/*
 * Copyright (C) 2021  P. J. McDermott
 *
 * This file is part of Maze Fight
 *
 * Maze Fight 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.
 *
 * Maze Fight 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 Maze Fight.  If not, see <http://www.gnu.org/licenses/>.
 */

#include <SDL.h>
#include <SDL_ttf.h>
#include <errno.h>
#include <string.h>
#include "../tk.h"
#include "../util.h"
#include "widget.h"

struct mftk_text {
	struct mftk_widget  parent;
	char                min_char;
	char                max_char;
	size_t              len;
	size_t              cur;
	int                 y;
	int                 w;
	int                 h;
	char               *val;
	TTF_Font           *font;
	int                 line_skip;
	int                 ascent;
	SDL_Color          *color;
	SDL_Texture        *texture;
};

static void
_mftk_text_layout(struct mftk_widget *w __attribute__((__unused__)))
{
	/* Size set in constructor */
}

static int
_mftk_text_event(struct mftk_widget *w, SDL_Event *e,
		int x __attribute__((__unused__)),
		int y __attribute__((__unused__)))
{
	struct mftk_text *t = (struct mftk_text *) w;

	/* TODO */
	t->texture = NULL;
	return 0;
}

static int
_mftk_text_render_val(struct mftk_text *t, SDL_Renderer *renderer)
{
	SDL_Surface *surface;
	int          max_y;
	const char  *c;
	int          glyph_max_y;

	surface = TTF_RenderUTF8_Blended(t->font, t->val, *t->color);
	if (surface == NULL) {
		SDL_LogError(SDL_LOG_CATEGORY_APPLICATION,
				"Couldn't create surface: %s",
				TTF_GetError());
		return -1;
	}

	t->texture = SDL_CreateTextureFromSurface(renderer, surface);
	if (t->texture == NULL) {
		SDL_LogError(SDL_LOG_CATEGORY_APPLICATION,
				"Couldn't create texture: %s",
				SDL_GetError());
		SDL_FreeSurface(surface);
		return -1;
	}

	max_y = 0;
	for (c = t->val; *c != '\0'; ++c) {
		if (TTF_GlyphMetrics(t->font, *c, NULL, NULL, NULL,
					&glyph_max_y, NULL) < 0) {
			SDL_LogError(SDL_LOG_CATEGORY_APPLICATION,
					"Couldn't get glyph metrics: %s",
					TTF_GetError());
			continue;
		}
		if (glyph_max_y > max_y) {
			max_y = glyph_max_y;
		}
	}
	t->y = (t->line_skip - t->ascent) / 2 + (t->ascent - max_y);
	t->w = surface->w;
	t->h = surface->h;

	SDL_FreeSurface(surface);

	return 0;
}

static int
_mftk_text_render(struct mftk_widget *w, SDL_Renderer *renderer, int x, int y)
{
	struct mftk_text *t = (struct mftk_text *) w;
	SDL_Rect          rect;
	char             *val;
	int               cur_x;

	if (t->texture == NULL && _mftk_text_render_val(t, renderer) < 0) {
		return -1;
	}

	rect.x =        x;
	rect.y = t->y + y;
	rect.w = t->w;
	rect.h = t->h;

	val = mf_strdup(t->val);
	if (val == NULL) {
		SDL_LogError(SDL_LOG_CATEGORY_APPLICATION,
				"Couldn't render widget: %s",
				strerror(errno));
		return -1;
	}
	val[t->cur] = '\0';
	TTF_SizeUTF8(t->font, val, &cur_x, NULL);

	if (SDL_RenderCopy(renderer, t->texture, NULL, &rect) < 0 ||
			SDL_SetRenderDrawColor(renderer,
				t->color->r, t->color->g,
				t->color->b, t->color->a) < 0 ||
			SDL_RenderDrawLine(renderer,
				x + cur_x, y + t->y, x + cur_x, y + t->h) < 0 ||
			SDL_RenderDrawLine(renderer,
				x, y + w->h, x + w->w, y + w->h) < 0) {
		SDL_LogError(SDL_LOG_CATEGORY_APPLICATION,
				"Couldn't render widget: %s",
				SDL_GetError());
		free(val);
		return -1;
	}

	free(val);
	return 0;
}

static void
_mftk_text_destroy(struct mftk_widget *w)
{
	struct mftk_text *t = (struct mftk_text *) w;

	free(t->val);
	SDL_DestroyTexture(t->texture);
}

struct mftk_widget *
mftk_text_new(char min_char, char max_char, size_t len, const char *val,
		TTF_Font *font, SDL_Color *color)
{
	struct mftk_widget *w;
	struct mftk_text   *t;
	int                 advance;
	char                ch;

	mftk_widget_init_focusable(w, t, text);

	t->min_char  = min_char;
	t->max_char  = max_char;
	t->len       = len;
	t->cur       = strlen(val);
	t->val       = mf_strdup(val);
	t->font      = font;
	t->line_skip = TTF_FontLineSkip(font);
	t->ascent    = TTF_FontAscent  (font);
	t->color     = color;
	t->texture   = NULL;

	w->w = 0;
	for (ch = min_char; ch <= max_char; ++ch) {
		if (TTF_GlyphMetrics(font, ch, NULL, NULL, NULL, NULL, &advance)
				< 0) {
			SDL_LogError(SDL_LOG_CATEGORY_APPLICATION,
					"Couldn't get glyph metrics: %s",
					TTF_GetError());
			continue;
		}
		advance *= len;
		if (advance > w->w) {
			w->w = advance;
		}
	}
	w->h = t->line_skip + 1;

	return w;
}