package docker

import (
    "context"
    "github.com/docker/docker/api/types"
    "github.com/docker/docker/api/types/events"
    "github.com/docker/docker/client"
    "io"
    "log"
    "sort"
    "strings"
)

type dockerClient struct {
    cli *client.Client
}

type DockerClient interface {
    ListContainers() ([]Container, error)
    ContainerLogs(ctx context.Context, id string) (io.ReadCloser, error)
    Events(ctx context.Context) (<-chan events.Message, <-chan error)
}

func NewDockerClient() DockerClient {
    cli, err := client.NewClientWithOpts(client.FromEnv)
    if err != nil {
        log.Fatal(err)
    }
    return &dockerClient{cli}
}

func (d *dockerClient) ListContainers() ([]Container, error) {
    list, err := d.cli.ContainerList(context.Background(), types.ContainerListOptions{})
    if err != nil {
        return nil, err
    }

    var containers []Container
    for _, c := range list {

        container := Container{
            ID:      c.ID[:12],
            Names:   c.Names,
            Name:    strings.TrimPrefix(c.Names[0], "/"),
            Image:   c.Image,
            ImageID: c.ImageID,
            Command: c.Command,
            Created: c.Created,
            State:   c.State,
            Status:  c.Status,
        }
        containers = append(containers, container)
    }

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

    return containers, nil
}

func (d *dockerClient) ContainerLogs(ctx context.Context, id string) (io.ReadCloser, error) {
    options := types.ContainerLogsOptions{ShowStdout: true, ShowStderr: true, Follow: true, Tail: "300", Timestamps: true}
    return d.cli.ContainerLogs(ctx, id, options)
}

func (d *dockerClient) Events(ctx context.Context) (<-chan events.Message, <-chan error) {
    return d.cli.Events(ctx, types.EventsOptions{})
}