/*
  MSP430 Emulator
  Copyright (C) 2020 Rudolf Geosits (rgeosits@live.esu.edu)

  "MSP430 Emulator" is free software: you can redistribute it and/or modify
  it under the terms of the GNU General Public License as published by
  the Free Software Foundation, either version 3 of the License, or
  (at your option) any later version.

  "MSP430 Emulator" is distributed in the hope that it will be useful,
  but WITHOUT ANY WARRANTY; without even the implied warranty of
  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
  GNU General Public License for more details.

  You should have received a copy of the GNU General Public License
  along with this program. If not, see <https://www.gnu.org/licenses/>.
*/

#include <string.h>
#include "emu_server.h"

#define TXIFG 0x02
#define RXIFG 0x01
#define HIGH  1
#define LOW   0
#define OUT   1
#define IN    0

//
#define MAX_UPLOAD_FILENAME_SIZE 0xFFFF+1
char UploadFileName[MAX_UPLOAD_FILENAME_SIZE] = {0};

Emulator *emu = NULL;
uint8_t *data;
int lent;

void *thrd (void *ctxt) 
{
  Usci *usci = (Usci *)ctxt;
  int i, j = 0;
  int len = lent;
  uint8_t *bytes = data;

  //printf("len is %d\nstr is %s\n", len, bytes);

  while (true) {
    usleep(333);
    while (*usci->IFG2 & RXIFG);
    uint8_t thing = *(bytes);

    if (thing == '\n') {                  
      thing = '\r';
    }                          
    
    //printf("Got 0x%02X '%c'\n", thing, thing);
    
    if (*bytes == '\\') {
      ++bytes;
      if (*bytes == 'h' || *bytes == 'H') {
	++bytes;
	
	char buf[3] = {*((char*)bytes), *((char*)bytes+1), 0};

	//printf("%s - %s\n", buf, bytes);
	thing = (uint8_t) strtoul(buf, NULL, 16);

	++bytes;
      }  
    }	  

    *usci->UCA0RXBUF = thing;    
    *usci->IFG2 |= RXIFG;
	    
    //printf("\n0x%04X in UCA0RXBUF\n", (uint8_t)*usci->UCA0RXBUF);

    //puts("waiting..");
    while (*usci->IFG2 & RXIFG);
    //puts("done");
    //*usci->IFG2 |= RXIFG;
    
    if (*usci->UCA0RXBUF == '\r') break;
    ++bytes;
  }

  return NULL;
}

int callback_emu (struct lws *wsi, enum lws_callback_reasons reason, void *user, void *in, size_t len)
{
  Cpu *cpu = emu->cpu;
  Port_1 *p1 = emu->cpu->p1;
  Debugger *deb = emu->debugger;

  switch (reason)
  {
    case LWS_CALLBACK_ESTABLISHED:
    {
      puts("connection established");
      
      // Flip ready flag for the emulator to begin
      deb->web_server_ready = true;

      // get the ball rolling
      //libwebsocket_callback_on_writable(this, wsi);
      lws_callback_on_writable(wsi);
      
      break;
    }
      
    case LWS_CALLBACK_SERVER_WRITEABLE:
    {
        if ( !packet_queue_empty(emu) )
        {
            Packet p = packet_dequeue(emu);
	  
            void *msg = p.message;
            size_t msg_len = p.length;
            uint8_t op = p.opcode;
	
            //printf("[%s] of len %u, opcode: %u\n\n",
            //(char *)msg, (unsigned int)msg_len, op);
	
            // Leave room for websock header/trailer & opcode
            size_t pack_len = msg_len + sizeof(op) + LWS_SEND_BUFFER_PRE_PADDING + LWS_SEND_BUFFER_POST_PADDING;
	
            void *packet = malloc(pack_len);
	
            // Zero out our packet
            memset( ((uint8_t*)packet + LWS_SEND_BUFFER_PRE_PADDING), 0, msg_len + sizeof(op) );

            // Place opcode into packet
            *((uint8_t *)((uint8_t*)packet + LWS_SEND_BUFFER_PRE_PADDING)) = op;
	
            // Place message into packet
            memcpy( ((uint8_t*)packet + LWS_SEND_BUFFER_PRE_PADDING + sizeof(op)), (const void *)p.message, msg_len);

            /*
            int i;
            for (i = 0;i < pack_len;i++){
            printf( "%02X (%c) | ", *((uint8_t *)(packet+i)),
	            *((char *)(packet+i)) );
            }
            puts("\n");
            */

            lws_write(wsi, ((unsigned char*)(packet))+LWS_SEND_BUFFER_PRE_PADDING, msg_len + sizeof(op), LWS_WRITE_BINARY);
	  
            free(p.message);
            free(packet);
        }

        static bool p1_0_on = false;
        static bool p1_1_on = false;
        static bool p1_2_on = false;
        static bool p1_3_on = false;
        static bool p1_4_on = false;
        static bool p1_5_on = false;
        static bool p1_6_on = false;
        static bool p1_7_on = false;
      
        // P1.0 ON/OFF
        if (p1->DIR_0 == OUT)
        {
            if (p1->OUT_0 == HIGH)
            {
                if (p1_0_on == false)
                {
                    send_control(emu, P1_0_ON_PACKET, NULL, 0);
                    p1_0_on = true;
                }
            }
            else if (p1->OUT_0 == LOW)
            {
                if (p1_0_on == true)
                {
                    send_control(emu, P1_0_OFF_PACKET, NULL, 0);
                    p1_0_on = false;
                }
            }
        }

      // P1.1 ON/OFF
      if (p1->DIR_1 == OUT) {
	if (p1->OUT_1 == HIGH) {	  
	  if (p1_1_on == false) {
	    send_control(emu, P1_1_ON_PACKET, NULL, 0);
	    p1_1_on = true;
	  }
	}
	else if (p1->OUT_1 == LOW) {
	  if (p1_1_on == true) {
	    send_control(emu, P1_1_OFF_PACKET, NULL, 0);
	    p1_1_on = false;
	  }
	}
      }

      // P1.2 ON/OFF
      if (p1->DIR_2 == OUT) {
	if (p1->OUT_2 == HIGH) {	  
	  if (p1_2_on == false) {
	    send_control(emu, P1_2_ON_PACKET, NULL, 0);
        puts("p2 on");
	    p1_2_on = true;
	  }
	}
	else if (p1->OUT_2 == LOW) {
	  if (p1_2_on == true) {
	    send_control(emu, P1_2_OFF_PACKET, NULL, 0);
	    p1_2_on = false;
	  }
	}
      }

      // P1.3 ON/OFF
      if (p1->DIR_3 == OUT) {
	if (p1->OUT_3 == HIGH) {	  
	  if (p1_3_on == false) {
	    send_control(emu, P1_3_ON_PACKET, NULL, 0);
	    p1_3_on = true;
	  }
	}
	else if (p1->OUT_3 == LOW) {
	  if (p1_3_on == true) {
	    send_control(emu, P1_3_OFF_PACKET, NULL, 0);
	    p1_3_on = false;
	  }
	}
      }

      // P1.4 ON/OFF
      if (p1->DIR_4 == OUT) {
	if (p1->OUT_4 == HIGH) {	  
	  if (p1_4_on == false) {
	    send_control(emu, P1_4_ON_PACKET, NULL, 0);
	    p1_4_on = true;
	  }
	}
	else if (p1->OUT_4 == LOW) {
	  if (p1_4_on == true) {
	    send_control(emu, P1_4_OFF_PACKET, NULL, 0);
	    p1_4_on = false;
	  }
	}
      }

      // P1.5 ON/OFF
      if (p1->DIR_5 == OUT) {
	if (p1->OUT_5 == HIGH) {	  
	  if (p1_5_on == false) {
	    send_control(emu, P1_5_ON_PACKET, NULL, 0);
	    p1_5_on = true;
	  }
	}
	else if (p1->OUT_5 == LOW) {
	  if (p1_5_on == true) {
	    send_control(emu, P1_5_OFF_PACKET, NULL, 0);
	    p1_5_on = false;
	  }
	}
      }
      
      // P1.6 ON/OFF
      if (p1->DIR_6 == OUT) {
	if (p1->OUT_6 == HIGH) {	  
	  if (p1_6_on == false) {
	    send_control(emu, P1_6_ON_PACKET, NULL, 0);
	    p1_6_on = true;
	  }
	}
	else if (p1->OUT_6 == LOW) {
	  if (p1_6_on == true) {
	    send_control(emu, P1_6_OFF_PACKET, NULL, 0);
	    p1_6_on = false;
	  }
	}
      }

      // P1.7 ON/OFF
      if (p1->DIR_7 == OUT) {
	if (p1->OUT_7 == HIGH) {	  
	  if (p1_7_on == false) {
	    send_control(emu, P1_7_ON_PACKET, NULL, 0);
	    p1_7_on = true;
	  }
	}
	else if (p1->OUT_7 == LOW) {
	  if (p1_7_on == true) {
	    send_control(emu, P1_7_OFF_PACKET, NULL, 0);
	    p1_7_on = false;
	  }
	}
      }      

      lws_callback_on_writable( wsi);
      break;
    }

    case LWS_CALLBACK_CLIENT_CONNECTION_ERROR: {
      puts("Connection Error");
      break;
    }

    case LWS_CALLBACK_CLOSED: {
      puts("Connection Closed");
      exit(0);
      break;
    }

    case LWS_CALLBACK_CLIENT_WRITEABLE: {
      puts("cli writable");
      break;
    }

    case LWS_CALLBACK_RECEIVE:
    {
        static FILE *fp = NULL;
        static bool upload_in_progress = false;
        static uint32_t uploaded_bytes;

        static uint16_t FileSize = 0;

        char *buf = (char *)in;      
      
        if (upload_in_progress)
        { // Continue transaction of upload
            int i;

            for (i = 0;i < len;i++)
            {
                fwrite(&buf[i], 1, 1, fp);
                uploaded_bytes++;

                if (uploaded_bytes >= FileSize)
                {
                    puts("met bytes");
                    fclose(fp);
                   // system("msp430-objcopy -O binary tmp.elf tmp.bin");
                    char cmdline[255] = "objcopy -I elf32-little -O binary \"";
                    strcat(cmdline, UploadFileName);
                    strcat(cmdline, "\" tmp.bin");
                    system(cmdline);

//                    std::string ObjCopyLine = "objcopy -I elf32-little -O binary \"" + std::string(UploadFileName) + "\" tmp.bin";
//                    system(ObjCopyLine.c_str());


                    deb->web_firmware_uploaded = true;
                    upload_in_progress = false;
                    return 0;
                }
            }
	
            return 0;
        }
      
        unsigned char opcode = buf[0];
        printf("opcode: %02X\n", *(uint8_t*)in);
      
        switch (opcode)
        {
            case 0x00: // Upload File
            {
                // Get the 32-bit length of the file
                FileSize = ntohs( *((uint16_t*)((uint8_t*)in + 1)) );

                // Get the 8-bit length of the ASCII filename
                uint16_t FileNameSize = ntohs(*((uint16_t*)((uint8_t*)in + 3)));

	            printf(" Got file size %u, got data len %u for first callback.\n", (unsigned int)FileSize, (unsigned int)len);

                // Ensure that the file isn't too big, otherwise just quit on the user for now
	            if (FileSize >= 0xFFFF)
                {
                    print_console(emu, "File Size Not Supported. Quitting.\n");
                    deb->quit = true;
                    exit(1);
                }

                // for now assume the entire filename is uploaded, and has no 0 at the end so add one
                memset(UploadFileName, 0, MAX_UPLOAD_FILENAME_SIZE);
                memmove(&UploadFileName[0], &buf[5], FileNameSize);

                printf(" Got name size %u, name %s.\n", FileNameSize, UploadFileName);

                upload_in_progress = true;
	            uploaded_bytes = 0;
	            fp = fopen(UploadFileName, "wb");

	            // Get Any Bytes that are in with this packet
	            for (uint32_t i = 5+FileNameSize;i < len;i++)
                {	         
	                fwrite(&buf[i], 1, 1, fp);
	                uploaded_bytes++;

	                if (uploaded_bytes >= FileSize)
                    {
	                    puts("met bytes");
	                    fclose(fp);

	                    //system("msp430-objcopy -O binary tmp.elf tmp.bin");
//                        std::string ObjCopyLine = "objcopy -I elf32-little -O binary \"" + std::string(UploadFileName) + "\" tmp.bin";
//                        system(ObjCopyLine.c_str());

                        char cmdline[255] = "objcopy -I elf32-little -O binary \"";
                        strcat(cmdline, UploadFileName);
                        strcat(cmdline, "\" tmp.bin");
                        system(cmdline);

	                    deb->web_firmware_uploaded = true;
	                    upload_in_progress = false;
	                    return 0;
	                }
	            }

	            break;
	        }

                 case 0x01: { // PLAY
	     printf("Got play\n");
	     cpu->running = true;
	     deb->debug_mode = false;
	     update_register_display(emu);

	     return 0;
	 }
            
                 case 0x02: { // PAUSE
	     printf("Got pause\n");

	     if (cpu->running) {
	         cpu->running = false;
	         deb->debug_mode = true;

	         // display first round of registers
	         display_registers(emu);
	         disassemble(emu, cpu->pc, 1);
	         update_register_display(emu);
	     }
	     
	     return 0;
	 }

                 case 0x03: { // SERIAL DATA
	     if (len > 1000) exit(1);

	     lent = len - 1;
	     data = ((uint8_t*)in + 1);
	     
	     pthread_t t;
	     if( pthread_create(&t, NULL, thrd, (void *)cpu->usci ) ) {
	         fprintf(stderr, "Error creating thread\n");                                        
	     }
	     
	     //printf("Got serial data %s ... %d bytes long\n", 
	     //(char *)(in + 1), (unsigned int)len - 1);
	     
	     return 0;
	 }

     case 0x04: { // Console Input Data
	     if (len > 1000) exit(1);

	     buf = buf + 1;	     
	     printf("%s\n", buf);

	     if (!cpu->running && deb->debug_mode) {
	         exec_cmd(emu, buf, len);	    
	         update_register_display(emu);
	     }

	     return 0;
                 }
            
                 default: break;
            }
        }
    
    default: {
        break;
    }
}
        
    return 0;
}

void *web_server (void *ctxt)
{
  emu = (Emulator *) ctxt;
  Debugger *deb = emu->debugger;

    int port = 9001;
    //struct libwebsocket_context *context;
    struct lws_context *context;

    struct lws_context_creation_info context_info = {0};

    context_info.port = deb->ws_port;
    context_info.iface = NULL;
    context_info.protocols = protocols;
    context_info.extensions = NULL;
    context_info.ssl_cert_filepath = NULL;
    context_info.ssl_private_key_filepath = NULL;
    context_info.ssl_ca_filepath = NULL;
    context_info.gid = -1;
    context_info.uid = -1;
    context_info.options = 0;
    context_info.ka_time = false;
    context_info.ka_probes = false;
    context_info.ka_interval = false;

  // Initialize packet queuing system
  init_packet_queue(emu);
  
  // create libwebsocket context representing this server
  context = lws_create_context(&context_info);

  if (context == NULL) {
    fprintf(stderr, "libwebsocket init failed\n");
    deb->quit = true;
    exit(1);
  }
    
  printf("starting server...\n");
    
  while (true) {
    lws_service(context, 10); // ms
    usleep(1000);
  }

  lws_context_destroy(context);
  return NULL;
}

void send_control(Emulator *emu, uint8_t opcode, void *data, size_t data_size)
{
  const static uint8_t NUM_OPCODE_BYTES   = 1;
  const static uint8_t NUM_DATA_LEN_BYTES = 1;

  if (data == NULL) { // Simple case
    packet_enqueue(emu, (void *)&opcode, 1, CONTROL_PACKET_OPCODE);
  }
  else { // data case ( OP DL DATADATADATA )
    uint8_t full_packet[NUM_OPCODE_BYTES + NUM_DATA_LEN_BYTES + data_size];

    // First part of packet is the opcode for specific control type
    memcpy(full_packet, (void *)&opcode, NUM_OPCODE_BYTES);

    // Second part is the data length field for following data
    memcpy(full_packet + NUM_OPCODE_BYTES, &data_size, 
	   NUM_DATA_LEN_BYTES);

    // Third part is the data itself.
    memcpy(full_packet + NUM_OPCODE_BYTES + NUM_DATA_LEN_BYTES, 
	   data, data_size);
    
    /*
    int i;
    for (i = 0;i < 1+size;i++) {
      printf("%02X ", *(uint8_t *)(full_packet + i));
    }
    puts(" .");
    */

    packet_enqueue(emu, (void *)&full_packet, 
		   NUM_OPCODE_BYTES + NUM_DATA_LEN_BYTES + data_size, 
		   CONTROL_PACKET_OPCODE);
    
  }
}

void print_serial (Emulator *emu, char *buf) 
{
  packet_enqueue(emu, buf, strlen(buf) + 1, SERIAL_PACKET_OPCODE);
}

void print_console (Emulator *emu, const char *buf)
{
    packet_enqueue(emu, (void*)buf, strlen(buf) + 1, CONSOLE_PACKET_OPCODE);
}

int callback_http (
		   struct lws *wsi,
		   //enum libwebsocket_callback_reasons reason, 
		   enum lws_callback_reasons reason, 
		   void *user, void *in, size_t len)
{
  return 0;
}