#include <imgui.h>

#include "../log.h"
#include "logs.h"

static inline void logs_scrolling_region(ImFont* monospace_font, bool* autoscrolling) {
    ImGui::PushFont(monospace_font);
    ImGui::PushStyleVar(ImGuiStyleVar_ItemSpacing, ImVec2(0, 0));

    ImGuiListClipper clipper;
    clipper.Begin(static_cast<int>(log_entry_line_offsets.size()));
    while (clipper.Step()) {
        for (int i_u = clipper.DisplayStart; i_u < clipper.DisplayEnd; i_u++) {
            // what'd we do if we log the error about an error failing to show logs
            assert(i_u >= 0);
            size_t i = static_cast<size_t>(i_u);

            const char* start_offset = &log_entries[log_entry_line_offsets[i]];
            const char* end_offset = log_entry_line_offsets.size() > i + 1
                ? &log_entries[log_entry_line_offsets[i + 1] - 1]
                : &log_entries[log_entries.size()];
            ImGui::TextUnformatted(start_offset, end_offset);
        }
    }
    clipper.End();

    ImGui::PopStyleVar();
    ImGui::PopFont();

    if (ImGui::GetScrollY() >= ImGui::GetScrollMaxY()) {
        *autoscrolling = true;
        ImGui::SetScrollHereY(1.0f);
    }
}

void logs_window(ImFont* monospace_font, bool* autoscrolling, bool* p_open) {
    if (!ImGui::Begin("LogMeow Logs", p_open)) {
        ImGui::End();
        return;
    }

    if (ImGui::Button("Clear")) {
        log_entries.clear();
        log_entry_line_offsets = {0};
    }
    ImGui::SameLine();
    if (ImGui::Button("Copy")) {
        ImGui::SetClipboardText(log_entries.c_str());
    }

    ImGui::Separator();
    // copied from imgui/imgui_demo.cpp: [SECTION] Example App: Debug Console / ShowExampleAppConsole()
    // and [SECTION] Example App: Long Text / ShowExampleAppLongText()
    // and [SECTION] Example App: Debug Log / ShowExampleAppLog()
    if (ImGui::BeginChild("ScrollingRegion", ImVec2(0, 0), false, ImGuiWindowFlags_HorizontalScrollbar)) {
        logs_scrolling_region(monospace_font, autoscrolling);
    }
    ImGui::EndChild();
    ImGui::End();
}