#include "common/common.h"
#include <stdbool.h>

typedef struct {
  char* buffer;
  int x;
  int y;
  uint32_t process;
  uint32_t stdin;
  uint32_t stdout;
  uint32_t width;
  uint32_t height;
} procbuffer;

void scrollBuffer(procbuffer* buf) {
  for (int y=0; y<buf->height; y++)
    for (int x=0; x<buf->width; x++)
      if (y != buf->height-1)
        buf->buffer[y*buf->width+x] = buf->buffer[(y+1)*buf->width+x];
      else
        buf->buffer[y*buf->width+x] = ' ';
}

void writeToBuf(char c, procbuffer* buf) {
  switch (c) {
    case '\n':
      buf->x = 0;
      buf->y++;
      break;
    
    case '\b':
      if (buf->x > 0)
        buf->x--;
      else if (buf->y > 0) {
        buf->x = buf->width-1;
        buf->y--;
      }
      buf->buffer[buf->y*buf->width+buf->x] = ' ';
      break;

    default:
      buf->buffer[buf->y*buf->width+buf->x++] = c;
  }
  if (buf->x == buf->width) {
    buf->x = 0;
    buf->y++;
  }
  if (buf->y == buf->height) {
    buf->y--;
    scrollBuffer(buf);
  }
}

void writeCountToBuf(int count, char* c, procbuffer* buf) {
  while (count--) {
    writeToBuf(*(c++), buf);
  }
}

void clearBuf(procbuffer* buf) {
  for (int i=0; i<buf->height*buf->width;i++) {
    buf->buffer[i] = ' ';
  }
  buf->x = 0;
  buf->y = 0;
}

void writeStrToBuf(char* c, procbuffer* b) {
  char* s = c;
  while(*s)
    writeToBuf(*(s++), b);
}

void setCurPos(int x, int y) {
  char pset[11] = "\x1b[000;000H";
  for (int i=0; i<y;i++) {
    pset[4]++;
    if (pset[4] == 0x3a) {
      pset[4] = 0x30;
      pset[3]++;
    }
    if (pset[3] == 0x3a) {
      pset[3] = 0x30;
      pset[2]++;
    }
  }
  for (int i=0; i<x;i++) {
    pset[8]++;
    if (pset[8] == 0x3a) {
      pset[8] = 0x30;
      pset[7]++;
    }
    if (pset[7] == 0x3a) {
      pset[7] = 0x30;
      pset[6]++;
    }
  }
  print(pset);
}

void displayBuf(procbuffer* b, int dx, int dy) {
  print("\x1b[42;36;1m");
  char pset[9] = "\x1b[000;000H";
  for (int i=0; i<b->height; i++) {
    setCurPos(dx, dy++);
    write(b->width, 0, b->buffer+(b->width*i));
  }
}

void readline(int count, char* buffer) {
  int index = 0;
  char c;
  while (index < count) {
    if (read(1, 1, &c)) {
      if (c == '\n')
        break;
      if (c == '\b') {
        if (index == 0)
          continue;
        else {
          index--;
          buffer[index] = 0;
          write(1, 0, &c);
          continue;
        }
      }

      buffer[index++] = c;
      write(1, 0, &c);
    }
  }
}

bool strcmp(char* a, char* b) {
  int index=0;
  while (a[index])
    if (a[index] == b[index])
      index++;
    else
      return false;
  return true;
}

bool strcmpcnt(int count, char* a, char* b) {
  int index=0;
  while (index < count)
    if (a[index] == b[index])
      index++;
    else
      return false;
  return true;
}

int main() {
  int width = getCurrentTerminalWidth();
  int height = getCurrentTerminalHeight();

  int bufferWidth = (width - 4) / 2;
  int bufferHeight = (height - 4);

  bindToKeyboard();

  char space = ' ';
  char plus = '+';

  print("\x1b[1;1H");
  for (int i=0; i < 1000; i++)
    write(1, 0, &space);
  print("\x1b[1;1H");
  print("\x1b[45;33;1m");

  for (int i=0; i<width;i++)
    write(1, 0, &plus);
  for (int i=0; i<bufferHeight;i++) {
    write(1, 0, &plus);
    for (int j=0; j<bufferWidth; j++)
      write(1, 0, &space);
    write(1, 0, &plus);
    write(1, 0, &plus);
    for (int j=0; j<bufferWidth; j++)
      write(1, 0, &space);
    write(1, 0, &plus);
  }
  for (int i=0; i<width;i++)
    write(1, 0, &plus);
  write(1, 0, &plus);
  for (int i=0; i< width - 2; i++)
    write(1, 0, &space);
  write(1, 0, &plus);
  for (int i=0; i<width;i++)
    write(1, 0, &plus);

  uint32_t program = fopen("/hello.bin");
  uint32_t p1 = exec(program);
  uint32_t p1out = bindStdout(p1);
  uint32_t p1in = bindStdin(p1);
  fclose(program);
  program = fopen("/timer.bin");
  uint32_t p2 = exec(program);
  uint32_t p2out = bindStdout(p2);
  uint32_t p2in = bindStdin(p2);
  fclose(program);

  procbuffer b1 = {
    .buffer = malloc(bufferWidth * bufferHeight),
    .x = 0,
    .y = 0,
    .process = p1,
    .stdin = p1in,
    .stdout = p1out,
    .width = bufferWidth,
    .height = bufferHeight
  };

  procbuffer b2 = {
    .buffer = malloc(bufferWidth * bufferHeight),
    .x = 0,
    .y = 0,
    .process = p2,
    .stdin = p2in,
    .stdout = p2out,
    .width = bufferWidth,
    .height = bufferHeight
  };

  procbuffer* selectedBuf = &b1;

  writeStrToBuf("XoSH (XOS SHell) v0.0.1\nPress : to use commands.\n :help for help.\n", &b1);

  while (1) {
    char c[128];
    int succ = 0;
    if (b1.process)
      if (succ = read(128, b1.stdout, c))
        writeCountToBuf(succ, c, &b1);
    if (b2.process)
      if (succ = read(128, b2.stdout, c))
        writeCountToBuf(succ, c, &b2);
    if (read(1, 1, c)) {
      if (c[0] == ':') {
        char buf[32] = {0};
        print("\x1b[45;33;1m");
        setCurPos(2, height-1);
        print(":                                ");
        setCurPos(3, height-1);
        readline(32, buf);
        if (strcmpcnt(6, buf, "switch")) {
          if (selectedBuf == &b1) {
            selectedBuf = &b2;
          } else {
            selectedBuf = &b1;
          }
        } else if (strcmpcnt(4, buf, "help")) {
          writeStrToBuf("\n--------\n", selectedBuf);
          writeStrToBuf(":help\n", selectedBuf);
          writeStrToBuf("  Displays this message.\n", selectedBuf);
          writeStrToBuf(":switch\n", selectedBuf);
          writeStrToBuf("  Switches which process you're using\n", selectedBuf);
          writeStrToBuf(":kill\n", selectedBuf);
          writeStrToBuf("  Kills the current process\n", selectedBuf);
          writeStrToBuf(":load <filename>\n", selectedBuf);
          writeStrToBuf("  Loads and executes the program <filename>\n", selectedBuf);
          writeStrToBuf(":ls <path>\n", selectedBuf);
          writeStrToBuf("  Lists the files in directory <path>\n", selectedBuf);
          writeStrToBuf(":clear\n", selectedBuf);
          writeStrToBuf("  Clears the buffer\n", selectedBuf);
          
          writeStrToBuf("--------\n", selectedBuf);
        } else if (strcmpcnt(4, buf, "kill")) {
          if (selectedBuf->process) {
            kill(selectedBuf->process);
            clearBuf(selectedBuf);
            selectedBuf->process = 0;
            selectedBuf->stdin = 0;
            selectedBuf->stdout = 0;
          }
        } else if (strcmpcnt(4, buf, "load")) {
          if (!selectedBuf->process) {
            char* potFn = buf+5;
            uint32_t fh = fopen(potFn);
            selectedBuf->process = exec(fh);
            selectedBuf->stdout = bindStdout(selectedBuf->process);
            selectedBuf->stdin = bindStdin(selectedBuf->process);
            fclose(fh);
          }
        } else if (strcmpcnt(2, buf, "ls")) {
          uint32_t size = getDentsSize((char*)(buf+3));
          FSDirectoryListing* listing = (FSDirectoryListing*)malloc(size);
          getDents((char*)(buf+3), listing);
          writeStrToBuf("\n", selectedBuf);
          for (int i=0; i<listing->count; i++) {
            writeCountToBuf(listing->entries[i].path.length, listing->entries[i].path.path, selectedBuf);
            writeStrToBuf("\n", selectedBuf);
          }
          free(listing);
        } else if (strcmpcnt(5, buf, "clear")) {
          clearBuf(selectedBuf);
        }
      } else {
        if (selectedBuf->process)
          write(1, selectedBuf->stdin, c);
      }
    }
    
    displayBuf(&b1, 2, 2);
    displayBuf(&b2, bufferWidth+4, 2);
  }
}