s) {
            case State::ROOM_INTRO:
                return "ROOM_INTRO";
            case State::PLAYING:
                return "PLAYING";
            case State::ROOM_OUTRO:
                return "ROOM_OUTRO";
        }
        return "?";
    }

}  // namespace RoomFsm