package controllers

import (
	"github.com/jesseduffield/lazygit/pkg/gocui"
	"github.com/jesseduffield/lazygit/pkg/gui/types"
)

// given we have no fields here, arguably we shouldn't even need this factory
// struct, but we're maintaining consistency with the other files.
type VerticalScrollControllerFactory struct {
	c *ControllerCommon
}

func NewVerticalScrollControllerFactory(c *ControllerCommon) *VerticalScrollControllerFactory {
	return &VerticalScrollControllerFactory{
		c: c,
	}
}

func (self *VerticalScrollControllerFactory) Create(context types.Context) types.IController {
	return &VerticalScrollController{
		baseController: baseController{},
		c:              self.c,
		context:        context,
	}
}

type VerticalScrollController struct {
	baseController
	c *ControllerCommon

	context types.Context
}

func (self *VerticalScrollController) Context() types.Context {
	return self.context
}

func (self *VerticalScrollController) GetKeybindings(opts types.KeybindingsOpts) []*types.Binding {
	return []*types.Binding{}
}

func (self *VerticalScrollController) GetMouseKeybindings(opts types.KeybindingsOpts) []*gocui.ViewMouseBinding {
	return []*gocui.ViewMouseBinding{
		{
			ViewName: self.context.GetViewName(),
			Key:      gocui.MouseWheelUp,
			Handler: func(gocui.ViewMouseBindingOpts) error {
				return self.HandleScrollUp()
			},
		},
		{
			ViewName: self.context.GetViewName(),
			Key:      gocui.MouseWheelDown,
			Handler: func(gocui.ViewMouseBindingOpts) error {
				return self.HandleScrollDown()
			},
		},
	}
}

func (self *VerticalScrollController) HandleScrollUp() error {
	self.context.GetViewTrait().ScrollUp(self.c.UserConfig().Gui.ScrollHeight)

	return nil
}

func (self *VerticalScrollController) HandleScrollDown() error {
	scrollHeight := self.c.UserConfig().Gui.ScrollHeight
	self.context.GetViewTrait().ScrollDown(scrollHeight)

	if manager := self.c.GetViewBufferManagerForView(self.context.GetView()); manager != nil {
		manager.ReadLines(scrollHeight)
	}

	return nil
}
