#include "../include/error.h"
#include "../include/util.h"
#include "../include/url.h"
#include <assert.h>
#include <stdio.h>
#include <string.h>
#include <stdlib.h>

char valid_path[]   = "-._~:/?#[]@!$&'()*+,;%=";

typedef enum lm_state {
  URL_PROTOCOL_0 = 0,
  URL_SPLIT_1 = 1,
  URL_HOST_2 = 2,
  URL_PATH_3 = 3,
} lm_state_t;

uint16_t lm_url_default(char *protocol){
  if(eq(protocol, "ftp"))
    return 21;
  else if(eq(protocol, "ftps"))
    return 990;
  else if(eq(protocol, "http"))
    return 80;
  else if(eq(protocol, "https"))
    return 443;
  else if(eq(protocol, "mptp"))
    return 5858;
  return 0;
}

bool lm_url_parse(lm_url_t *url, char *str){
  // clear out every variable
  bzero(url->protocol, sizeof(url->protocol));
  url->host = NULL;
  url->path = NULL;
  url->port = 0;

  // stores the string size
  size_t strl = 0, index = 0, pos = 0;
  
  // make sure the URL string size is not too large
  // extra 4 for "://" and ":"
  if((strl = strlen(str)) > URL_PROTOCOL_MAX+URL_PATH_MAX+URL_HOST_MAX+4){
    lm_error_set(LM_ERR_URLTooLarge);
    return false;
  }

  lm_state_t state = URL_PROTOCOL_0;
  char buffer[strl+1]; // temporary buffer
  bool ret = false; // return value
  
  // clear out the temporary buffer
  bzero(buffer, strl+1);

  while ((buffer[index] = *(str+pos)) != 0) {
    switch (state) {
    case URL_PROTOCOL_0:
      if(index > URL_PROTOCOL_MAX){
        lm_error_set(LM_ERR_URLBadProtocol);
        goto end;
      }

      if (!is_letter(buffer[index]) && !is_digit(buffer[index]) && buffer[index] != ':'){
        lm_error_set(LM_ERR_URLBadChar);
        goto end;
      }

      if(buffer[index] != ':')
        break;

      if(0 == index){
        lm_error_set(LM_ERR_URLBadProtocol);
        goto end;
      }

      buffer[index] = 0;
      memcpy(url->protocol, buffer, index+1);
      goto next;

    case URL_SPLIT_1:
      if(index > 1){
        lm_error_set(LM_ERR_URLBadProtocol);
        goto end;
      }

      if (buffer[index] != '/'){
        lm_error_set(LM_ERR_URLBadChar);
        goto end;
      }

      if(index != 1)
        break;

      if(buffer[index-1] != '/' || buffer[index] != '/'){
        lm_error_set(LM_ERR_URLBadProtocol);
        goto end;
      }

      goto next;

    case URL_HOST_2:
      if(index > URL_HOST_MAX){
        lm_error_set(LM_ERR_URLHostLarge);
        goto end;
      }

      if (!is_letter(buffer[index]) && !is_digit(buffer[index]) && buffer[index] != '.' && buffer[index] != ':' && buffer[index] != '/'){
        lm_error_set(LM_ERR_URLBadChar);
        goto end;
      }

      if(buffer[index] != '/')
        break;

      if(index == 0){
        lm_error_set(LM_ERR_URLBadHost);
        goto end;
      }

      buffer[index] = 0;
      url->host = malloc((index+1)*sizeof(char));
      memcpy(url->host, buffer, index+1);
      goto next;

    case URL_PATH_3:
      if(index > URL_PATH_MAX){
        lm_error_set(LM_ERR_URLPathLarge);
        goto end;
      }

      if (!is_letter(buffer[index]) && !is_digit(buffer[index]) && !contains(valid_path, buffer[index])){
        lm_error_set(LM_ERR_URLBadChar);
        goto end;
      }

      break;

    default:
      assert(false);
    }

    index++;
    pos++;
    continue;

  next:
    bzero(buffer, strl+1);
    state++;
    index = 0;
    pos++;
  }

  switch (state) {
    case URL_HOST_2:
      if(index == 0){
        lm_error_set(LM_ERR_URLBadHost);
        goto end;
      }

      if(index > URL_HOST_MAX){
        lm_error_set(LM_ERR_URLHostLarge);
        goto end;
      }

      url->host = malloc((index+1)*sizeof(char));
      memcpy(url->host, buffer, index+1);
      
      url->path = malloc(2*sizeof(char));
      url->path[0] = '/';
      url->path[1] = 0;
      break;

    case URL_PATH_3:
      url->path = malloc((index+2)*sizeof(char));
      url->path[0] = '/';
      memcpy(url->path+1, buffer, index+1);
      break;

    default:
      lm_error_set(LM_ERR_URLEnd);
      goto end;
  }

  ret = true;

end:
  if(!ret && NULL != url->host)
    free(url->host);

  if(!ret && NULL != url->path)
    free(url->path);

  return ret;
}

void lm_url_free(lm_url_t *url){
  if(NULL != url->host)
    free(url->host);

  if(NULL != url->path)
    free(url->path);
}