win = require("window")
log = require("log")
world = require("world")
Component = require("ecs.component")
GraphicsComponent = require("ecs.graphics")
NetworkedComponent = require("ecs.networked")
PredictedComponent = require("ecs.predicted")
ScriptComponent = require("ecs.script")
CharacterControllerComponent = require("ecs.char_controller")
shader_world = require("shaders.world")

--win.scene:append(shader_world)
--pp = am.postprocess({
	--clear_color: vec4(0.2, 0.2, 0.3, 1),
	--depth_buffer: true,
	----stencil_buffer: true,
	--width: win.width,
	--height: win.height,
--})
pp = am.group!
pp\append(shader_world.node)
GraphicsComponent.node = pp
ScriptComponent.node = pp
PredictedComponent.node = pp
NetworkedComponent.node = pp

-- Base entity of our ECS
class Entity
	id: 1
	new: (id, components) => -- [id], [components]
		ent_reg = world.domain == "client" and world.level.entities or world.level_sync.ents
		id_cur = id or #ent_reg + 1
		@created_at = debug.traceback!
		assert(id_cur < 10, "Got more then 10 entities")
		while ent_reg[id_cur] != nil
			id_cur += 1
		log.debug("Want to create an entity with id" .. id_cur .. ", registry is:" .. tostring(ent_reg) .. "\n" .. debug.traceback(), {"ecs"})
		assert(ent_reg[id_cur] == nil, "Attempted to create entity with the same id as one that already exists: " .. tostring(id_cur) .. ", entities were:" .. tostring(ent_reg))

		log.info("Creating entity " .. id_cur .. " domain is: " .. world.domain, {"ecs"})
		ent_reg[id_cur] = @
		@reg = ent_reg
		@id = id_cur
		-- Bookkeeping for O(1) access for components
		@c_by_type = {}
		@c_by_name = {}
		--Entity is responsible for the component -> entity link
		@components = components or {}
		for name, component in pairs(@components)
			component.entity = @
			@c_by_type[component.__class] = @c_by_type[component.__class] or {}
			@c_by_type[component.__class][name] = component
		for name, component in pairs(@components)
			assert(component.join, "Component " .. name .. " does not have a join method.")
			component\join(@)
			component\post_join(@)
	add: (component, cid) =>
		assert(component, "Failed to find component:" .. tostring(component))
		assert(type(component) == "table", "Component must be a table")
		assert(component.__class, "Component must have a class")
		component.entity = @
		component\join(@, cid)
		component\post_join(@, cid)
		if cid == nil
			cid = #@components + 1
			while @components[cid]
				cid += 1
		assert(@components[cid] == nil, "Already had a component with id" .. tostring(cid))
		@components[cid] = component
		@c_by_type[component.__class] = @c_by_type[component.__class] or {}
		@c_by_type[component.__class][cid] = component
		assert(@c_by_name[component.name] == nil, "Duplicate components named" .. component.name)
		@c_by_name[component.name] = component
		@
	remove: (cid) =>
		component = @components[cid]
		component.entity = nil
		component\leave(@)
		component
		@components[cid] = nil
		@c_by_type[component.__class][cid] = nil
		@c_by_name[component.name] = nil
	destroy: () =>
		for name, component in pairs(@components)
			@remove(name)
		@reg[@id] = nil

	get: (cid) =>
		@components[cid]

	serialize: () =>
		components = {}
		for i, component in pairs(@components)
			component_name = component.__class.__name
			if not component.serialize
				log.warn("Component:" .. component_name .. " does not have a .serialize()", {"ecs"})
				continue
			component_data = component\serialize!
			components[i] = string.format(
				"%d\0%s%d\0%s",
				#component_name, component_name,
				#component_data, component_data
			)
		return table.concat(components, "\0")
	
	--@deserialize: (data) =>
		--error("Deserialize called")
		--log.info("Deserializing entity from data of length " .. tostring(data and #data or 0), {"ecs"})
		--ent = @!
		---- Empty payload -> empty entity
		--if not data or #data == 0
			--return ent
		---- Map serialized component type names back to their classes
		--component_types = {
			--[GraphicsComponent.__name]: GraphicsComponent
			--[NetworkedComponent.__name]: NetworkedComponent
			--[PredictedComponent.__name]: PredictedComponent
			--[ScriptComponent.__name]: ScriptComponent
			--[CharacterControllerComponent.__name]: CharacterControllerComponent
			--[PhysicsComponent.__name]: PhysicsComponent
		--}
		--pointer = 1
		--len = #data
		--while pointer <= len
			---- Read component name length (digits up to first NUL)
			--name_len_end = string.find(data, "\0", pointer)
			--if not name_len_end
				--break
			--name_len_str = string.sub(data, pointer, name_len_end - 1)
			--name_len = tonumber(name_len_str)
			--if not name_len or name_len <= 0
				--break
			--pointer = name_len_end + 1
			---- Read component type name
			--component_name = string.sub(data, pointer, pointer + name_len - 1)
			--pointer += name_len
			---- Read component data length (digits up to next NUL)
			--data_len_end = string.find(data, "\0", pointer)
			--if not data_len_end
				--break
			--data_len_str = string.sub(data, pointer, data_len_end - 1)
			--data_len = tonumber(data_len_str)
			--if not data_len or data_len < 0
				--break
			--pointer = data_len_end + 1
			---- Read component payload
			--component_data = string.sub(data, pointer, pointer + data_len - 1)
			--pointer += data_len
			---- Skip inter-component separator if present
			--if string.sub(data, pointer, pointer) == "\0"
				--pointer += 1
			--ctype = component_types[component_name]
			--if not ctype
				--log.warn("Unknown component type during deserialize: " .. tostring(component_name), {"ecs"})
				--continue
			--if not ctype.deserialize
				--log.warn("Component type " .. tostring(component_name) .. " does not implement .deserialize()", {"ecs"})
				--continue
			---- Let the component class decide how to interpret its payload
			--component = ctype.deserialize(component_data)
			--if component
				--ent\add(component)
		--return ent

	__tostring: () =>
		components_str = tostring(@components)
		return string.format("%s : {\n%s\n}\t%q",@@__name, components_str\gsub("^","\t"), @created_at)

class PhysicsComponent extends Component
	new: (name, properties) =>
		assert(properties and properties.shape, "Failed to find a shape for physics component")
		super(name, properties)

{
	:Component
	:Entity
	:NetworkedComponent
	:PredictedComponent
	:GraphicsComponent
	:PhysicsComponent
	:ScriptComponent
	:CharacterControllerComponent
	node: pp
}