package upgrade

import (
	"context"
	"fmt"
	"io"
	"time"

	"github.com/charmbracelet/bubbles/spinner"
	tea "github.com/charmbracelet/bubbletea"
	"github.com/charmbracelet/lipgloss"
	"github.com/pkg/errors"
	"github.com/siderolabs/talos/pkg/machinery/api/machine"
	"github.com/siderolabs/talos/pkg/machinery/client"
)

var upgraderBoxStyle = lipgloss.NewStyle().
	Border(lipgloss.RoundedBorder()).
	Padding(1,1).
	Width(60).
	BorderTop(true).
	BorderBottom(true).
	BorderLeft(true).
	BorderRight(true)

type Upgrader struct {
	core *CoreState
	node *Node

	spinner spinner.Model

	done   bool
	failed bool

	Message string
	Status  string
}

func NewUpgrader(core *CoreState, node *Node) (*Upgrader, error) {
	u := &Upgrader{
		core: core,
		node: node,
		spinner: spinner.New(
			spinner.WithSpinner(spinner.Dot),
		),
	}

	ctx := client.WithNode(u.core.ctx, u.node.node.Metadata.ID())

	resp, err := u.node.node.Client.MachineClient.Upgrade(ctx, &machine.UpgradeRequest{
		Image:      u.core.SelectedImage,
		Preserve:   false,
		Stage:      true,
		Force:      false,
		RebootMode: machine.UpgradeRequest_RebootMode(machine.RebootRequest_DEFAULT),
	})
	if err != nil {
		return nil, errors.Wrap(err, "failed to upgrade node")
	}

	var actorID string

	for _, m := range resp.GetMessages() {
		if actorID = m.GetActorId(); actorID != "" {
			break
		}
	}

	if actorID == "" {
		return nil, errors.New("failed to collect actor ID; cannot watch upgrade progress")
	}

	go u.EventWatcher(ctx, actorID)

	u.Message = "launched upgrade"
	u.Status = "init"

	return u, nil
}

func (u *Upgrader) EventWatcher(ctx context.Context, actorID string) {
	for ctx.Err() == nil {
		if err := u.EventWatchInstance(ctx, actorID); err != nil {
			u.Status = err.Error()

			time.Sleep(time.Second)

			continue
		}

		return
	}
}

func (u *Upgrader) EventWatchInstance(ctx context.Context, actorID string) error {
	eventsClient, err := u.node.node.Client.MachineClient.Events(ctx, &machine.EventsRequest{
		WithActorId: actorID,
	})
	if err != nil {
		return errors.Wrap(err, "failed to get event watcher")
	}

	for ctx.Err() == nil {
		rawEv, err := eventsClient.Recv()
		if errors.Is(err, io.EOF) {
			return errors.New("stream closed")
		}

		if err != nil {
			return errors.Wrap(err, "failed to receive event")
		}

		if rawEv.GetMetadata().GetStatus().GetMessage() == "" {
			continue
		}

		ev, err := client.UnmarshalEvent(rawEv)
		if err != nil {
			return errors.Wrapf(err, "failed to decode received event %+v", rawEv)
		}

		switch msg := ev.Payload.(type) {
		case *machine.PhaseEvent:
			u.Message = fmt.Sprintf("phase: %s action: %v", msg.GetPhase(), msg.GetAction())
			u.Status = "running"
		case *machine.TaskEvent:
			u.Message = fmt.Sprintf("task: %s action: %v", msg.GetTask(), msg.GetAction())
			u.Status = "running"
		case *machine.SequenceEvent:
			var errMessage string

			if msg.GetError().GetMessage() != "" {
				errMessage = fmt.Sprintf("error: [code: %v message: %v]",
					msg.GetError().GetCode(),
					msg.GetError().GetMessage(),
				)
			}

			u.Message = fmt.Sprintf("sequence: %s action: %v%v",
				msg.GetSequence(), msg.GetAction(), errMessage)
			u.Status = "running"

			if errMessage != "" {
				return errors.Errorf("sequence error: %s", errMessage)
			}
		case *machine.MachineStatusEvent:
			if msg.GetStage() == machine.MachineStatusEvent_RUNNING {
				u.Message = "upgraded"
				u.Status = "finished"

				return nil
			}
			u.Message = fmt.Sprintf("stage: %v ready: %v unmetCond: %v",
				msg.GetStage(), msg.GetStatus().GetReady(), msg.GetStatus().GetUnmetConditions())
			u.Status = "running"
		case *machine.ServiceStateEvent:
			u.Message = fmt.Sprintf("service: %v message: %v healthy: %v",
				msg.GetService(), msg.GetMessage(), msg.GetHealth().GetHealthy())
			u.Status = "running"
		default:
			u.Status = "unhandled event"
		}
	}

	return nil
}

func (u *Upgrader) Init() tea.Cmd {
	return u.spinner.Tick
}

func (u *Upgrader) Update(msg tea.Msg) (tea.Model, tea.Cmd) {
	switch msg := msg.(type) {
	case tea.KeyMsg:
		return u, tea.Quit
	case spinner.TickMsg:
		if u.failed {
			return nil, tea.Quit
		}

		if u.done {
			return NewSelectNode(u.core), nil
		}

		var cmd tea.Cmd

		u.spinner, cmd = u.spinner.Update(msg)

		return u, cmd
	default:
		return u, nil
	}
}

func (u *Upgrader) View() string {
	return upgraderBoxStyle.Render(fmt.Sprintf("%s %s: %s", u.spinner.View(), u.Status, u.Message))
}

func (u *Upgrader) Tick() (cmd tea.Cmd) {
	return u.spinner.Tick
}