/*
	vid_common_vulkan.c

	Common Vulkan video driver functions

	Copyright (C) 2019      Bill Currie <bill@taniwha.org>

	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:

		Free Software Foundation, Inc.
		59 Temple Place - Suite 330
		Boston, MA  02111-1307, USA

*/
#ifdef HAVE_CONFIG_H
# include "config.h"
#endif

#ifdef HAVE_MATH_H
# include <math.h>
#endif

#include <string.h>

#include "QF/cexpr.h"
#include "QF/cmem.h"
#include "QF/cvar.h"
#include "QF/dstring.h"
#include "QF/hash.h"
#include "QF/heapsort.h"
#include "QF/plist.h"
#include "QF/va.h"
#include "QF/scene/entity.h"
#include "QF/Vulkan/capture.h"
#include "QF/Vulkan/command.h"
#include "QF/Vulkan/debug.h"
#include "QF/Vulkan/device.h"
#include "QF/Vulkan/instance.h"
#include "QF/Vulkan/staging.h"
#include "QF/Vulkan/swapchain.h"

#include "QF/Vulkan/qf_lighting.h"
#include "QF/Vulkan/qf_main.h"
#include "QF/Vulkan/qf_renderpass.h"
#include "QF/Vulkan/qf_vid.h"

#include "r_internal.h"
#include "vid_vulkan.h"

#include "vkparse.h"
#include "libs/video/renderer/vulkan/vkparse.hinc"

static exprsym_t builtin_plist_syms[] = {
	{ .name = "qfpipeline",
	  .value = (void *)
#include "libs/video/renderer/vulkan/qfpipeline.plc"
		},
	{ .name = "deferred",
	  .value = (void *)
#include "libs/video/renderer/vulkan/deferred.plc"
		},
	{ .name = "shadow",
	  .value = (void *)
#include "libs/video/renderer/vulkan/shadow.plc"
		},
	{ .name = "forward",
	  .value = (void *)
#include "libs/video/renderer/vulkan/forward.plc"
		},
	{}
};
static plitem_t **builtin_plists;
static exprtab_t builtin_configs = { .symbols = builtin_plist_syms };

int vulkan_frame_count;
static cvar_t vulkan_frame_count_cvar = {
	.name = "vulkan_frame_count",
	.description =
		"Number of frames to render in the background. More frames can "
		"increase performance, but at the cost of latency. The default of 3 is"
		" recommended.",
	.default_value = "3",
	.flags = CVAR_NONE,
	.value = { .type = &cexpr_int, .value = &vulkan_frame_count },
};
int vulkan_presentation_mode;
static cvar_t vulkan_presentation_mode_cvar = {
	.name = "vulkan_presentation_mode",
	.description =
		"desired presentation mode (may fall back to fifo).",
	.default_value = "mailbox",
	.flags = CVAR_NONE,
	.value = {
		.type = &VkPresentModeKHR_type,
		.value = &vulkan_presentation_mode,
	},
};
int msaaSamples;
static cvar_t msaaSamples_cvar = {
	.name = "msaaSamples",
	.description =
		"desired MSAA sample size.",
	.default_value = "VK_SAMPLE_COUNT_1_BIT",
	.flags = CVAR_NONE,
	.value = { .type = &VkSampleCountFlagBits_type, .value = &msaaSamples },
};
static exprenum_t validation_enum;
static exprtype_t validation_type = {
	.name = "vulkan_use_validation",
	.size = sizeof (int),
	.binops = cexpr_flag_binops,
	.unops = cexpr_flag_unops,
	.data = &validation_enum,
	.get_string = cexpr_flags_get_string,
};

static int validation_values[] = {
	0,
	VK_DEBUG_UTILS_MESSAGE_SEVERITY_FLAG_BITS_MAX_ENUM_EXT,
};
static exprsym_t validation_symbols[] = {
	{"none", &validation_type, validation_values + 0},
	{"all", &validation_type, validation_values + 1},
	{}
};
static exprtab_t validation_symtab = {
	validation_symbols,
};
static exprenum_t validation_enum = {
	&validation_type,
	&validation_symtab,
};
static cvar_t vulkan_use_validation_cvar = {
	.name = "vulkan_use_validation",
	.description =
		"enable KRONOS Validation Layer if available (requires instance "
		"restart).",
	.default_value = "error|warning",
	.flags = CVAR_NONE,
	.value = { .type = &validation_type, .value = &vulkan_use_validation },
};

static void
vulkan_frame_count_f (void *data, const cvar_t *cvar)
{
	if (vulkan_frame_count < 1) {
		Sys_Printf ("Invalid frame count: %d. Setting to 1\n",
					vulkan_frame_count);
		vulkan_frame_count = 1;
	}
}

static void
Vulkan_Init_Cvars (void)
{
	int         num_syms = 0;
	for (exprsym_t *sym = VkDebugUtilsMessageSeverityFlagBitsEXT_symbols;
		 sym->name; sym++, num_syms++) {
	}
	for (exprsym_t *sym = validation_symbols; sym->name; sym++, num_syms++) {
	}
	validation_symtab.symbols = calloc (num_syms + 1, sizeof (exprsym_t));
	num_syms = 0;
	for (exprsym_t *sym = VkDebugUtilsMessageSeverityFlagBitsEXT_symbols;
		 sym->name; sym++, num_syms++) {
		validation_symtab.symbols[num_syms] = *sym;
		validation_symtab.symbols[num_syms].type = &validation_type;
	}
	for (exprsym_t *sym = validation_symbols; sym->name; sym++, num_syms++) {
		validation_symtab.symbols[num_syms] = *sym;
	}
	Cvar_Register (&vulkan_use_validation_cvar, 0, 0);
	// FIXME implement fallback choices (instead of just fifo)
	Cvar_Register (&vulkan_presentation_mode_cvar, 0, 0);
	Cvar_Register (&vulkan_frame_count_cvar, vulkan_frame_count_f, 0);
	Cvar_Register (&msaaSamples_cvar, 0, 0);
	R_Init_Cvars ();
}

static const char *instance_extensions[] = {
	VK_KHR_SURFACE_EXTENSION_NAME,
	VK_KHR_GET_PHYSICAL_DEVICE_PROPERTIES_2_EXTENSION_NAME,
	0,
};

static const char *device_extensions[] = {
	VK_KHR_SWAPCHAIN_EXTENSION_NAME,
	0,
};

void
Vulkan_Init_Common (vulkan_ctx_t *ctx)
{
	Sys_MaskPrintf (SYS_vulkan, "Vulkan_Init_Common\n");

	QFV_InitParse (ctx);
	Vulkan_Init_Cvars ();
	ctx->instance = QFV_CreateInstance (ctx, PACKAGE_STRING, 0x000702ff, 0,
										instance_extensions);//FIXME version
	DARRAY_INIT (&ctx->renderPasses, 4);
}

static void
clear_table (hashtab_t **table)
{
	if (*table) {
		hashtab_t  *tab = *table;
		*table = 0;
		Hash_DelTable (tab);
	}
}

void
Vulkan_Shutdown_Common (vulkan_ctx_t *ctx)
{
	PL_Free (ctx->pipelineDef);
	if (ctx->capture) {
		QFV_DestroyCapture (ctx->capture);
	}
	if (ctx->frames.size) {
		Vulkan_DestroyFrames (ctx);
	}
	if (ctx->swapchain) {
		QFV_DestroySwapchain (ctx->swapchain);
	}
	ctx->instance->funcs->vkDestroySurfaceKHR (ctx->instance->instance,
											   ctx->surface, 0);
	clear_table (&ctx->pipelineLayouts);
	clear_table (&ctx->setLayouts);
	clear_table (&ctx->shaderModules);
	clear_table (&ctx->descriptorPools);
	clear_table (&ctx->samplers);
	if (ctx->device) {
		QFV_DestroyDevice (ctx->device);
	}
	if (ctx->instance) {
		QFV_DestroyInstance (ctx->instance);
	}
	ctx->instance = 0;
	ctx->unload_vulkan (ctx);
}

void
Vulkan_CreateDevice (vulkan_ctx_t *ctx)
{
	ctx->device = QFV_CreateDevice (ctx, device_extensions);

	//FIXME msaa and deferred rendering...
	//also, location
	ctx->msaaSamples = 1;
	/*ctx->msaaSamples = min ((VkSampleCountFlagBits) msaaSamples,
							QFV_GetMaxSampleCount (device->physDev));
	if (ctx->msaaSamples > 1) {
		name = "renderpass_msaa";
	}*/
}

void
Vulkan_CreateStagingBuffers (vulkan_ctx_t *ctx)
{
	// FIXME configurable?
	ctx->staging = QFV_CreateStagingBuffer (ctx->device, "vulkan_ctx",
											32*1024*1024, ctx->cmdpool);
}

void
Vulkan_CreateSwapchain (vulkan_ctx_t *ctx)
{
	VkSwapchainKHR old_swapchain = 0;
	if (ctx->swapchain) {
		old_swapchain = ctx->swapchain->swapchain;
		free (ctx->swapchain);
	}
	ctx->swapchain = QFV_CreateSwapchain (ctx, old_swapchain);
	if (old_swapchain && ctx->swapchain->swapchain != old_swapchain) {
		ctx->device->funcs->vkDestroySwapchainKHR (ctx->device->dev,
												   old_swapchain, 0);
	}
}

static void
build_configs (vulkan_ctx_t *ctx)
{
	int         num_plists = 0;
	for (exprsym_t *sym = builtin_plist_syms; sym->name; sym++) {
		num_plists++;
	}
	builtin_plists = malloc (num_plists * sizeof (plitem_t *));
	num_plists = 0;
	for (exprsym_t *sym = builtin_plist_syms; sym->name; sym++) {
		plitem_t   *item = PL_GetPropertyList (sym->value, &ctx->hashctx);
		if (!item) {
			// Syntax errors in the compiled-in plists are unrecoverable
			Sys_Error ("Error parsing plist for %s", sym->name);
		}
		builtin_plists[num_plists] = item;
		sym->value = &builtin_plists[num_plists];
		sym->type = &cexpr_plitem;
		num_plists++;
	}
	exprctx_t   ectx = { .hashctx = &ctx->hashctx };
	cexpr_init_symtab (&builtin_configs, &ectx);
}

plitem_t *
Vulkan_GetConfig (vulkan_ctx_t *ctx, const char *name)
{
	if (!builtin_configs.tab) {
		build_configs (ctx);
	}

	plitem_t   *config = 0;
	exprval_t   result = { .type = &cexpr_plitem, .value = &config };
	exprctx_t   ectx = {
		.result = &result,
		.symtab = &builtin_configs,
		.memsuper = new_memsuper (),
		.hashctx = &ctx->hashctx,
		.messages = PL_NewArray (),
	};
	if (cexpr_eval_string (name, &ectx)) {
		dstring_t  *msg = dstring_newstr ();

		for (int i = 0; i < PL_A_NumObjects (ectx.messages); i++) {
			dasprintf (msg, "%s\n",
					   PL_String (PL_ObjectAtIndex (ectx.messages, i)));
		}
		Sys_Printf ("%s", msg->str);
		dstring_delete (msg);
		config = 0;
	}
	PL_Free (ectx.messages);
	delete_memsuper (ectx.memsuper);
	return config;
}

static plitem_t *
qfv_load_pipeline (vulkan_ctx_t *ctx, const char *name)
{
	if (!ctx->pipelineDef) {
		ctx->pipelineDef = Vulkan_GetConfig (ctx, "qfpipeline");
	}

	plitem_t   *item = ctx->pipelineDef;
	if (!item || !(item = PL_ObjectForKey (item, name))) {
		Sys_Printf ("error loading %s\n", name);
	} else {
		Sys_MaskPrintf (SYS_vulkan_parse, "Found %s def\n", name);
	}
	return item;
}

static int
renderpass_cmp (const void *_a, const void *_b)
{
	const qfv_renderpass_t *a = _a;
	const qfv_renderpass_t *b = _b;
	return a->order - b->order;
}

void
Vulkan_CreateRenderPasses (vulkan_ctx_t *ctx)
{
	Vulkan_Main_CreateRenderPasses (ctx);

	heapsort (ctx->renderPasses.a, ctx->renderPasses.size,
			  sizeof (qfv_renderpass_t *), renderpass_cmp);
}

void
Vulkan_DestroyRenderPasses (vulkan_ctx_t *ctx)
{
	for (size_t i = 0; i < ctx->renderPasses.size; i++) {
		Vulkan_DestroyRenderPass (ctx, ctx->renderPasses.a[i]);
	}
}

VkPipeline
Vulkan_CreateComputePipeline (vulkan_ctx_t *ctx, const char *name)
{
	plitem_t   *item = qfv_load_pipeline (ctx, "pipelines");
	if (!(item = PL_ObjectForKey (item, name))) {
		Sys_Printf ("error loading pipeline %s\n", name);
		return 0;
	} else {
		Sys_MaskPrintf (SYS_vulkan_parse, "Found pipeline def %s\n", name);
	}
	VkPipeline pipeline = QFV_ParseComputePipeline (ctx, item,
													 ctx->pipelineDef);
	QFV_duSetObjectName (ctx->device, VK_OBJECT_TYPE_PIPELINE, pipeline,
						 va (ctx->va_ctx, "pipeline:%s", name));
	return pipeline;
}

VkPipeline
Vulkan_CreateGraphicsPipeline (vulkan_ctx_t *ctx, const char *name)
{
	plitem_t   *item = qfv_load_pipeline (ctx, "pipelines");
	if (!(item = PL_ObjectForKey (item, name))) {
		Sys_Printf ("error loading pipeline %s\n", name);
		return 0;
	} else {
		Sys_MaskPrintf (SYS_vulkan_parse, "Found pipeline def %s\n", name);
	}
	VkPipeline pipeline = QFV_ParseGraphicsPipeline (ctx, item,
													 ctx->pipelineDef);
	QFV_duSetObjectName (ctx->device, VK_OBJECT_TYPE_PIPELINE, pipeline,
						 va (ctx->va_ctx, "pipeline:%s", name));
	return pipeline;
}

VkDescriptorPool
Vulkan_CreateDescriptorPool (vulkan_ctx_t *ctx, const char *name)
{
	hashtab_t  *tab = ctx->descriptorPools;
	const char *path;
	path = va (ctx->va_ctx, "$"QFV_PROPERTIES".descriptorPools.%s", name);
	__auto_type pool = (VkDescriptorPool) QFV_GetHandle (tab, path);
	if (pool) {
		return pool;
	}

	plitem_t   *item = qfv_load_pipeline (ctx, "descriptorPools");
	if (!(item = PL_ObjectForKey (item, name))) {
		Sys_Printf ("error loading descriptor pool %s\n", name);
		return 0;
	} else {
		Sys_MaskPrintf (SYS_vulkan_parse, "Found descriptor pool def %s\n",
						name);
	}
	pool = QFV_ParseDescriptorPool (ctx, item, ctx->pipelineDef);
	QFV_AddHandle (tab, path, (uint64_t) pool);
	QFV_duSetObjectName (ctx->device, VK_OBJECT_TYPE_DESCRIPTOR_POOL, pool,
						 va (ctx->va_ctx, "descriptor_pool:%s", name));
	return pool;
}

VkPipelineLayout
Vulkan_CreatePipelineLayout (vulkan_ctx_t *ctx, const char *name)
{
	hashtab_t  *tab = ctx->pipelineLayouts;
	const char *path;
	path = va (ctx->va_ctx, "$"QFV_PROPERTIES".pipelineLayouts.%s", name);
	__auto_type layout = (VkPipelineLayout) QFV_GetHandle (tab, path);
	if (layout) {
		return layout;
	}

	plitem_t   *item = qfv_load_pipeline (ctx, "pipelineLayouts");
	if (!(item = PL_ObjectForKey (item, name))) {
		Sys_Printf ("error loading pipeline layout %s\n", name);
		return 0;
	} else {
		Sys_MaskPrintf (SYS_vulkan_parse, "Found pipeline layout def %s\n",
						name);
	}
	layout = QFV_ParsePipelineLayout (ctx, item, ctx->pipelineDef);
	QFV_AddHandle (tab, path, (uint64_t) layout);
	QFV_duSetObjectName (ctx->device, VK_OBJECT_TYPE_PIPELINE_LAYOUT, layout,
						 va (ctx->va_ctx, "pipeline_layout:%s", name));
	return layout;
}

VkSampler
Vulkan_CreateSampler (vulkan_ctx_t *ctx, const char *name)
{
	hashtab_t  *tab = ctx->samplers;
	const char *path;
	path = va (ctx->va_ctx, "$"QFV_PROPERTIES".samplers.%s", name);
	__auto_type sampler = (VkSampler) QFV_GetHandle (tab, path);
	if (sampler) {
		return sampler;
	}

	plitem_t   *item = qfv_load_pipeline (ctx, "samplers");
	if (!(item = PL_ObjectForKey (item, name))) {
		Sys_Printf ("error loading sampler %s\n", name);
		return 0;
	} else {
		Sys_MaskPrintf (SYS_vulkan_parse, "Found sampler def %s\n", name);
	}
	sampler = QFV_ParseSampler (ctx, item, ctx->pipelineDef);
	QFV_AddHandle (tab, path, (uint64_t) sampler);
	QFV_duSetObjectName (ctx->device, VK_OBJECT_TYPE_SAMPLER, sampler,
						 va (ctx->va_ctx, "sampler:%s", name));
	return sampler;
}

VkDescriptorSetLayout
Vulkan_CreateDescriptorSetLayout(vulkan_ctx_t *ctx, const char *name)
{
	hashtab_t  *tab = ctx->setLayouts;
	const char *path;
	path = va (ctx->va_ctx, "$"QFV_PROPERTIES".setLayouts.%s", name);
	__auto_type set = (VkDescriptorSetLayout) QFV_GetHandle (tab, path);
	if (set) {
		return set;
	}

	plitem_t   *item = qfv_load_pipeline (ctx, "setLayouts");
	if (!(item = PL_ObjectForKey (item, name))) {
		Sys_Printf ("error loading descriptor set %s\n", name);
		return 0;
	} else {
		Sys_MaskPrintf (SYS_vulkan_parse, "Found descriptor set def %s\n",
						name);
	}
	set = QFV_ParseDescriptorSetLayout (ctx, item, ctx->pipelineDef);
	QFV_AddHandle (tab, path, (uint64_t) set);
	QFV_duSetObjectName (ctx->device, VK_OBJECT_TYPE_DESCRIPTOR_SET_LAYOUT,
						 set, va (ctx->va_ctx, "descriptor_set:%s", name));
	return set;
}

void
Vulkan_CreateFrames (vulkan_ctx_t *ctx)
{
	qfv_device_t *device = ctx->device;
	VkCommandPool cmdpool = ctx->cmdpool;

	if (!ctx->frames.grow) {
		DARRAY_INIT (&ctx->frames, 4);
	}

	DARRAY_RESIZE (&ctx->frames, vulkan_frame_count);

	__auto_type cmdBuffers = QFV_AllocCommandBufferSet (ctx->frames.size,
														alloca);
	QFV_AllocateCommandBuffers (device, cmdpool, 0, cmdBuffers);

	for (size_t i = 0; i < ctx->frames.size; i++) {
		__auto_type frame = &ctx->frames.a[i];
		frame->framebuffer = 0;
		frame->fence = QFV_CreateFence (device, 1);
		frame->imageAvailableSemaphore = QFV_CreateSemaphore (device);
		frame->renderDoneSemaphore = QFV_CreateSemaphore (device);
		frame->cmdBuffer = cmdBuffers->a[i];
	}
}

void
Vulkan_CreateCapture (vulkan_ctx_t *ctx)
{
	ctx->capture = QFV_CreateCapture (ctx->device, ctx->frames.size,
									  ctx->swapchain, ctx->cmdpool);
}

void
Vulkan_DestroyFrames (vulkan_ctx_t *ctx)
{
	qfv_device_t *device = ctx->device;
	qfv_devfuncs_t *df = device->funcs;
	VkDevice    dev = device->dev;

	for (size_t i = 0; i < ctx->frames.size; i++) {
		__auto_type frame = &ctx->frames.a[i];
		df->vkDestroyFence (dev, frame->fence, 0);
		df->vkDestroySemaphore (dev, frame->imageAvailableSemaphore, 0);
		df->vkDestroySemaphore (dev, frame->renderDoneSemaphore, 0);
		frame->framebuffer = 0;
	}

	DARRAY_CLEAR (&ctx->frames);
}

void
Vulkan_BeginEntityLabel (vulkan_ctx_t *ctx, VkCommandBuffer cmd,
						 entity_t *ent)
{
	qfv_device_t *device = ctx->device;
	int         entaddr = (intptr_t) ent & 0xfffff;
	vec4f_t     pos = Transform_GetWorldPosition (ent->transform);
	vec4f_t     dir = normalf (pos - (vec4f_t) { 0, 0, 0, 1 });
	vec4f_t     color = 0.5 * dir + (vec4f_t) {0.5, 0.5, 0.5, 1 };

	QFV_CmdBeginLabel (device, cmd,
					   va (ctx->va_ctx, "ent %05x [%g, %g, %g]", entaddr,
						   VectorExpand (pos)), color);
}