/* SPDX-License-Identifier: Zlib */

#include <stdlib.h>
#include <stdarg.h>
#include <string.h>
#include <stdio.h>
#include <math.h>
#include <gtk/gtk.h>
#include <girara/datastructures.h>
#include <girara/session.h>
#include <girara/settings.h>
#include <girara/utils.h>

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

double zathura_correct_zoom_value(girara_session_t* session, const double zoom) {
  if (session == NULL) {
    return zoom;
  }

  /* zoom limitations */
  int zoom_min_int = 10;
  int zoom_max_int = 1000;
  girara_setting_get(session, "zoom-min", &zoom_min_int);
  girara_setting_get(session, "zoom-max", &zoom_max_int);

  const double zoom_min = zoom_min_int * 0.01;
  const double zoom_max = zoom_max_int * 0.01;

  if (zoom < zoom_min) {
    return zoom_min;
  } else if (zoom > zoom_max) {
    return zoom_max;
  } else {
    return zoom;
  }
}

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

  char* content_type = zathura_content_type_guess(zathura->content_type_context, path, NULL);
  if (content_type == NULL) {
    return false;
  }

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

  return plugin != NULL;
}

static void index_element_free(void* data, GObject* UNUSED(object)) {
  zathura_index_element_t* element = data;
  zathura_index_element_free(element);
}

void document_index_build(girara_session_t* session, GtkTreeModel* model, GtkTreeIter* parent,
                          girara_tree_node_t* tree) {
  girara_list_t* list = girara_node_get_children(tree);

  for (size_t idx = 0; idx != girara_list_size(list); ++idx) {
    girara_tree_node_t* node               = girara_list_nth(list, idx);
    zathura_index_element_t* index_element = girara_node_get_data(node);
    const zathura_link_type_t type         = zathura_link_get_type(index_element->link);
    const zathura_link_target_t target     = zathura_link_get_target(index_element->link);

    gchar* description  = NULL;
    gchar* description2 = NULL;

    if (type == ZATHURA_LINK_GOTO_DEST) {
      zathura_t* zathura   = session->global.data;
      zathura_page_t* page = zathura_document_get_page(zathura->document, target.page_number);
      const char* label    = zathura_page_get_label(page, NULL);

      if (label != NULL) {
        description  = g_strdup_printf("Page %s", label);
        description2 = g_strdup_printf("(%d)", target.page_number + 1);
      } else {
        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);
    gchar* markup = g_markup_escape_text(index_element->title, -1);
    gtk_tree_store_set(GTK_TREE_STORE(model), &tree_iter, 0, markup, 1, description, 2, description2, 3, index_element,
                       -1);
    g_free(markup);
    g_free(description2);
    g_free(description);
    g_object_weak_ref(G_OBJECT(model), index_element_free, index_element);

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

typedef struct {
  GtkTreeIter current_iter;
  unsigned int current_page;
} SearchData;

static gboolean search_current_index(GtkTreeModel* model, GtkTreePath* UNUSED(path), GtkTreeIter* iter, gpointer data) {
  SearchData* search_data = (SearchData*)data;
  zathura_index_element_t* index_element;
  gtk_tree_model_get(model, iter, 3, &index_element, -1);
  zathura_link_target_t target = zathura_link_get_target(index_element->link);
  if (target.page_number > search_data->current_page) {
    return TRUE; // terminate foreach loop
  }
  search_data->current_iter = *iter;
  return FALSE;
}

static void tree_view_scroll_to_cell(zathura_t* zathura) {
  GtkTreeView* tree_view = gtk_container_get_children(GTK_CONTAINER(zathura->ui.index))->data;
  gtk_tree_view_scroll_to_cell(tree_view, zathura->global.current_index_path, NULL, TRUE, 0.5, 0.0);
}

void index_scroll_to_current_page(zathura_t* zathura) {
  GtkTreeView* tree_view = gtk_container_get_children(GTK_CONTAINER(zathura->ui.index))->data;
  GtkTreeModel* model    = gtk_tree_view_get_model(tree_view);

  SearchData search_data;
  gtk_tree_model_get_iter_first(model, &search_data.current_iter);
  search_data.current_page = zathura_document_get_current_page_number(zathura->document);
  gtk_tree_model_foreach(model, search_current_index, &search_data);

  GtkTreePath* current_path = gtk_tree_model_get_path(model, &search_data.current_iter);
  if (zathura->global.current_index_path != NULL) {
    gtk_tree_path_free(zathura->global.current_index_path);
  }
  zathura->global.current_index_path = gtk_tree_path_copy(current_path);
  gtk_tree_view_expand_to_path(tree_view, current_path);

  g_idle_add(G_SOURCE_FUNC(tree_view_scroll_to_cell), zathura);
  gtk_tree_view_set_cursor(tree_view, current_path, NULL, FALSE);
  gtk_tree_path_free(current_path);
}

static 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:
    return rectangle;
  }

  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;
}

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(const zathura_plugin_manager_t* plugin_manager, bool markup) {
  if (plugin_manager == NULL) {
    return NULL;
  }

  GString* string = g_string_new(NULL);

  /* zathura version */
  g_string_append(string, "zathura " ZATHURA_VERSION);
  g_string_append_printf(string, "\ngirara " GIRARA_VERSION " (runtime: %s)", girara_version());

  const 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(plugin_manager);
  if (plugins != NULL) {
    for (size_t idx = 0; idx != girara_list_size(plugins); ++idx) {
      const zathura_plugin_t* plugin   = girara_list_nth(plugins, idx);
      const char* name                 = zathura_plugin_get_name(plugin);
      zathura_plugin_version_t version = zathura_plugin_get_version(plugin);
      g_string_append_printf(string, format, (name == NULL) ? "-" : name, version.major, version.minor, version.rev,
                             zathura_plugin_get_path(plugin));
    }
  }

#if GLIB_CHECK_VERSION(2, 76, 0)
  return g_string_free_and_steal(string);
#else
  return g_string_free(string, FALSE);
#endif
}

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

  char* value = NULL;
  girara_setting_get(zathura->ui.session, "selection-clipboard", &value);
  if (value == NULL) {
    return NULL;
  }

  GdkAtom* selection = g_try_malloc(sizeof(GdkAtom));
  if (selection == NULL) {
    g_free(selection);
    return NULL;
  }

  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;
}

char* write_first_page_column_list(unsigned int* first_page_columns, unsigned int size) {
  if (first_page_columns == NULL) {
    return NULL;
  }

  GString* buffer = g_string_new(NULL);
  for (unsigned int i = 0; i < size; i++) {
    if (i != 0) {
      g_string_append_printf(buffer, ":%u", first_page_columns[i]);
    } else {
      g_string_append_printf(buffer, "%u", first_page_columns[i]);
    }
  }

#if GLIB_CHECK_VERSION(2, 76, 0)
  return g_string_free_and_steal(buffer);
#else
  return g_string_free(buffer, FALSE);
#endif
}

unsigned int* parse_first_page_column_list(const char* first_page_column_list, unsigned int* size) {
  if (first_page_column_list == NULL || size == NULL) {
    return NULL;
  }

  char** tokens       = g_strsplit(first_page_column_list, ":", 0);
  unsigned int length = g_strv_length(tokens);

  unsigned int* settings = g_malloc_n(length, sizeof(unsigned int));
  for (unsigned int i = 0; i < length; i++) {
    guint64 column = 1;

    if (g_ascii_string_to_unsigned(tokens[i], 10, 1, i + 1, &column, NULL) == TRUE && column <= UINT_MAX) {
      settings[i] = (unsigned int)column;
    } else {
      settings[i] = 1;
    }
  }

  g_strfreev(tokens);

  *size = length;
  return settings;
}

unsigned int find_first_page_column(const char* first_page_column_list, const unsigned int pages_per_row) {
  /* sanity checks */
  unsigned int first_page_column = 1;
  g_return_val_if_fail(first_page_column_list != NULL, first_page_column);
  g_return_val_if_fail(pages_per_row > 0, first_page_column);

  unsigned int size      = 0;
  unsigned int* settings = parse_first_page_column_list(first_page_column_list, &size);

  if (pages_per_row <= size) {
    first_page_column = settings[pages_per_row - 1];
  } else if (size > 0) {
    first_page_column = settings[size - 1];
  }

  g_free(settings);

  return first_page_column;
}

char* increment_first_page_column(const char* first_page_column_list, const unsigned int pages_per_row, int incr) {
  /* sanity checks */
  if (first_page_column_list == NULL) {
    first_page_column_list = "";
  }
  /* This function is a no-op for 1 column layout */
  if (pages_per_row <= 1) {
    return g_strdup(first_page_column_list);
  }

  unsigned int size      = 0;
  unsigned int* settings = parse_first_page_column_list(first_page_column_list, &size);

  /* Lookup current setting. Signed value to avoid negative overflow when modifying it later. */
  int column = 1;
  if (pages_per_row <= size) {
    column = settings[pages_per_row - 1];
  } else if (size > 0) {
    column = settings[size - 1];
  }

  /* increment and normalise to [1,pages_per_row]. */
  column += incr;
  column %= pages_per_row; /* range [-pages_per_row+1, pages_per_row-1] */
  if (column <= 0)
    column += pages_per_row; /* range [1, pages_per_row] */

  /* Write back, creating the new cell if necessary. */
  if (pages_per_row <= size) {
    settings[pages_per_row - 1] = column;
  } else {
    /* extend settings array */
    settings = g_realloc_n(settings, pages_per_row, sizeof(*settings));
    for (unsigned int i = size; i < pages_per_row - 1; i++) {
      /* The value of the last set cell is normally used for all largers pages_per_row,
       * so duplicate it to the newly created cells. */
      settings[i] = settings[size - 1];
    }
    settings[pages_per_row - 1] = column;
    size                        = pages_per_row;
  }

  char* new_column_list = write_first_page_column_list(settings, size);
  g_free(settings);
  return new_column_list;
}

bool parse_color(GdkRGBA* color, const char* str) {
  if (gdk_rgba_parse(color, str) == FALSE) {
    girara_warning("Failed to parse color string '%s'.", str);
    return false;
  }
  return true;
}

typedef struct zathura_point_s {
  uintptr_t x;
  uintptr_t y;
} zathura_point_t;

static int cmp_point(const void* va, const void* vb) {
  const zathura_point_t* a = va;
  const zathura_point_t* b = vb;

  if (a->x == b->x) {
    if (a->y == b->y) {
      return 0;
    }

    return a->y < b->y ? -1 : 1;
  }

  return a->x < b->x ? -1 : 1;
}

static uintptr_t ufloor(double f) {
  return floor(f);
}

static uintptr_t uceil(double f) {
  return ceil(f);
}

static int cmp_uint(const void* vx, const void* vy) {
  const uintptr_t x = (uintptr_t)vx;
  const uintptr_t y = (uintptr_t)vy;

  return x == y ? 0 : (x > y ? 1 : -1);
}

static int cmp_rectangle(const void* vr1, const void* vr2) {
  const zathura_rectangle_t* r1 = vr1;
  const zathura_rectangle_t* r2 = vr2;

  return (ufloor(r1->x1) == ufloor(r2->x1) && uceil(r1->x2) == uceil(r2->x2) && ufloor(r1->y1) == ufloor(r2->y1) &&
          uceil(r1->y2) == uceil(r2->y2))
             ? 0
             : -1;
}

static bool girara_list_append_unique(girara_list_t* l, girara_compare_function_t cmp, void* item) {
  if (girara_list_find(l, cmp, item) != NULL) {
    return false;
  }

  girara_list_append(l, item);
  return true;
}

static void append_unique_point(girara_list_t* list, const uintptr_t x, const uintptr_t y) {
  zathura_point_t* p = g_try_malloc(sizeof(zathura_point_t));
  if (p == NULL) {
    return;
  }

  p->x = x;
  p->y = y;

  if (girara_list_append_unique(list, cmp_point, p) == false) {
    g_free(p);
  }
}

static void rectangle_to_points(void* vrect, void* vlist) {
  const zathura_rectangle_t* rect = vrect;
  girara_list_t* list             = vlist;

  append_unique_point(list, ufloor(rect->x1), ufloor(rect->y1));
  append_unique_point(list, ufloor(rect->x1), uceil(rect->y2));
  append_unique_point(list, uceil(rect->x2), ufloor(rect->y1));
  append_unique_point(list, uceil(rect->x2), uceil(rect->y2));
}

static void append_unique_uint(girara_list_t* list, const uintptr_t v) {
  girara_list_append_unique(list, cmp_uint, (void*)v);
}

// transform a rectangle into multiple new ones according a grid of points
static void cut_rectangle(const zathura_rectangle_t* rect, girara_list_t* points, girara_list_t* rectangles) {
  // Lists of ordred relevant points
  girara_list_t* xs = girara_sorted_list_new(cmp_uint);
  girara_list_t* ys = girara_sorted_list_new(cmp_uint);

  append_unique_uint(xs, uceil(rect->x2));
  append_unique_uint(ys, uceil(rect->y2));

  for (size_t idx = 0; idx != girara_list_size(points); ++idx) {
    const zathura_point_t* pt = girara_list_nth(points, idx);
    if (pt->x > ufloor(rect->x1) && pt->x < uceil(rect->x2)) {
      append_unique_uint(xs, pt->x);
    }
    if (pt->y > ufloor(rect->y1) && pt->y < uceil(rect->y2)) {
      append_unique_uint(ys, pt->y);
    }
  }

  double x = ufloor(rect->x1);
  for (size_t idx = 0; idx != girara_list_size(xs); ++idx) {
    const uintptr_t cx = (uintptr_t)girara_list_nth(xs, idx);
    double y           = ufloor(rect->y1);
    for (size_t inner_idx = 0; inner_idx != girara_list_size(ys); ++inner_idx) {
      const uintptr_t cy     = (uintptr_t)girara_list_nth(ys, inner_idx);
      zathura_rectangle_t* r = g_try_malloc(sizeof(zathura_rectangle_t));

      *r = (zathura_rectangle_t){x, y, cx, cy};
      y  = cy;
      girara_list_append_unique(rectangles, cmp_rectangle, r);
    }
    x = cx;
  }

  girara_list_free(xs);
  girara_list_free(ys);
}

girara_list_t* flatten_rectangles(girara_list_t* rectangles) {
  girara_list_t* new_rectangles = girara_list_new2(g_free);
  girara_list_t* points         = girara_list_new2(g_free);
  girara_list_foreach(rectangles, rectangle_to_points, points);

  for (size_t idx = 0; idx != girara_list_size(rectangles); ++idx) {
    const zathura_rectangle_t* r = girara_list_nth(rectangles, idx);
    cut_rectangle(r, points, new_rectangles);
  }
  girara_list_free(points);
  return new_rectangles;
}
