--[[
	An internal method used by the reconciler to construct a new component
	instance and attach it to the given virtualNode.
]]

function Component:__mount(reconciler, virtualNode)
	if config.internalTypeChecks then
		internalAssert(Type.of(self) == Type.StatefulComponentClass, "Invalid use of `__mount`")
		internalAssert(Type.of(virtualNode) == Type.VirtualNode, "Expected arg #2 to be of type VirtualNode")
	end

	local currentElement = virtualNode.currentElement
	local hostParent = virtualNode.hostParent

	-- Contains all the information that we want to keep from consumers of
	-- Roact, or even other parts of the codebase like the reconciler.
	local internalData = {
		reconciler = reconciler,
		virtualNode = virtualNode,
		componentClass = self,
		lifecyclePhase = ComponentLifecyclePhase.Init,
	}

	local instance = {
		[Type] = Type.StatefulComponentInstance,
		[InternalData] = internalData,
	}

	setmetatable(instance, self)

	virtualNode.instance = instance

	local props = currentElement.props

	if self.defaultProps ~= nil then
		props = assign({}, self.defaultProps, props)
	end

	instance:__validateProps(props)

	instance.props = props

	local newContext = assign({}, virtualNode.context)
	instance._context = newContext

	instance.state = assign({}, instance:__getDerivedState(instance.props, {}))

	if instance.init ~= nil then
		instance:init(instance.props)
	end

	-- It's possible for init() to redefine _context!
	virtualNode.context = instance._context

	internalData.lifecyclePhase = ComponentLifecyclePhase.Render
	local renderResult = instance:render()

	internalData.lifecyclePhase = ComponentLifecyclePhase.ReconcileChildren
	reconciler.updateVirtualNodeWithRenderResult(virtualNode, hostParent, renderResult)

	if instance.didMount ~= nil then
		internalData.lifecyclePhase = ComponentLifecyclePhase.DidMount
		instance:didMount()
	end

	if internalData.pendingState ~= nil then
		-- __update will handle pendingState, so we don't pass any new element or state
		instance:__update(nil, nil)
	end

	internalData.lifecyclePhase = ComponentLifecyclePhase.Idle
end
