#include <stdio.h>
#include <windows.h>

#include "environment.hpp"

static HANDLE hStdin = NULL;
static HANDLE hStdout = NULL;
static int savedConsoleOutputModeIsValid = 0;
static DWORD savedConsoleOutputMode = 0;
static int savedConsoleInputModeIsValid = 0;
static DWORD savedConsoleInputMode = 0;

static void disableRawMode(void)
{
  printf("\x1b[0m");
  fflush(stdout);

  if (savedConsoleOutputModeIsValid)
    SetConsoleMode(hStdout, savedConsoleOutputMode);
  if (savedConsoleInputModeIsValid)
    SetConsoleMode(hStdin, savedConsoleInputMode);
}

int enableRawMode(void)
{
  // Make sure the console state will be returned to its original state
  // when this program ends
  atexit(disableRawMode);

  // Get handles for stdin and stdout
  hStdin = GetStdHandle(STD_INPUT_HANDLE);
  if (hStdin == INVALID_HANDLE_VALUE || hStdin == NULL)
    return 1;
  hStdout = GetStdHandle(STD_OUTPUT_HANDLE);
  if (hStdout == INVALID_HANDLE_VALUE || hStdout == NULL)
    return 1;

  // Set console to "raw" mode

  if (!GetConsoleMode(hStdout, &savedConsoleOutputMode))
    return 1;
  savedConsoleOutputModeIsValid = 1;
  DWORD newOutputMode = savedConsoleOutputMode;
  newOutputMode |= ENABLE_PROCESSED_OUTPUT;
  newOutputMode &= ~ENABLE_WRAP_AT_EOL_OUTPUT;
  newOutputMode |= ENABLE_VIRTUAL_TERMINAL_PROCESSING;
  if (!SetConsoleMode(hStdout, newOutputMode))
    return 1;
  if (!GetConsoleMode(hStdin, &savedConsoleInputMode))
    return 1;
  savedConsoleInputModeIsValid = 1;
  DWORD newInputMode = savedConsoleInputMode;
  newInputMode &= ~ENABLE_ECHO_INPUT;
  newInputMode &= ~ENABLE_LINE_INPUT;
  newInputMode &= ~ENABLE_PROCESSED_INPUT;
  newInputMode |= ENABLE_VIRTUAL_TERMINAL_INPUT;
  if (!SetConsoleMode(hStdin, newInputMode))
    return 1;

  return 0;
}

// https://stackoverflow.com/questions/6812224/getting-terminal-size-in-c-for-windows
int getWindowSize(int *rows, int *cols)
{
  CONSOLE_SCREEN_BUFFER_INFO csbi;

  GetConsoleScreenBufferInfo(GetStdHandle(STD_OUTPUT_HANDLE), &csbi);
  *cols = csbi.srWindow.Right - csbi.srWindow.Left + 1;
  *rows = csbi.srWindow.Bottom - csbi.srWindow.Top + 1;
  return 0;
}

int writeTerm(const char *buf, int length)
{
  unsigned long wrote = 0;
  WriteConsoleA(hStdout, buf, length, &wrote, NULL);
  return (int)wrote;
}

int readTerm(char *buf, int length)
{
  unsigned long read = 0;
  ReadConsoleA(hStdin, buf, length, &read, NULL);
  return (int)read;
}