#include "game/scenes/game_over_fsm.hpp"

#include <algorithm>
#include <array>

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

namespace {

    // Llegeix un sub-camp sencer d'un node YAML. Si manca, retorna el
    // fallback. Mateix patró que `RoomFsm::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 GameOverFsm {

    auto loadConfig(const std::string& yaml_path) -> Config {
        Config cfg{};
        auto bytes = Resource::Helper::loadFile(yaml_path);
        if (bytes.empty()) {
            Log::warn("GameOverFsm", "{} absent — uso fallbacks compilats", yaml_path);
            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("game_over")) {
            const auto& n = yaml["game_over"];
            cfg.continue_text_enter_ms = readChildInt(n, "continue_text_enter_ms", cfg.continue_text_enter_ms);
            cfg.continue_text_hold_ms = readChildInt(n, "continue_text_hold_ms", cfg.continue_text_hold_ms);
            cfg.continue_text_exit_ms = readChildInt(n, "continue_text_exit_ms", cfg.continue_text_exit_ms);
            cfg.continue_count_start = readChildInt(n, "continue_count_start", cfg.continue_count_start);
            cfg.game_over_text_hold_ms = readChildInt(n, "game_over_text_hold_ms", cfg.game_over_text_hold_ms);
            cfg.game_over_text_exit_ms = readChildInt(n, "game_over_text_exit_ms", cfg.game_over_text_exit_ms);
            cfg.game_over_wait_ms = readChildInt(n, "game_over_wait_ms", cfg.game_over_wait_ms);
            cfg.fade_out_ms = readChildInt(n, "fade_out_ms", cfg.fade_out_ms);
            cfg.black_hold_ms = readChildInt(n, "black_hold_ms", cfg.black_hold_ms);
            if (n.contains("continue_music_speed")) {
                cfg.continue_music_speed = n["continue_music_speed"].get_value<float>();
            }
            if (n.contains("game_over_music_track")) {
                cfg.game_over_music_track = n["game_over_music_track"].get_value<std::string>();
            }
            if (n.contains("countdown_sound_key")) {
                cfg.countdown_sound_key = n["countdown_sound_key"].get_value<std::string>();
            }
        }

        Log::info("GameOverFsm", "timings carregats des de {} (continue hold {}ms, fade {}ms)", yaml_path, cfg.continue_text_hold_ms, cfg.fade_out_ms);
        return cfg;
    }

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

        t.elapsed_ms += delta_ms;

        if (current == State::CONTINUE_PROMPT) {
            const std::array<int, 3> DURS = {
                cfg.continue_text_enter_ms,
                cfg.continue_text_hold_ms,
                cfg.continue_text_exit_ms,
            };
            while (t.phase < static_cast<int>(DURS.size()) && t.elapsed_ms >= DURS[t.phase]) {
                t.elapsed_ms -= DURS[t.phase];
                // Si acabem la fase 1 (hold) sense cancel·lació, saltem
                // directament a GAME_OVER — el panel queda amunt i no
                // es reprodueix l'exit anim. La fase 2 (exit) només
                // s'executa si el GameScene l'ha forçada amb
                // `cancelContinuePrompt`.
                if (t.phase == 1) {
                    return State::GAME_OVER;
                }
                ++t.phase;
            }
            if (t.phase >= static_cast<int>(DURS.size())) { return State::OFF; }
            return current;
        }

        if (current == State::GAME_OVER) {
            const std::array<int, 3> DURS = {
                cfg.game_over_text_hold_ms,
                cfg.game_over_text_exit_ms,
                cfg.game_over_wait_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::FADE_OUT; }
            return current;
        }

        // FADE_OUT
        const std::array<int, 2> DURS = {
            cfg.fade_out_ms,
            cfg.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;
        }
        if (t.phase >= static_cast<int>(DURS.size())) { return State::DONE; }
        return current;
    }

    void cancelContinuePrompt(State current, Transition& t) {
        if (current != State::CONTINUE_PROMPT) { return; }
        if (t.phase >= 2) { return; }  // ja en exit anim, no-op
        t.phase = 2;
        t.elapsed_ms = 0;
    }

    auto countdownSecondsRemaining(State current, const Transition& t, const Config& cfg) -> int {
        if (current != State::CONTINUE_PROMPT) { return 0; }
        if (t.phase != 1) { return 0; }
        // La sèrie és [start, start-1, ..., 1, 0]: en total `start+1`
        // graons. El primer número visible és `start` i l'últim 0 es
        // manté durant el seu graó abans que la fase 1 acabi i la FSM
        // salti a GAME_OVER. Si `start == 0` només es mostra "0"
        // durant tot el hold.
        const int START = std::max(0, cfg.continue_count_start);
        const int STEP_COUNT = START + 1;
        const int STEP_MS = std::max(1, cfg.continue_text_hold_ms / STEP_COUNT);
        const int CONSUMED = t.elapsed_ms / STEP_MS;
        return std::clamp(START - CONSUMED, 0, START);
    }

    auto stateName(State s) -> const char* {
        switch (s) {
            case State::OFF:
                return "OFF";
            case State::CONTINUE_PROMPT:
                return "CONTINUE_PROMPT";
            case State::GAME_OVER:
                return "GAME_OVER";
            case State::FADE_OUT:
                return "FADE_OUT";
            case State::DONE:
                return "DONE";
        }
        return "?";
    }

}  // namespace GameOverFsm