/* 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 <math.h>
#include <gtk/gtk.h>
#include <girara/session.h>
#include <girara/utils.h>
#include <girara/settings.h>
#include <glib/gi18n.h>

#include "links.h"
#include "utils.h"
#include "zathura.h"
#include "internal.h"
#include "document.h"
#include "page.h"
#include "plugin.h"

#include <girara/datastructures.h>

#define BLOCK_SIZE 64

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

  const char* res = strrchr(path, '.');
  if (res == NULL) {
    return NULL;
  }

  return res + 1;
}

bool
file_valid_extension(zathura_t* zathura, const char* path)
{
  if (zathura == NULL || path == NULL || zathura->plugins.manager == NULL) {
    return false;
  }

  const gchar* content_type = g_content_type_guess(path, NULL, 0, NULL);
  if (content_type == NULL) {
    return false;
  }

  zathura_plugin_t* plugin = zathura_plugin_manager_get_plugin(zathura->plugins.manager, content_type);
  g_free((void*)content_type);

  return (plugin == NULL) ? false : true;
}

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;
}

void
document_index_build(GtkTreeModel* model, GtkTreeIter* parent,
                     girara_tree_node_t* tree)
{
  girara_list_t* list        = girara_node_get_children(tree);
  GIRARA_LIST_FOREACH(list, girara_tree_node_t*, iter, node)
  zathura_index_element_t* index_element = (zathura_index_element_t*)girara_node_get_data(node);

  zathura_link_type_t type     = zathura_link_get_type(index_element->link);
  zathura_link_target_t target = zathura_link_get_target(index_element->link);

  gchar* description = NULL;
  if (type == ZATHURA_LINK_GOTO_DEST) {
    description = g_strdup_printf("Page %d", target.page_number + 1);
  } else {
    description = g_strdup(target.value);
  }

  GtkTreeIter tree_iter;
  gtk_tree_store_append(GTK_TREE_STORE(model), &tree_iter, parent);
  gtk_tree_store_set(GTK_TREE_STORE(model), &tree_iter, 0, index_element->title, 1, description, 2, index_element, -1);
  g_object_weak_ref(G_OBJECT(model), (GWeakNotify) zathura_index_element_free, index_element);
  g_free(description);

  if (girara_node_get_num_children(node) > 0) {
    document_index_build(model, &tree_iter, node);
  }

  GIRARA_LIST_FOREACH_END(list, gchar*, iter, name);
}

void
page_calculate_offset(zathura_t* zathura, zathura_page_t* page, page_offset_t* offset)
{
  g_return_if_fail(page != NULL);
  g_return_if_fail(offset != NULL);
  GtkWidget* widget = zathura_page_get_widget(zathura, page);

  g_return_if_fail(gtk_widget_translate_coordinates(widget,
                   zathura->ui.page_widget, 0, 0, &(offset->x), &(offset->y)) == true);
}

zathura_rectangle_t
rotate_rectangle(zathura_rectangle_t rectangle, unsigned int degree, double height, double width)
{
  zathura_rectangle_t tmp;
  switch (degree) {
    case 90:
      tmp.x1 = height - rectangle.y2;
      tmp.x2 = height - rectangle.y1;
      tmp.y1 = rectangle.x1;
      tmp.y2 = rectangle.x2;
      break;
    case 180:
      tmp.x1 = width - rectangle.x2;
      tmp.x2 = width - rectangle.x1;
      tmp.y1 = height - rectangle.y2;
      tmp.y2 = height - rectangle.y1;
      break;
    case 270:
      tmp.x1 = rectangle.y1;
      tmp.x2 = rectangle.y2;
      tmp.y1 = width - rectangle.x2;
      tmp.y2 = width - rectangle.x1;
      break;
    default:
      tmp.x1 = rectangle.x1;
      tmp.x2 = rectangle.x2;
      tmp.y1 = rectangle.y1;
      tmp.y2 = rectangle.y2;
  }

  return tmp;
}

zathura_rectangle_t
recalc_rectangle(zathura_page_t* page, zathura_rectangle_t rectangle)
{
  if (page == NULL) {
    goto error_ret;
  }

  zathura_document_t* document = zathura_page_get_document(page);

  if (document == NULL) {
    goto error_ret;
  }

  double page_height = zathura_page_get_height(page);
  double page_width  = zathura_page_get_width(page);
  double scale       = zathura_document_get_scale(document);

  zathura_rectangle_t tmp = rotate_rectangle(rectangle, zathura_document_get_rotation(document), page_height, page_width);
  tmp.x1 *= scale;
  tmp.x2 *= scale;
  tmp.y1 *= scale;
  tmp.y2 *= scale;

  return tmp;

error_ret:

  return rectangle;
}

double
page_calc_height_width(zathura_page_t* page, unsigned int* page_height, unsigned int* page_width, bool rotate)
{
  g_return_val_if_fail(page != NULL && page_height != NULL && page_width != NULL, 0.0);

  zathura_document_t* document = zathura_page_get_document(page);
  if (document == NULL) {
    return 0.0;
  }

  double height = zathura_page_get_height(page);
  double width  = zathura_page_get_width(page);
  double scale  = zathura_document_get_scale(document);
  double real_scale;

  if (rotate && zathura_document_get_rotation(document) % 180) {
    *page_width  = ceil(height * scale);
    *page_height = ceil(width  * scale);
    real_scale = MAX(*page_width / height, *page_height / width);
  } else {
    *page_width  = ceil(width  * scale);
    *page_height = ceil(height * scale);
    real_scale = MAX(*page_width / width, *page_height / height);
  }

  return real_scale;
}

void
zathura_get_document_size(zathura_t* zathura,
                          unsigned int cell_height, unsigned int cell_width,
                          unsigned int* height, unsigned int* width)
{
  g_return_if_fail(zathura != NULL && zathura->document != NULL &&
                   height != NULL && width != NULL);

  unsigned int pages_per_row = 1;
  girara_setting_get(zathura->ui.session, "pages-per-row", &pages_per_row);
  if (pages_per_row == 0)
    pages_per_row = 1;

  unsigned int first_page_column = 1;
  girara_setting_get(zathura->ui.session, "first-page-column", &first_page_column);
  if (first_page_column < 1)
    first_page_column = 1;
  if (first_page_column > pages_per_row)
    first_page_column = (first_page_column - 1) % pages_per_row + 1;

  int padding = 1;
  girara_setting_get(zathura->ui.session, "page-padding", &padding);

  double scale = zathura_document_get_scale(zathura->document);

  cell_height = ceil(cell_height * scale);
  cell_width  = ceil(cell_width * scale);

  *width = pages_per_row * cell_width + (pages_per_row - 1) * padding;
  unsigned int effective_number_of_pages =
    zathura_document_get_number_of_pages(zathura->document) +
    first_page_column - 1;
  unsigned int rows = effective_number_of_pages / pages_per_row +
                     (effective_number_of_pages % pages_per_row ? 1 : 0);
  *height = rows * cell_height + (rows - 1) * padding;
}

GtkWidget*
zathura_page_get_widget(zathura_t* zathura, zathura_page_t* page)
{
  if (zathura == NULL || page == NULL || zathura->pages == NULL) {
    return NULL;
  }

  unsigned int page_number = zathura_page_get_index(page);

  return zathura->pages[page_number];
}

void
document_draw_search_results(zathura_t* zathura, bool value)
{
  if (zathura == NULL || zathura->document == NULL || zathura->pages == NULL) {
    return;
  }

  unsigned int number_of_pages = zathura_document_get_number_of_pages(zathura->document);
  for (unsigned int page_id = 0; page_id < number_of_pages; page_id++) {
    g_object_set(zathura->pages[page_id], "draw-search-results", (value == true) ? TRUE : FALSE, NULL);
  }
}

char*
zathura_get_version_string(zathura_t* zathura, bool markup)
{
  if (zathura == NULL) {
    return NULL;
  }

  GString* string = g_string_new(NULL);

  /* zathura version */
  char* zathura_version = g_strdup_printf("zathura %d.%d.%d", ZATHURA_VERSION_MAJOR, ZATHURA_VERSION_MINOR, ZATHURA_VERSION_REV);
  g_string_append(string, zathura_version);
  g_free(zathura_version);

  char* format = (markup == true) ? "\n<i>(plugin)</i> %s (%d.%d.%d) <i>(%s)</i>" : "\n(plugin) %s (%d.%d.%d) (%s)";

  /* plugin information */
  girara_list_t* plugins = zathura_plugin_manager_get_plugins(zathura->plugins.manager);
  if (plugins != NULL) {
    GIRARA_LIST_FOREACH(plugins, zathura_plugin_t*, iter, plugin)
    char* name = zathura_plugin_get_name(plugin);
    zathura_plugin_version_t version = zathura_plugin_get_version(plugin);
    char* text = g_strdup_printf(format,
                                 (name == NULL) ? "-" : name,
                                 version.major,
                                 version.minor,
                                 version.rev,
                                 zathura_plugin_get_path(plugin)
                                );
    g_string_append(string, text);
    g_free(text);
    GIRARA_LIST_FOREACH_END(plugins, zathura_plugin_t*, iter, plugin);
  }

  char* version = string->str;
  g_string_free(string, FALSE);

  return version;
}

char*
replace_substring(const char* string, const char* old, const char* new)
{
  if (string == NULL || old == NULL || new == NULL) {
    return NULL;
  }

  size_t old_len = strlen(old);
  size_t new_len = strlen(new);

  /* count occurences */
  unsigned int count = 0;
  unsigned int i = 0;

  for (i = 0; string[i] != '\0'; i++) {
    if (strstr(&string[i], old) == &string[i]) {
      i += (old_len - 1);
      count++;
    }
  }

  if (count == 0) {
    return NULL;
  }

  char* ret = g_malloc0(sizeof(char) * (i - count * old_len + count * new_len + 1));
  i = 0;

  /* replace */
  while (*string != '\0') {
    if (strstr(string, old) == string) {
      strncpy(&ret[i], new, new_len);
      i += new_len;
      string += old_len;
    } else {
      ret[i++] = *string++;
    }
  }

  return ret;
}

GdkAtom* get_selection(zathura_t* zathura)
{
    g_return_val_if_fail(zathura != NULL, NULL);

    char* value;
    girara_setting_get(zathura->ui.session, "selection-clipboard", &value);

    GdkAtom* selection = g_malloc(sizeof(GdkAtom));

    if (strcmp(value, "primary") == 0) {
      *selection = GDK_SELECTION_PRIMARY;
    } else if (strcmp(value, "clipboard") == 0) {
      *selection = GDK_SELECTION_CLIPBOARD;
    } else {
      girara_error("Invalid value for the selection-clipboard setting");
      g_free(value);
      g_free(selection);

      return NULL;
    }

    g_free(value);

    return selection;
}