/*
Copyright (c) 2013 Daniele Bartolini, Michele Rossi
Copyright (c) 2012 Daniele Bartolini, Simone Boscaratto

Permission is hereby granted, free of charge, to any person
obtaining a copy of this software and associated documentation
files (the "Software"), to deal in the Software without
restriction, including without limitation the rights to use,
copy, modify, merge, publish, distribute, sublicense, and/or sell
copies of the Software, and to permit persons to whom the
Software is furnished to do so, subject to the following
conditions:

The above copyright notice and this permission notice shall be
included in all copies or substantial portions of the Software.

THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES
OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT
HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY,
WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR
OTHER DEALINGS IN THE SOFTWARE.
*/

#include "allocator.h"
#include "file.h"
#include "filesystem.h"
#include "string_utils.h"
#include "json_parser.h"
#include "vector.h"
#include "log.h"
#include "matrix4x4.h"
#include "physics_types.h"
#include "quaternion.h"
#include "resource.h"
#include "temp_allocator.h"
#include "types.h"
#include "vector3.h"
#include "camera.h"
#include "unit_resource.h"

namespace crown
{
namespace unit_resource
{
	struct Projection
	{
		const char* name;
		ProjectionType::Enum type;
	};

	static const Projection s_projection[] =
	{
		{ "perspective",  ProjectionType::PERSPECTIVE  },
		{ "orthographic", ProjectionType::ORTHOGRAPHIC }
	};

	static ProjectionType::Enum projection_name_to_enum(const char* name)
	{
		for (uint32_t i = 0; i < ProjectionType::COUNT; i++)
		{
			if (string::strcmp(name, s_projection[i].name) == 0)
				return s_projection[i].type;
		}

		CE_FATAL("Bad projection type");
		return (ProjectionType::Enum)0;
	}

	const StringId32 NO_PARENT = 0xFFFFFFFF;

	struct GraphNode
	{
		StringId32 name;
		StringId32 parent;
		Vector3 position;
		Quaternion rotation;
	};

	struct GraphNodeDepth
	{
		StringId32 name;
		uint32_t index;
		uint32_t depth;

		bool operator()(const GraphNodeDepth& a, const GraphNodeDepth& b)
		{
			return a.depth < b.depth;
		}
	};

	uint32_t compute_link_depth(const GraphNode& node, const Array<GraphNode>& nodes)
	{
		if (node.parent == NO_PARENT) return 0;
		else
		{
			for (uint32_t i = 0; i < array::size(nodes); i++)
			{
				if (nodes[i].name == node.parent)
				{
					return 1 + compute_link_depth(nodes[i], nodes);
				}
			}
		}

		CE_FATAL("Node not found");
		return 0;
	}

	uint32_t find_node_index(StringId32 name, const Array<GraphNodeDepth>& node_depths)
	{
		for (uint32_t i = 0; i < array::size(node_depths); i++)
		{
			if (node_depths[i].name == name)
			{
				return i;
			}
		}

		CE_FATAL("Node not found");
		return 0;
	}

	int32_t find_node_parent_index(uint32_t node, const Array<GraphNode>& nodes, const Array<GraphNodeDepth>& node_depths)
	{
		StringId32 parent_name = nodes[node_depths[node].index].parent;

		if (parent_name == NO_PARENT) return -1;
		for (uint32_t i = 0; i < array::size(node_depths); i++)
		{
			if (parent_name == node_depths[i].name)
			{
				return i;
			}
		}

		CE_FATAL("Node not found");
		return 0;
	}

	void parse_nodes(JSONElement e, Array<GraphNode>& nodes, Array<GraphNodeDepth>& node_depths)
	{
		Vector<DynamicString> keys(default_allocator());
		e.to_keys(keys);

		for (uint32_t k = 0; k < vector::size(keys); k++)
		{
			const char* node_name = keys[k].c_str();
			JSONElement node = e.key(node_name);

			GraphNode gn;
			gn.name = string::murmur2_32(node_name, string::strlen(node_name));
			gn.parent = NO_PARENT;

			if (!node.key("parent").is_nil())
			{
				DynamicString parent_name;
				node.key("parent").to_string(parent_name);
				gn.parent = string::murmur2_32(parent_name.c_str(), parent_name.length(), 0);
			}

			JSONElement pos = node.key("position");
			JSONElement rot = node.key("rotation");
			gn.position = Vector3(pos[0].to_float(), pos[1].to_float(), pos[2].to_float());
			gn.rotation = Quaternion(Vector3(rot[0].to_float(), rot[1].to_float(), rot[2].to_float()), rot[3].to_float());

			GraphNodeDepth gnd;
			gnd.name = gn.name;
			gnd.index = array::size(nodes);
			gnd.depth = 0;

			array::push_back(nodes, gn);
			array::push_back(node_depths, gnd);
		}
	}

	void parse_cameras(JSONElement e, Array<UnitCamera>& cameras, const Array<GraphNodeDepth>& node_depths)
	{
		Vector<DynamicString> keys(default_allocator());
		e.to_keys(keys);

		for (uint32_t k = 0; k < vector::size(keys); k++)
		{
			const char* camera_name = keys[k].c_str();
			JSONElement camera = e.key(camera_name);
			JSONElement node = camera.key("node");
			JSONElement type = camera.key("type");

			DynamicString node_name;
			node.to_string(node_name);
			DynamicString camera_type;
			type.to_string(camera_type);

			StringId32 node_name_hash = string::murmur2_32(node_name.c_str(), node_name.length());

			UnitCamera cn;
			cn.name = string::murmur2_32(camera_name, string::strlen(camera_name));
			cn.node = find_node_index(node_name_hash, node_depths);
			cn.type = projection_name_to_enum(camera_type.c_str());
			cn.fov =  camera.key_or_nil("fov").to_float(16.0f / 9.0f);
			cn.near = camera.key_or_nil("near_clip_distance").to_float(0.01f);
			cn.far =  camera.key_or_nil("far_clip_distance").to_float(1000.0f);

			array::push_back(cameras, cn);
		}
	}

	void parse_renderables(JSONElement e, Array<UnitRenderable>& renderables, const Array<GraphNodeDepth>& node_depths)
	{
		Vector<DynamicString> keys(default_allocator());
		e.to_keys(keys);

		for (uint32_t k = 0; k < vector::size(keys); k++)
		{
			const char* renderable_name = keys[k].c_str();
			JSONElement renderable = e.key(renderable_name);

			DynamicString node_name; renderable.key("node").to_string(node_name);
			StringId32 node_name_hash = string::murmur2_32(node_name.c_str(), node_name.length(), 0);

			UnitRenderable rn;
			rn.name = string::murmur2_32(renderable_name, string::strlen(renderable_name), 0);
			rn.node = find_node_index(node_name_hash, node_depths);
			rn.visible = renderable.key("visible").to_bool();

			DynamicString res_type;
			renderable.key("type").to_string(res_type);

			if (res_type == "mesh")
			{
				rn.type = UnitRenderable::MESH;
				rn.resource = renderable.key("resource").to_resource_id("mesh").name;
			}
			else if (res_type == "sprite")
			{
				rn.type = UnitRenderable::SPRITE;
				rn.resource = renderable.key("resource").to_resource_id("sprite").name;
			}
			else
			{
				CE_ASSERT(false, "Oops, unknown renderable type: '%s'", res_type.c_str());
			}

			array::push_back(renderables, rn);
		}
	}

	void parse_keys(JSONElement e, Array<Key>& generic_keys, Array<char>& values)
	{
		Vector<DynamicString> keys(default_allocator());
		e.to_keys(keys);

		for (uint32_t k = 0; k < vector::size(keys); k++)
		{
			const char* key = keys[k].c_str();
			JSONElement value = e.key(key);

			Key out_key;
			out_key.name = string::murmur2_32(key, string::strlen(key));
			out_key.offset = array::size(values);

			if (value.is_bool()) out_key.type = ValueType::BOOL;
			else if (value.is_number()) out_key.type = ValueType::FLOAT;
			else if (value.is_string()) out_key.type = ValueType::STRING;
			else if (value.is_array() && value.size() == 3) out_key.type = ValueType::VECTOR3;
			else CE_FATAL("Value type not supported");

			array::push_back(generic_keys, out_key);

			switch (out_key.type)
			{
				case ValueType::BOOL:
				{
					uint32_t val = value.to_bool();
					array::push(values, (char*) &val, sizeof(uint32_t));
					break;
				}
				case ValueType::FLOAT:
				{
					float val = value.to_float();
					array::push(values, (char*) &val, sizeof(float));
					break;
				}
				case ValueType::STRING:
				{
					DynamicString val;
					value.to_string(val);
					StringId32 val_hash = string::murmur2_32(val.c_str(), val.length());
					array::push(values, (char*) &val_hash, sizeof(StringId32));
					break;
				}
				case ValueType::VECTOR3:
				{
					float val[3];
					val[0] = value[0].to_float();
					val[1] = value[1].to_float();
					val[2] = value[2].to_float();
					array::push(values, (char*) val, sizeof(float) * 3);
					break;
				}
				default:
				{
					CE_FATAL("Oops, you should not be here");
					return;
				}
			}
		}
	}

	void parse_materials(JSONElement e, Array<UnitMaterial>& materials)
	{
		for (uint32_t i = 0; i < e.size(); i++)
		{
			ResourceId mat_id = e[i].to_resource_id("material");
			UnitMaterial um;
			um.id = mat_id.name;
			array::push_back(materials, um);
		}
	}

	void compile(const char* path, CompileOptions& opts)
	{
		static const uint32_t VERSION = 1;

		Buffer buf = opts.read(path);
		JSONParser json(array::begin(buf));
		JSONElement root = json.root();

		ResourceId				m_physics_resource;
		Array<GraphNode>		m_nodes(default_allocator());
		Array<GraphNodeDepth>	m_node_depths(default_allocator());
		Array<UnitCamera>		m_cameras(default_allocator());
		Array<UnitRenderable>	m_renderables(default_allocator());
		Array<Key>				m_keys(default_allocator());
		Array<char>				m_values(default_allocator());
		Array<UnitMaterial>		m_materials(default_allocator());

		// Check for nodes
		if (root.has_key("nodes")) parse_nodes(root.key("nodes"), m_nodes, m_node_depths);

		for (uint32_t i = 0; i < array::size(m_nodes); i++)
		{
			m_node_depths[i].depth = compute_link_depth(m_nodes[i], m_nodes);
		}

		std::sort(array::begin(m_node_depths), array::end(m_node_depths), GraphNodeDepth());

		if (root.has_key("renderables")) parse_renderables(root.key("renderables"), m_renderables, m_node_depths);
		if (root.has_key("cameras")) parse_cameras(root.key("cameras"), m_cameras, m_node_depths);
		if (root.has_key("keys")) parse_keys(root.key("keys"), m_keys, m_values);
		if (root.has_key("materials")) parse_materials(root.key("materials"), m_materials);

		// Check if the unit has a .physics resource
		DynamicString unit_name(path);
		unit_name.strip_trailing(".unit");
		DynamicString physics_name = unit_name;
		physics_name += ".physics";
		if (opts._fs.exists(physics_name.c_str()))
		{
			m_physics_resource = ResourceId("physics", unit_name.c_str());
		}
		else
		{
			m_physics_resource = ResourceId();
		}

		ResourceId sprite_anim;
		sprite_anim.type = 0;
		sprite_anim.name = 0;
		if (root.has_key("sprite_animation"))
			sprite_anim = root.key("sprite_animation").to_resource_id("sprite_animation");

		UnitResource ur;
		ur.version = VERSION;
		ur.physics_resource = m_physics_resource.name;
		ur.sprite_animation = sprite_anim.name;
		ur.num_renderables = array::size(m_renderables);
		ur.num_materials = array::size(m_materials);
		ur.num_cameras = array::size(m_cameras);
		ur.num_scene_graph_nodes = array::size(m_nodes);
		ur.num_keys = array::size(m_keys);
		ur.values_size = array::size(m_values);

		uint32_t offt = sizeof(UnitResource);
		ur.renderables_offset         = offt; offt += sizeof(UnitRenderable) * ur.num_renderables;
		ur.materials_offset           = offt; offt += sizeof(UnitMaterial) * ur.num_materials;
		ur.cameras_offset             = offt; offt += sizeof(UnitCamera) * ur.num_cameras;
		ur.scene_graph_nodes_offset   = offt; offt += sizeof(UnitNode) * ur.num_scene_graph_nodes;
		ur.keys_offset                = offt; offt += sizeof(Key) * ur.num_keys;
		ur.values_offset              = offt;

		opts.write(ur.version);
		opts.write(ur._pad);
		opts.write(ur.physics_resource);
		opts.write(ur.sprite_animation);
		opts.write(ur.num_renderables);
		opts.write(ur.renderables_offset);
		opts.write(ur.num_materials);
		opts.write(ur.materials_offset);
		opts.write(ur.num_cameras);
		opts.write(ur.cameras_offset);
		opts.write(ur.num_scene_graph_nodes);
		opts.write(ur.scene_graph_nodes_offset);
		opts.write(ur.num_keys);
		opts.write(ur.keys_offset);
		opts.write(ur.values_size);
		opts.write(ur.values_offset);

		// Renderables
		for (uint32_t i = 0; i < array::size(m_renderables); i++)
		{
			opts.write(m_renderables[i].type);
			opts.write(m_renderables[i]._pad);
			opts.write(m_renderables[i].resource);
			opts.write(m_renderables[i].name);
			opts.write(m_renderables[i].node);
			opts.write(m_renderables[i].visible);
			opts.write(m_renderables[i]._pad1[0]);
			opts.write(m_renderables[i]._pad1[1]);
			opts.write(m_renderables[i]._pad1[2]);
			opts.write(m_renderables[i]._pad2[0]);
			opts.write(m_renderables[i]._pad2[1]);
			opts.write(m_renderables[i]._pad2[2]);
			opts.write(m_renderables[i]._pad2[3]);
		}

		// Materials
		for (uint32_t i = 0; i < array::size(m_materials); i++)
		{
			opts.write(m_materials[i]);
		}

		// Cameras
		for (uint32_t i = 0; i < array::size(m_cameras); i++)
		{
			opts.write(m_cameras[i].name);
			opts.write(m_cameras[i].node);
			opts.write(m_cameras[i].type);
			opts.write(m_cameras[i].fov);
			opts.write(m_cameras[i].near);
			opts.write(m_cameras[i].far);
		}

		// Write node poses
		for (uint32_t i = 0; i < ur.num_scene_graph_nodes; i++)
		{
			uint32_t node_index = m_node_depths[i].index;
			GraphNode& node = m_nodes[node_index];
			UnitNode un;
			un.name = node.name;
			un.parent = find_node_parent_index(i, m_nodes, m_node_depths);
			un.pose = Matrix4x4(node.rotation, node.position);

			opts.write(un.name);
			opts.write(un.pose);
			opts.write(un.parent);
		}

		// Key/values
		for (uint32_t i = 0; i < array::size(m_keys); i++)
		{
			opts.write(m_keys[i].name);
			opts.write(m_keys[i].type);
			opts.write(m_keys[i].offset);
		}

		for (uint32_t i = 0; i < array::size(m_values); i++)
		{
			opts.write(m_values[i]);
		}
	}

	void* load(File& file, Allocator& a)
	{
		const size_t file_size = file.size();
		void* res = a.allocate(file_size);
		file.read(res, file_size);
		return res;
	}

	void online(StringId64 /*id*/, ResourceManager& /*rm*/)
	{
	}

	void offline(StringId64 /*id*/, ResourceManager& /*rm*/)
	{
	}

	void unload(Allocator& allocator, void* resource)
	{
		allocator.deallocate(resource);
	}

	StringId64 sprite_animation(const UnitResource* ur)
	{
		return ur->sprite_animation;
	}

	StringId64 physics_resource(const UnitResource* ur)
	{
		return ur->physics_resource;
	}

	uint32_t num_renderables(const UnitResource* ur)
	{
		return ur->num_renderables;
	}

	const UnitRenderable* get_renderable(const UnitResource* ur, uint32_t i)
	{
		CE_ASSERT(i < num_renderables(ur), "Index out of bounds");

		UnitRenderable* begin = (UnitRenderable*) ((char*)ur + ur->renderables_offset);
		return &begin[i];
	}

	uint32_t num_materials(const UnitResource* ur)
	{
		return ur->num_materials;
	}

	const UnitMaterial* get_material(const UnitResource* ur, uint32_t i)
	{
		CE_ASSERT(i < num_materials(ur), "Index out of bounds");

		UnitMaterial* begin = (UnitMaterial*) ((char*)ur + ur->materials_offset);
		return &begin[i];
	}	

	uint32_t num_cameras(const UnitResource* ur)
	{
		return ur->num_cameras;
	}

	const UnitCamera* get_camera(const UnitResource* ur, uint32_t i)
	{
		CE_ASSERT(i < num_cameras(ur), "Index out of bounds");

		UnitCamera* begin = (UnitCamera*) ((char*)ur + ur->cameras_offset);
		return &begin[i];
	}

	uint32_t num_scene_graph_nodes(const UnitResource* ur)
	{
		return ur->num_scene_graph_nodes;
	}

	const UnitNode* scene_graph_nodes(const UnitResource* ur)
	{
		return (UnitNode*) ((char*)ur + ur->scene_graph_nodes_offset);
	}

	uint32_t num_keys(const UnitResource* ur)
	{
		return ur->num_keys;
	}

	bool has_key(const UnitResource* ur, const char* k)
	{
		const uint32_t nk = num_keys(ur);
		Key* begin = (Key*) ((char*)ur + ur->keys_offset);

		for (uint32_t i = 0; i < nk; i++)
		{
			if (begin[i].name == string::murmur2_32(k, string::strlen(k)))
			{
				return true;
			}
		}

		return false;
	}

	bool get_key(const UnitResource* ur, const char* k, Key& out_k)
	{
		const uint32_t nk = num_keys(ur);
		Key* begin = (Key*) ((char*)ur + ur->keys_offset);

		for (uint32_t i = 0; i < nk; i++)
		{
			if (begin[i].name == string::murmur2_32(k, string::strlen(k)))
			{
				out_k = begin[i];
				return true;
			}
		}

		return false;
	}

	uint32_t values_size(const UnitResource* ur)
	{
		return ur->values_size;
	}

	const char* values(const UnitResource* ur)
	{
		return ((char*)ur + ur->values_offset);
	}
} // namespace unit_resource
} // namespace crown