#include <windows.h>
#include "registration_api.h"
#include <string>
#include <algorithm>
#include <cctype>

#define IDC_STATUS_LABEL 101
#define IDC_MACHINE_CODE_LABEL 102
#define IDC_MACHINE_CODE_EDIT 103
#define IDC_EXPIRATION_LABEL 104
#define IDC_EXPIRATION_EDIT 105
#define IDC_GENERATE_BUTTON 106

LRESULT CALLBACK WndProc(HWND, UINT, WPARAM, LPARAM);

static HWND hMachineCodeEdit, hExpirationEdit, hStatusLabel;

void UpdateValidationStatus(HWND hwnd) {
    int result = ValidateLicenseFile();
    std::string statusText;
    switch (result) {
        case 0:
            statusText = "License Status: VALID";
            break;
        case 1:
            statusText = "License Status: INVALID or NOT FOUND";
            break;
        case 2:
            statusText = "License Status: EXPIRED";
            break;
    }
    SetWindowText(hStatusLabel, statusText.c_str());
}

int WINAPI WinMain(HINSTANCE hInstance, HINSTANCE hPrevInstance, LPSTR lpCmdLine, int nCmdShow) {
    WNDCLASSEX wc = {0};
    wc.cbSize = sizeof(WNDCLASSEX);
    wc.style = 0;
    wc.lpfnWndProc = WndProc;
    wc.cbClsExtra = 0;
    wc.cbWndExtra = 0;
    wc.hInstance = hInstance;
    wc.hIcon = LoadIcon(NULL, IDI_APPLICATION);
    wc.hCursor = LoadCursor(NULL, IDC_ARROW);
    wc.hbrBackground = (HBRUSH)(COLOR_WINDOW + 1);
    wc.lpszMenuName = NULL;
    wc.lpszClassName = "RegistrationWindowClass";
    wc.hIconSm = LoadIcon(NULL, IDI_APPLICATION);

    if (!RegisterClassEx(&wc)) {
        MessageBox(NULL, "Window Registration Failed!", "Error!", MB_ICONEXCLAMATION | MB_OK);
        return 0;
    }

    HWND hwnd = CreateWindowEx(
        WS_EX_CLIENTEDGE,
        "RegistrationWindowClass",
        "Software Registration",
        (WS_OVERLAPPED | WS_CAPTION | WS_SYSMENU | WS_MINIMIZEBOX),
        CW_USEDEFAULT, CW_USEDEFAULT, 480, 250,
        NULL, NULL, hInstance, NULL);

    if (hwnd == NULL) {
        MessageBox(NULL, "Window Creation Failed!", "Error!", MB_ICONEXCLAMATION | MB_OK);
        return 0;
    }

    ShowWindow(hwnd, nCmdShow);
    UpdateWindow(hwnd);

    MSG Msg;
    while (GetMessage(&Msg, NULL, 0, 0) > 0) {
        TranslateMessage(&Msg);
        DispatchMessage(&Msg);
    }
    return Msg.wParam;
}

LRESULT CALLBACK WndProc(HWND hwnd, UINT msg, WPARAM wParam, LPARAM lParam) {
    switch (msg) {
        case WM_CREATE: {
            // --- Top Part: Validation Status ---
            hStatusLabel = CreateWindow("STATIC", "Checking license...", WS_VISIBLE | WS_CHILD | SS_CENTER, 20, 20, 420, 20, hwnd, (HMENU)IDC_STATUS_LABEL, NULL, NULL);
            UpdateValidationStatus(hwnd);

            // --- Bottom Part: License Generation ---
            CreateWindow("STATIC", "--- License Generation ---", WS_VISIBLE | WS_CHILD | SS_CENTER, 20, 60, 420, 20, hwnd, NULL, NULL, NULL);
            CreateWindow("STATIC", "Machine Code:", WS_VISIBLE | WS_CHILD, 20, 90, 150, 20, hwnd, (HMENU)IDC_MACHINE_CODE_LABEL, NULL, NULL);
            hMachineCodeEdit = CreateWindow("EDIT", "", WS_VISIBLE | WS_CHILD | WS_BORDER, 180, 90, 260, 20, hwnd, (HMENU)IDC_MACHINE_CODE_EDIT, NULL, NULL);

            CreateWindow("STATIC", "Expiration (YYYY-MM-DD):", WS_VISIBLE | WS_CHILD, 20, 120, 150, 20, hwnd, (HMENU)IDC_EXPIRATION_LABEL, NULL, NULL);
            hExpirationEdit = CreateWindow("EDIT", "2099-12-31", WS_VISIBLE | WS_CHILD | WS_BORDER, 180, 120, 120, 20, hwnd, (HMENU)IDC_EXPIRATION_EDIT, NULL, NULL);

            CreateWindow("BUTTON", "Generate License File", WS_VISIBLE | WS_CHILD | BS_DEFPUSHBUTTON, 180, 160, 180, 30, hwnd, (HMENU)IDC_GENERATE_BUTTON, NULL, NULL);
            
            break;
        }
        case WM_COMMAND: {
            switch (LOWORD(wParam)) {
                case IDC_GENERATE_BUTTON: {
                    char machineCode[256];
                    char expirationDate[11];
                    GetWindowText(hMachineCodeEdit, machineCode, 256);
                    GetWindowText(hExpirationEdit, expirationDate, 11);

                    if (strlen(machineCode) == 0) {
                        MessageBox(hwnd, "Please enter a machine code.", "Error", MB_ICONERROR);
                        break;
                    }

                    // Note: We are now using the function that takes the machine code as an argument
                    int result = GenerateLicenseFileFromCode(machineCode, expirationDate);
                    if (result == 0) {
                        MessageBox(hwnd, "License.data generated successfully!", "Success", MB_OK);
                        // Re-validate and update the status label
                        UpdateValidationStatus(hwnd);
                    } else {
                        MessageBox(hwnd, "Failed to generate license file!", "Error", MB_ICONERROR);
                    }
                    break;
                }
            }
            break;
        }
        case WM_CLOSE:
            DestroyWindow(hwnd);
            break;
        case WM_DESTROY:
            PostQuitMessage(0);
            break;
        default:
            return DefWindowProc(hwnd, msg, wParam, lParam);
    }
    return 0;
}