#include <windows.h>
#include <iostream>
#include <stdio.h>
#include <fstream>
#include <vector>
#include <string>
#include <cstdlib>
#include "Shlwapi.h" // necessary for PathFileExists()
#include <shlobj.h>  // necessary for SHGetFolderPath()

using namespace std;

#define ID_FOLDERPATH1 1
#define ID_FOLDERPATH2 2
#define ID_FOLDERPATH3 3
#define ID_GETPATH     4

static HINSTANCE gInstance;
UINT controlMsgs[] = {ID_FOLDERPATH1,ID_FOLDERPATH2,ID_FOLDERPATH3};

// Functions List //
LRESULT CALLBACK WndProc(HWND hwnd, UINT msg, WPARAM wParam, LPARAM lParam);
void displayRecentPaths(HWND hwnd, UINT controlMsg[]);
void recordRecentPaths(HWND hwnd, UINT controlMsg[]);
string getFolderPath(HWND hwnd);
vector<string> readFile(string fileName);
void writeFile(string fileName, vector<string> content);


int WINAPI WinMain(HINSTANCE gInstance, HINSTANCE hPrevInstance, LPSTR lpCmdLine, int nCmdShow)
{
    WNDCLASSEX wc;
    HWND hwnd;
    MSG Msg;

    //Step 1: Registering the Window Class
    wc.cbSize        = sizeof(WNDCLASSEX);
    wc.style         = 0;
    wc.lpfnWndProc   = WndProc;
    wc.cbClsExtra    = 0;
    wc.cbWndExtra    = 0;
    wc.hInstance     = gInstance;
    wc.hIcon         = LoadIcon(NULL, IDI_APPLICATION);
    wc.hCursor       = LoadCursor(NULL, IDC_ARROW);
    wc.hbrBackground = (HBRUSH)(DKGRAY_BRUSH);
    wc.lpszMenuName  = NULL;
    wc.lpszClassName = "My Class";
    wc.hIconSm       = LoadIcon(NULL, IDI_APPLICATION);

    // if registration of main class fails
    if(!RegisterClassEx(&wc))
    {
        MessageBox(NULL, "Window Registration Failed!", "Error!",
            MB_ICONEXCLAMATION | MB_OK);
        return 0;
    }

    // Step 2: Creating the Window
    hwnd = CreateWindowEx(
        WS_EX_CLIENTEDGE,
        "My Class",
        "Find Application Data",
        WS_OVERLAPPEDWINDOW,
        CW_USEDEFAULT, CW_USEDEFAULT, 600, 500,
        NULL, NULL, gInstance, NULL);

    if(hwnd == NULL)
    {
        MessageBox(NULL, "Window Creation Failed!", "Error!",
            MB_ICONEXCLAMATION | MB_OK);
        return 0;
    }
    
    ShowWindow(hwnd, nCmdShow);
    UpdateWindow(hwnd);
    
    // Step 3: The Message Loop
    while(GetMessage(&Msg, NULL, 0, 0) > 0)
    {
        TranslateMessage(&Msg);
        DispatchMessage(&Msg);
    }
    return Msg.wParam;
}

// Step 4: the Window Procedure
LRESULT CALLBACK WndProc(HWND hwnd, UINT msg, WPARAM wParam, LPARAM lParam)
{
    
    switch(msg)
    {
        case WM_CREATE:
        {      
             HWND hEdit = CreateWindowEx(0,"Edit","path captured here...",WS_VISIBLE|WS_CHILD|WS_BORDER|ES_AUTOHSCROLL,
                                         10,10,170,20,hwnd,(HMENU)ID_FOLDERPATH1,gInstance,NULL);
             
             HWND hEdit1 = CreateWindowEx(0,"Edit","path captured here...",WS_VISIBLE|WS_CHILD|WS_BORDER|ES_AUTOHSCROLL,
                                         10,35,170,20,hwnd,(HMENU)ID_FOLDERPATH2,gInstance,NULL);
             
             HWND hEdit2 = CreateWindowEx(0,"Edit","path captured here...",WS_VISIBLE|WS_CHILD|WS_BORDER|ES_AUTOHSCROLL,
                                         10,60,170,20,hwnd,(HMENU)ID_FOLDERPATH3,gInstance,NULL);                                  
             
             HWND hButton = CreateWindowEx(0,"Button","Random",WS_VISIBLE|WS_CHILD|WS_BORDER|BS_PUSHBUTTON,
                                         60,85,120,20,hwnd,(HMENU)ID_GETPATH,gInstance,NULL);          
        }
        break;
        case WM_COMMAND:
        {
            switch (LOWORD(wParam)) {
                  
                  case ID_GETPATH:
                  {    // Find the local computers path to the APP DATA folder regardless of
                       // of which version of windows the local system is using
                       string folderPath;

                       if( SHGetFolderPath(NULL,CSIDL_APPDATA,NULL,
                           0,(LPTSTR)folderPath.c_str()) == S_OK )  
                       {
                          HWND hEdit = GetDlgItem(hwnd,ID_FOLDERPATH1);
                          SetWindowText(hEdit,folderPath.c_str());
                          // The below uses the APP DATA path create & store a file in it.
                          // PathAppend(szPath, TEXT("New Doc.txt"));
                          // HANDLE hFile = CreateFile(szPath, ...);
                       }
                       
                  }     
                  break;
                  default:
                  break; 
            } 
        }
        break;
        case WM_CLOSE:
            DestroyWindow(hwnd);
        break;
        case WM_DESTROY:
            PostQuitMessage(0);
        break;
        default: return DefWindowProc(hwnd, msg, wParam, lParam);
        break;
    }
}

void displayRecentPaths(HWND hwnd,UINT controlMsg[])
{
   // Post: Read data file for most recent directories accessed. If data file doesn't exist 
   //       then we create it.
   
   string appDataFile = getFolderPath(hwnd); // get file path
   
   // if APP DATA file exists: write paths to text file; ELSE create APP DATA file
   if (PathFileExists((LPTSTR)appDataFile.c_str()) == true) {
       vector <string> paths = readFile(appDataFile);
       // display most recent accessed directories in edit boxes
       for (int i=0; i<paths.size(); i++) {          
           HWND hEdit = GetDlgItem(hwnd,controlMsg[i]);
           SetWindowText(hEdit,(LPTSTR)paths.at(i).c_str());
       }
       paths.clear();  // erase paths data (VERY IMPORTANT)
   }
   else {
        //HANDLE hFile = CreateFile((LPTSTR)appDataFile.c_str(), ...); // create file
   }
}

void recordRecentPaths(HWND hwnd, UINT controlMsg[])
{
   // Post: Saves the most recent folder directories accessed by application
   
   HWND hEdit;
   vector<string>paths; // SHOULD BE GLOBAL
   
   // Get folder paths
   for (int i=0; i<3; i++) {
       
       int len = GetWindowTextLength(GetDlgItem(hwnd,controlMsg[i]));
       // if window has text in it
       if (len > 0) {
           char buffer[len+2];
           GetDlgItemText(hwnd,controlMsg[i],buffer,sizeof(buffer));
           paths.push_back((string)buffer);
       }
   }
   
   string appDataFile; // = getFolderPath;
   
   // Save paths to folder
   if (paths.size() > 0) {
       writeFile(appDataFile,paths);
   }
}

string getFolderPath(HWND hwnd)
{
   // Post: Returns the path to specified folder
           
   string folderPath;

   if( SHGetFolderPath(NULL,CSIDL_APPDATA,NULL,0,(LPTSTR)folderPath.c_str()) == S_OK )  
   {
      PathAppend((LPTSTR)folderPath.c_str(),("RandomPlaylistPathData.txt"));
      return folderPath;
   }
   else {
      MessageBox(hwnd,"Failed to retrieve path to APP DATA folder","Error",MB_OK|MB_ICONERROR);
   }
}

vector<string> readFile(string fileName)
{
   // Post: Reads a file & stores contents line by line in vector
   
   ifstream infile;
   vector<string> result;        // vector to store contents of file in
   string tempStr;
   
   infile.open(fileName.c_str());
   
   if (!infile) {
       MessageBox(NULL,"Failed to read randomPlaylistPathData.txt file","Error",
                  MB_OK|MB_ICONERROR);
   }
   
   while (!infile.eof()) {       
        getline(infile,tempStr,'\n');
        result.push_back(tempStr);
   }
   
   infile.close();
   
   return result;
}

void writeFile(string fileName, vector<string> content)
{
   // Post: Write vector to text file(fileName) line by line
   
   ofstream outfile;
       
   outfile.open((LPTSTR)fileName.c_str());
   
   if (!outfile) {
       MessageBox(NULL,"Failed to write to randomPlaylistPathData.txt file","Error",
                  MB_OK|MB_ICONERROR);
   }
       
   for (int i=0; i<content.size(); i++) {
           
        outfile << content.at(i) << "\n";
   }
       
   outfile.close();
}