package views

import (
	"fmt"
	"io"
	"strings"

	"github.com/derailed/k9s/internal/config"
	"github.com/derailed/tview"
	"github.com/gdamore/tcell"
	"github.com/rs/zerolog/log"
)

type logView struct {
	*tview.Flex

	app        *appView
	logs       *detailsView
	status     *statusView
	parent     masterView
	ansiWriter io.Writer
	autoScroll bool
	actions    keyActions
}

func newLogView(title string, parent masterView) *logView {
	v := logView{Flex: tview.NewFlex(), app: parent.appView()}
	v.autoScroll = true
	v.parent = parent
	v.SetBorder(true)
	v.SetBackgroundColor(config.AsColor(parent.appView().styles.Style.Log.BgColor))
	v.SetBorderPadding(0, 0, 1, 1)
	v.logs = newDetailsView(parent.appView(), parent.backFn())
	{
		v.logs.SetBorder(false)
		v.logs.setCategory("Logs")
		v.logs.SetDynamicColors(true)
		v.logs.SetTextColor(config.AsColor(parent.appView().styles.Style.Log.FgColor))
		v.logs.SetBackgroundColor(config.AsColor(parent.appView().styles.Style.Log.BgColor))
		v.logs.SetWrap(true)
		v.logs.SetMaxBuffer(parent.appView().config.K9s.LogBufferSize)
	}
	v.ansiWriter = tview.ANSIWriter(v.logs)
	v.status = newStatusView(parent.appView())
	v.SetDirection(tview.FlexRow)
	v.AddItem(v.status, 1, 1, false)
	v.AddItem(v.logs, 0, 1, true)

	v.actions = keyActions{
		tcell.KeyEscape: {description: "Back", action: v.backCmd, visible: true},
		KeyC:            {description: "Clear", action: v.clearCmd, visible: true},
		KeyS:            {description: "Toggle AutoScroll", action: v.toggleScrollCmd, visible: true},
		KeyG:            {description: "Top", action: v.topCmd, visible: false},
		KeyShiftG:       {description: "Bottom", action: v.bottomCmd, visible: false},
		KeyF:            {description: "Up", action: v.pageUpCmd, visible: false},
		KeyB:            {description: "Down", action: v.pageDownCmd, visible: false},
	}
	v.logs.SetInputCapture(v.keyboard)

	return &v
}

// Hints show action hints
func (v *logView) hints() hints {
	return v.actions.toHints()
}

func (v *logView) keyboard(evt *tcell.EventKey) *tcell.EventKey {
	key := evt.Key()
	if key == tcell.KeyRune {
		key = tcell.Key(evt.Rune())
	}
	if m, ok := v.actions[key]; ok {
		log.Debug().Msgf(">> LogView handled %s", tcell.KeyNames[key])
		return m.action(evt)
	}

	return evt
}

func (v *logView) logLine(line string) {
	fmt.Fprintln(v.ansiWriter, tview.Escape(line))
}

func (v *logView) log(lines fmt.Stringer) {
	v.logs.Clear()
	fmt.Fprintln(v.ansiWriter, lines.String())
}

func (v *logView) flush(index int, buff []string) {
	if index == 0 {
		return
	}
	v.logLine(strings.Join(buff[:index], "\n"))
	if v.autoScroll {
		v.app.QueueUpdateDraw(func() {
			v.update()
			v.logs.ScrollToEnd()
		})
	}
}

func (v *logView) update() {
	status := "Off"
	if v.autoScroll {
		status = "On"
	}
	v.status.update([]string{fmt.Sprintf("Autoscroll: %s", status)})
}

// ----------------------------------------------------------------------------
// Actions...

func (v *logView) toggleScrollCmd(evt *tcell.EventKey) *tcell.EventKey {
	v.autoScroll = !v.autoScroll
	if v.autoScroll {
		v.app.flash().info("Autoscroll is on.")
		v.logs.ScrollToEnd()
	} else {
		v.logs.PageUp()
		v.app.flash().info("Autoscroll is off.")
	}
	v.update()

	return nil
}

func (v *logView) backCmd(evt *tcell.EventKey) *tcell.EventKey {
	return v.parent.backFn()(evt)
}

func (v *logView) topCmd(evt *tcell.EventKey) *tcell.EventKey {
	v.app.flash().info("Top of logs...")
	v.logs.ScrollToBeginning()
	return nil
}

func (v *logView) bottomCmd(*tcell.EventKey) *tcell.EventKey {
	v.app.flash().info("Bottom of logs...")
	v.logs.ScrollToEnd()
	return nil
}

func (v *logView) pageUpCmd(*tcell.EventKey) *tcell.EventKey {
	if v.logs.PageUp() {
		v.app.flash().info("Reached Top ...")
	}
	return nil
}

func (v *logView) pageDownCmd(*tcell.EventKey) *tcell.EventKey {
	if v.logs.PageDown() {
		v.app.flash().info("Reached Bottom ...")
	}
	return nil
}

func (v *logView) clearCmd(*tcell.EventKey) *tcell.EventKey {
	v.app.flash().info("Clearing logs...")
	v.logs.Clear()
	v.logs.ScrollTo(0, 0)
	return nil
}