#include "game/editor/editor.hpp"

#ifdef _DEBUG

#include <SDL3/SDL.h>

#include <algorithm>

#include "core/input/key_config.hpp"
#include "core/locale/locale.hpp"
#include "core/rendering/notification_presets.hpp"
#include "core/rendering/screen.hpp"
#include "core/rendering/surface.hpp"
#include "core/resources/resource_cache.hpp"
#include "core/resources/resource_helper.hpp"
#include "core/system/event_buffer.hpp"
#include "game/map/tilemap.hpp"
#include "utils/defaults.hpp"
#include "utils/defines.hpp"

namespace {

    // Geometria del TilePicker en espai canvas. `cols × rows_visible` tiles
    // encapsulats dins d'un rectangle amb `PICKER_MARGIN` per vora. Com que
    // el tileset real (p.ex. 32×16 tiles de 16 px = 512×256) no cabria a
    // 1× dins del canvas 336×240, linealitzem els índexs i els repartim
    // en una graella que SÍ cap, amb scroll vertical per veure la resta.
    struct PickerLayout {
        int x{0};
        int y{0};
        int w{0};
        int h{0};
        int cols{0};
        int rows_visible{0};
        int tile_size{0};
        int total_tiles{0};
        int max_scroll{0};
    };

    auto layoutPicker(const Tilemap& tm) -> PickerLayout {
        PickerLayout lay{};
        lay.tile_size = tm.getTileSize();
        const int M = Defaults::Editor::PICKER_MARGIN;
        const int INNER_W = GameCanvas::WIDTH - (2 * M);
        const int INNER_H = GameCanvas::HEIGHT - (2 * M);
        if (lay.tile_size <= 0) { return lay; }
        lay.cols = INNER_W / lay.tile_size;
        lay.rows_visible = INNER_H / lay.tile_size;
        lay.x = M;
        lay.y = M;
        lay.w = lay.cols * lay.tile_size;
        lay.h = lay.rows_visible * lay.tile_size;
        const auto TILESET = Resource::Cache::get().getSurface(tm.getTilesetPath());
        if (TILESET != nullptr) {
            const int TCOLS = TILESET->getWidth() / lay.tile_size;
            const int TROWS = TILESET->getHeight() / lay.tile_size;
            lay.total_tiles = TCOLS * TROWS;
        }
        const int TOTAL_ROWS = (lay.cols > 0) ? ((lay.total_tiles + lay.cols - 1) / lay.cols) : 0;
        lay.max_scroll = std::max(0, TOTAL_ROWS - lay.rows_visible);
        return lay;
    }

}  // namespace

void Editor::enter() {
    if (active_) { return; }
    active_ = true;
    Notification::notify(Locale::get().text("input.editor_on"));
}

// cppcheck-suppress constParameterReference
// Tilemap& mutable per simetria amb `toggle()` i per futures
// invalidacions de caches d'edició, encara que `save()` sigui const.
void Editor::exit(Tilemap& tilemap) {
    if (!active_) { return; }
    active_ = false;
    picker_open_ = false;
    // Resolem la ruta via Resource::Helper perquè en Debug el root de
    // dades és AEE_SOURCE_DIR (ruta absoluta al repo), no el CWD. Sense
    // això, el writer obriria `data/maps/pyramid.yaml` relatiu al CWD
    // i fallaria sempre excepte si el binari es llança des del repo root.
    const auto ABS_PATH = Resource::Helper::resolve(Defaults::Editor::SAVE_PATH);
    const bool SAVED = tilemap.save(ABS_PATH);
    Notification::notify(Locale::get().text(SAVED ? "input.editor_off" : "input.editor_save_error"));
}

void Editor::toggle(Tilemap& tilemap) {
    if (active_) {
        exit(tilemap);
    } else {
        enter();
    }
}

void Editor::update(int /*delta_ms*/, Tilemap& tilemap) {
    if (!active_) { return; }

    // Posició del ratolí en coordenades del canvas (independent del
    // zoom de finestra i del mode d'escalat).
    float mouse_x = 0.0F;
    float mouse_y = 0.0F;
    SDL_GetMouseState(&mouse_x, &mouse_y);
    const auto CP = Screen::get().windowToCanvas(mouse_x, mouse_y);
    const int CX = static_cast<int>(CP.x);
    const int CY = static_cast<int>(CP.y);

    // Consumim tecles pròpies del picker abans que cap altre handler
    // (GlobalInputs) les vegi. ESC només es consumeix si el picker està
    // obert — fora d'ell segueix arribant a GlobalInputs per la seva
    // acció de confirmar-eixida.
    const SDL_Scancode PICKER_SC = KeyConfig::get().scancode("editor_picker");
    for (auto it = EventBuffer::events.begin(); it != EventBuffer::events.end();) {
        bool consumed = false;
        if (it->type == SDL_EVENT_KEY_DOWN) {
            if (PICKER_SC != SDL_SCANCODE_UNKNOWN && it->key.scancode == PICKER_SC) {
                picker_open_ = !picker_open_;
                if (picker_open_) { picker_scroll_ = 0; }
                consumed = true;
            } else if (picker_open_ && it->key.scancode == SDL_SCANCODE_ESCAPE) {
                picker_open_ = false;
                consumed = true;
            }
        }
        if (consumed) {
            it = EventBuffer::events.erase(it);
        } else {
            ++it;
        }
    }

    if (picker_open_) {
        updatePicker(tilemap, CX, CY);
    } else {
        updateMap(tilemap, CX, CY);
    }
}

void Editor::updateMap(Tilemap& tilemap, int canvas_x, int canvas_y) {
    // Cursor → cel·la del tilemap. Fora del mapa deixem -1/-1 perquè
    // `render()` sàpiga no dibuixar preview i `setTileAt` ignori el clic.
    const int TS = tilemap.getTileSize();
    const int MX = canvas_x - tilemap.getOriginX();
    const int MY = canvas_y - tilemap.getOriginY();
    cursor_col_ = -1;
    cursor_row_ = -1;
    if (TS > 0 && MX >= 0 && MY >= 0) {
        const int C = MX / TS;
        const int R = MY / TS;
        if (C < tilemap.getCols() && R < tilemap.getRows()) {
            cursor_col_ = C;
            cursor_row_ = R;
        }
    }

    for (const auto& ev : EventBuffer::events) {
        if (ev.type != SDL_EVENT_MOUSE_BUTTON_DOWN) { continue; }
        if (ev.button.button == SDL_BUTTON_LEFT) {
            if (brush_ >= 0 && cursor_col_ >= 0 && cursor_row_ >= 0) {
                tilemap.setTileAt(cursor_col_, cursor_row_, brush_);
            }
        } else if (ev.button.button == SDL_BUTTON_RIGHT) {
            brush_ = -1;
        }
    }
}

void Editor::updatePicker(const Tilemap& tilemap, int canvas_x, int canvas_y) {
    const auto LAY = layoutPicker(tilemap);
    picker_hover_ = -1;
    if (canvas_x >= LAY.x && canvas_x < LAY.x + LAY.w && canvas_y >= LAY.y && canvas_y < LAY.y + LAY.h && LAY.tile_size > 0) {
        const int VC = (canvas_x - LAY.x) / LAY.tile_size;
        const int VR = (canvas_y - LAY.y) / LAY.tile_size;
        const int IDX = ((picker_scroll_ + VR) * LAY.cols) + VC;
        if (IDX < LAY.total_tiles) { picker_hover_ = IDX; }
    }

    for (const auto& ev : EventBuffer::events) {
        if (ev.type == SDL_EVENT_MOUSE_WHEEL) {
            picker_scroll_ -= static_cast<int>(ev.wheel.y);
            picker_scroll_ = std::clamp(picker_scroll_, 0, LAY.max_scroll);
        } else if (ev.type == SDL_EVENT_MOUSE_BUTTON_DOWN && ev.button.button == SDL_BUTTON_LEFT) {
            if (picker_hover_ >= 0) {
                brush_ = picker_hover_;
                picker_open_ = false;
            }
        }
    }
}

void Editor::render(const Tilemap& tilemap) const {
    if (!active_) { return; }
    auto& screen = Screen::get();
    constexpr int W = GameCanvas::WIDTH;
    constexpr int H = GameCanvas::HEIGHT;

    if (picker_open_) {
        renderPicker(tilemap);
    } else if (brush_ >= 0 && cursor_col_ >= 0 && cursor_row_ >= 0) {
        // Preview del brush sota el cursor (només quan el picker és tancat).
        const int PX = tilemap.getOriginX() + (cursor_col_ * tilemap.getTileSize());
        const int PY = tilemap.getOriginY() + (cursor_row_ * tilemap.getTileSize());
        tilemap.renderTilePreview(PX, PY, brush_);
    }

    constexpr auto BORDER = Defaults::Editor::BORDER_ARGB;
    screen.fillRect(0, 0, W, 1, BORDER);
    screen.fillRect(0, H - 1, W, 1, BORDER);
    screen.fillRect(0, 0, 1, H, BORDER);
    screen.fillRect(W - 1, 0, 1, H, BORDER);
}

void Editor::renderPicker(const Tilemap& tilemap) const {
    const auto LAY = layoutPicker(tilemap);
    auto& screen = Screen::get();
    screen.fillRect(LAY.x, LAY.y, LAY.w, LAY.h, Defaults::Editor::PICKER_BG_ARGB);

    for (int vr = 0; vr < LAY.rows_visible; ++vr) {
        const int LOGICAL_ROW = picker_scroll_ + vr;
        for (int vc = 0; vc < LAY.cols; ++vc) {
            const int IDX = (LOGICAL_ROW * LAY.cols) + vc;
            if (IDX >= LAY.total_tiles) { break; }
            const int PX = LAY.x + (vc * LAY.tile_size);
            const int PY = LAY.y + (vr * LAY.tile_size);
            tilemap.renderTilePreview(PX, PY, IDX);
        }
    }

    if (picker_hover_ >= 0 && LAY.cols > 0) {
        const int VR = (picker_hover_ / LAY.cols) - picker_scroll_;
        const int VC = picker_hover_ % LAY.cols;
        if (VR >= 0 && VR < LAY.rows_visible) {
            const int PX = LAY.x + (VC * LAY.tile_size);
            const int PY = LAY.y + (VR * LAY.tile_size);
            const int TS = LAY.tile_size;
            constexpr auto C = Defaults::Editor::PICKER_HOVER_ARGB;
            screen.fillRect(PX, PY, TS, 1, C);
            screen.fillRect(PX, PY + TS - 1, TS, 1, C);
            screen.fillRect(PX, PY, 1, TS, C);
            screen.fillRect(PX + TS - 1, PY, 1, TS, C);
        }
    }
}

#endif  // _DEBUG