package ui

import (
	"context"
	"encoding/json"
	"fmt"
	"io"
	"sort"
	"strings"
	"time"

	"coopcloud.tech/abra/pkg/formatter"
	"coopcloud.tech/abra/pkg/logs"
	tea "github.com/charmbracelet/bubbletea"
	"github.com/docker/cli/cli/command/service/progress"
	containerTypes "github.com/docker/docker/api/types/container"
	"github.com/docker/docker/api/types/filters"
	dockerClient "github.com/docker/docker/client"
	"github.com/docker/docker/pkg/jsonmessage"
)

var IsRunning bool

type statusMsg struct {
	stream  stream
	jsonMsg jsonmessage.JSONMessage
}

type progressCompleteMsg struct {
	stream stream
	failed bool
}

type healthcheckMsg struct {
	stream stream
	health string
}

type ServiceMeta struct {
	Name string
	ID   string
}

type Model struct {
	appName string
	cl      *dockerClient.Client
	count   int
	ctx     context.Context
	timeout time.Duration
	width   int
	filters filters.Args

	Streams  *[]stream
	Logs     *[]string
	Failed   bool
	TimedOut bool
	Quit     bool
}

func (m Model) complete() bool {
	if m.count == len(*m.Streams) {
		return true
	}
	return false
}

type stream struct {
	Name string
	Err  error

	decoder  *json.Decoder
	id       string
	reader   *io.PipeReader
	writer   *io.PipeWriter
	status   string
	retries  int
	health   string
	rollback bool
}

func (s stream) String() string {
	out := fmt.Sprintf("{decoder: %v, ", s.decoder)
	out += fmt.Sprintf("err: %v, ", s.Err)
	out += fmt.Sprintf("id: %s, ", s.id)
	out += fmt.Sprintf("name: %s, ", s.Name)
	out += fmt.Sprintf("reader: %v, ", s.reader)
	out += fmt.Sprintf("writer: %v, ", s.writer)
	out += fmt.Sprintf("status: %s, ", s.status)
	return out
}

func (s stream) progress(m Model) tea.Msg {
	if err := progress.ServiceProgress(m.ctx, m.cl, s.id, s.writer); err != nil {
		return progressCompleteMsg{
			stream: s,
			failed: true,
		}
	}

	return progressCompleteMsg{stream: s}
}

func (s stream) process() tea.Msg {
	var jsonMsg jsonmessage.JSONMessage

	if err := s.decoder.Decode(&jsonMsg); err != nil {
		if err == io.EOF {
			// NOTE(d1): end processing messages
			return nil
		}
	}

	return statusMsg{
		stream:  s,
		jsonMsg: jsonMsg,
	}
}

func (s stream) healthcheck(m Model) tea.Msg {
	filters := filters.NewArgs()
	filters.Add("name", fmt.Sprintf("^%s", s.Name))

	containers, err := m.cl.ContainerList(m.ctx, containerTypes.ListOptions{Filters: filters})
	if err != nil {
		s.Err = err
		return healthcheckMsg{stream: s}
	}

	if len(containers) == 0 {
		return healthcheckMsg{stream: s}
	}

	container := containers[0]
	containerState, err := m.cl.ContainerInspect(m.ctx, container.ID)
	if err != nil {
		s.Err = err
		return healthcheckMsg{stream: s}
	}

	var health string
	if containerState.State.Health != nil {
		health = containerState.State.Health.Status
	}

	return healthcheckMsg{stream: s, health: health}
}

func DeployInitialModel(
	ctx context.Context,
	cl *dockerClient.Client,
	services []ServiceMeta,
	appName string,
	timeout time.Duration,
	filters filters.Args,
) Model {
	var streams []stream
	for _, service := range services {
		r, w := io.Pipe()
		d := json.NewDecoder(r)
		streams = append(streams, stream{
			Name:    service.Name,
			id:      service.ID,
			reader:  r,
			writer:  w,
			decoder: d,
			retries: -1, // NOTE(d1): skip first attempt
			health:  "?",
		})
	}

	sort.Slice(streams, func(i, j int) bool {
		return streams[i].Name < streams[j].Name
	})

	return Model{
		ctx:     ctx,
		cl:      cl,
		appName: appName,
		timeout: timeout,
		filters: filters,
		Streams: &streams,
		Logs:    &[]string{},
	}
}

func (m Model) Init() tea.Cmd {
	var cmds []tea.Cmd

	for _, stream := range *m.Streams {
		cmds = append(
			cmds,
			[]tea.Cmd{
				func() tea.Msg { return stream.progress(m) },
				func() tea.Msg { return stream.process() },
				func() tea.Msg { return stream.healthcheck(m) },
			}...,
		)
	}

	cmds = append(cmds, func() tea.Msg { return deployTimeout(m) })
	cmds = append(cmds, func() tea.Msg { return m.gatherLogs() })

	return tea.Batch(cmds...)
}

func (m Model) gatherLogs() tea.Msg {
	var services []string
	for _, s := range *m.Streams {
		services = append(services, s.Name)
	}

	opts := logs.TailOpts{
		AppName:  m.appName,
		Services: services,
		StdErr:   true,
		Buffer:   m.Logs,
		ToBuffer: true,
		Filters:  m.filters,
	}

	// NOTE(d1): not interested in log polling errors. if we don't see logs it
	// will hopefully be self-evident based on what happened in the deployment
	logs.TailLogs(m.cl, opts)

	return nil
}

type timeoutMsg struct{}

func deployTimeout(m Model) tea.Msg {
	<-time.After(m.timeout)
	return timeoutMsg{}
}

func (m Model) Update(msg tea.Msg) (tea.Model, tea.Cmd) {
	var cmds []tea.Cmd

	switch msg := msg.(type) {
	case tea.KeyMsg:
		switch msg.String() {
		case "ctrl+c", "q":
			m.Quit = true
			return m, tea.Quit
		}

	case tea.WindowSizeMsg:
		m.width = msg.Width

	case progressCompleteMsg:
		if msg.failed {
			m.Failed = true
		}

		m.count += 1

		if m.complete() {
			return m, tea.Quit
		}

	case timeoutMsg:
		m.TimedOut = true
		return m, tea.Quit

	case healthcheckMsg:
		for idx, s := range *m.Streams {
			if s.id == msg.stream.id {
				h := "?"
				if s.health != "" {
					h = s.health
				}
				if msg.health != "" {
					h = msg.health
				}
				(*m.Streams)[idx].health = h
			}
		}

		cmds = append(
			cmds,
			func() tea.Msg { return msg.stream.healthcheck(m) },
		)

	case statusMsg:
		for idx, s := range *m.Streams {
			if s.id == msg.stream.id {

				if msg.jsonMsg.ID == "rollback" {
					m.Failed = true
					(*m.Streams)[idx].rollback = true
				}

				if msg.jsonMsg.ID != "overall progress" {
					newStatus := strings.ToLower(msg.jsonMsg.Status)
					currentStatus := (*m.Streams)[idx].status

					if !strings.Contains(currentStatus, "starting") &&
						strings.Contains(newStatus, "starting") {
						(*m.Streams)[idx].retries += 1
					}

					if (*m.Streams)[idx].rollback {
						if msg.jsonMsg.ID == "rollback" {
							(*m.Streams)[idx].status = newStatus
						}
					} else {
						(*m.Streams)[idx].status = newStatus
					}
				}
			}
		}

		cmds = append(
			cmds,
			func() tea.Msg { return msg.stream.process() },
		)
	}

	return m, tea.Batch(cmds...)
}

func (m Model) View() string {
	body := strings.Builder{}

	for _, stream := range *m.Streams {
		split := strings.Split(stream.Name, "_")
		short := split[len(split)-1]

		newLineSpacing := "  "
		for range len(short) {
			newLineSpacing += " "
		}

		status := stream.status
		if strings.Contains(stream.status, "converged") && !stream.rollback {
			status = "succeeded"
		}
		if strings.Contains(stream.status, "rolled back") {
			status = "rolled back"
		}

		retries := 0
		if stream.retries > 0 {
			retries = stream.retries
		}

		output := fmt.Sprintf("%s: %s (retries: %v, healthcheck: %s)",
			formatter.BoldStyle.Render(short),
			status,
			retries,
			stream.health,
		)

		body.WriteString(output)
		body.WriteString("\n")
	}

	return body.String()
}