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

#pragma once

#include <memory>
#include <string>
#include <functional>
#include <thread>
#include <atomic>
#include <chrono>
#include "data/wallet_state.h"
#include "ui/sidebar.h"
#include "ui/windows/console_tab.h"
#include "imgui.h"

// Forward declarations
namespace dragonx {
    namespace rpc { 
        class RPCClient;
        class RPCWorker;
        struct ConnectionConfig;
    }
    namespace config { class Settings; }
    namespace daemon { class EmbeddedDaemon; class XmrigManager; }
    namespace util { class Bootstrap; class SecureVault; }
}

namespace dragonx {

/**
 * @brief First-run wizard states
 */
enum class WizardPhase {
    None,               // No wizard — normal operation
    BootstrapOffer,     // Step 1: offer bootstrap download
    BootstrapInProgress,// downloading / extracting
    BootstrapFailed,    // error with retry/skip option
    Appearance,         // Step 2: visual effects / performance options
    EncryptOffer,       // Step 3: offer wallet encryption
    EncryptInProgress,  // encrypting + daemon restarting
    PinSetup,           // Step 4: optional PIN setup (after encryption)
    Done                // wizard complete, launch normally
};

/**
 * @brief Encrypt-wallet dialog phases (settings page flow)
 */
enum class EncryptDialogPhase {
    PassphraseEntry,    // Enter & confirm passphrase
    Encrypting,         // In-progress animation
    PinSetup,           // Offer PIN after successful encryption
    Done                // Finished — close dialog
};

/**
 * @brief Main application class
 * 
 * Manages application state, RPC connection, and coordinates UI rendering.
 */
class App {
public:
    App();
    ~App();

    // Non-copyable
    App(const App&) = delete;
    App& operator=(const App&) = delete;

    /**
     * @brief Initialize the application
     * @return true if initialization succeeded
     */
    bool init();

    /**
     * @brief Update application state (called every frame)
     */
    void update();

    /**
     * @brief Render the application UI (called every frame)
     */
    void render();

    /**
     * @brief Clean shutdown
     */
    void shutdown();

    /**
     * @brief Check if app should exit (render loop can stop)
     * Enforces minimum 1-second display of shutdown screen so user sees feedback.
     */
    bool shouldQuit() const {
        if (!quit_requested_ || !shutdown_complete_) return false;
        auto elapsed = std::chrono::steady_clock::now() - shutdown_start_time_;
        return elapsed >= std::chrono::seconds(1);
    }

    /**
     * @brief Request application exit — begins async shutdown
     */
    void requestQuit();

    /**
     * @brief Begin graceful shutdown (called on window close)
     * Starts daemon stop on a background thread while UI keeps rendering.
     */
    void beginShutdown();

    /**
     * @brief Whether we are in the shutdown phase
     */
    bool isShuttingDown() const { return shutting_down_; }

    /**
     * @brief Render the shutdown overlay (called instead of normal UI during shutdown)
     */
    void renderShutdownScreen();

    /**
     * @brief Render loading overlay in content area while daemon is starting/syncing
     * @param contentH Height of the content area child window
     */
    void renderLoadingOverlay(float contentH);

    // Accessors for subsystems
    rpc::RPCClient* rpc() { return rpc_.get(); }
    rpc::RPCWorker* worker() { return worker_.get(); }
    config::Settings* settings() { return settings_.get(); }
    WalletState& state() { return state_; }
    const WalletState& state() const { return state_; }
    const WalletState& getWalletState() const { return state_; }

    // Connection state (convenience wrappers)
    bool isConnected() const { return state_.connected; }
    int getBlockHeight() const { return state_.sync.blocks; }
    const std::string& getConnectionStatus() const { return connection_status_; }
    const std::string& getDaemonStatus() const { return daemon_status_; }

    // Balance info (convenience wrappers)
    double getShieldedBalance() const { return state_.shielded_balance; }
    double getTransparentBalance() const { return state_.transparent_balance; }
    double getTotalBalance() const { return state_.total_balance; }
    double getUnconfirmedBalance() const { return state_.unconfirmed_balance; }

    // Addresses
    const std::vector<AddressInfo>& getZAddresses() const { return state_.z_addresses; }
    const std::vector<AddressInfo>& getTAddresses() const { return state_.t_addresses; }

    // Transactions
    const std::vector<TransactionInfo>& getTransactions() const { return state_.transactions; }

    // Mining
    const MiningInfo& getMiningInfo() const { return state_.mining; }
    void startMining(int threads);
    void stopMining();
    bool isMiningToggleInProgress() const { return mining_toggle_in_progress_.load(std::memory_order_relaxed); }

    // Pool mining (xmrig)
    void startPoolMining(int threads);
    void stopPoolMining();

    // Peers
    const std::vector<PeerInfo>& getPeers() const { return state_.peers; }
    const std::vector<BannedPeer>& getBannedPeers() const { return state_.bannedPeers; }
    void banPeer(const std::string& ip, int duration_seconds = 86400);
    void unbanPeer(const std::string& ip);
    void clearBans();

    // Address operations
    void createNewZAddress(std::function<void(const std::string&)> callback = nullptr);
    void createNewTAddress(std::function<void(const std::string&)> callback = nullptr);

    // Hide/unhide addresses from the address list (persisted in settings)
    void hideAddress(const std::string& addr);
    void unhideAddress(const std::string& addr);
    bool isAddressHidden(const std::string& addr) const;
    int getHiddenAddressCount() const;

    void favoriteAddress(const std::string& addr);
    void unfavoriteAddress(const std::string& addr);
    bool isAddressFavorite(const std::string& addr) const;

    // Key export/import
    void exportPrivateKey(const std::string& address, std::function<void(const std::string&)> callback);
    void exportAllKeys(std::function<void(const std::string&)> callback);
    void importPrivateKey(const std::string& key, std::function<void(bool, const std::string&)> callback);
    
    // Wallet backup
    void backupWallet(const std::string& destination, std::function<void(bool, const std::string&)> callback);

    // Transaction operations  
    void sendTransaction(const std::string& from, const std::string& to, 
                        double amount, double fee, const std::string& memo,
                        std::function<void(bool success, const std::string& result)> callback);

    // Force refresh
    void refreshNow();
    void refreshMiningInfo();
    void refreshPeerInfo();
    void refreshMarketData();
    
    // UI navigation
    void setCurrentPage(ui::NavPage page) { current_page_ = page; }
    ui::NavPage getCurrentPage() const { return current_page_; }
    
    // Dialog triggers (used by settings page to open modal dialogs)
    void showImportKeyDialog() { show_import_key_ = true; }
    void showExportKeyDialog() { show_export_key_ = true; }
    void showBackupDialog() { show_backup_ = true; }
    void showAboutDialog() { show_about_ = true; }
    
    // Legacy tab compat — maps int to NavPage
    void setCurrentTab(int tab);
    int getCurrentTab() const { return static_cast<int>(current_page_); }
    
    // Payment URI handling
    void handlePaymentURI(const std::string& uri);
    bool hasPendingPayment() const { return pending_payment_valid_; }
    void clearPendingPayment() { pending_payment_valid_ = false; }
    std::string getPendingToAddress() const { return pending_to_address_; }
    double getPendingAmount() const { return pending_amount_; }
    std::string getPendingMemo() const { return pending_memo_; }
    std::string getPendingLabel() const { return pending_label_; }
    
    // Embedded daemon control
    bool startEmbeddedDaemon();
    void stopEmbeddedDaemon();
    bool isEmbeddedDaemonRunning() const;
    bool isUsingEmbeddedDaemon() const { return use_embedded_daemon_; }
    void setUseEmbeddedDaemon(bool use) { use_embedded_daemon_ = use; }

    // Get daemon memory usage in MB (uses embedded daemon handle if available,
    // falls back to platform-level process scan for external daemons)
    double getDaemonMemoryUsageMB() const;

    // Diagnostic string describing daemon memory detection path (for debugging)
    const std::string& getDaemonMemDiag() const { return daemon_mem_diag_; }

    // Background gradient overlay texture
    void setGradientTexture(ImTextureID tex) { gradient_tex_ = tex; }
    ImTextureID getGradientTexture() const { return gradient_tex_; }

    // Logo texture accessor (wallet branding icon)
    ImTextureID getLogoTexture() const { return logo_tex_; }

    // Coin logo texture accessor (DragonX currency icon for balance tab)
    ImTextureID getCoinLogoTexture() const { return coin_logo_tex_; }

    /**
     * @brief Reload theme images (background gradient + logo) from new paths
     * @param bgPath Path to background image override (empty = use default)
     * @param logoPath Path to logo image override (empty = use default)
     */
    void reloadThemeImages(const std::string& bgPath, const std::string& logoPath);

    // Wizard / first-run
    WizardPhase getWizardPhase() const { return wizard_phase_; }
    bool isFirstRun() const;

    /**
     * @brief Stop daemon and re-run the setup wizard
     * Called from Settings. Daemon restarts automatically when wizard completes.
     */
    void restartWizard();

    /**
     * @brief Restart the embedded daemon (e.g. after changing debug categories)
     * Shows "Restarting daemon..." in the loading overlay while the daemon cycles.
     */
    void restartDaemon();

    // Wallet encryption helpers
    void encryptWalletWithPassphrase(const std::string& passphrase);
    void unlockWallet(const std::string& passphrase, int timeout);
    void lockWallet();
    void changePassphrase(const std::string& oldPass, const std::string& newPass);

    // Dialog triggers for encryption (from settings page)
    void showEncryptDialog() {
        show_encrypt_dialog_ = true;
        encrypt_dialog_phase_ = EncryptDialogPhase::PassphraseEntry;
        encrypt_status_.clear();
        memset(encrypt_pass_buf_, 0, sizeof(encrypt_pass_buf_));
        memset(encrypt_confirm_buf_, 0, sizeof(encrypt_confirm_buf_));
        memset(enc_dlg_pin_buf_, 0, sizeof(enc_dlg_pin_buf_));
        memset(enc_dlg_pin_confirm_buf_, 0, sizeof(enc_dlg_pin_confirm_buf_));
        enc_dlg_saved_passphrase_.clear();
        enc_dlg_pin_status_.clear();
    }
    void showChangePassphraseDialog() { show_change_passphrase_ = true; }
    void showDecryptDialog() {
        show_decrypt_dialog_ = true;
        decrypt_phase_ = 0; // passphrase entry
        decrypt_status_.clear();
        decrypt_in_progress_ = false;
        memset(decrypt_pass_buf_, 0, sizeof(decrypt_pass_buf_));
    }

    // Dialog triggers for PIN (from settings page)
    void showPinSetupDialog() { show_pin_setup_ = true; pin_status_.clear(); }
    void showPinChangeDialog() { show_pin_change_ = true; pin_status_.clear(); }
    void showPinRemoveDialog() { show_pin_remove_ = true; pin_status_.clear(); }
    bool hasPinVault() const;

    /// @brief Check if RPC worker has queued results waiting to be processed
    bool hasPendingRPCResults() const;

private:
    // Subsystems
    std::unique_ptr<rpc::RPCClient> rpc_;
    std::unique_ptr<rpc::RPCWorker> worker_;
    std::unique_ptr<config::Settings> settings_;
    std::unique_ptr<daemon::EmbeddedDaemon> embedded_daemon_;
    std::unique_ptr<daemon::XmrigManager> xmrig_manager_;
    bool pending_antivirus_dialog_ = false;  // Show Windows Defender help dialog

    // Wallet state
    WalletState state_;

    // Shutdown state
    std::atomic<bool> shutting_down_{false};
    std::atomic<bool> shutdown_complete_{false};
    std::atomic<bool> refresh_in_progress_{false};
    bool address_list_dirty_ = false;   // P8: dedup rebuildAddressList
    std::string shutdown_status_;
    std::thread shutdown_thread_;
    float shutdown_timer_ = 0.0f;
    std::chrono::steady_clock::time_point shutdown_start_time_;

    // Daemon restart (e.g. after changing debug log categories)
    std::atomic<bool> daemon_restarting_{false};
    std::thread daemon_restart_thread_;

    // UI State
    bool quit_requested_ = false;
    bool show_demo_window_ = false;
    bool show_settings_ = false;
    bool show_about_ = false;
    bool show_import_key_ = false;
    bool show_export_key_ = false;
    bool show_backup_ = false;
    bool show_address_book_ = false;
    
    // Embedded daemon state
    bool use_embedded_daemon_ = true;
    std::string daemon_status_;
    mutable std::string daemon_mem_diag_;  // diagnostic info for daemon memory detection
    
    // Export/Import state
    std::string export_result_;
    char import_key_input_[512] = {0};
    std::string export_address_;
    std::string import_status_;
    bool import_success_ = false;
    std::string backup_status_;
    bool backup_success_ = false;

    // Connection
    std::string connection_status_ = "Disconnected";
    bool connection_in_progress_ = false;
    float loading_timer_ = 0.0f;  // spinner animation for loading overlay

    // Current page (sidebar navigation)
    ui::NavPage current_page_ = ui::NavPage::Overview;
    ui::NavPage prev_page_    = ui::NavPage::Overview;
    float page_alpha_         = 1.0f;  // 0→1 fade on page switch
    bool  sidebar_collapsed_  = false; // true = icon-only mode
    bool  sidebar_user_toggled_ = false; // user manually toggled — suppress auto-collapse
    float sidebar_width_anim_ = 0.0f;  // animated width (0 = uninitialized)
    float prev_dpi_scale_     = 0.0f;  // detect DPI changes to snap sidebar width

    // Background gradient overlay
    ImTextureID gradient_tex_ = 0;

    // Logo texture (reload on skin change / dark↔light switch)
    ImTextureID logo_tex_ = 0;
    int logo_w_ = 0;
    int logo_h_ = 0;
    bool logo_loaded_ = false;
    bool logo_is_dark_variant_ = true; // tracks which variant is currently loaded

    // Coin logo texture (DragonX currency icon, separate from wallet branding)
    ImTextureID coin_logo_tex_ = 0;
    int coin_logo_w_ = 0;
    int coin_logo_h_ = 0;
    bool coin_logo_loaded_ = false;

    // Console tab
    ui::ConsoleTab console_tab_;
    
    // Pending payment from URI
    bool pending_payment_valid_ = false;
    std::string pending_to_address_;
    double pending_amount_ = 0.0;
    std::string pending_memo_;
    std::string pending_label_;

    // Timers (in seconds since last update)
    float refresh_timer_ = 0.0f;
    float price_timer_ = 0.0f;
    float fast_refresh_timer_ = 0.0f;  // For mining stats

    // Refresh intervals (seconds)
    static constexpr float REFRESH_INTERVAL = 5.0f;
    static constexpr float PRICE_INTERVAL = 60.0f;
    static constexpr float FAST_REFRESH_INTERVAL = 1.0f;

    // Mining refresh guard (prevents worker queue pileup)
    std::atomic<bool> mining_refresh_in_progress_{false};
    int mining_slow_counter_ = 0;  // counts fast ticks; fires slow refresh every N

    // Mining toggle guard (prevents concurrent setgenerate calls)
    std::atomic<bool> mining_toggle_in_progress_{false};

    // Auto-shield guard (prevents concurrent auto-shield operations)
    std::atomic<bool> auto_shield_pending_{false};

    // P4: Incremental transaction cache
    int last_tx_block_height_ = -1;  // block height at last full tx fetch

    // Dirty flags for demand-driven refresh
    bool addresses_dirty_ = true;           // true → refreshAddresses() will run
    bool encryption_state_prefetched_ = false; // suppress duplicate getwalletinfo on connect

    // First-run wizard state
    WizardPhase wizard_phase_ = WizardPhase::None;
    std::unique_ptr<util::Bootstrap> bootstrap_;
    std::string wizard_pending_passphrase_;  // held until daemon connects
    std::string wizard_saved_passphrase_;    // held until PinSetup completes/skipped

    // Deferred encryption (wizard background task)
    std::string deferred_encrypt_passphrase_;
    std::string deferred_encrypt_pin_;
    bool deferred_encrypt_pending_ = false;

    // Wizard: stopping an external daemon before bootstrap
    bool wizard_stopping_external_ = false;
    std::string wizard_stop_status_;
    std::thread wizard_stop_thread_;

    // PIN vault
    std::unique_ptr<util::SecureVault> vault_;

    // Lock screen state
    bool lock_screen_was_visible_ = false; // tracks lock→unlock transitions for auto-focus
    bool lock_use_pin_ = true;  // true = PIN input, false = passphrase input
    char lock_pin_buf_[16] = {};
    char lock_passphrase_buf_[256] = {};
    std::string lock_error_msg_;
    float lock_error_timer_ = 0.0f;
    int lock_attempts_ = 0;
    float lock_lockout_timer_ = 0.0f;
    bool lock_unlock_in_progress_ = false;

    // Encrypt wallet dialog state
    bool show_encrypt_dialog_ = false;
    bool show_change_passphrase_ = false;
    EncryptDialogPhase encrypt_dialog_phase_ = EncryptDialogPhase::PassphraseEntry;
    char encrypt_pass_buf_[256] = {};
    char encrypt_confirm_buf_[256] = {};
    char change_old_pass_buf_[256] = {};
    char change_new_pass_buf_[256] = {};
    char change_confirm_buf_[256] = {};
    std::string encrypt_status_;
    bool encrypt_in_progress_ = false;
    std::string enc_dlg_saved_passphrase_;   // held for PIN setup after encrypt
    char enc_dlg_pin_buf_[16] = {};
    char enc_dlg_pin_confirm_buf_[16] = {};
    std::string enc_dlg_pin_status_;

    // PIN setup dialog state (settings page)
    bool show_pin_setup_ = false;
    bool show_pin_change_ = false;
    bool show_pin_remove_ = false;
    char pin_buf_[16] = {};
    char pin_confirm_buf_[16] = {};
    char pin_old_buf_[16] = {};
    char pin_passphrase_buf_[256] = {};
    std::string pin_status_;
    bool pin_in_progress_ = false;

    // Decrypt wallet dialog state
    bool show_decrypt_dialog_ = false;
    int decrypt_phase_ = 0;  // 0=passphrase, 1=working, 2=done, 3=error
    char decrypt_pass_buf_[256] = {};
    std::string decrypt_status_;
    bool decrypt_in_progress_ = false;

    // Wizard PIN setup state
    char wizard_pin_buf_[16] = {};
    char wizard_pin_confirm_buf_[16] = {};
    std::string wizard_pin_status_;

    // Auto-lock on idle
    std::chrono::steady_clock::time_point last_interaction_ = std::chrono::steady_clock::now();

    // Private methods - rendering
    void renderStatusBar();
    void renderAboutDialog();
    void renderImportKeyDialog();
    void renderExportKeyDialog();
    void renderBackupDialog();
    void renderFirstRunWizard();
    void renderLockScreen();
    void renderEncryptWalletDialog();
    void renderDecryptWalletDialog();
    void renderPinDialogs();
    void renderAntivirusHelpDialog();
    void processDeferredEncryption();

    // Private methods - connection
    void tryConnect();
    void onConnected();
    void onDisconnected(const std::string& reason);

    // Private methods - data refresh
    void refreshData();
    void refreshBalance();
    void refreshAddresses();
    void refreshTransactions();
    void refreshPrice();
    void refreshWalletEncryptionState();
    void checkAutoLock();
};

} // namespace dragonx