package layout

import (
	ui "github.com/gizak/termui/v3"
	"github.com/sqshq/sampler/component"
	"github.com/sqshq/sampler/component/runchart"
	"github.com/sqshq/sampler/component/util"
	"github.com/sqshq/sampler/config"
	"github.com/sqshq/sampler/console"
	"github.com/sqshq/sampler/data"
	"image"
	"math"
	"time"
)

// Layout represents component arrangement on the screen
type Layout struct {
	ui.Block
	Components       []*component.Component
	statusbar        *component.StatusBar
	menu             *component.Menu
	intro            *component.Intro
	nag              *component.NagWindow
	ChangeModeEvents chan Mode
	mode             Mode
	selection        int
	positionsChanged bool
	startupTime      time.Time
}

type Mode rune

const (
	ModeDefault          Mode = 0
	ModeIntro            Mode = 1
	ModeNag              Mode = 2
	ModePause            Mode = 3
	ModeComponentSelect  Mode = 4
	ModeMenuOptionSelect Mode = 5
	ModeComponentMove    Mode = 6
	ModeComponentResize  Mode = 7
	ModeChartPinpoint    Mode = 8
)

const (
	minDimension         = 3
	statusbarHeight      = 1
	nagWindowDurationSec = 5
)

func NewLayout(statusline *component.StatusBar, menu *component.Menu, intro *component.Intro, nag *component.NagWindow) *Layout {

	width, height := ui.TerminalDimensions()
	block := *ui.NewBlock()
	block.SetRect(0, 0, width, height)
	intro.SetRect(0, 0, width, height)
	nag.SetRect(0, 0, width, height)
	statusline.SetRect(0, height-statusbarHeight, width, height)

	return &Layout{
		Block:            block,
		Components:       make([]*component.Component, 0),
		statusbar:        statusline,
		menu:             menu,
		intro:            intro,
		nag:              nag,
		mode:             ModeDefault,
		selection:        0,
		ChangeModeEvents: make(chan Mode, 10),
		startupTime:      time.Now(),
	}
}

func (l *Layout) AddComponent(cpt *component.Component) {
	l.Components = append(l.Components, cpt)
}

func (l *Layout) StartWithIntro() {
	l.mode = ModeIntro
}

func (l *Layout) StartWithNagWindow() {
	l.mode = ModeNag
}

func (l *Layout) changeMode(m Mode) {
	if m == ModeComponentResize || m == ModeComponentMove {
		l.positionsChanged = true
	}
	l.mode = m
	l.ChangeModeEvents <- m
}

func (l *Layout) HandleMouseClick(x int, y int) {
	if l.mode == ModeIntro || l.mode == ModeNag {
		return
	}
	l.menu.Idle()
	selected, i := l.findComponentAtPoint(image.Point{X: x, Y: y})
	if selected == nil {
		l.changeMode(ModeDefault)
	} else {
		l.selection = i
		l.menu.Highlight(selected)
		l.changeMode(ModeComponentSelect)
	}
}

func (l *Layout) HandleKeyboardEvent(e string) {

	selected := l.getSelection()

	switch e {
	case console.KeyPause1, console.KeyPause2:
		if l.mode == ModePause {
			l.changeMode(ModeDefault)
			l.statusbar.TogglePause()
		} else {
			if selected.Type == config.TypeRunChart {
				selected.CommandChannel <- &data.Command{Type: runchart.CommandDisableSelection}
			}
			l.menu.Idle()
			l.changeMode(ModePause)
			l.statusbar.TogglePause()
		}
	case console.KeyEnter:
		switch l.mode {
		case ModeComponentSelect:
			l.menu.Choose()
			l.changeMode(ModeMenuOptionSelect)
		case ModeMenuOptionSelect:
			option := l.menu.GetSelectedOption()
			switch option {
			case component.MenuOptionMove:
				l.changeMode(ModeComponentMove)
				l.menu.MoveOrResize()
			case component.MenuOptionResize:
				l.changeMode(ModeComponentResize)
				l.menu.MoveOrResize()
			case component.MenuOptionPinpoint:
				l.changeMode(ModeChartPinpoint)
				l.menu.Idle()
				selected.CommandChannel <- &data.Command{Type: runchart.CommandMoveSelection, Value: 0}
			case component.MenuOptionResume:
				l.changeMode(ModeDefault)
				l.menu.Idle()
			}
		case ModeComponentMove:
			fallthrough
		case ModeComponentResize:
			l.menu.Idle()
			l.changeMode(ModeDefault)
			break
		case ModeIntro:
			page := l.intro.GetSelectedPage()
			if page == component.IntroPageWelcome {
				l.intro.NextPage()
			} else {
				l.changeMode(ModeDefault)
			}
		case ModeNag:
			l.nag.Accept()
		}
	case console.KeyEsc:
		l.resetAlerts()
		switch l.mode {
		case ModeChartPinpoint:
			selected.CommandChannel <- &data.Command{Type: runchart.CommandDisableSelection}
			fallthrough
		case ModeComponentSelect:
			fallthrough
		case ModeMenuOptionSelect:
			l.menu.Idle()
			l.changeMode(ModeDefault)
		case ModeComponentMove:
			fallthrough
		case ModeComponentResize:
			l.menu.Idle()
			l.changeMode(ModeDefault)
		}
	case console.KeyLeft:
		switch l.mode {
		case ModeDefault:
			l.changeMode(ModeComponentSelect)
			l.menu.Highlight(l.getComponent(l.selection))
		case ModeChartPinpoint:
			selected.CommandChannel <- &data.Command{Type: runchart.CommandMoveSelection, Value: -1}
		case ModeComponentSelect:
			l.moveSelection(e)
			l.menu.Highlight(l.getComponent(l.selection))
		case ModeComponentMove:
			selected.Move(-1, 0)
		case ModeComponentResize:
			selected.Resize(-1, 0)
		}
	case console.KeyRight:
		switch l.mode {
		case ModeDefault:
			l.changeMode(ModeComponentSelect)
			l.menu.Highlight(l.getComponent(l.selection))
		case ModeChartPinpoint:
			selected.CommandChannel <- &data.Command{Type: runchart.CommandMoveSelection, Value: 1}
		case ModeComponentSelect:
			l.moveSelection(e)
			l.menu.Highlight(l.getComponent(l.selection))
		case ModeComponentMove:
			selected.Move(1, 0)
		case ModeComponentResize:
			selected.Resize(1, 0)
		}
	case console.KeyUp:
		switch l.mode {
		case ModeDefault:
			l.changeMode(ModeComponentSelect)
			l.menu.Highlight(l.getComponent(l.selection))
		case ModeComponentSelect:
			l.moveSelection(e)
			l.menu.Highlight(l.getComponent(l.selection))
		case ModeMenuOptionSelect:
			l.menu.Up()
		case ModeComponentMove:
			selected.Move(0, -1)
		case ModeComponentResize:
			selected.Resize(0, -1)
		case ModeIntro:
			l.intro.Up()
		}
	case console.KeyDown:
		switch l.mode {
		case ModeDefault:
			l.changeMode(ModeComponentSelect)
			l.menu.Highlight(l.getComponent(l.selection))
		case ModeComponentSelect:
			l.moveSelection(e)
			l.menu.Highlight(l.getComponent(l.selection))
		case ModeMenuOptionSelect:
			l.menu.Down()
		case ModeComponentMove:
			selected.Move(0, 1)
		case ModeComponentResize:
			selected.Resize(0, 1)
		case ModeIntro:
			l.intro.Down()
		}
	}
}

func (l *Layout) ChangeDimensions(width, height int) {
	l.SetRect(0, 0, width, height)
}

func (l *Layout) getComponent(i int) *component.Component {
	return l.Components[i]
}

func (l *Layout) getSelection() *component.Component {
	return l.Components[l.selection]
}

func (l *Layout) moveSelection(direction string) {

	previouslySelected := l.getSelection()
	newlySelectedIndex := l.selection + 1

	for i, current := range l.Components {

		if current == previouslySelected {
			continue
		}

		if newlySelectedIndex >= len(l.Components) {
			newlySelectedIndex = i
		}

		var previouslySelectedCornerPoint image.Point
		var newlySelectedCornerPoint image.Point
		var currentCornerPoint image.Point

		switch direction {
		case console.KeyLeft:
			previouslySelectedCornerPoint = util.GetRectLeftSideCenter(previouslySelected.GetRect())
			newlySelectedCornerPoint = util.GetRectRightSideCenter(l.getComponent(newlySelectedIndex).GetRect())
			currentCornerPoint = util.GetRectRightSideCenter(current.GetRect())
		case console.KeyRight:
			previouslySelectedCornerPoint = util.GetRectRightSideCenter(previouslySelected.GetRect())
			newlySelectedCornerPoint = util.GetRectLeftSideCenter(l.getComponent(newlySelectedIndex).GetRect())
			currentCornerPoint = util.GetRectLeftSideCenter(current.GetRect())
		case console.KeyUp:
			previouslySelectedCornerPoint = util.GetRectTopSideCenter(previouslySelected.GetRect())
			newlySelectedCornerPoint = util.GetRectBottomSideCenter(l.getComponent(newlySelectedIndex).GetRect())
			currentCornerPoint = util.GetRectBottomSideCenter(current.GetRect())
		case console.KeyDown:
			previouslySelectedCornerPoint = util.GetRectBottomSideCenter(previouslySelected.GetRect())
			newlySelectedCornerPoint = util.GetRectTopSideCenter(l.getComponent(newlySelectedIndex).GetRect())
			currentCornerPoint = util.GetRectTopSideCenter(current.GetRect())
		}

		switch direction {
		case console.KeyLeft:
			fallthrough
		case console.KeyRight:
			if ui.AbsInt(currentCornerPoint.X-previouslySelectedCornerPoint.X) <= ui.AbsInt(newlySelectedCornerPoint.X-previouslySelectedCornerPoint.X) {
				if ui.AbsInt(currentCornerPoint.Y-previouslySelectedCornerPoint.Y) <= ui.AbsInt(newlySelectedCornerPoint.Y-previouslySelectedCornerPoint.Y) {
					newlySelectedIndex = i
				}
			}
		case console.KeyUp:
			fallthrough
		case console.KeyDown:
			if ui.AbsInt(currentCornerPoint.Y-previouslySelectedCornerPoint.Y) <= ui.AbsInt(newlySelectedCornerPoint.Y-previouslySelectedCornerPoint.Y) {
				if ui.AbsInt(currentCornerPoint.X-previouslySelectedCornerPoint.X) <= ui.AbsInt(newlySelectedCornerPoint.X-previouslySelectedCornerPoint.X) {
					newlySelectedIndex = i
				}
			}
		}
	}

	if newlySelectedIndex < len(l.Components) {
		l.selection = newlySelectedIndex
	}
}

func (l *Layout) Draw(buffer *ui.Buffer) {

	columnWidth := float64(l.GetRect().Dx()) / float64(console.ColumnsCount)
	rowHeight := float64(l.GetRect().Dy()-statusbarHeight) / float64(console.RowsCount)

	for _, c := range l.Components {
		rectangle := calculateComponentCoordinates(c, columnWidth, rowHeight)
		c.SetRect(rectangle.Min.X, rectangle.Min.Y, rectangle.Max.X, rectangle.Max.Y)
	}

	if l.mode == ModeIntro {
		l.intro.SetRect(l.Min.X, l.Min.Y, l.Max.X, l.Max.Y)
		l.intro.Draw(buffer)
		return
	}

	if l.mode == ModeNag {
		if l.nag.IsAccepted() && time.Since(l.startupTime).Seconds() > nagWindowDurationSec {
			l.mode = ModeDefault
		} else {
			l.nag.SetRect(l.Min.X, l.Min.Y, l.Max.X, l.Max.Y)
			l.nag.Draw(buffer)
			return
		}
	}

	for _, c := range l.Components {
		c.Draw(buffer)
	}

	l.statusbar.SetRect(
		0, l.GetRect().Dy()-statusbarHeight,
		l.GetRect().Dx(), l.GetRect().Dy())

	l.statusbar.Draw(buffer)
	l.menu.Draw(buffer)
}

func (l *Layout) findComponentAtPoint(point image.Point) (*component.Component, int) {

	columnWidth := float64(l.GetRect().Dx()) / float64(console.ColumnsCount)
	rowHeight := float64(l.GetRect().Dy()-statusbarHeight) / float64(console.RowsCount)

	for i, c := range l.Components {

		rectangle := calculateComponentCoordinates(c, columnWidth, rowHeight)

		if point.In(rectangle) {
			return c, i
		}
	}

	return nil, -1
}

func calculateComponentCoordinates(c *component.Component, columnWidth float64, rowHeight float64) image.Rectangle {

	x1 := math.Floor(float64(c.Location.X) * columnWidth)
	y1 := math.Floor(float64(c.Location.Y) * rowHeight)
	x2 := x1 + math.Floor(float64(c.Size.X))*columnWidth
	y2 := y1 + math.Floor(float64(c.Size.Y))*rowHeight

	if x2-x1 < minDimension {
		x2 = x1 + minDimension
	}

	if y2-y1 < minDimension {
		y2 = y1 + minDimension
	}

	return image.Rectangle{Min: image.Point{
		X: int(x1), Y: int(y1)},
		Max: image.Point{X: int(x2), Y: int(y2)},
	}
}

func (l *Layout) resetAlerts() {
	for _, c := range l.Components {
		c.AlertChannel <- nil
	}
}

func (l *Layout) WerePositionsChanged() bool {
	return l.positionsChanged
}