#include "lumacs/tui_editor.hpp"
#include "lumacs/editor_core.hpp"
#include "lumacs/lua_api.hpp"
#include <ncurses.h>
#include <iostream>
#include <fstream>
#include <memory>
#include <chrono>
#include <string>
#include <sstream>
#include <algorithm>

// Global debug log
extern std::ofstream debug_log;
std::ofstream debug_log("lumacs_debug.log");

using namespace lumacs;

/// ncurses-based TUI frontend for Lumacs
class TuiEditor : public IEditorView {
public:
    TuiEditor() : core_(nullptr) {}
    
    ~TuiEditor() override {
        endwin(); // Cleanup ncurses
    }

    // IEditorView methods
    void init() override;
    void run() override;
    void handle_editor_event(EditorEvent event) override;
    void set_core(EditorCore* core) override;

private:
    enum class Mode {
        Normal,
        Command,       // Minibuffer entry
        FindFile,      // Find file prompt
        BufferSwitch,  // Buffer switching with completion
        KillBuffer,    // Kill buffer with completion
        ConfirmKill,   // Confirm killing modified buffer
        ISearch        // Incremental search
    };
    
    EditorCore* core_ = nullptr; // Raw pointer to EditorCore, not owned
    bool should_quit_ = false;
    std::string message_line_;
    int height_ = 0, width_ = 0;
    
    // Input state
    Mode mode_ = Mode::Normal;
    std::string command_buffer_;

    // ISearch state
    std::string isearch_query_;
    bool isearch_forward_ = true;
    Position isearch_start_pos_;
    std::optional<Range> isearch_match_;
    bool isearch_failed_ = false;

    // Completion state
    std::vector<std::string> completion_candidates_;
    size_t completion_index_ = 0;
    std::string completion_prefix_;

    // Minibuffer history
    std::vector<std::string> command_history_;
    std::vector<std::string> buffer_switch_history_;
    std::vector<std::string> kill_buffer_history_;
    std::vector<std::string> isearch_history_;
    size_t history_index_ = 0;

    // Meta key handling
    bool waiting_for_meta_ = false;
    std::chrono::steady_clock::time_point meta_time_;
    static constexpr auto META_TIMEOUT = std::chrono::milliseconds(100);
    
    // Private helper method declarations
    std::string resolve_key(int ch);
    std::vector<std::string>& get_current_history();
    void add_to_history(const std::string& entry);
    void previous_history();
    void next_history();
    void reset_history_navigation();
    void update_completion_candidates(const std::string& prefix);
    void reset_completion();
    void perform_search(bool find_next);
    bool handle_input(int ch);
    bool process_key(const std::string& key_name);
    void execute_command(const std::string& cmd);
    int get_attributes_for_face(const std::string& face_name);
    void render();
    void render_layout_node(std::shared_ptr<LayoutNode> node, int x, int y, int width, int height);
    void render_window(std::shared_ptr<Window> window, int x, int y, int width, int height);
    void render_window_modeline(std::shared_ptr<Window> window, int x, int y, int width, bool is_active);
    void render_status_line();
    void render_message_line();
};

// --- TuiEditor Public Method Definitions ---

void TuiEditor::init() {
    // Initialize ncurses
    initscr();
    cbreak();           // Disable line buffering
    noecho();           // Don't echo pressed keys
    keypad(stdscr, TRUE); // Enable special keys
    raw();              // Enable all control characters
    timeout(50);        // Set 50ms timeout for getch() to avoid blocking forever
    
    // Color support
    if (has_colors()) {
        start_color();
        use_default_colors();
    }
    
    // Get screen dimensions
    getmaxyx(stdscr, height_, width_);
    
    // Initialize theme colors for ncurses
    if (has_colors() && core_->active_theme()) {
        core_->active_theme()->initialize_ncurses_colors();
    }
    
    // Set initial viewport size (leave room for status and message lines)
    int content_height = height_ - 2; // -1 for status, -1 for message
    bool show_line_numbers = core_->config().get<bool>("show_line_numbers", true);
    int line_number_width = show_line_numbers ? core_->config().get<int>("line_number_width", 6) : 0;
    int content_width = width_ - line_number_width;
    core_->set_viewport_size(content_width, content_height);
    
    debug_log << "ncurses editor initialized: " << width_ << "x" << height_ << std::endl;
}

void TuiEditor::run() {
    should_quit_ = false;
    
    // Initial render
    render();
    
    while (!should_quit_) {
        // Handle screen resize
        int new_height, new_width;
        getmaxyx(stdscr, new_height, new_width);
        if (new_height != height_ || new_width != width_) {
            height_ = new_height;
            width_ = new_width;
            int content_height = height_ - 2;
            bool show_line_numbers = core_->config().get<bool>("show_line_numbers", true);
            int line_number_width = show_line_numbers ? core_->config().get<int>("line_number_width", 6) : 0;
            int content_width = width_ - line_number_width;
            core_->set_viewport_size(content_width, content_height);
            debug_log << "Screen resized to: " << width_ << "x" << height_ << std::endl;
            debug_log << "Content area: " << content_width << "x" << content_height << std::endl;
            render();  // Re-render after resize
        }
        
        // Get input (with timeout)
        int ch = getch();
        
        // Only process input and render if we got actual input (not timeout)
        if (ch != ERR) {
            handle_input(ch);
            render();
        }
    }
}

void TuiEditor::handle_editor_event(EditorEvent event) { // existing method
    if (event == EditorEvent::Quit) {
        should_quit_ = true;
    } else if (event == EditorEvent::Message) {
        message_line_ = core_->last_message();
    } else if (event == EditorEvent::CommandMode) {
        mode_ = Mode::Command;
        command_buffer_.clear();
        reset_completion();
        reset_history_navigation();
    } else if (event == EditorEvent::BufferSwitchMode) {
        mode_ = Mode::BufferSwitch;
        command_buffer_.clear();
        reset_completion();
        reset_history_navigation();
    } else if (event == EditorEvent::KillBufferMode) {
        mode_ = Mode::KillBuffer;
        command_buffer_.clear();
        reset_completion();
        reset_history_navigation();
    } else if (event == EditorEvent::FindFileMode) {
        mode_ = Mode::FindFile;
        command_buffer_.clear();
        reset_completion();
        reset_history_navigation();
    } else if (event == EditorEvent::ISearchMode) {
        mode_ = Mode::ISearch;
        isearch_query_.clear();
        isearch_forward_ = true;
        isearch_start_pos_ = core_->cursor();
        isearch_match_ = std::nullopt;
        isearch_failed_ = false;
    } else if (event == EditorEvent::ISearchBackwardMode) {
        mode_ = Mode::ISearch;
        isearch_query_.clear();
        isearch_forward_ = false;
        isearch_start_pos_ = core_->cursor();
        isearch_match_ = std::nullopt;
        isearch_failed_ = false;
    }
}

void TuiEditor::set_core(EditorCore* core) {
    core_ = core;
}

// --- TuiEditor Private Helper Method Definitions ---

/// Convert ncurses key code to our key name format
std::string TuiEditor::resolve_key(int ch) {
    debug_log << "=== NCURSES INPUT DEBUG ===" << std::endl;
    debug_log << "Raw key code: " << ch << " (0x" << std::hex << ch << std::dec << ")" << std::endl;
    
    std::string key_name;
    
    // Handle special ncurses key codes first
    if (ch >= KEY_MIN) {
        switch (ch) {
            case KEY_UP: key_name = "ArrowUp"; break;
            case KEY_DOWN: key_name = "ArrowDown"; break;
            case KEY_LEFT: key_name = "ArrowLeft"; break;
            case KEY_RIGHT: key_name = "ArrowRight"; break;
            case KEY_HOME: key_name = "Home"; break;
            case KEY_END: key_name = "End"; break;
            case KEY_BACKSPACE: key_name = "Backspace"; break;
            case KEY_DC: key_name = "Delete"; break;
            case KEY_ENTER: key_name = "Return"; break;
            case KEY_F(3): key_name = "F3"; break;
            case KEY_F(4): key_name = "F4"; break;
            default:
                debug_log << "Unknown special key: " << ch << " (ignoring)" << std::endl;
                // Return empty string to ignore unknown special keys
                return "";
        }
    } else {
        // Handle normal ASCII characters and control codes
        switch (ch) {
            case 127: // DEL
            case 8:   // BS  
                key_name = "Backspace"; break;
            case '\n':
            case '\r':
                key_name = "Return"; break;
            case '\t': 
                key_name = "Tab"; break;
            case 27: 
                key_name = "Escape"; break;
            default:
                // Control characters (1-26, excluding special cases)
                if (ch >= 1 && ch >= 1 && ch <= 26 && ch != 8 && ch != 9 && ch != 10 && ch != 13) {
                    char letter = 'a' + (ch - 1);
                    key_name = "C-" + std::string(1, letter);
                    debug_log << "Control character detected: " << ch << " -> " << key_name << std::endl;
                }
                // Printable ASCII characters
                else if (ch >= 32 && ch <= 126) {
                    key_name = std::string(1, static_cast<char>(ch));
                }
                // Extended characters (might be Meta combinations)
                else if (ch >= 128 && ch < 256) {
                    char base_char = ch - 128;
                    if (base_char >= 32 && base_char <= 126) {
                        key_name = "M-" + std::string(1, base_char);
                    }
                }
                else {
                    debug_log << "Unhandled character code: " << ch << std::endl;
                }
        }
    }
    
    debug_log << "Resolved key: '" << key_name << "'" << std::endl;
    debug_log << "============================" << std::endl;
    
    return key_name;
}

// History management
std::vector<std::string>& TuiEditor::get_current_history() {
    switch (mode_) {
        case Mode::Command: return command_history_;
        case Mode::BufferSwitch: return buffer_switch_history_;
        case Mode::KillBuffer: return kill_buffer_history_;
        case Mode::ISearch: return isearch_history_;
        default: return command_history_;
    }
}

void TuiEditor::add_to_history(const std::string& entry) {
    if (entry.empty()) return;
    
    auto& history = get_current_history();
    
    // Remove if already exists (move to front)
    auto it = std::find(history.begin(), history.end(), entry);
    if (it != history.end()) {
        history.erase(it);
    }
    
    // Add to front
    history.insert(history.begin(), entry);
    
    // Limit history size
    const size_t MAX_HISTORY = 100;
    if (history.size() > MAX_HISTORY) {
        history.resize(MAX_HISTORY);
    }
}

void TuiEditor::previous_history() {
    auto& history = get_current_history();
    if (history.empty()) return;
    
    if (history_index_ < history.size()) {
        command_buffer_ = history[history_index_];
        history_index_++;
    }
}

void TuiEditor::next_history() {
    auto& history = get_current_history();
    if (history.empty() || history_index_ == 0) return;
    
    history_index_--;
    if (history_index_ == 0) {
        command_buffer_ = "";
    } else {
        command_buffer_ = history[history_index_ - 1];
    }
}

void TuiEditor::reset_history_navigation() {
    history_index_ = 0;
}

void TuiEditor::update_completion_candidates(const std::string& prefix) {
    std::vector<std::string> candidates;

    if (mode_ == Mode::Command) {
        // Get command names from Lua
        auto& lua = core_->lua_api()->state();
        sol::function get_names = lua["get_command_names"];
        if (get_names.valid()) {
            candidates = get_names.call<std::vector<std::string>>();
        }
    } else {
        // Default to buffer names for BufferSwitch/KillBuffer
        candidates = core_->get_buffer_names();
    }

    completion_candidates_.clear();

    if (prefix.empty()) {
        completion_candidates_ = candidates;
    } else {
        for (const auto& name : candidates) {
            if (name.size() >= prefix.size() &&
                name.substr(0, prefix.size()) == prefix) {
                completion_candidates_.push_back(name);
            }
        }
    }

    completion_index_ = 0;
}

// Helper to reset completion state
void TuiEditor::reset_completion() {
    completion_candidates_.clear();
    completion_index_ = 0;
    completion_prefix_.clear();
}

void TuiEditor::perform_search(bool find_next) {
    if (isearch_query_.empty()) {
        isearch_match_ = std::nullopt;
        isearch_failed_ = false;
        return;
    }

    Position start_search = core_->cursor();
    if (find_next) {
        if (isearch_forward_) {
            // Forward: move cursor forward 1 char to find next
            if (start_search.column < core_->buffer().line(start_search.line).size()) {
                start_search.column++;
            } else if (start_search.line < core_->buffer().line_count() - 1) {
                start_search.line++;
                start_search.column = 0;
            }
        } else {
            // Backward: move cursor backward 1 char
            if (start_search.column > 0) {
                start_search.column--;
            } else if (start_search.line > 0) {
                start_search.line--;
                start_search.column = core_->buffer().line(start_search.line).size();
            }
        }
    }

    std::optional<Range> result;
    if (isearch_forward_) {
        result = core_->buffer().find(isearch_query_, start_search);
    } else {
        result = core_->buffer().find_backward(isearch_query_, start_search);
    }

    if (result) {
        isearch_match_ = result;
        isearch_failed_ = false;
        core_->set_cursor(result->start);
        core_->adjust_scroll();
    } else {
        isearch_failed_ = true;
    }
}

bool TuiEditor::handle_input(int ch) {
    // Handle confirmation mode
    if (mode_ == Mode::ConfirmKill) {
        if (ch == 'y' || ch == 'Y') {
            if (core_->close_buffer(command_buffer_)) {
                message_line_ = "Closed modified buffer: " + command_buffer_;
            } else {
                message_line_ = "Failed to close buffer";
            }
            mode_ = Mode::Normal;
            command_buffer_.clear();
            reset_completion();
        } else if (ch == 'n' || ch == 'N' || ch == 27) { // n or ESC
            mode_ = Mode::Normal;
            message_line_ = "Cancelled kill buffer";
            command_buffer_.clear();
            reset_completion();
        }
        return true;
    }

    // Handle ISearch
    if (mode_ == Mode::ISearch) {
        // C-g (7) or ESC (27) -> Cancel
        if (ch == 27 || ch == 7) {
            core_->set_cursor(isearch_start_pos_);
            mode_ = Mode::Normal;
            message_line_ = "Quit";
            return true;
        }
        // RET -> Accept
        if (ch == '\n' || ch == '\r') {
            mode_ = Mode::Normal;
            message_line_ = "Mark saved";
            core_->buffer().set_mark(isearch_start_pos_);
            return true;
        }
        // C-s (19) -> Next
        if (ch == 19) {
            isearch_forward_ = true;
            perform_search(true);
            return true;
        }
        // C-r (18) -> Prev
        if (ch == 18) {
            isearch_forward_ = false;
            perform_search(true);
            return true;
        }
        // Backspace
        if (ch == KEY_BACKSPACE || ch == 127 || ch == 8) {
            if (!isearch_query_.empty()) {
                isearch_query_.pop_back();
                perform_search(false);
            }
            return true;
        }
        // Printable
        if (ch >= 32 && ch <= 126) {
            isearch_query_ += static_cast<char>(ch);
            perform_search(false);
            return true;
        }
        
        // Other keys -> Exit and process
        mode_ = Mode::Normal;
        return handle_input(ch);
    }

    // Handle minibuffer/command mode
    if (mode_ == Mode::Command || mode_ == Mode::FindFile ||
        mode_ == Mode::BufferSwitch || mode_ == Mode::KillBuffer) {

        // ESC - cancel
        if (ch == 27) {
            mode_ = Mode::Normal;
            command_buffer_.clear();
            reset_completion();
            message_line_ = "Cancelled";
            return true;
        }

        // TAB - completion
        if (ch == '\t' && (mode_ == Mode::BufferSwitch || mode_ == Mode::KillBuffer || mode_ == Mode::Command)) {
            if (completion_candidates_.empty()) {
                // First TAB: save prefix and get candidates
                completion_prefix_ = command_buffer_;
                update_completion_candidates(completion_prefix_);

                if (!completion_candidates_.empty()) {
                    command_buffer_ = completion_candidates_[0];
                    completion_index_ = 0;
                } else {
                    message_line_ = "No matches";
                }
            } else {
                // Cycle through candidates
                completion_index_ = (completion_index_ + 1) % completion_candidates_.size();
                command_buffer_ = completion_candidates_[completion_index_];
            }
            return true;
        }

        // Return - execute
        if (ch == '\n' || ch == '\r') {
            // Add to history before execution
            add_to_history(command_buffer_);
            
            if (mode_ == Mode::Command) {
                execute_command(command_buffer_);
            } else if (mode_ == Mode::FindFile) {
                if (core_->load_file(command_buffer_)) {
                    message_line_ = "Loaded: " + command_buffer_;
                    core_->lua_api()->execute("auto_activate_major_mode()") ;
                } else {
                    message_line_ = "Failed to load: " + command_buffer_;
                }
            } else if (mode_ == Mode::BufferSwitch) {
                if (core_->switch_buffer_in_window(command_buffer_)) {
                    message_line_ = "Switched to: " + command_buffer_;
                    core_->lua_api()->execute("auto_activate_major_mode()") ;
                } else {
                    message_line_ = "Buffer not found: " + command_buffer_;
                }
            } else if (mode_ == Mode::KillBuffer) {
                // Check for modification
                auto buf = core_->get_buffer_by_name(command_buffer_);
                if (buf && buf->is_modified()) {
                    mode_ = Mode::ConfirmKill;
                    message_line_ = "Buffer modified! Kill anyway? (y/n)";
                    return true;
                }

                if (core_->close_buffer(command_buffer_)) {
                    message_line_ = "Closed buffer: " + command_buffer_;
                } else {
                    message_line_ = "Failed to close buffer: " + command_buffer_;
                }
            }
            mode_ = Mode::Normal;
            command_buffer_.clear();
            reset_completion();
            reset_history_navigation();
            return true;
        }

        // M-p (Alt+p) - Previous history
        if (ch == '\x90') { // Meta+p
            previous_history();
            reset_completion();
            return true;
        }
        
        // M-n (Alt+n) - Next history  
        if (ch == '\x8E') { // Meta+n
            next_history();
            reset_completion();
            return true;
        }

        // Backspace
        if (ch == KEY_BACKSPACE || ch == 127 || ch == 8) {
            if (!command_buffer_.empty()) {
                command_buffer_.pop_back();
                reset_completion(); // Reset completion on edit
                reset_history_navigation(); // Reset history on edit
            } else {
                mode_ = Mode::Normal;
            }
            return true;
        }

        // Printable characters
        if (ch >= 32 && ch <= 126) {
            command_buffer_ += static_cast<char>(ch);
            reset_completion(); // Reset completion on new input
            return true;
        }
        return true;
    }

    // Check for expired meta key
    if (waiting_for_meta_) {
        auto now = std::chrono::steady_clock::now();
        if (now - meta_time_ > META_TIMEOUT) {
            debug_log << "Meta timeout, treating ESC as Escape key" << std::endl;
            waiting_for_meta_ = false;
            // Process the ESC as a normal Escape key
            std::string final_key = "Escape";
            if (core_->lua_api()->execute_key_binding(final_key)) {
                core_->record_key_sequence(final_key);
                return true;
            }
            message_line_ = "Key: " + final_key;
            return false;
        }
    }

    // If we're waiting for a meta key and got one, combine them
    if (waiting_for_meta_) {
        waiting_for_meta_ = false;
        std::string base_key = resolve_key(ch);
        if (base_key.empty()) {
            debug_log << "Empty base key after ESC, ignoring" << std::endl;
            return false;
        }

        std::string key_name = "M-" + base_key;
        debug_log << "Meta sequence complete: " << key_name << std::endl;

        // Continue processing this meta key below
        return process_key(key_name);
    }

    // Check if this is the start of a meta sequence
    if (ch == 27) { // ESC
        waiting_for_meta_ = true;
        meta_time_ = std::chrono::steady_clock::now();
        debug_log << "ESC received, waiting for meta key..." << std::endl;
        return true;
    }

    // Normal mode - resolve key and try bindings
    std::string key_name = resolve_key(ch);
    if (key_name.empty()) {
        debug_log << "Empty key name, ignoring input" << std::endl;
        return false;
    }

    return process_key(key_name);
}

bool TuiEditor::process_key(const std::string& key_name) {
    debug_log << "Processing key: " << key_name << std::endl;

    // Use the new keybinding system
    KeyResult result = core_->lua_api()->process_key(key_name);
    
    switch (result) {
        case KeyResult::Executed:
            debug_log << "Key binding executed successfully" << std::endl;
            message_line_.clear(); // Clear any partial sequence display
            // Record the key if we're recording a macro (but not if it's F3/F4 themselves)
            if (key_name != "F3" && key_name != "F4") {
                core_->record_key_sequence(key_name);
            }
            return true;
            
        case KeyResult::Failed:
            debug_log << "Key binding execution failed" << std::endl;
            message_line_ = "Command failed";
            return true; // Key was handled, even though it failed
            
        case KeyResult::Partial:
            // Building a multi-key sequence
            message_line_ = core_->keybinding_manager().current_sequence_display();
            debug_log << "Partial sequence: " << message_line_ << std::endl;
            return true;
            
        case KeyResult::Timeout:
            debug_log << "Key sequence timed out" << std::endl;
            message_line_ = "Sequence timeout";
            // Fall through to try fallback bindings
            break;
            
        case KeyResult::Unbound:
            debug_log << "No key binding found, trying C++ fallbacks" << std::endl;
            // Fall through to C++ fallback bindings
            break;
    }
    
    // Clear any sequence display since we're not in a partial state
    message_line_.clear();
    
    // C++ fallback bindings - these should eventually be moved to Lua
    
    // Quit
    if (key_name == "C-q") {
        core_->request_quit();
        return true;
    }
    
    // Command mode
    if (key_name == "M-x") {
        mode_ = Mode::Command;
        command_buffer_.clear();
        return true;
    }
    
    // Navigation fallbacks (these should be in Lua)
    if (key_name == "ArrowUp") { 
        core_->move_up();
        return true; 
    }
    if (key_name == "ArrowDown") { 
        core_->move_down();
        return true; 
    }
    if (key_name == "ArrowLeft") { 
        core_->move_left();
        return true; 
    }
    if (key_name == "ArrowRight") { 
        core_->move_right();
        return true; 
    }
    if (key_name == "Home") { core_->move_to_line_start(); return true; }
    if (key_name == "End") { core_->move_to_line_end(); return true; }
    
    // Editing fallbacks (these should also be in Lua)
    if (key_name == "Backspace") {
        auto cursor = core_->cursor();
        core_->buffer().erase_char(cursor);
        if (cursor.column > 0) {
            core_->set_cursor({cursor.line, cursor.column - 1});
        } else if (cursor.line > 0) {
            size_t prev_line_len = core_->buffer().line(cursor.line - 1).size();
            core_->set_cursor({cursor.line - 1, prev_line_len});
        }
        return true;
    }
    
    if (key_name == "Delete") {
        auto cursor = core_->cursor();
        if (cursor.column < core_->buffer().line(cursor.line).size()) {
            core_->buffer().erase_char({cursor.line, cursor.column + 1});
        } else if (cursor.line < core_->buffer().line_count() - 1) {
            core_->buffer().erase_char({cursor.line + 1, 0});
        }
        return true;
    }
    
    if (key_name == "Return") {
        auto cursor = core_->cursor();
        core_->buffer().insert_newline(cursor);
        core_->set_cursor({cursor.line + 1, 0});
        return true;
    }
    
    if (key_name == "Tab") {
        auto cursor = core_->cursor();
        core_->buffer().insert(cursor, "    ");
        core_->set_cursor({cursor.line, cursor.column + 4});
        return true;
    }
    
    // Insert printable characters (use original key_name for this)
    if (key_name.size() == 1 && key_name[0] >= 32 && key_name[0] <= 126) {
        auto cursor = core_->cursor();
        core_->buffer().insert_char(cursor, key_name[0]);
        core_->set_cursor({cursor.line, cursor.column + 1});
        return true;
    }
    
    return false;
}

void TuiEditor::execute_command(const std::string& cmd) {
    if (cmd.empty()) return;
    
    std::istringstream iss(cmd);
    std::string command;
    iss >> command;
    
    if (command == "q" || command == "quit") {
        core_->request_quit();
        return;
    }
    
    if (command == "w" || command == "write") {
        core_->buffer().save();
        message_line_ = "Saved";
        return;
    }
    
    if (command == "wq") {
        core_->buffer().save();
        core_->request_quit();
        return;
    }
    
    if (command == "e" || command == "edit") {
        std::string path;
        std::getline(iss >> std::ws, path);
                    if (!path.empty()) {
                        if (core_->load_file(path)) {
                            message_line_ = "Loaded: " + path;
                            core_->lua_api()->execute("auto_activate_major_mode()") ;
                        } else {                message_line_ = "Failed to load: " + path;
            }
        } else {
            message_line_ = "Usage: :e <filename>";
        }
        return;
    }
    
    // Try executing via command registry first
    auto& lua = core_->lua_api()->state();
    sol::function exec_cmd = lua["execute_extended_command"];
    if (exec_cmd.valid()) {
        bool result = exec_cmd(cmd);
        if (result) {
            return;
        }
    }

    // Fallback: Try executing as Lua code
    if (core_->lua_api()->execute(cmd)) {
        message_line_ = "Lua executed";
    } else {
        message_line_ = "Unknown command: " + cmd;
    }
}

int TuiEditor::get_attributes_for_face(const std::string& face_name) {
    auto theme = core_->active_theme();
    if (!theme) return 0;
    return theme->get_face_attributes_ncurses(face_name);
}

void TuiEditor::render() {
    // Clear and update screen info
    getmaxyx(stdscr, height_, width_);
    
    // Set background color from theme
    auto theme = core_->active_theme();
    if (theme) {
        int bg_color_pair = theme->get_color_pair(ThemeElement::Background);
        bkgd(bg_color_pair);
    }
    clear();
    
    // Calculate content area (leave room for message line only)
    int content_height = height_ - 1; 
    int content_width = width_;
    
    // Render the layout tree recursively (now includes per-window modelines)
    render_layout_node(core_->root_layout(), 0, 0, content_width, content_height);
    
    // Global message/command line (last line)
    render_message_line();
    
    // Refresh screen
    refresh();
}

void TuiEditor::render_layout_node(std::shared_ptr<LayoutNode> node, int x, int y, int width, int height) {
    if (!node) return;
    
    if (node->type == LayoutNode::Type::Leaf) {
        // Render a single window
        render_window(node->window, x, y, width, height);
    } else if (node->type == LayoutNode::Type::HorizontalSplit) {
        // Split horizontally: top and bottom windows
        int top_height = height / 2;
        int bottom_height = height - top_height;
        
        render_layout_node(node->child1, x, y, width, top_height);
        render_layout_node(node->child2, x, y + top_height, width, bottom_height);
    } else if (node->type == LayoutNode::Type::VerticalSplit) {
        // Split vertically: left and right windows  
        int separator_width = (width > 2) ? 1 : 0;
        int available_width = width - separator_width;

        int left_width = available_width / 2;
        int right_width = available_width - left_width;
        
        render_layout_node(node->child1, x, y, left_width, height);

        // Draw separator if enabled
        if (separator_width > 0) {
            int attrs = get_attributes_for_face("window-divider");
            attron(attrs);
            
            int sep_x = x + left_width;
            for (int i = 0; i < height; ++i) {
                mvaddch(y + i, sep_x, ACS_VLINE);
            }
            
            attroff(attrs);
        }

        render_layout_node(node->child2, x + left_width + separator_width, y, right_width, height);
    }
}

void TuiEditor::render_window(std::shared_ptr<Window> window, int x, int y, int width, int height) {
    if (!window) return;
    
    // Check configuration for line numbers and modeline
    bool show_line_numbers = core_->config().get<bool>("show_line_numbers", true);
    bool show_modeline = core_->config().get<bool>("show_modeline", true);
    int line_number_width = show_line_numbers ? core_->config().get<int>("line_number_width", 6) : 0;
    int modeline_height = show_modeline ? 1 : 0;
    
    // Update window viewport size (reserve space for modeline)
    int content_width = width - line_number_width;
    int content_height = height - modeline_height;
    window->set_viewport_size(content_width, content_height);
    
    // Get window data
    const auto& buffer = window->buffer();
    const auto cursor = window->cursor();
    auto [start_line, end_line] = window->visible_line_range();
    bool is_active = (window == core_->active_window());
    
    debug_log << "Render window at " << x << "," << y << " size " << width << "x" << height 
              << " viewport=" << start_line << "-" << end_line 
              << " cursor=(" << cursor.line << "," << cursor.column << ")"
              << " active=" << is_active << std::endl;
    
    // Render buffer lines
    for (int screen_y = 0; screen_y < content_height && start_line + screen_y < end_line; ++screen_y) {
        size_t buffer_line_idx = start_line + screen_y;
        const auto& line_text = buffer.line(buffer_line_idx);
        
        // Clear this line
        move(y + screen_y, x);
        for (int i = 0; i < width; ++i) addch(' ');
        
        // Line number (if enabled)
        if (show_line_numbers) {
            mvprintw(y + screen_y, x, "%3zu   ", buffer_line_idx + 1);
        }

        // Line content with syntax highlighting
        if (!line_text.empty()) {
            int max_content_width = content_width - 1;
            const auto& styles = buffer.get_line_styles(buffer_line_idx);

            if (styles.empty()) {
                // No styles, render as plain text
                std::string display_text = line_text;
                if ((int)display_text.length() > max_content_width) {
                    display_text = display_text.substr(0, max_content_width - 3) + "...";
                }
                mvprintw(y + screen_y, x + line_number_width, "%s", display_text.c_str());
            } else {
                // Render with syntax highlighting
                size_t pos = 0;
                int screen_x = x + line_number_width;

                for (const auto& styled : styles) {
                    size_t start = styled.range.start.column;
                    size_t end = std::min(styled.range.end.column, line_text.size());

                    // Render unstyled text before this styled range
                    if (pos < start && pos < line_text.size()) {
                        size_t len = std::min(start - pos, line_text.size() - pos);
                        std::string unstyled = line_text.substr(pos, len);
                        mvprintw(y + screen_y, screen_x, "%s", unstyled.c_str());
                        screen_x += unstyled.length();
                        pos = start;
                    }

                    // Render styled text
                    if (pos < end && pos < line_text.size()) {
                        size_t len = std::min(end - pos, line_text.size() - pos);
                        std::string styled_text = line_text.substr(pos, len);

                        // Apply color
                        int attrs = get_attributes_for_face(styled.attr.face_name);
                        attron(attrs);
                        mvprintw(y + screen_y, screen_x, "%s", styled_text.c_str());
                        attroff(attrs);

                        screen_x += styled_text.length();
                        pos = end;
                    }
                }

                // Render remaining unstyled text
                if (pos < line_text.size()) {
                    std::string remaining = line_text.substr(pos);
                    if ((int)(screen_x - x - line_number_width + remaining.length()) > max_content_width) {
                        remaining = remaining.substr(0, max_content_width - (screen_x - x - line_number_width) - 3) + "...";
                    }
                    mvprintw(y + screen_y, screen_x, "%s", remaining.c_str());
                }
            }
        }

        // Highlight ISearch match
        if (mode_ == Mode::ISearch && isearch_match_ && isearch_match_->start.line == buffer_line_idx) {
            size_t match_start = isearch_match_->start.column;
            size_t match_len = isearch_match_->end.column - match_start;
            if (match_start < line_text.size()) {
                size_t display_len = std::min(match_len, line_text.size() - match_start);
                std::string matched_text = line_text.substr(match_start, display_len);
                
                int match_x = x + line_number_width + match_start;
                // Simple clipping check
                if (match_x < x + width) {
                    int attrs = get_attributes_for_face(isearch_failed_ ? "isearch-fail" : "isearch");
                    if (attrs == 0) attrs = A_REVERSE; // Fallback
                    
                    attron(attrs);
                    mvprintw(y + screen_y, match_x, "%s", matched_text.c_str());
                    attroff(attrs);
                }
            }
        }
        
        // Show cursor if this is the cursor line and this is the active window
        if (buffer_line_idx == cursor.line && is_active && mode_ == Mode::Normal) {
            int cursor_screen_x = x + line_number_width + cursor.column;
            if (cursor_screen_x < x + width) {
                char cursor_char = ' ';
                if (cursor.column < line_text.size()) {
                    cursor_char = line_text[cursor.column];
                }
                
                int attrs = get_attributes_for_face("cursor");
                if (attrs == 0) attrs = A_REVERSE;
                
                attron(attrs);
                mvaddch(y + screen_y, cursor_screen_x, cursor_char);
                attroff(attrs);
            }
        }
    }
    
    // Fill remaining lines (for empty lines below buffer) - no tildes
    size_t displayed_lines = std::min((size_t)content_height, end_line - start_line);
    for (int screen_y = displayed_lines; screen_y < content_height; ++screen_y) {
        move(y + screen_y, x);
        for (int i = 0; i < width; ++i) addch(' ');
    }
    
    // Render modeline for this window
    if (show_modeline) {
        render_window_modeline(window, x, y + content_height, width, is_active);
    }
}

void TuiEditor::render_window_modeline(std::shared_ptr<Window> window, int x, int y, int width, bool is_active) {
    const auto& buffer = window->buffer();
    const auto cursor = window->cursor();
    
    // Choose modeline colors
    std::string face_name = is_active ? "mode-line" : "mode-line-inactive";
    int attrs = get_attributes_for_face(face_name);
    if (attrs == 0) attrs = is_active ? A_REVERSE : A_DIM;
    
    attron(attrs);
    
    // Clear the modeline
    move(y, x);
    for (int i = 0; i < width; ++i) addch(' ');
    
    // Create modeline content
    std::string modeline;
    
    // Buffer name and modification status
    modeline += buffer.name();
    if (buffer.is_modified()) modeline += " [+] ";
    
    // Cursor position
    modeline += " | " + std::to_string(cursor.line + 1) + ":" + std::to_string(cursor.column + 1);
    
    // Major mode (if available)
    // TODO: Add major mode support when available
    
    // Right-aligned content (percentage through file)
    std::string right_side;
    if (buffer.line_count() > 0) {
        int percentage = (cursor.line * 100) / (buffer.line_count() - 1);
        right_side = " " + std::to_string(percentage) + "%";
    }
    
    // Truncate modeline if too long
    int available_width = width - right_side.length();
    if ((int)modeline.length() > available_width) {
        modeline = modeline.substr(0, available_width - 3) + "...";
    }
    
    // Render left side
    mvprintw(y, x, "%s", modeline.c_str());
    
    // Render right side
    if (!right_side.empty()) {
        mvprintw(y, x + width - right_side.length(), "%s", right_side.c_str());
    }
    
    // Turn off modeline attributes
    attroff(attrs);
}

void TuiEditor::render_status_line() {
    const auto cursor = core_->cursor();
    const auto& buffer = core_->buffer();

    int status_y = height_ - 2;
    int attrs = get_attributes_for_face("mode-line");
    if (attrs == 0) attrs = A_REVERSE;

    attron(attrs);
    move(status_y, 0);
    clrtoeol();

    std::string status = buffer.name();
    if (buffer.is_modified()) status += " [+] ";
    status += " | " + std::to_string(cursor.line + 1) + ":" + std::to_string(cursor.column + 1);
    status += " | " + std::to_string(width_) + "x" + std::to_string(height_);
    if (mode_ == Mode::Command) status += " [CMD]";
    else if (mode_ == Mode::FindFile) status += " [FILE]";
    else if (mode_ == Mode::BufferSwitch) status += " [BUFFER]";
    else if (mode_ == Mode::KillBuffer) status += " [KILL]";
    else if (mode_ == Mode::ConfirmKill) status += " [CONFIRM]";
    else if (mode_ == Mode::ISearch) status += " [I-SEARCH]";

    mvprintw(status_y, 0, "%s", status.c_str());
    attroff(attrs);
}

void TuiEditor::render_message_line() {
    int msg_y = height_ - 1;
    int attrs = get_attributes_for_face("minibuffer-prompt");
    
    attron(attrs);
    move(msg_y, 0);
    clrtoeol();

    if (mode_ == Mode::Command) {
        mvprintw(msg_y, 0, ":%s", command_buffer_.c_str());
    } else if (mode_ == Mode::FindFile) {
        mvprintw(msg_y, 0, "Find file: %s", command_buffer_.c_str());
    } else if (mode_ == Mode::BufferSwitch) {
        std::string prompt = "Switch to buffer: " + command_buffer_;
        if (!completion_candidates_.empty()) {
            prompt += " [" + std::to_string(completion_index_ + 1) + "/" +
                      std::to_string(completion_candidates_.size()) + "]";
        }
        mvprintw(msg_y, 0, "%s", prompt.c_str());
    } else if (mode_ == Mode::KillBuffer) {
        std::string prompt = "Kill buffer: " + command_buffer_;
        if (!completion_candidates_.empty()) {
            prompt += " [" + std::to_string(completion_index_ + 1) + "/" +
                      std::to_string(completion_candidates_.size()) + "]";
        }
        mvprintw(msg_y, 0, "%s", prompt.c_str());
    } else if (mode_ == Mode::ISearch) {
        std::string prompt = (isearch_failed_ ? "Failing " : "") + std::string("I-search: ") + isearch_query_;
        mvprintw(msg_y, 0, "%s", prompt.c_str());
    } else if (!message_line_.empty()) {
        mvprintw(msg_y, 0, "%s", message_line_.c_str());
    }
    
    attroff(attrs);
}

namespace lumacs {
std::unique_ptr<IEditorView> create_tui_editor() {
    return std::make_unique<TuiEditor>();
}
}