/* SPDX-License-Identifier: GPL-3.0-or-later */
/* Copyright (C) 2021 KikooDX */

#include "conf.h"
#include "editing_area/draw.h"
#include "editing_area/level.h"
#include "info.h"
#include "mouse.h"
#include "options.h"
#include "scale.h"
#include "shared_data.h"
#include <raylib.h>
#include <stdbool.h>
#include <stdio.h>
#include <stdlib.h>
#include <sys/wait.h>

static void init_mouse(struct Options options);
static void update_mouse(int *mouse_x, int *mouse_y, struct Level level,
                         struct SharedData *shared_data);

int editing_area_main(struct Options options,
                      struct SharedData *shared_data)
{
	int mouse_x;
	int mouse_y;
	int error;
	struct Level level;
	level.data = NULL;
	Texture2D tileset;

	/* initialize raylib */
	InitWindow(options.editor_width * options.editor_scale,
	           options.editor_height * options.editor_scale,
	           "SLE main window");
	SetWindowState(FLAG_WINDOW_RESIZABLE);
	SetTargetFPS(options.editor_target_fps);
	/* load textures */
	tileset = LoadTexture(options.tileset_path);

	/* render targets used for upscaling */
	const RenderTexture2D rend_target = LoadRenderTexture(
	    options.editor_width, options.editor_height);
	const RenderTexture2D flip_target = LoadRenderTexture(
	    options.editor_width, options.editor_height);

	/* only proceed if tileset is large enough */
	if (tileset.width < options.tile_width ||
	    tileset.height < options.tile_height) {
		fprintf(stderr,
		        "ERROR: tileset size is invalid, expected at "
		        "least [%d ; %d], got [%d ; %d]\n",
		        options.tile_width, options.tile_height,
		        tileset.width, tileset.height);
		goto panic;
	}

	/* load level or create empty one */
	if (options.level_create) {
		if (level_create(&level, options))
			goto panic;
	} else if (level_read(&level, options.level_path))
		goto panic;

	while (!WindowShouldClose()) {
		/* update */
		init_mouse(options);
		update_mouse(&mouse_x, &mouse_y, level, shared_data);

		/* draw */
		BeginDrawing();
		BeginTextureMode(rend_target);

		ClearBackground(options.editor_bg_color);
		level_draw(level, options, tileset);
		editor_mouse_draw(options, mouse_x, mouse_y);

		EndTextureMode();

		/* flip texture */
		BeginTextureMode(flip_target);
		DrawTexture(rend_target.texture, 0, 0, WHITE);
		EndTextureMode();

		/* draw upscaled render */
		ClearBackground(BLACK);
		DrawTextureEx(flip_target.texture,
		              offset_editor(options), 0,
		              scale_editor(options), WHITE);
		EndDrawing();
	}

	/* save level */
	level_write(level, options.level_path);

panic:

	/* deinit */
	level_free(&level);

	/* unload raylib stuff */
	UnloadTexture(tileset);
	UnloadRenderTexture(rend_target);
	UnloadRenderTexture(flip_target);
	CloseWindow();

	/* tell to the child process it can end */
	shared_data->end_child = true;

	/* wait for child process to exit */
	wait(NULL);

	return EXIT_SUCCESS;
}

static void init_mouse(struct Options options)
{
	const float scaling = scale_editor(options);
	const Vector2 off = offset_editor(options);
	SetMouseOffset(-options.editor_draw_offset_x - off.x,
	               -options.editor_draw_offset_y - off.y);
	SetMouseScale(1.0 / scaling / options.tile_width,
	              1.0 / scaling / options.tile_height);
}

static void update_mouse(int *mouse_x, int *mouse_y, struct Level level,
                         struct SharedData *shared_data)
{
	const bool left_click = IsMouseButtonDown(0);
	const bool right_click = IsMouseButtonDown(1);
	const bool middle_click = IsMouseButtonPressed(2);

	update_mouse_position(mouse_x, mouse_y, level.width - 1,
	                      level.height - 1);

	/* set tile */
	if (left_click)
		level.data[*mouse_x + *mouse_y * level.width] =
		    shared_data->selected_tile;
	/* remove tile */
	if (right_click)
		level.data[*mouse_x + *mouse_y * level.width] = 0;
	/* set tile to pointed cell (pick tile) */
	if (middle_click) {
		INFO_VAR("%d",
		         level.data[*mouse_x + *mouse_y * level.width]);
		shared_data->selected_tile =
		    level.data[*mouse_x + *mouse_y * level.width];
	}
}