package tui

import (
	"fmt"

	"github.com/gdamore/tcell/v2"
	"github.com/rivo/tview"
)

type TabPrimitive interface {
	tview.Primitive
	ForceRedraw()
}

type Tabs struct {
	*tview.Flex

	names    []string
	items    map[string]tview.Primitive
	selector *tview.TextView
	pages    *tview.Pages
	fallover bool
	unlock   bool
}

func NewTabs(selectorAtTop bool) *Tabs {
	widget := &Tabs{
		Flex:     tview.NewFlex(),
		names:    []string{},
		items:    make(map[string]tview.Primitive),
		fallover: true,
	}
	widget.SetDirection(tview.FlexRow)

	// Selector
	widget.selector = tview.NewTextView().
		SetDynamicColors(true).
		SetRegions(true).
		SetWrap(false).
		SetTextAlign(tview.AlignLeft)
	widget.selector.SetHighlightedFunc(
		func(added, removed, remaining []string) {
			if len(added) == 0 {
				return
			}

			widget.pages.SwitchToPage(added[0])
		},
	)
	if selectorAtTop {
		widget.AddItem(widget.selector, 1, 0, false)
	}

	// Pages
	widget.pages = tview.NewPages()
	widget.AddItem(widget.pages, 0, 1, false)

	if !selectorAtTop {
		widget.AddItem(widget.selector, 1, 0, false)
	}

	return widget
}

func (widget *Tabs) AllowFallover(allow bool) {
	widget.fallover = allow
}

func (widget *Tabs) AddText(text string) {
	fmt.Fprint(widget.selector, text)
}

func (widget *Tabs) AddTab(name string, label string, item tview.Primitive, visible bool) {
	widget.names = append(widget.names, name)
	widget.items[name] = item
	fmt.Fprintf(widget.selector, `["%s"][darkcyan]%s[white][""]  `, name, label)
	widget.pages.AddPage(name, item, true, false)
	if visible {
		widget.Select(name)
	}
}

func (widget *Tabs) Select(name string) {
	widget.selector.Highlight(name)
}

func (widget *Tabs) Next() tview.Primitive {
	widget.unlock = true
	if len(widget.names) == 0 {
		return nil
	}

	index := -1
	highlights := widget.selector.GetHighlights()
	if len(highlights) > 0 {
		currentName := highlights[0]
		for currentIndex, name := range widget.names {
			if name == currentName {
				index = currentIndex
				break
			}
		}
	}

	index++
	if index >= len(widget.names) {
		if widget.fallover {
			index = 0
		} else {
			index = len(widget.names) - 1
		}
	}

	widget.selector.Highlight(widget.names[index])

	return widget.items[widget.names[index]]
}

func (widget *Tabs) Prev() tview.Primitive {
	widget.unlock = true
	if len(widget.names) == 0 {
		return nil
	}

	index := len(widget.names)
	highlights := widget.selector.GetHighlights()
	if len(highlights) > 0 {
		currentName := highlights[0]
		for currentIndex, name := range widget.names {
			if name == currentName {
				index = currentIndex
				break
			}
		}
	}

	index--
	if index < 0 {
		if widget.fallover {
			index = len(widget.names) - 1
		} else {
			index = 0
		}
	}

	widget.selector.Highlight(widget.names[index])

	return widget.items[widget.names[index]]
}

func (widget *Tabs) Focus(delegate func(p tview.Primitive)) {
	delegate(widget.pages)
}

func (widget *Tabs) Draw(screen tcell.Screen) {
	if widget.unlock {
		widgetX, widgetY, widgetWidth, widgetHeight := widget.GetInnerRect()
		screen.LockRegion(widgetX, widgetY, widgetWidth, widgetHeight, false)
		widget.unlock = false
	}

	widget.Flex.Draw(screen)
}