/*
 * ***** BEGIN GPL LICENSE BLOCK *****
 *
 * This program 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 2
 * of the License, or (at your option) any later version.
 *
 * This program 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 this program; if not, write to the Free Software Foundation,
 * Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
 *
 * The Original Code is Copyright (C) 2006 Blender Foundation.
 * All rights reserved.
 *
 * The Original Code is: all of this file.
 *
 * Contributor(s): none yet.
 *
 * ***** END GPL LICENSE BLOCK *****
 */

/** \file blender/render/intern/source/external_engine.c
 *  \ingroup render
 */

#include <stddef.h>
#include <stdlib.h>
#include <string.h>

#include "MEM_guardedalloc.h"

#include "BLT_translation.h"

#include "BLI_listbase.h"
#include "BLI_string.h"
#include "BLI_utildefines.h"

#include "DNA_object_types.h"

#include "BKE_camera.h"
#include "BKE_global.h"
#include "BKE_colortools.h"
#include "BKE_layer.h"
#include "BKE_node.h"
#include "BKE_report.h"
#include "BKE_scene.h"

#include "DEG_depsgraph.h"
#include "DEG_depsgraph_debug.h"
#include "DEG_depsgraph_query.h"

#include "RNA_access.h"

#ifdef WITH_PYTHON
#include "BPY_extern.h"
#endif

#include "RE_engine.h"
#include "RE_pipeline.h"
#include "RE_bake.h"

#include "DRW_engine.h"

#include "initrender.h"
#include "renderpipeline.h"
#include "render_types.h"
#include "render_result.h"

/* Render Engine Types */

ListBase R_engines = {NULL, NULL};

void RE_engines_init(void)
{
	DRW_engines_register();
}

void RE_engines_exit(void)
{
	RenderEngineType *type, *next;

	DRW_engines_free();

	for (type = R_engines.first; type; type = next) {
		next = type->next;

		BLI_remlink(&R_engines, type);

		if (!(type->flag & RE_INTERNAL)) {
			if (type->ext.free)
				type->ext.free(type->ext.data);

			MEM_freeN(type);
		}
	}
}

void RE_engines_register(RenderEngineType *render_type)
{
	if (render_type->draw_engine) {
		DRW_engine_register(render_type->draw_engine);
	}
	BLI_addtail(&R_engines, render_type);
}

RenderEngineType *RE_engines_find(const char *idname)
{
	RenderEngineType *type;

	type = BLI_findstring(&R_engines, idname, offsetof(RenderEngineType, idname));
	if (!type)
		type = BLI_findstring(&R_engines, "BLENDER_EEVEE", offsetof(RenderEngineType, idname));

	return type;
}

bool RE_engine_is_external(Render *re)
{
	return (re->engine && re->engine->type && re->engine->type->render);
}

bool RE_engine_is_opengl(RenderEngineType *render_type)
{
	/* TODO refine? Can we have ogl render engine without ogl render pipeline? */
	return (render_type->draw_engine != NULL) &&
	       DRW_engine_render_support(render_type->draw_engine);
}

/* Create, Free */

RenderEngine *RE_engine_create(RenderEngineType *type)
{
	return RE_engine_create_ex(type, false);
}

RenderEngine *RE_engine_create_ex(RenderEngineType *type, bool use_for_viewport)
{
	RenderEngine *engine = MEM_callocN(sizeof(RenderEngine), "RenderEngine");
	engine->type = type;

	if (use_for_viewport) {
		engine->flag |= RE_ENGINE_USED_FOR_VIEWPORT;

		BLI_threaded_malloc_begin();
	}

	return engine;
}

void RE_engine_free(RenderEngine *engine)
{
#ifdef WITH_PYTHON
	if (engine->py_instance) {
		BPY_DECREF_RNA_INVALIDATE(engine->py_instance);
	}
#endif

	if (engine->flag & RE_ENGINE_USED_FOR_VIEWPORT) {
		BLI_threaded_malloc_end();
	}

	MEM_freeN(engine);
}

/* Render Results */

static RenderPart *get_part_from_result(Render *re, RenderResult *result)
{
	RenderPart *pa;

	for (pa = re->parts.first; pa; pa = pa->next) {
		if (result->tilerect.xmin == pa->disprect.xmin - re->disprect.xmin &&
		    result->tilerect.ymin == pa->disprect.ymin - re->disprect.ymin &&
		    result->tilerect.xmax == pa->disprect.xmax - re->disprect.xmin &&
		    result->tilerect.ymax == pa->disprect.ymax - re->disprect.ymin)
		{
			return pa;
		}
	}

	return NULL;
}

RenderResult *RE_engine_begin_result(
        RenderEngine *engine, int x, int y, int w, int h, const char *layername, const char *viewname)
{
	Render *re = engine->re;
	RenderResult *result;
	rcti disprect;

	/* ensure the coordinates are within the right limits */
	CLAMP(x, 0, re->result->rectx);
	CLAMP(y, 0, re->result->recty);
	CLAMP(w, 0, re->result->rectx);
	CLAMP(h, 0, re->result->recty);

	if (x + w > re->result->rectx)
		w = re->result->rectx - x;
	if (y + h > re->result->recty)
		h = re->result->recty - y;

	/* allocate a render result */
	disprect.xmin = x;
	disprect.xmax = x + w;
	disprect.ymin = y;
	disprect.ymax = y + h;

	result = render_result_new(re, &disprect, 0, RR_USE_MEM, layername, viewname);

	/* todo: make this thread safe */

	/* can be NULL if we CLAMP the width or height to 0 */
	if (result) {
		render_result_clone_passes(re, result, viewname);

		RenderPart *pa;

		/* Copy EXR tile settings, so pipeline knows whether this is a result
		 * for Save Buffers enabled rendering.
		 */
		result->do_exr_tile = re->result->do_exr_tile;

		BLI_addtail(&engine->fullresult, result);

		result->tilerect.xmin += re->disprect.xmin;
		result->tilerect.xmax += re->disprect.xmin;
		result->tilerect.ymin += re->disprect.ymin;
		result->tilerect.ymax += re->disprect.ymin;

		pa = get_part_from_result(re, result);

		if (pa)
			pa->status = PART_STATUS_IN_PROGRESS;
	}

	return result;
}

void RE_engine_update_result(RenderEngine *engine, RenderResult *result)
{
	Render *re = engine->re;

	if (result) {
		result->renlay = result->layers.first; /* weak, draws first layer always */
		re->display_update(re->duh, result, NULL);
	}
}

void RE_engine_add_pass(RenderEngine *engine, const char *name, int channels, const char *chan_id, const char *layername)
{
	Render *re = engine->re;

	if (!re || !re->result) {
		return;
	}

	render_result_add_pass(re->result, name, channels, chan_id, layername, NULL);
}

void RE_engine_end_result(RenderEngine *engine, RenderResult *result, int cancel, int highlight, int merge_results)
{
	Render *re = engine->re;

	if (!result) {
		return;
	}

	/* merge. on break, don't merge in result for preview renders, looks nicer */
	if (!highlight) {
		/* for exr tile render, detect tiles that are done */
		RenderPart *pa = get_part_from_result(re, result);

		if (pa) {
			pa->status = (!cancel && merge_results)? PART_STATUS_MERGED: PART_STATUS_RENDERED;
		}
		else if (re->result->do_exr_tile) {
			/* if written result does not match any tile and we are using save
			 * buffers, we are going to get openexr save errors */
			fprintf(stderr, "RenderEngine.end_result: dimensions do not match any OpenEXR tile.\n");
		}
	}

	if (!cancel || merge_results) {
		if (re->result->do_exr_tile) {
			if (!cancel && merge_results) {
				render_result_exr_file_merge(re->result, result, re->viewname);
			}
		}
		else if (!(re->test_break(re->tbh) && (re->r.scemode & R_BUTS_PREVIEW)))
			render_result_merge(re->result, result);

		/* draw */
		if (!re->test_break(re->tbh)) {
			result->renlay = result->layers.first; /* weak, draws first layer always */
			re->display_update(re->duh, result, NULL);
		}
	}

	/* free */
	BLI_remlink(&engine->fullresult, result);
	render_result_free(result);
}

RenderResult *RE_engine_get_result(RenderEngine *engine)
{
	return engine->re->result;
}

/* Cancel */

int RE_engine_test_break(RenderEngine *engine)
{
	Render *re = engine->re;

	if (re)
		return re->test_break(re->tbh);

	return 0;
}

/* Statistics */

void RE_engine_update_stats(RenderEngine *engine, const char *stats, const char *info)
{
	Render *re = engine->re;

	/* stats draw callback */
	if (re) {
		re->i.statstr = stats;
		re->i.infostr = info;
		re->stats_draw(re->sdh, &re->i);
		re->i.infostr = NULL;
		re->i.statstr = NULL;
	}

	/* set engine text */
	engine->text[0] = '\0';

	if (stats && stats[0] && info && info[0])
		BLI_snprintf(engine->text, sizeof(engine->text), "%s | %s", stats, info);
	else if (info && info[0])
		BLI_strncpy(engine->text, info, sizeof(engine->text));
	else if (stats && stats[0])
		BLI_strncpy(engine->text, stats, sizeof(engine->text));
}

void RE_engine_update_progress(RenderEngine *engine, float progress)
{
	Render *re = engine->re;

	if (re) {
		CLAMP(progress, 0.0f, 1.0f);
		re->progress(re->prh, progress);
	}
}

void RE_engine_update_memory_stats(RenderEngine *engine, float mem_used, float mem_peak)
{
	Render *re = engine->re;

	if (re) {
		re->i.mem_used = mem_used;
		re->i.mem_peak = mem_peak;
	}
}

void RE_engine_report(RenderEngine *engine, int type, const char *msg)
{
	Render *re = engine->re;

	if (re)
		BKE_report(engine->re->reports, type, msg);
	else if (engine->reports)
		BKE_report(engine->reports, type, msg);
}

void RE_engine_set_error_message(RenderEngine *engine, const char *msg)
{
	Render *re = engine->re;
	if (re != NULL) {
		RenderResult *rr = RE_AcquireResultRead(re);
		if (rr) {
			if (rr->error != NULL) {
				MEM_freeN(rr->error);
			}
			rr->error = BLI_strdup(msg);
		}
		RE_ReleaseResult(re);
	}
}

const char *RE_engine_active_view_get(RenderEngine *engine)
{
	Render *re = engine->re;
	return RE_GetActiveRenderView(re);
}

void RE_engine_active_view_set(RenderEngine *engine, const char *viewname)
{
	Render *re = engine->re;
	RE_SetActiveRenderView(re, viewname);
}

float RE_engine_get_camera_shift_x(RenderEngine *engine, Object *camera, int use_spherical_stereo)
{
	Render *re = engine->re;

	/* when using spherical stereo, get camera shift without multiview, leaving stereo to be handled by the engine */
	if (use_spherical_stereo)
		re = NULL;

	return BKE_camera_multiview_shift_x(re ? &re->r : NULL, camera, re->viewname);
}

void RE_engine_get_camera_model_matrix(
        RenderEngine *engine, Object *camera, int use_spherical_stereo, float *r_modelmat)
{
	Render *re = engine->re;

	/* when using spherical stereo, get model matrix without multiview, leaving stereo to be handled by the engine */
	if (use_spherical_stereo)
		re = NULL;

	BKE_camera_multiview_model_matrix(re ? &re->r : NULL, camera, re->viewname, (float (*)[4])r_modelmat);
}

int RE_engine_get_spherical_stereo(RenderEngine *engine, Object *camera)
{
	Render *re = engine->re;
	return BKE_camera_multiview_spherical_stereo(re ? &re->r : NULL, camera) ? 1 : 0;
}

rcti* RE_engine_get_current_tiles(Render *re, int *r_total_tiles, bool *r_needs_free)
{
	static rcti tiles_static[BLENDER_MAX_THREADS];
	const int allocation_step = BLENDER_MAX_THREADS;
	RenderPart *pa;
	int total_tiles = 0;
	rcti *tiles = tiles_static;
	int allocation_size = BLENDER_MAX_THREADS;

	BLI_rw_mutex_lock(&re->partsmutex, THREAD_LOCK_READ);

	*r_needs_free = false;

	if (re->engine && (re->engine->flag & RE_ENGINE_HIGHLIGHT_TILES) == 0) {
		*r_total_tiles = 0;
		BLI_rw_mutex_unlock(&re->partsmutex);
		return NULL;
	}

	for (pa = re->parts.first; pa; pa = pa->next) {
		if (pa->status == PART_STATUS_IN_PROGRESS) {
			if (total_tiles >= allocation_size) {
				/* Just in case we're using crazy network rendering with more
				 * slaves as BLENDER_MAX_THREADS.
				 */
				allocation_size += allocation_step;
				if (tiles == tiles_static) {
					/* Can not realloc yet, tiles are pointing to a
					 * stack memory.
					 */
					tiles = MEM_mallocN(allocation_size * sizeof(rcti), "current engine tiles");
				}
				else {
					tiles = MEM_reallocN(tiles, allocation_size * sizeof(rcti));
				}
				*r_needs_free = true;
			}
			tiles[total_tiles] = pa->disprect;

			total_tiles++;
		}
	}
	BLI_rw_mutex_unlock(&re->partsmutex);
	*r_total_tiles = total_tiles;
	return tiles;
}

RenderData *RE_engine_get_render_data(Render *re)
{
	return &re->r;
}

/* Depsgraph */
static void engine_depsgraph_init(RenderEngine *engine, ViewLayer *view_layer)
{
	Main *bmain = engine->re->main;
	Scene *scene = engine->re->scene;

	engine->depsgraph = DEG_graph_new(scene, view_layer, DAG_EVAL_RENDER);
	DEG_debug_name_set(engine->depsgraph, "RENDER");

	BKE_scene_graph_update_for_newframe(engine->depsgraph, bmain);
}

static void engine_depsgraph_free(RenderEngine *engine)
{
	DEG_graph_free(engine->depsgraph);

	engine->depsgraph = NULL;
}

void RE_engine_frame_set(RenderEngine *engine, int frame, float subframe)
{
	if(!engine->depsgraph) {
		return;
	}

#ifdef WITH_PYTHON
	BPy_BEGIN_ALLOW_THREADS;
#endif

	Render *re = engine->re;
	double cfra = (double)frame + (double)subframe;

	CLAMP(cfra, MINAFRAME, MAXFRAME);
	BKE_scene_frame_set(re->scene, cfra);
	BKE_scene_graph_update_for_newframe(engine->depsgraph, re->main);

	BKE_scene_camera_switch_update(re->scene);

#ifdef WITH_PYTHON
	BPy_END_ALLOW_THREADS;
#endif
}

/* Bake */
void RE_bake_engine_set_engine_parameters(Render *re, Main *bmain, Scene *scene)
{
	re->scene = scene;
	re->main = bmain;
	render_copy_renderdata(&re->r, &scene->r);
}

bool RE_bake_has_engine(Render *re)
{
	RenderEngineType *type = RE_engines_find(re->r.engine);
	return (type->bake != NULL);
}

bool RE_bake_engine(
        Render *re, Depsgraph *depsgraph, Object *object,
        const int object_id, const BakePixel pixel_array[],
        const size_t num_pixels, const int depth,
        const eScenePassType pass_type, const int pass_filter,
        float result[])
{
	RenderEngineType *type = RE_engines_find(re->r.engine);
	RenderEngine *engine;
	bool persistent_data = (re->r.mode & R_PERSISTENT_DATA) != 0;

	/* set render info */
	re->i.cfra = re->scene->r.cfra;
	BLI_strncpy(re->i.scene_name, re->scene->id.name + 2, sizeof(re->i.scene_name) - 2);
	re->i.totface = re->i.totvert = re->i.totstrand = re->i.totlamp = re->i.tothalo = 0;

	/* render */
	engine = re->engine;

	if (!engine) {
		engine = RE_engine_create(type);
		re->engine = engine;
	}

	engine->flag |= RE_ENGINE_RENDERING;

	/* TODO: actually link to a parent which shouldn't happen */
	engine->re = re;

	engine->resolution_x = re->winx;
	engine->resolution_y = re->winy;

	RE_parts_init(re);
	engine->tile_x = re->r.tilex;
	engine->tile_y = re->r.tiley;

	if (type->bake) {
		engine->depsgraph = depsgraph;

		/* update is only called so we create the engine.session */
		if (type->update)
			type->update(engine, re->main, engine->depsgraph);

		type->bake(engine,
		           engine->depsgraph,
		           object,
		           pass_type,
		           pass_filter,
		           object_id,
		           pixel_array,
		           num_pixels,
		           depth,
		           result);

		engine->depsgraph = NULL;
	}

	engine->tile_x = 0;
	engine->tile_y = 0;
	engine->flag &= ~RE_ENGINE_RENDERING;

	BLI_rw_mutex_lock(&re->partsmutex, THREAD_LOCK_WRITE);

	/* re->engine becomes zero if user changed active render engine during render */
	if (!persistent_data || !re->engine) {
		RE_engine_free(engine);
		re->engine = NULL;
	}

	RE_parts_free(re);
	BLI_rw_mutex_unlock(&re->partsmutex);

	if (BKE_reports_contain(re->reports, RPT_ERROR))
		G.is_break = true;

	return true;
}

/* Render */

int RE_engine_render(Render *re, int do_all)
{
	RenderEngineType *type = RE_engines_find(re->r.engine);
	RenderEngine *engine;
	bool persistent_data = (re->r.mode & R_PERSISTENT_DATA) != 0;

	/* verify if we can render */
	if (!type->render)
		return 0;
	if ((re->r.scemode & R_BUTS_PREVIEW) && !(type->flag & RE_USE_PREVIEW))
		return 0;
	if (do_all && !(type->flag & RE_USE_POSTPROCESS))
		return 0;
	if (!do_all && (type->flag & RE_USE_POSTPROCESS))
		return 0;

	/* Lock drawing in UI during data phase. */
	if (re->draw_lock) {
		re->draw_lock(re->dlh, 1);
	}

	/* update animation here so any render layer animation is applied before
	 * creating the render result */
	if ((re->r.scemode & (R_NO_FRAME_UPDATE | R_BUTS_PREVIEW)) == 0) {
		render_update_anim_renderdata(re, &re->scene->r, &re->scene->view_layers);
	}

	/* create render result */
	BLI_rw_mutex_lock(&re->resultmutex, THREAD_LOCK_WRITE);
	if (re->result == NULL || !(re->r.scemode & R_BUTS_PREVIEW)) {
		int savebuffers = RR_USE_MEM;

		if (re->result)
			render_result_free(re->result);

		if ((type->flag & RE_USE_SAVE_BUFFERS) && (re->r.scemode & R_EXR_TILE_FILE))
			savebuffers = RR_USE_EXR;
		re->result = render_result_new(re, &re->disprect, 0, savebuffers, RR_ALL_LAYERS, RR_ALL_VIEWS);
	}
	BLI_rw_mutex_unlock(&re->resultmutex);

	if (re->result == NULL) {
		/* Clear UI drawing locks. */
		if (re->draw_lock) {
			re->draw_lock(re->dlh, 0);
		}
		/* Too small image is handled earlier, here it could only happen if
		 * there was no sufficient memory to allocate all passes.
		 */
		BKE_report(re->reports, RPT_ERROR, "Failed allocate render result, out of memory");
		G.is_break = true;
		return 1;
	}

	/* set render info */
	re->i.cfra = re->scene->r.cfra;
	BLI_strncpy(re->i.scene_name, re->scene->id.name + 2, sizeof(re->i.scene_name));
	re->i.totface = re->i.totvert = re->i.totstrand = re->i.totlamp = re->i.tothalo = 0;

	/* render */
	engine = re->engine;

	if (!engine) {
		engine = RE_engine_create(type);
		re->engine = engine;
	}

	engine->flag |= RE_ENGINE_RENDERING;

	/* TODO: actually link to a parent which shouldn't happen */
	engine->re = re;

	if (re->flag & R_ANIMATION)
		engine->flag |= RE_ENGINE_ANIMATION;
	if (re->r.scemode & R_BUTS_PREVIEW)
		engine->flag |= RE_ENGINE_PREVIEW;
	engine->camera_override = re->camera_override;
	engine->layer_override = re->layer_override;

	engine->resolution_x = re->winx;
	engine->resolution_y = re->winy;

	RE_parts_init(re);
	engine->tile_x = re->partx;
	engine->tile_y = re->party;

	if (re->result->do_exr_tile)
		render_result_exr_file_begin(re);

	/* Clear UI drawing locks. */
	if (re->draw_lock) {
		re->draw_lock(re->dlh, 0);
	}

	if (type->render) {
		FOREACH_VIEW_LAYER_TO_RENDER_BEGIN(re, view_layer_iter)
		{
			if (re->draw_lock) {
				re->draw_lock(re->dlh, 1);
			}

			ViewLayer *view_layer = BLI_findstring(&re->scene->view_layers, view_layer_iter->name, offsetof(ViewLayer, name));
			engine_depsgraph_init(engine, view_layer);

			if (type->update) {
				type->update(engine, re->main, engine->depsgraph);
			}

			if (re->draw_lock) {
				re->draw_lock(re->dlh, 0);
			}

			type->render(engine, engine->depsgraph);

			engine_depsgraph_free(engine);
		}
		FOREACH_VIEW_LAYER_TO_RENDER_END;
	}

	engine->tile_x = 0;
	engine->tile_y = 0;
	engine->flag &= ~RE_ENGINE_RENDERING;

	render_result_free_list(&engine->fullresult, engine->fullresult.first);

	BLI_rw_mutex_lock(&re->partsmutex, THREAD_LOCK_WRITE);

	/* re->engine becomes zero if user changed active render engine during render */
	if (!persistent_data || !re->engine) {
		RE_engine_free(engine);
		re->engine = NULL;
	}

	if (re->result->do_exr_tile) {
		BLI_rw_mutex_lock(&re->resultmutex, THREAD_LOCK_WRITE);
		render_result_save_empty_result_tiles(re);
		render_result_exr_file_end(re);
		BLI_rw_mutex_unlock(&re->resultmutex);
	}

	if (re->r.scemode & R_EXR_CACHE_FILE) {
		BLI_rw_mutex_lock(&re->resultmutex, THREAD_LOCK_WRITE);
		render_result_exr_file_cache_write(re);
		BLI_rw_mutex_unlock(&re->resultmutex);
	}

	RE_parts_free(re);
	BLI_rw_mutex_unlock(&re->partsmutex);

	if (BKE_reports_contain(re->reports, RPT_ERROR))
		G.is_break = true;

#ifdef WITH_FREESTYLE
	if (re->r.mode & R_EDGE_FRS)
		RE_RenderFreestyleExternal(re);
#endif

	return 1;
}

void RE_engine_register_pass(struct RenderEngine *engine, struct Scene *scene, struct ViewLayer *view_layer,
                             const char *name, int UNUSED(channels), const char *UNUSED(chanid), int type)
{
	/* The channel information is currently not used, but is part of the API in case it's needed in the future. */

	if (!(scene && view_layer && engine)) {
		return;
	}

	/* Register the pass in all scenes that have a render layer node for this layer.
	 * Since multiple scenes can be used in the compositor, the code must loop over all scenes
	 * and check whether their nodetree has a node that needs to be updated. */
	/* NOTE: using G_MAIN seems valid here,
	 * unless we want to register that for every other temp Main we could generate??? */
	for (Scene *sce = G_MAIN->scene.first; sce; sce = sce->id.next) {
		if (sce->nodetree) {
			ntreeCompositRegisterPass(sce->nodetree, scene, view_layer, name, type);
		}
	}
}