#include "kpi_card.h"
#include "sparkline.h"
#include "core/tokens.h"
#include <imgui.h>
#include <cstdio>

void kpi_card(const char* label, float value, float delta_percent,
              const float* history, int history_count,
              const char* format) {
    using namespace fn_tokens;

    // Card container — surface bg, border, rounded, padding.
    // Mirrors Mantine <Paper withBorder shadow="xs" radius="md" p="md" /> used in
    // @fn_library/kpi_card.tsx, adapted for ImGui dark theme.
    ImGui::PushStyleColor(ImGuiCol_ChildBg, colors::surface);
    ImGui::PushStyleColor(ImGuiCol_Border, colors::border);
    ImGui::PushStyleVar(ImGuiStyleVar_ChildRounding, radius::md);
    ImGui::PushStyleVar(ImGuiStyleVar_ChildBorderSize, 1.0f);
    ImGui::PushStyleVar(ImGuiStyleVar_WindowPadding, ImVec2(spacing::md, spacing::md));

    // Unique child id per label so multiple cards in the same window don't collide.
    char child_id[96];
    std::snprintf(child_id, sizeof(child_id), "##kpi_%s", label);

    float width = ImGui::GetContentRegionAvail().x;
    if (width < 1.0f) width = 1.0f;

    ImGui::BeginChild(child_id, ImVec2(width, 0),
                      ImGuiChildFlags_Borders | ImGuiChildFlags_AutoResizeY);

    // Label — muted (Mantine "dimmed" text)
    ImGui::PushStyleColor(ImGuiCol_Text, colors::text_muted);
    ImGui::TextUnformatted(label);
    ImGui::PopStyleColor();

    // Value — scaled up (Mantine fw={700} fontSize=1.875rem)
    ImGui::SetWindowFontScale(1.8f);
    char value_buf[64];
    std::snprintf(value_buf, sizeof(value_buf), format, value);
    ImGui::TextUnformatted(value_buf);
    ImGui::SetWindowFontScale(1.0f);

    // Delta badge — only render when meaningful
    const bool has_delta = delta_percent != 0.0f;
    const bool has_history = history != nullptr && history_count > 0;

    if (has_delta || has_history) {
        const bool positive = delta_percent >= 0.0f;
        const ImVec4 delta_color = positive ? colors::success : colors::error;

        if (has_delta) {
            char delta_buf[32];
            if (positive) {
                std::snprintf(delta_buf, sizeof(delta_buf), "\xe2\x96\xb2 +%.1f%%", delta_percent);
            } else {
                std::snprintf(delta_buf, sizeof(delta_buf), "\xe2\x96\xbc %.1f%%", delta_percent);
            }
            ImGui::PushStyleColor(ImGuiCol_Text, delta_color);
            ImGui::TextUnformatted(delta_buf);
            ImGui::PopStyleColor();
        }

        if (has_history) {
            sparkline(label, history, history_count, delta_color, 120.0f, 24.0f);
        }
    }

    ImGui::EndChild();

    ImGui::PopStyleVar(3);
    ImGui::PopStyleColor(2);
}