package view

import (
	"errors"

	"github.com/derailed/k9s/internal/render"
	"github.com/derailed/k9s/internal/resource"
	"github.com/derailed/k9s/internal/ui"
	"github.com/gdamore/tcell"
	"github.com/rs/zerolog/log"
	v1 "k8s.io/api/core/v1"
	"k8s.io/apimachinery/pkg/apis/meta/v1/unstructured"
	"k8s.io/apimachinery/pkg/labels"
	"k8s.io/apimachinery/pkg/runtime"
)

const (
	podTitle   = "Pods"
	shellCheck = "command -v bash >/dev/null && exec bash || exec sh"
)

// Pod represents a pod viewer.
type Pod struct {
	ResourceViewer
}

// NewPod returns a new viewer.
func NewPod(title, gvr string, list resource.List) ResourceViewer {
	p := Pod{
		ResourceViewer: NewLogsExtender(
			NewResource(podTitle, gvr, list),
			func() string { return "" },
		),
	}
	p.BindKeys()
	p.GetTable().SetEnterFn(p.showContainers)

	return &p
}

func (p *Pod) BindKeys() {
	p.Actions().Add(ui.KeyActions{
		tcell.KeyCtrlK: ui.NewKeyAction("Kill", p.killCmd, true),
		ui.KeyS:        ui.NewKeyAction("Shell", p.shellCmd, true),
		ui.KeyShiftR:   ui.NewKeyAction("Sort Ready", p.GetTable().SortColCmd(1, true), false),
		ui.KeyShiftS:   ui.NewKeyAction("Sort Status", p.GetTable().SortColCmd(2, true), false),
		ui.KeyShiftT:   ui.NewKeyAction("Sort Restart", p.GetTable().SortColCmd(3, false), false),
		ui.KeyShiftC:   ui.NewKeyAction("Sort CPU", p.GetTable().SortColCmd(4, false), false),
		ui.KeyShiftM:   ui.NewKeyAction("Sort MEM", p.GetTable().SortColCmd(5, false), false),
		ui.KeyShiftX:   ui.NewKeyAction("Sort CPU%", p.GetTable().SortColCmd(6, false), false),
		ui.KeyShiftZ:   ui.NewKeyAction("Sort MEM%", p.GetTable().SortColCmd(7, false), false),
		ui.KeyShiftI:   ui.NewKeyAction("Sort IP", p.GetTable().SortColCmd(8, true), false),
		ui.KeyShiftO:   ui.NewKeyAction("Sort Node", p.GetTable().SortColCmd(9, true), false),
	})
}

func (p *Pod) showContainers(app *App, ns, res, sel string) {
	ns, n := namespaced(sel)
	o, err := p.App().factory.Get(ns, "v1/pods", n, labels.Everything())
	if err != nil {
		app.Flash().Err(err)
		log.Error().Err(err).Msgf("Pod %s not found", sel)
		return
	}

	var pod v1.Pod
	if runtime.DefaultUnstructuredConverter.FromUnstructured(o.(*unstructured.Unstructured).Object, &pod); err != nil {
		app.Flash().Err(err)
	}
	list := resource.NewContainerList(app.Conn(), &pod)

	// Spawn child view
	p.App().inject(NewContainer(fqn(pod.Namespace, pod.Name), list))
}

// Protocol...

func (p *Pod) killCmd(evt *tcell.EventKey) *tcell.EventKey {
	sels := p.GetTable().GetSelectedItems()
	if len(sels) == 0 {
		return evt
	}

	p.GetTable().ShowDeleted()
	for _, res := range sels {
		p.App().Flash().Infof("Delete resource %s %s", p.List().GetName(), res)
		if err := p.List().Resource().Delete(res, true, false); err != nil {
			p.App().Flash().Errf("Delete failed with %s", err)
		} else {
			p.App().forwarders.Kill(res)
		}
	}
	p.Refresh()

	return nil
}

func (p *Pod) shellCmd(evt *tcell.EventKey) *tcell.EventKey {
	sel := p.GetTable().GetSelectedItem()
	if sel == "" {
		return evt
	}

	row := p.GetTable().GetSelectedRowIndex()
	status := ui.TrimCell(p.GetTable().SelectTable, row, p.GetTable().NameColIndex()+2)
	if status != render.Running {
		p.App().Flash().Errf("%s is not in a running state", sel)
		return nil
	}
	cc, err := fetchContainers(p.List(), sel, false)
	if err != nil {
		p.App().Flash().Errf("Unable to retrieve containers %s", err)
		return evt
	}
	if len(cc) == 1 {
		p.shellIn(sel, "")
		return nil
	}
	picker := NewPicker()
	picker.populate(cc)
	picker.SetSelectedFunc(func(i int, t, d string, r rune) {
		p.shellIn(sel, t)
	})
	p.App().inject(picker)

	return evt
}

func (p *Pod) shellIn(path, co string) {
	p.Stop()
	shellIn(p.App(), path, co)
	p.Start()
}

// ----------------------------------------------------------------------------
// Helpers...

func fetchContainers(l resource.List, po string, includeInit bool) ([]string, error) {
	if len(po) == 0 {
		return []string{}, nil
	}
	return l.Resource().(resource.Containers).Containers(po, includeInit)
}

func shellIn(a *App, path, co string) {
	args := computeShellArgs(path, co, a.Config.K9s.CurrentContext, a.Conn().Config().Flags().KubeConfig)
	log.Debug().Msgf("Shell args %v", args)
	if !runK(true, a, args...) {
		a.Flash().Err(errors.New("Shell exec failed"))
	}
}

func computeShellArgs(path, co, context string, kcfg *string) []string {
	args := make([]string, 0, 15)
	args = append(args, "exec", "-it")
	args = append(args, "--context", context)
	ns, po := namespaced(path)
	args = append(args, "-n", ns)
	args = append(args, po)
	if kcfg != nil && *kcfg != "" {
		args = append(args, "--kubeconfig", *kcfg)
	}
	if co != "" {
		args = append(args, "-c", co)
	}

	return append(args, "--", "sh", "-c", shellCheck)
}