// DragonX Wallet - ImGui Edition
// Copyright 2024-2026 The Hush Developers
// Released under the GPLv3

#pragma once

#include "../colors.h"
#include "../typography.h"
#include "../layout.h"
#include "../../schema/ui_schema.h"
#include "buttons.h"
#include "imgui.h"
#include "imgui_internal.h"

namespace dragonx {
namespace ui {
namespace material {

// ============================================================================
// Material Design App Bar Component
// ============================================================================
// Based on https://m2.material.io/components/app-bars-top
//
// The top app bar displays information and actions relating to the current
// screen.

enum class AppBarType {
    Regular,       // Standard height (56/64dp)
    Prominent,     // Extended height for larger titles
    Dense          // Smaller height for desktop
};

/**
 * @brief App bar configuration
 */
struct AppBarSpec {
    AppBarType type = AppBarType::Regular;
    ImU32 backgroundColor = 0;     // 0 = use elevated surface
    bool elevated = true;          // Show elevation
    bool centerTitle = false;      // Center title (default: left)
    float elevation = 4.0f;        // Elevation in dp
};

/**
 * @brief Begin a top app bar
 * 
 * @param id Unique identifier
 * @param spec App bar configuration
 * @return true if app bar is visible
 */
bool BeginAppBar(const char* id, const AppBarSpec& spec = AppBarSpec());

/**
 * @brief End app bar
 */
void EndAppBar();

/**
 * @brief Set app bar navigation icon (left side)
 * 
 * @param icon Icon text (e.g., "☰" for menu)
 * @param tooltip Optional tooltip
 * @return true if clicked
 */
bool AppBarNavIcon(const char* icon, const char* tooltip = nullptr);

/**
 * @brief Set app bar title
 */
void AppBarTitle(const char* title);

/**
 * @brief Add app bar action button (right side)
 * 
 * @param icon Icon text
 * @param tooltip Optional tooltip
 * @return true if clicked
 */
bool AppBarAction(const char* icon, const char* tooltip = nullptr);

/**
 * @brief Begin app bar action menu (for overflow)
 */
bool BeginAppBarMenu(const char* icon);

/**
 * @brief End app bar action menu
 */
void EndAppBarMenu();

/**
 * @brief Add menu item to app bar menu
 */
bool AppBarMenuItem(const char* label, const char* icon = nullptr);

// ============================================================================
// Implementation
// ============================================================================

struct AppBarState {
    ImVec2 barMin;
    ImVec2 barMax;
    float height;
    float navIconWidth;
    float actionsStartX;
    float titleX;
    bool hasNavIcon;
    bool centerTitle;
    ImU32 backgroundColor;
};

static AppBarState g_appBarState;

inline bool BeginAppBar(const char* id, const AppBarSpec& spec) {
    ImGuiWindow* window = ImGui::GetCurrentWindow();
    if (window->SkipItems)
        return false;
    
    ImGui::PushID(id);
    
    ImGuiIO& io = ImGui::GetIO();
    
    // Calculate height based on type
    float barHeight;
    switch (spec.type) {
        case AppBarType::Prominent:
            barHeight = 128.0f;
            break;
        case AppBarType::Dense:
            barHeight = 48.0f;
            break;
        default:
            barHeight = size::AppBarHeight;  // 56dp
            break;
    }
    
    g_appBarState.height = barHeight;
    g_appBarState.hasNavIcon = false;
    g_appBarState.centerTitle = spec.centerTitle;
    g_appBarState.navIconWidth = 0;
    g_appBarState.actionsStartX = io.DisplaySize.x;  // Will be adjusted as actions added
    
    // Bar position (always at top)
    g_appBarState.barMin = ImVec2(0, 0);
    g_appBarState.barMax = ImVec2(io.DisplaySize.x, barHeight);
    
    // Background color
    if (spec.backgroundColor != 0) {
        g_appBarState.backgroundColor = spec.backgroundColor;
    } else {
        g_appBarState.backgroundColor = Surface(Elevation::Dp4);
    }
    
    // Draw app bar background
    ImDrawList* drawList = window->DrawList;
    drawList->AddRectFilled(g_appBarState.barMin, g_appBarState.barMax, g_appBarState.backgroundColor);
    
    // Bottom divider/shadow
    if (spec.elevated) {
        drawList->AddLine(
            ImVec2(g_appBarState.barMin.x, g_appBarState.barMax.y),
            ImVec2(g_appBarState.barMax.x, g_appBarState.barMax.y),
            schema::UI().resolveColor("var(--app-bar-shadow)", IM_COL32(0, 0, 0, 50))
        );
    }
    
    // Set up layout
    g_appBarState.titleX = spacing::dp(2);  // Default title position
    
    return true;
}

inline void EndAppBar() {
    ImGui::PopID();
}

inline bool AppBarNavIcon(const char* icon, const char* tooltip) {
    ImGuiWindow* window = ImGui::GetCurrentWindow();
    if (window->SkipItems)
        return false;
    
    g_appBarState.hasNavIcon = true;
    g_appBarState.navIconWidth = size::TouchTarget;
    
    // Position nav icon on left
    float iconX = spacing::dp(0.5f);  // 4dp left margin
    float centerY = g_appBarState.barMin.y + g_appBarState.height * 0.5f;
    
    ImVec2 buttonPos(iconX, centerY - size::TouchTarget * 0.5f);
    
    // Draw icon button
    ImGui::SetCursorScreenPos(buttonPos);
    bool clicked = IconButton(icon, tooltip);
    
    // Update title position
    g_appBarState.titleX = iconX + size::TouchTarget + spacing::dp(1);
    
    return clicked;
}

inline void AppBarTitle(const char* title) {
    ImGuiWindow* window = ImGui::GetCurrentWindow();
    if (window->SkipItems)
        return;
    
    float centerY = g_appBarState.barMin.y + g_appBarState.height * 0.5f;
    
    // Calculate title position
    float titleX;
    if (g_appBarState.centerTitle) {
        // Center title between nav icon and actions
        float availableWidth = g_appBarState.actionsStartX - g_appBarState.titleX;
        Typography::instance().pushFont(TypeStyle::H6);
        float titleWidth = ImGui::CalcTextSize(title).x;
        Typography::instance().popFont();
        titleX = g_appBarState.titleX + (availableWidth - titleWidth) * 0.5f;
    } else {
        titleX = g_appBarState.titleX;
    }
    
    // Render title
    Typography::instance().pushFont(TypeStyle::H6);
    float titleY = centerY - ImGui::GetFontSize() * 0.5f;
    
    ImDrawList* drawList = window->DrawList;
    drawList->AddText(ImVec2(titleX, titleY), OnSurface(), title);
    
    Typography::instance().popFont();
}

inline bool AppBarAction(const char* icon, const char* tooltip) {
    ImGuiWindow* window = ImGui::GetCurrentWindow();
    if (window->SkipItems)
        return false;
    
    // Actions are positioned from right edge
    g_appBarState.actionsStartX -= size::TouchTarget;
    
    float centerY = g_appBarState.barMin.y + g_appBarState.height * 0.5f;
    ImVec2 buttonPos(g_appBarState.actionsStartX, centerY - size::TouchTarget * 0.5f);
    
    ImGui::SetCursorScreenPos(buttonPos);
    return IconButton(icon, tooltip);
}

inline bool BeginAppBarMenu(const char* icon) {
    ImGuiWindow* window = ImGui::GetCurrentWindow();
    if (window->SkipItems)
        return false;
    
    // Position menu button
    g_appBarState.actionsStartX -= size::TouchTarget;
    
    float centerY = g_appBarState.barMin.y + g_appBarState.height * 0.5f;
    ImVec2 buttonPos(g_appBarState.actionsStartX, centerY - size::TouchTarget * 0.5f);
    
    ImGui::SetCursorScreenPos(buttonPos);
    
    bool menuOpen = false;
    if (IconButton(icon, "More options")) {
        ImGui::OpenPopup("##appbar_menu");
    }
    
    // Style the popup menu
    ImGui::PushStyleVar(ImGuiStyleVar_WindowPadding, ImVec2(0, spacing::dp(1)));
    ImGui::PushStyleVar(ImGuiStyleVar_PopupRounding, size::MenuCornerRadius);
    ImGui::PushStyleColor(ImGuiCol_PopupBg, ImGui::ColorConvertU32ToFloat4(Surface(Elevation::Dp8)));
    
    if (ImGui::BeginPopup("##appbar_menu")) {
        menuOpen = true;
    }
    
    return menuOpen;
}

inline void EndAppBarMenu() {
    ImGui::EndPopup();
    ImGui::PopStyleColor();
    ImGui::PopStyleVar(2);
}

inline bool AppBarMenuItem(const char* label, const char* icon) {
    ImGuiWindow* window = ImGui::GetCurrentWindow();
    
    const float itemHeight = size::ListItemHeight;
    const float itemWidth = 200.0f;  // Menu min width
    
    ImVec2 pos = window->DC.CursorPos;
    ImRect itemBB(pos, ImVec2(pos.x + itemWidth, pos.y + itemHeight));
    
    ImGuiID id = window->GetID(label);
    ImGui::ItemSize(itemBB);
    if (!ImGui::ItemAdd(itemBB, id))
        return false;
    
    bool hovered, held;
    bool pressed = ImGui::ButtonBehavior(itemBB, id, &hovered, &held);
    
    // Draw
    ImDrawList* drawList = window->DrawList;
    
    if (hovered) {
        drawList->AddRectFilled(itemBB.Min, itemBB.Max, schema::UI().resolveColor("var(--hover-overlay)", IM_COL32(255, 255, 255, 10)));
    }
    
    float contentX = pos.x + spacing::dp(2);
    float centerY = pos.y + itemHeight * 0.5f;
    
    // Icon
    if (icon) {
        drawList->AddText(ImVec2(contentX, centerY - 12.0f), OnSurfaceMedium(), icon);
        contentX += 24.0f + spacing::dp(2);
    }
    
    // Label
    Typography::instance().pushFont(TypeStyle::Body1);
    float labelY = centerY - ImGui::GetFontSize() * 0.5f;
    drawList->AddText(ImVec2(contentX, labelY), OnSurface(), label);
    Typography::instance().popFont();
    
    if (pressed) {
        ImGui::CloseCurrentPopup();
    }
    
    return pressed;
}

} // namespace material
} // namespace ui
} // namespace dragonx