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

#include <imgui.h>

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 });
        }
    }
}

constexpr int kWidth = 40;
constexpr int kHeight = 100;
constexpr float kScale = 4.0f;
constexpr ImVec2 kSize(kWidth* kScale, kHeight* kScale);

static ImVec2 TrSandbox2Screen(ImVec2 origin, Pt pt) {
    return ImVec2(origin.x + kScale * pt.x, origin.y - kScale * pt.y);
}

struct ImRect {
    ImVec2 top_left;
    ImVec2 bottom_right;
};
// Assuming inclusive-inclusive rectangle
static ImRect TrSandbox2Screen(ImVec2 origin, Rect r) {
    return {
        ImVec2(origin.x + kScale * r.bl.x, origin.y - kScale * (r.tr.y+1)),
        ImVec2(origin.x + kScale * (r.tr.x + 1), origin.y - kScale * r.bl.y),
    };
}

void ShowEverything() {
    ImGui::Begin("Sandbox");
    static Sandbox sandbox(40, 100);
    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();
        gl.upload(reinterpret_cast<const char*>(sandbox.bitmap), kWidth, kHeight);
    }

    // TODO this makes things very wrong (no proper assignment operator)
    // if (ImGui::Button("Reset sandbox")) {
    //     sandbox = Sandbox(40, 100);
    // }
    // ImGui::SameLine();
    if (ImGui::Button("Add sand")) {
        AddSand(sandbox);
    }

    auto sandbox_topleft = ImGui::GetCursorScreenPos();
    ImGui::Image(gl.as_imgui(), kSize, ImVec2(0, 1), ImVec2(1, 0));
    // bottom-left corner of the sandbox, in screen space
    auto origin = sandbox_topleft;
    origin.y += kSize.y;

    if (show_dirty_rect) {
        auto dl = ImGui::GetWindowDrawList();
        auto [top_left, bottom_right] = TrSandbox2Screen(origin, sandbox.dirty_writeto);
        dl->AddRect(top_left, bottom_right, IM_COL32(255, 0, 0, 255));
    }

    ImGui::End();

    ImGui::ShowDemoWindow();
}