/* See LICENSE file for license and copyright information */

#include <stdlib.h>
#include <stdarg.h>
#include <string.h>
#include <stdio.h>
#include <unistd.h>
#include <sys/types.h>
#include <sys/wait.h>

#include "utils.h"
#include "zathura.h"
#include "document.h"

#define BLOCK_SIZE 64

bool
file_exists(const char* path)
{
  if (!access(path, F_OK)) {
    return true;
  } else {
    return false;
  }
}

const char*
file_get_extension(const char* path)
{
  if (!path) {
    return NULL;
  }

  unsigned int i = strlen(path);
  for (; i > 0; i--)
  {
    if (*(path + i) != '.') {
      continue;
    } else {
      break;
    }
  }

  if (!i) {
    return NULL;
  }

  return path + i + 1;
}

bool
file_valid_extension(zathura_t* zathura, const char* path)
{
  if (path == NULL) {
    return false;
  }

  const char* file_extension = file_get_extension(path);

  if (file_extension == NULL) {
    return false;
  }

  girara_list_iterator_t* iter = girara_list_iterator(zathura->plugins.plugins);
  if (iter == NULL) {
    return false;
  }

  do {
    zathura_document_plugin_t* plugin = (zathura_document_plugin_t*) girara_list_iterator_data(iter);
    if (!strcmp(file_extension, plugin->file_extension)) {
      return true;
    }
  } while (girara_list_iterator_next(iter));
  girara_list_iterator_free(iter);

  return false;
}

bool
execute_command(char* const argv[], char** output)
{
  if (!output) {
    return false;
  }

  int p[2];
  if (pipe(p)) {
    return -1;
  }

  pid_t pid = fork();

  if (pid == -1) { // failure
    return false;
  } else if (pid == 0) { // child
    dup2(p[1], 1);
    close(p[0]);

    if (execvp(argv[0], argv) == -1) {
      return false;
    }
  } else { // parent
    dup2(p[0], 0);
    close(p[1]);

    /* read output */
    unsigned int bc = BLOCK_SIZE;
    unsigned int i  = 0;
    char* buffer    = malloc(sizeof(char) * bc);
    *output = NULL;

    if (!buffer) {
      close(p[0]);
      return false;
    }

    char c;
    while (1 == read(p[0], &c, 1)) {
      buffer[i++] = c;

      if (i == bc) {
        bc += BLOCK_SIZE;
        char* tmp = realloc(buffer, sizeof(char) * bc);

        if (!tmp) {
          free(buffer);
          close(p[0]);
          return false;
        }

        buffer = tmp;
      }
    }

    char* tmp = realloc(buffer, sizeof(char) * (bc + 1));
    if (!tmp) {
      free(buffer);
      close(p[0]);
      return false;
    }

    buffer = tmp;
    buffer[i] = '\0';

    *output = buffer;

    /* wait for child to terminate */
    waitpid(pid, NULL, 0);
    close(p[0]);
  }

  return true;
}

GtkWidget*
page_blank(unsigned int width, unsigned int height)
{
  if ((width == 0) || (height == 0)) {
    return NULL;
  }

  guchar* buffer = malloc(sizeof(guchar) * (width * height * 1));
  if (!buffer) {
    return NULL;
  }

  /* draw white */
  for (unsigned int i = 0; i < width * height; i++) {
    buffer[i] = 255;
  }

  GdkPixbuf* pixbuf = gdk_pixbuf_new_from_data(buffer, GDK_COLORSPACE_RGB, FALSE, 8,
    width, height, 1, NULL, NULL);

  if (!pixbuf) {
    free(buffer);
    return NULL;
  }

  /* convert to image */
  GtkWidget* image = gtk_image_new();
  if (!image) {
    free(buffer);
    g_object_unref(pixbuf);
    return false;
  }

  gtk_image_set_from_pixbuf(GTK_IMAGE(image), pixbuf);
  gtk_widget_show(image);

  /*free(buffer);*/ // XXX: Read documentation
  g_object_unref(pixbuf);

  return image;
}

void
document_index_build(GtkTreeModel* model, GtkTreeIter* parent, girara_tree_node_t* tree)
{
  /*girara_list_t* list        = girara_node_get_children(tree);*/
  /*girara_list_iterator_t* it = girara_list_iterator(list);*/

  /*do {*/
    /*zathura_index_element_t* index_element = (zathura_index_element_t*) girara_list_iterator_data(it);*/
  /*} while ((it = girara_list_iterator_next(it)));*/
}

char*
string_concat(const char* string1, ...)
{
  if(!string1) {
    return NULL;
  }

  va_list args;
  char* s;
  int l = strlen(string1) + 1;

  /* calculate length */
  va_start(args, string1);

  s = va_arg(args, char*);

  while(s) {
    l += strlen(s);
    s = va_arg(args, char*);
  }

  va_end(args);

  /* prepare */
  char* c = malloc(sizeof(char) * l);
  char* p = c;

  /* copy */
  char* d = p;
  char* x = (char*) string1;

  do {
    *d++ = *x;
  } while (*x++ != '\0');

  p = d - 1;

  va_start(args, string1);

  s = va_arg(args, char*);

  while(s) {
    d = p;
    x = s;

    do {
      *d++ = *x;
    } while (*x++ != '\0');

    p = d - 1;
    s = va_arg(args, char*);
  }

  va_end(args);

  return c;
}


page_offset_t*
page_calculate_offset(zathura_page_t* page)
{
  if (page == NULL || page->document == NULL || page->document->zathura == NULL) {
    return NULL;
  }

  page_offset_t* offset = malloc(sizeof(page_offset_t));

  if (offset == NULL) {
    return NULL;
  }

  zathura_document_t* document = page->document;
  zathura_t* zathura           = document->zathura;

  if (gtk_widget_translate_coordinates(page->event_box, zathura->ui.page_view, 0, 0, &(offset->x), &(offset->y)) == false) {
    free(offset);
    return NULL;
  }

  return offset;
}