package azure

import (
	"context"
	"fmt"
	"io"
	"net/http"
	"time"

	"github.com/Azure/azure-sdk-for-go/services/containerinstance/mgmt/2018-10-01/containerinstance"
	"github.com/Azure/go-autorest/autorest"
	"github.com/Azure/go-autorest/autorest/to"
	tm "github.com/buger/goterm"
	"github.com/gobwas/ws"
	"github.com/gobwas/ws/wsutil"
	"github.com/pkg/errors"

	"github.com/docker/api/azure/login"
	"github.com/docker/api/context/store"
	"github.com/docker/api/progress"
)

const aciDockerUserAgent = "docker-cli"

func createACIContainers(ctx context.Context, aciContext store.AciContext, groupDefinition containerinstance.ContainerGroup) error {
	containerGroupsClient, err := getContainerGroupsClient(aciContext.SubscriptionID)
	if err != nil {
		return errors.Wrapf(err, "cannot get container group client")
	}

	// Check if the container group already exists
	_, err = containerGroupsClient.Get(ctx, aciContext.ResourceGroup, *groupDefinition.Name)
	if err != nil {
		if err, ok := err.(autorest.DetailedError); ok {
			if err.StatusCode != http.StatusNotFound {
				return err
			}
		} else {
			return err
		}
	} else {
		return fmt.Errorf("container group %q already exists", *groupDefinition.Name)
	}

	return createOrUpdateACIContainers(ctx, aciContext, groupDefinition)
}

func createOrUpdateACIContainers(ctx context.Context, aciContext store.AciContext, groupDefinition containerinstance.ContainerGroup) error {
	w := progress.ContextWriter(ctx)
	containerGroupsClient, err := getContainerGroupsClient(aciContext.SubscriptionID)
	if err != nil {
		return errors.Wrapf(err, "cannot get container group client")
	}
	w.Event(progress.Event{
		ID:         *groupDefinition.Name,
		Status:     progress.Working,
		StatusText: "Waiting",
	})

	future, err := containerGroupsClient.CreateOrUpdate(
		ctx,
		aciContext.ResourceGroup,
		*groupDefinition.Name,
		groupDefinition,
	)
	if err != nil {
		return err
	}

	w.Event(progress.Event{
		ID:         *groupDefinition.Name,
		Status:     progress.Done,
		StatusText: "Created",
	})
	for _, c := range *groupDefinition.Containers {
		w.Event(progress.Event{
			ID:         *c.Name,
			Status:     progress.Working,
			StatusText: "Waiting",
		})
	}

	err = future.WaitForCompletionRef(ctx, containerGroupsClient.Client)
	if err != nil {
		return err
	}

	for _, c := range *groupDefinition.Containers {
		w.Event(progress.Event{
			ID:         *c.Name,
			Status:     progress.Done,
			StatusText: "Done",
		})
	}

	return err
}

func getACIContainerGroup(ctx context.Context, aciContext store.AciContext, containerGroupName string) (containerinstance.ContainerGroup, error) {
	containerGroupsClient, err := getContainerGroupsClient(aciContext.SubscriptionID)
	if err != nil {
		return containerinstance.ContainerGroup{}, fmt.Errorf("cannot get container group client: %v", err)
	}

	return containerGroupsClient.Get(ctx, aciContext.ResourceGroup, containerGroupName)
}

func deleteACIContainerGroup(ctx context.Context, aciContext store.AciContext, containerGroupName string) (containerinstance.ContainerGroup, error) {
	containerGroupsClient, err := getContainerGroupsClient(aciContext.SubscriptionID)
	if err != nil {
		return containerinstance.ContainerGroup{}, fmt.Errorf("cannot get container group client: %v", err)
	}

	return containerGroupsClient.Delete(ctx, aciContext.ResourceGroup, containerGroupName)
}

func execACIContainer(ctx context.Context, aciContext store.AciContext, command, containerGroup string, containerName string) (c containerinstance.ContainerExecResponse, err error) {
	containerClient, err := getContainerClient(aciContext.SubscriptionID)
	if err != nil {
		return c, errors.Wrapf(err, "cannot get container client")
	}
	rows, cols := getTermSize()
	containerExecRequest := containerinstance.ContainerExecRequest{
		Command: to.StringPtr(command),
		TerminalSize: &containerinstance.ContainerExecRequestTerminalSize{
			Rows: rows,
			Cols: cols,
		},
	}

	return containerClient.ExecuteCommand(
		ctx,
		aciContext.ResourceGroup,
		containerGroup,
		containerName,
		containerExecRequest)
}

func getTermSize() (*int32, *int32) {
	rows := tm.Height()
	cols := tm.Width()
	return to.Int32Ptr(int32(rows)), to.Int32Ptr(int32(cols))
}

func exec(ctx context.Context, address string, password string, reader io.Reader, writer io.Writer) error {
	conn, _, _, err := ws.DefaultDialer.Dial(ctx, address)
	if err != nil {
		return err
	}
	err = wsutil.WriteClientMessage(conn, ws.OpText, []byte(password))
	if err != nil {
		return err
	}

	downstreamChannel := make(chan error, 10)
	upstreamChannel := make(chan error, 10)

	go func() {
		for {
			msg, _, err := wsutil.ReadServerData(conn)
			if err != nil {
				if err == io.EOF {
					downstreamChannel <- nil
					return
				}
				downstreamChannel <- err
				return
			}
			fmt.Fprint(writer, string(msg))
		}
	}()

	go func() {
		for {
			// We send each byte, byte-per-byte over the
			// websocket because the console is in raw mode
			buffer := make([]byte, 1)
			n, err := reader.Read(buffer)
			if err != nil {
				if err == io.EOF {
					upstreamChannel <- nil
					return
				}
				upstreamChannel <- err
				return
			}

			if n > 0 {
				err := wsutil.WriteClientMessage(conn, ws.OpText, buffer)
				if err != nil {
					upstreamChannel <- err
					return
				}
			}
		}
	}()

	for {
		select {
		case err := <-downstreamChannel:
			return errors.Wrap(err, "failed to read input from container")
		case err := <-upstreamChannel:
			return errors.Wrap(err, "failed to send input to container")
		}
	}
}

func getACIContainerLogs(ctx context.Context, aciContext store.AciContext, containerGroupName, containerName string) (string, error) {
	containerClient, err := getContainerClient(aciContext.SubscriptionID)
	if err != nil {
		return "", errors.Wrapf(err, "cannot get container client")
	}

	logs, err := containerClient.ListLogs(ctx, aciContext.ResourceGroup, containerGroupName, containerName, nil)
	if err != nil {
		return "", fmt.Errorf("cannot get container logs: %v", err)
	}
	return *logs.Content, err
}

func getContainerGroupsClient(subscriptionID string) (containerinstance.ContainerGroupsClient, error) {
	containerGroupsClient := containerinstance.NewContainerGroupsClient(subscriptionID)
	err := setupClient(&containerGroupsClient.Client)
	if err != nil {
		return containerinstance.ContainerGroupsClient{}, err
	}
	containerGroupsClient.PollingDelay = 5 * time.Second
	containerGroupsClient.RetryAttempts = 30
	containerGroupsClient.RetryDuration = 1 * time.Second
	return containerGroupsClient, nil
}

func setupClient(aciClient *autorest.Client) error {
	aciClient.UserAgent = aciDockerUserAgent
	auth, err := login.NewAuthorizerFromLogin()
	if err != nil {
		return err
	}
	aciClient.Authorizer = auth
	return nil
}

func getContainerClient(subscriptionID string) (containerinstance.ContainerClient, error) {
	containerClient := containerinstance.NewContainerClient(subscriptionID)
	err := setupClient(&containerClient.Client)
	if err != nil {
		return containerinstance.ContainerClient{}, err
	}
	return containerClient, nil
}