#include "ui.hpp"
#include "ogl.hpp"
#include "sandbox.hpp"

#include <imgui.h>
#include <memory>

static void AddSand(Sandbox& sb) {
    for (int y = 80; y <= 90; ++y) {
        for (int x = 10; x <= 13; ++x) {
            sb.set_sand(x, y, Tile{ .so = Tile::SAND });
        }
    }
}

struct ImRect {
    ImVec2 top_left;
    ImVec2 bottom_right;
};

struct SandboxCfg {
    int width = 40, height = 100;
    float tile_size = 4.0f;

    ImVec2 tr_sandbox2screen(ImVec2 origin, Pt pt) const {
        return ImVec2(origin.x + tile_size * pt.x, origin.y - tile_size * pt.y);
    }

    // Assuming inclusive-inclusive rectangle
    ImRect tr_sandbox2screen(ImVec2 origin, Rect r) const {
        return {
            ImVec2(origin.x + tile_size * r.bl.x, origin.y - tile_size * (r.tr.y + 1)),
            ImVec2(origin.x + tile_size * (r.tr.x + 1), origin.y - tile_size * r.bl.y),
        };
    }

    std::unique_ptr<Sandbox> make_sandbox() const {
        return std::make_unique<Sandbox>(width, height);
    }
};

void ShowEverything() {
    ImGui::Begin("Sandbox");

    static SandboxCfg cfg;
    static std::unique_ptr<Sandbox> sandbox = cfg.make_sandbox();
    static OglImage gl;

    static bool running = false;
    ImGui::Checkbox("Run", &running);
    static bool show_dirty_rect = true;
    ImGui::Checkbox("Show dirty rects", &show_dirty_rect);

    ImGui::Text("ncycle = %d", sandbox->ncycle);
    ImGui::SameLine();
    bool step = ImGui::Button("Step");

    if (step || running) {
        sandbox->simulate_step();
    }

    // TODO popup for changing these params?
    // TODO migrate existing content
    ImGui::InputInt("Sandbox width", &cfg.width);
    ImGui::InputInt("Sandbox height", &cfg.height);
    if (ImGui::Button("Recreate")) {
        sandbox = cfg.make_sandbox();
    }
    ImGui::SameLine();
    if (ImGui::Button("Add sand")) {
        AddSand(*sandbox);
    }

    ImVec2 img_size(cfg.tile_size * sandbox->width, cfg.tile_size * sandbox->height);
    auto img_topleft = ImGui::GetCursorScreenPos();
    gl.upload(reinterpret_cast<const char*>(sandbox->bitmap), sandbox->width, sandbox->height);
    ImGui::Image(gl.as_imgui(), img_size, ImVec2(0, 1), ImVec2(1, 0));
    // bottom-left corner of the sandbox, in screen space
    auto origin = img_topleft;
    origin.y += img_size.y;

    if (show_dirty_rect) {
        auto dl = ImGui::GetWindowDrawList();
        auto [top_left, bottom_right] = cfg.tr_sandbox2screen(origin, sandbox->dirty_writeto);
        dl->AddRect(top_left, bottom_right, IM_COL32(255, 0, 0, 255));
    }

    ImGui::End();

    ImGui::ShowDemoWindow();
}