package views

import (
	"context"
	"fmt"
	"path"
	"regexp"
	"strconv"
	"strings"
	"time"

	"github.com/gdamore/tcell"
	"github.com/k8sland/k9s/resource"
	"github.com/k8sland/k9s/resource/k8s"
	"github.com/k8sland/tview"
	log "github.com/sirupsen/logrus"
	"k8s.io/api/core/v1"
)

const noSelection = ""

type (
	details interface {
		tview.Primitive
		setTitle(string)
		clear()
		setActions(keyActions)
		update(resource.Properties)
	}

	resourceView struct {
		*tview.Pages

		app            *appView
		title          string
		selectedItem   string
		namespaces     map[int]string
		selectedNS     string
		suspendUpdate  bool
		list           resource.List
		extraActionsFn func(keyActions)
	}
)

func newResourceView(title string, app *appView, list resource.List, c colorerFn) resourceViewer {
	v := resourceView{
		app:        app,
		title:      title,
		list:       list,
		selectedNS: list.GetNamespace(),
		Pages:      tview.NewPages(),
	}

	table := newTableView(v.title, list.SortFn())
	table.SetColorer(c)
	table.SetSelectionChangedFunc(v.selChanged)
	v.AddPage(v.list.GetName(), table, true, true)

	var xray details
	if list.HasXRay() {
		xray = newXrayView(app)
	} else {
		xray = newYamlView(app)
	}
	xray.setActions(keyActions{
		tcell.KeyCtrlB: {description: "Back", action: v.back},
	})

	details := newDetailsView()
	details.setActions(keyActions{
		tcell.KeyCtrlB: {description: "Back", action: v.back},
	})

	v.AddPage("details", details, true, false)
	v.AddPage("xray", xray, true, false)

	return &v
}

// Init watches all running pods in given namespace
func (v *resourceView) init(ctx context.Context, ns string) {
	details := v.GetPrimitive("xray").(details)
	details.clear()

	v.selectedItem, v.selectedNS = noSelection, ns

	go func(ctx context.Context) {
		initTick := 0.1
		for {
			select {
			case <-ctx.Done():
				log.Printf("%s watcher canceled!", v.title)
				return
			case <-time.After(time.Duration(initTick) * time.Second):
				if !v.isSuspended() {
					v.refresh()
				}
				initTick = float64(v.app.refreshRate)
			}
		}
	}(ctx)
	v.refreshActions()
	v.CurrentPage().Item.(*tableView).Select(0, 0)
}

func (v *resourceView) selChanged(r, c int) {
	v.selectItem(r, c)
}

func (v *resourceView) colorFn(f colorerFn) {
	v.getTV().SetColorer(f)
}

// Protocol...

// Hints fetch menu hints
func (v *resourceView) hints() hints {
	return v.CurrentPage().Item.(hinter).hints()
}

// Actions...

func (v *resourceView) back(*tcell.EventKey) {
	v.switchPage(v.list.GetName())
}

func (v *resourceView) delete(*tcell.EventKey) {
	if !v.rowSelected() {
		return
	}

	v.getTV().setDeleted()
	v.app.flash(flashInfo, fmt.Sprintf("Deleting %s %s", v.list.GetName(), v.selectedItem))
	if err := v.list.Resource().Delete(v.selectedItem); err != nil {
		v.app.flash(flashErr, "Boom!", err.Error())
	}
	v.selectedItem = noSelection
}

func (v *resourceView) describe(*tcell.EventKey) {
	details := v.GetPrimitive("xray").(details)
	details.clear()

	if !v.rowSelected() {
		return
	}

	props, err := v.list.Describe(v.selectedItem)
	if err != nil {
		v.app.flash(flashErr, "Unable to get xray fields", err.Error())
		return
	}
	details.update(props)
	details.setTitle(fmt.Sprintf(" %s ", v.selectedItem))
	v.switchPage("xray")
}

func (v *resourceView) view(*tcell.EventKey) {
	if !v.rowSelected() {
		return
	}

	raw, err := v.list.Resource().Marshal(v.selectedItem)
	if err != nil {
		v.app.flash(flashErr, "Unable to marshal resource", err.Error())
		log.Error(err)
		return
	}

	var re = regexp.MustCompile(`([\w|\.|"|\-|\/|\@]+):(.*)`)
	str := re.ReplaceAllString(string(raw), `[aqua]$1: [white]$2`)

	details := v.GetPrimitive("details").(*detailsView)
	details.SetText(str)
	details.setTitle(v.selectedItem)
	v.switchPage("details")
}

func (v *resourceView) edit(*tcell.EventKey) {
	if !v.rowSelected() {
		return
	}
	v.app.flash(flashInfo, fmt.Sprintf("Editing %s %s", v.title, v.selectedItem))
	ns, s := namespaced(v.selectedItem)
	run(v.app, "edit", v.list.GetName(), "-n", ns, s)
	return
}

func (v *resourceView) switchNamespace(evt *tcell.EventKey) {
	v.suspend()
	{
		i, _ := strconv.Atoi(string(evt.Rune()))
		ns := v.namespaces[i]
		v.selectedNS = ns
		if ns == noSelection {
			ns = "all"
		}
		v.app.flash(flashInfo, fmt.Sprintf("Viewing `%s namespace...", ns))
		v.list.SetNamespace(v.selectedNS)
		v.refresh()
	}
	v.resume()
	v.selectedItem = noSelection
	v.getTV().resetTitle()
	v.app.resetCmd()
}

// Utils...

func (v *resourceView) suspend() {
	v.suspendUpdate = true
}

func (v *resourceView) resume() {
	v.suspendUpdate = false
}

func (v *resourceView) isSuspended() bool {
	return v.suspendUpdate
}

func (v *resourceView) refresh() {
	if _, ok := v.CurrentPage().Item.(*tableView); !ok {
		return
	}
	v.list.SetNamespace(v.selectedNS)
	if err := v.list.Reconcile(); err != nil {
		v.app.flash(flashErr, err.Error())
	}
	v.refreshActions()
	v.getTV().update(v.list.Data())
	v.app.infoView.refresh()
	v.app.Draw()
}

func (v *resourceView) getTV() *tableView {
	return v.GetPrimitive(v.list.GetName()).(*tableView)
}

func (v *resourceView) getSelectedItem() string {
	return v.selectedItem
}

func (v *resourceView) selectItem(r, c int) {
	if r == 0 {
		v.selectedItem = noSelection
		return
	}

	t := v.getTV()
	switch v.list.GetNamespace() {
	case resource.NotNamespaced:
		v.selectedItem = strings.TrimSpace(t.GetCell(r, 0).Text)
	case resource.AllNamespaces:
		v.selectedItem = path.Join(
			strings.TrimSpace(t.GetCell(r, 0).Text),
			strings.TrimSpace(t.GetCell(r, 1).Text),
		)
	default:
		v.selectedItem = path.Join(
			v.selectedNS,
			strings.TrimSpace(t.GetCell(r, 0).Text),
		)
	}
}

func (v *resourceView) switchPage(p string) {
	v.suspend()
	{
		v.SwitchToPage(p)
		h := v.GetPrimitive(p).(hinter)
		v.selectedNS = v.list.GetNamespace()
		v.app.setHints(h.hints())
		v.app.SetFocus(v.CurrentPage().Item)
	}
	v.resume()
}

func (v *resourceView) rowSelected() bool {
	item := v.getSelectedItem()
	return item != noSelection
}

func namespaced(n string) (string, string) {
	ns, po := path.Split(n)
	return strings.Trim(ns, "/"), po
}

func (v *resourceView) refreshActions() {
	if _, ok := v.CurrentPage().Item.(*tableView); !ok {
		return
	}

	nn, err := k8s.NewNamespace().List(defaultNS)
	if err != nil {
		v.app.flash(flashErr, "Unable to retrieve namespaces", err.Error())
		return
	}

	aa := keyActions{}
	if v.list.Access(resource.NamespaceAccess) {
		v.namespaces = make(map[int]string, len(nn))
		var i int
		aa[tcell.Key(numKeys[i])] = newKeyHandler("all", v.switchNamespace)
		v.namespaces[i] = resource.AllNamespaces
		i++

		for _, n := range nn {
			nsp := n.(v1.Namespace)
			v.namespaces[i] = nsp.Name
			aa[tcell.Key(numKeys[i])] = newKeyHandler(nsp.Name, v.switchNamespace)
			i++
		}
	}

	if v.list.Access(resource.EditAccess) {
		aa[tcell.KeyCtrlE] = newKeyHandler("Edit", v.edit)
	}
	if v.list.Access(resource.DeleteAccess) {
		aa[tcell.KeyCtrlD] = newKeyHandler("Delete", v.delete)
	}
	if v.list.Access(resource.ViewAccess) {
		aa[tcell.KeyCtrlV] = newKeyHandler("View", v.view)
	}
	if v.list.Access(resource.DescribeAccess) {
		aa[tcell.KeyCtrlX] = newKeyHandler("Describe", v.describe)
	}

	if v.extraActionsFn != nil {
		v.extraActionsFn(aa)
	}

	t := v.getTV()
	t.setActions(aa)
	v.app.setHints(t.hints())
}