Binary Tree Visualizer (Win32 GUI) *FINAL RELEASE*

#include <windows.h>
#include <windowsx.h>  // Add this line
#include <commctrl.h>
#include <string>
#include <vector>
#include <algorithm>  // Add this at the top with other includes
#include <functional>
#include <ctime>    // for time()
#include <cstdlib>  // for rand() and srand()
#include <random>
#include <sstream>
#include <iostream>
#include <richedit.h> // Include for Rich Edit control
#include <shellapi.h>

#pragma comment(lib, "Psapi.lib")
#pragma comment(lib, "comctl32.lib") // Link with the common controls library
//#pragma comment(lib, "riched32.lib")  // Link with the rich edit library
#pragma comment(lib, "Shell32.lib")

// Structure for a binary tree node
struct Node {
    int data;
    Node* left;
    Node* right;

    Node(int val) : data(val), left(nullptr), right(nullptr) {}
};

// Function to insert a new node into the binary tree
Node* insert(Node* root, int val) {
    if (!root) {
        return new Node(val);
    }

    if (val < root->data) {
        root->left = insert(root->left, val);
    }
    else {
        root->right = insert(root->right, val);
    }
    return root;
}


// Helper function to get the height of the tree
// Helper function to get the height of the tree
int getHeight(Node* root) {
    if (!root) return 0;
    return 1 + max(getHeight(root->left), getHeight(root->right));
}

// Helper function to add padding
std::string getPadding(int level) {
    return std::string(level * 6, ' ');
}

std::string getListString(Node* root, std::string prefix = "") {
    if (!root) return "";

    std::string result = prefix + "|_ " + std::to_string(root->data) + "\r\n";

    if (root->left) {
        bool hasRight = (root->right != nullptr);
        std::string newPrefix = prefix + (hasRight ? "|  " : "   ");
        result += getListString(root->left, newPrefix);
    }

    if (root->right) {
        std::string newPrefix = prefix + "   ";
        result += getListString(root->right, newPrefix);
    }

    return result;
}

// Modified getTreeString function with correct lambda capture
std::string getTreeString(Node* root) {
    if (!root) return "";

    std::vector<std::string> levels;
    int maxLevelWidth = 0;

    std::function<void(Node*, int, int)> traverse =
        [&](Node* node, int depth, int xOffset) {
        if (!node) return;

        while (levels.size() <= depth) {
            levels.push_back("");
        }

        int dataWidth = std::to_string(node->data).length();
        int centerX = xOffset + dataWidth / 2;

        levels[depth] += std::string(centerX - levels[depth].length(), ' ') + std::to_string(node->data);

        maxLevelWidth = (maxLevelWidth > levels[depth].length()) ? maxLevelWidth : (int)levels[depth].length();

        if (node->left || node->right) {
            int spacing = 3; // Reduced spacing between parent and children

            // Calculate child offsets for tighter spacing
            int leftChildOffset = xOffset - spacing;     // Closer to the "/"
            int rightChildOffset = xOffset + dataWidth + spacing - 1; // Closer to the "\"


            if (node->left) {
                while (levels.size() <= depth + 1) {
                    levels.push_back("");
                }
                levels[depth + 1] += std::string(centerX - 1 - levels[depth + 1].length(), ' ') + "/";
                traverse(node->left, depth + 2, leftChildOffset);
            }

            if (node->right) {
                while (levels.size() <= depth + 1) {
                    levels.push_back("");
                }
                levels[depth + 1] += std::string(centerX + 1 - levels[depth + 1].length(), ' ') + "\\";
                traverse(node->right, depth + 2, rightChildOffset);
            }
        }
    };

    traverse(root, 0, 20); // Smaller initial offset to move the tree left

    std::string result;
    for (const auto& level : levels) {
        result += level + std::string(maxLevelWidth - level.length(), ' ') + "\r\n";
    }
    return result;
}


LRESULT CALLBACK WindowProc(HWND hwnd, UINT uMsg, WPARAM wParam, LPARAM lParam);

int WINAPI wWinMain(HINSTANCE hInstance, HINSTANCE, PWSTR pCmdLine, int nCmdShow) {

    const wchar_t CLASS_NAME[] = L"BinaryTreeVisualizer";

    WNDCLASS wc = { };

    wc.lpfnWndProc = WindowProc;
    wc.hInstance = hInstance;
    wc.lpszClassName = CLASS_NAME;

    RegisterClass(&wc);

    HWND hwnd = CreateWindowEx(
        0,                              // Optional window styles.
        CLASS_NAME,                     // Window class
        L"Binary Tree Visualizer",    // Window text
        WS_OVERLAPPEDWINDOW,            // Window style

        CW_USEDEFAULT, CW_USEDEFAULT, 550, 400,

        NULL,       // Parent window
        NULL,       // Menu
        hInstance,  // Instance handle
        NULL        // Additional application data
    );

    if (hwnd == NULL) {
        return 0;
    }

    ShowWindow(hwnd, nCmdShow);

    // Run the message loop.
    MSG msg = { };
    while (GetMessage(&msg, NULL, 0, 0)) {
        TranslateMessage(&msg);
        DispatchMessage(&msg);
    }

    return 0;
}

LRESULT CALLBACK WindowProc(HWND hwnd, UINT uMsg, WPARAM wParam, LPARAM lParam) {
    static HWND hEdit, hDisplay, hTreeViewRadio, hListViewRadio, hGenerateButton;
    static Node* root = nullptr;

    switch (uMsg) {
    case WM_CREATE: {
        // Create Input Field
        hEdit = CreateWindowEx(WS_EX_CLIENTEDGE, L"EDIT", L"",
            WS_CHILD | WS_VISIBLE | WS_BORDER,
            10, 10, 100, 20, hwnd, NULL, NULL, NULL);

        // Create multiline Edit control for display
            // Create display Edit control with proper styles for newlines
        hDisplay = CreateWindowEx(WS_EX_CLIENTEDGE, L"EDIT", L"",
            WS_CHILD | WS_VISIBLE | WS_VSCROLL | WS_HSCROLL |
            ES_MULTILINE | ES_AUTOVSCROLL | ES_AUTOHSCROLL | ES_READONLY | ES_LEFT,
            10, 40, 510, 300, hwnd, NULL, NULL, NULL);

        // Radio Buttons
        hTreeViewRadio = CreateWindowEx(0, L"BUTTON", L"Tree View",
            WS_CHILD | WS_VISIBLE | BS_AUTORADIOBUTTON | WS_GROUP,
            120, 10, 100, 20, hwnd, (HMENU)1, NULL, NULL);

        hListViewRadio = CreateWindowEx(0, L"BUTTON", L"List View",
            WS_CHILD | WS_VISIBLE | BS_AUTORADIOBUTTON,
            230, 10, 100, 20, hwnd, (HMENU)2, NULL, NULL);

        // Generate Button
        hGenerateButton = CreateWindowEx(0, L"BUTTON", L"Generate Tree",
            WS_CHILD | WS_VISIBLE | BS_PUSHBUTTON,
            340, 10, 100, 20, hwnd, (HMENU)3, NULL, NULL);

        Button_SetCheck(hTreeViewRadio, BST_CHECKED);

        // Set monospace font
            // Set monospace font for better tree display
        HFONT hFont = CreateFont(16, 0, 0, 0, FW_NORMAL, FALSE, FALSE, FALSE,
            DEFAULT_CHARSET, OUT_DEFAULT_PRECIS, CLIP_DEFAULT_PRECIS,
            DEFAULT_QUALITY, FIXED_PITCH | FF_MODERN, L"Consolas");

        SendMessage(hDisplay, WM_SETFONT, (WPARAM)hFont, TRUE);

        // Set tab stops for the display Edit control (optional)
        DWORD tabStops = 16; // in dialog units
        SendMessage(hDisplay, EM_SETTABSTOPS, 1, (LPARAM)&tabStops);

        // Set text alignment to center
        //SendMessage(hDisplay, EM_SETALIGNMENT, ES_CENTER, 0);

        break;
    }

    case WM_COMMAND:
        if (LOWORD(wParam) == 3) { // Generate button clicked
            wchar_t buffer[256];
            GetWindowText(hEdit, buffer, 256);

            wchar_t* endptr;
            long numNodes = std::wcstol(buffer, &endptr, 10);

            if (*endptr == L'\0' && numNodes > 0 && numNodes <= 100) {
                delete root;
                root = nullptr;

                std::vector<int> numbers(numNodes);
                for (int i = 0; i < numNodes; ++i) {
                    numbers[i] = i + 1;
                }
                std::random_device rd;
                std::mt19937 g(rd());
                std::shuffle(numbers.begin(), numbers.end(), g);

                for (int num : numbers) {
                    root = insert(root, num);
                }

                std::string treeString;
                try {
                    if (Button_GetCheck(hTreeViewRadio) == BST_CHECKED) {
                        treeString = getTreeString(root);
                        std::string::size_type pos = 0;
                        while ((pos = treeString.find('\n', pos)) != std::string::npos) {
                            treeString.replace(pos, 1, "\r\n");
                            pos += 2;
                        }
                    }
                    else {
                        treeString = getListString(root);
                    }

                    int size_needed = MultiByteToWideChar(CP_UTF8, 0, treeString.c_str(), -1, NULL, 0);
                    if (size_needed == 0) {
                        OutputDebugString(L"MultiByteToWideChar failed\n");
                        break;
                    }

                    std::wstring wideStr(size_needed - 1, 0);
                    int converted_chars = MultiByteToWideChar(CP_UTF8, 0, treeString.c_str(), -1, &wideStr[0], size_needed);
                    if (converted_chars == 0) {
                        OutputDebugString(L"MultiByteToWideChar failed\n");
                        break;
                    }

                    SetWindowText(hDisplay, wideStr.c_str());

                    LONG_PTR style = GetWindowLongPtr(hDisplay, GWL_STYLE);
                    style |= ES_MULTILINE | ES_AUTOVSCROLL;
                    SetWindowLongPtr(hDisplay, GWL_STYLE, style);

                    SendMessage(hDisplay, WM_VSCROLL, SB_TOP, 0);
                    SendMessage(hDisplay, EM_SETSEL, 0, 0);
                    SendMessage(hDisplay, EM_SCROLLCARET, 0, 0);
                }
                catch (const std::exception& e) {
                    std::string error = "Exception: ";
                    error += e.what();
                    OutputDebugStringA(error.c_str());
                }
            }
            else {
                MessageBox(hwnd, L"Please enter a number between 1 and 100.", L"Invalid Input", MB_OK | MB_ICONWARNING);
            }
        }
        else if (LOWORD(wParam) == 1 || LOWORD(wParam) == 2) {  // Radio button handling
            if (root != nullptr) {
                std::string treeString;
                if (Button_GetCheck(hTreeViewRadio) == BST_CHECKED) {
                    treeString = getTreeString(root);
                    std::string::size_type pos = 0;
                    while ((pos = treeString.find('\n', pos)) != std::string::npos) {
                        treeString.replace(pos, 1, "\r\n");
                        pos += 2;
                    }
                }
                else {
                    treeString = getListString(root);
                }

                int size_needed = MultiByteToWideChar(CP_UTF8, 0, treeString.c_str(), -1, NULL, 0);
                if (size_needed == 0) {
                    OutputDebugString(L"MultiByteToWideChar failed (Radio)\n");
                    break;
                }
                std::wstring wideStr(size_needed - 1, 0);
                int converted = MultiByteToWideChar(CP_UTF8, 0, treeString.c_str(), -1, &wideStr[0], size_needed);
                if (converted == 0) {
                    OutputDebugString(L"MultiByteToWideChar failed (Radio)\n");
                    break;
                }

                SetWindowText(hDisplay, wideStr.c_str());

                LONG_PTR style = GetWindowLongPtr(hDisplay, GWL_STYLE);
                style |= ES_MULTILINE | ES_AUTOVSCROLL;
                SetWindowLongPtr(hDisplay, GWL_STYLE, style);

                SendMessage(hDisplay, WM_VSCROLL, SB_TOP, 0);
                SendMessage(hDisplay, EM_SETSEL, 0, 0);
                SendMessage(hDisplay, EM_SCROLLCARET, 0, 0);
            }
        }
        break;

    case WM_DESTROY:
        delete root; // Clean up
        PostQuitMessage(0);
        return 0;
    }
    return DefWindowProc(hwnd, uMsg, wParam, lParam);
}