package docker

import (
	"bytes"
	"context"
	"fmt"
	"io"
	"strconv"
	"strings"
	"time"

	"fergalla.com/dockerbot/internal/apperrors"
	"github.com/containerd/errdefs"
	"github.com/moby/moby/api/pkg/stdcopy"
	"github.com/moby/moby/client"
)

type DockerInfo struct {
	ctxDocker    context.Context
	dockerClient *client.Client
}

/* type ContainerStats struct {
	CPUPercent float64
	MemUsage   uint64
	MemLimit   uint64
	MemPercent float64
	NetInput   uint64
	NetOutput  uint64
}

type statsResponse struct {
	CPUStats struct {
		CPUUsage struct {
			TotalUsage  uint64   `json:"total_usage"`
			PercpuUsage []uint64 `json:"percpu_usage"`
		} `json:"cpu_usage"`
		SystemUsage uint64 `json:"system_cpu_usage"`
	} `json:"cpu_stats"`

	PreCPUStats struct {
		CPUUsage struct {
			TotalUsage uint64 `json:"total_usage"`
		} `json:"cpu_usage"`
		SystemUsage uint64 `json:"system_cpu_usage"`
	} `json:"precpu_stats"`

	MemoryStats struct {
		Usage uint64 `json:"usage"`
		Limit uint64 `json:"limit"`
	} `json:"memory_stats"`

	Networks map[string]struct {
		RxBytes uint64 `json:"rx_bytes"`
		TxBytes uint64 `json:"tx_bytes"`
	} `json:"networks"`
} */

type ContainerInspectInfo struct {
	ID           string
	Name         string
	Image        string
	Created      time.Time
	Path         string
	Command      string
	State        string
	Health       string
	RestartCount int
	StartedAt    time.Time
	FinishedAt   time.Time
	Ports        map[string]string
	Mounts       []string
	Networks     []string
}

type ContainerBasicInfo struct {
	Name   string
	Image  string
	State  string
	Health string
}

func New() (*DockerInfo, error) {
	ctx, cancel := context.WithTimeout(context.Background(), 5*time.Second)
	defer cancel()
	apiClient, err := client.New(client.FromEnv)
	if err != nil {
		return nil, err
	}

	return &DockerInfo{
		dockerClient: apiClient,
		ctxDocker:    ctx,
	}, nil
}

func (d *DockerInfo) ListContainers() ([]ContainerBasicInfo, error) {
	containers, err := d.dockerClient.ContainerList(d.ctxDocker, client.ContainerListOptions{All: true})
	if err != nil {
		return nil, err
	}
	var basicInfo []ContainerBasicInfo
	for _, c := range containers.Items {
		name := "unknown"
		if len(c.Names) > 0 {
			name = c.Names[0][1:]
		}
		image := c.Image
		state := c.State
		health := c.Health.Status
		basicInfo = append(basicInfo, ContainerBasicInfo{
			Name:   name,
			Image:  image,
			State:  string(state),
			Health: string(health),
		})
	}
	return basicInfo, nil
}

func (d *DockerInfo) GetContainerInfo(containerID string) (*ContainerInspectInfo, error) {
	containerJSON, err := d.dockerClient.ContainerInspect(d.ctxDocker, containerID, client.ContainerInspectOptions{})
	if err != nil {
		if errdefs.IsNotFound(err) {
			return nil, apperrors.ErrContainerNotFound
		}
		return nil, err
	}
	c := containerJSON.Container
	info := &ContainerInspectInfo{
		Name:         strings.TrimPrefix(c.Name, "/"),
		Image:        c.Config.Image,
		ID:           c.ID,
		Path:         c.Path,
		Command:      c.Path + " " + strings.Join(c.Args, " "),
		State:        string(c.State.Status),
		Health:       "none",
		RestartCount: c.RestartCount,
		Created:      strToTime(c.Created),
		StartedAt:    strToTime(c.State.StartedAt),
		FinishedAt:   strToTime(c.State.FinishedAt),
	}

	if c.State.Health != nil {
		info.Health = string(c.State.Health.Status)
	}

	info.Ports = make(map[string]string)
	for port, bindings := range c.NetworkSettings.Ports {
		if len(bindings) > 0 {
			info.Ports[port.String()] = bindings[0].HostPort
		}
	}

	for _, m := range c.Mounts {
		info.Mounts = append(info.Mounts, m.Source+"->"+m.Destination)
	}

	for name := range c.NetworkSettings.Networks {
		info.Networks = append(info.Networks, name)
	}
	return info, nil
}

func (d *DockerInfo) ContainerAction(containerID string, action string) error {
	var err error
	switch action {

	case "start":
		_, err = d.dockerClient.ContainerStart(d.ctxDocker, containerID, client.ContainerStartOptions{})

	case "stop":
		_, err = d.dockerClient.ContainerStop(d.ctxDocker, containerID, client.ContainerStopOptions{})

	case "restart":
		_, err = d.dockerClient.ContainerRestart(d.ctxDocker, containerID, client.ContainerRestartOptions{})

	case "pause":
		_, err = d.dockerClient.ContainerPause(d.ctxDocker, containerID, client.ContainerPauseOptions{})

	case "unpause":
		_, err = d.dockerClient.ContainerUnpause(d.ctxDocker, containerID, client.ContainerUnpauseOptions{})

	default:
		return fmt.Errorf("unknown docker action: %s", action)
	}
	if errdefs.IsNotFound(err) {
		return apperrors.ErrContainerNotFound
	} else {
		return err
	}
}

func (d *DockerInfo) GetContainerLogs(containerID string, tail int) (string, error) {
	opts := client.ContainerLogsOptions{
		ShowStdout: true,
		ShowStderr: true,
	}
	if tail != 0 {
		opts.Tail = strconv.Itoa(tail)
	}

	reader, err := d.dockerClient.ContainerLogs(d.ctxDocker, containerID, opts)
	if err != nil {
		if errdefs.IsNotFound(err) {
			return "", apperrors.ErrContainerNotFound
		} else {
			return "", err
		}
	}

	defer reader.Close()

	var stdoutBuf bytes.Buffer
	var stderrBuf bytes.Buffer

	_, err = stdcopy.StdCopy(&stdoutBuf, &stderrBuf, reader)
	if err != nil && err != io.EOF {
		return "", err
	}

	out := "\n\n⚠️ STDOUT:\n" + stdoutBuf.String()
	errOut := stderrBuf.String()

	if errOut != "" {
		out += "\n\n⚠️ STDERR:\n" + errOut
	}

	return out, nil
}

func strToTime(date string) time.Time {
	t, err := time.Parse(time.RFC3339Nano, date)
	if err != nil {
		t = time.Time{}
	}
	return t
}