package app

import (
	"context"
	"fmt"
	"io/ioutil"
	"path/filepath"
	"strconv"
	"strings"
	"time"

	"coopcloud.tech/abra/cli/internal"
	"coopcloud.tech/abra/pkg/autocomplete"
	"coopcloud.tech/abra/pkg/client"
	"coopcloud.tech/abra/pkg/config"
	containerPkg "coopcloud.tech/abra/pkg/container"
	"coopcloud.tech/abra/pkg/recipe"
	"coopcloud.tech/abra/pkg/upstream/container"
	"github.com/docker/cli/cli/command"
	"github.com/docker/docker/api/types"
	"github.com/docker/docker/api/types/filters"
	"github.com/sirupsen/logrus"
	"github.com/urfave/cli"
)

type backupConfig struct {
	preHookCmd  string
	postHookCmd string
	backupPaths []string
}

var appBackupCommand = cli.Command{
	Name:      "backup",
	Aliases:   []string{"bk"},
	Usage:     "Run app backup",
	ArgsUsage: "<domain> [<service>]",
	Flags: []cli.Flag{
		internal.DebugFlag,
	},
	Before:       internal.SubCommandBefore,
	BashComplete: autocomplete.AppNameComplete,
	Description: `
This command runs an app backup.

A backup command and pre/post hook commands are defined in the recipe
configuration. Abra reads this config and run the comands in the context of the
service. Pass <service> if you only want to back up a single service. All
backups are placed in the ~/.abra/backups directory.

Example:

    abra app backup example.com db
`,
	Action: func(c *cli.Context) error {
		app := internal.ValidateApp(c)

		recipe, err := recipe.Get(app.Recipe)
		if err != nil {
			logrus.Fatal(err)
		}

		backupConfigs := make(map[string]backupConfig)
		for _, service := range recipe.Config.Services {
			if backupsEnabled, ok := service.Deploy.Labels["backupbot.backup"]; ok {
				if backupsEnabled == "true" {
					fullServiceName := fmt.Sprintf("%s_%s", app.StackName(), service.Name)
					bkConfig := backupConfig{}

					logrus.Debugf("backup config detected for %s", fullServiceName)

					if paths, ok := service.Deploy.Labels["backupbot.backup.path"]; ok {
						logrus.Debugf("detected backup paths for %s: %s", fullServiceName, paths)
						bkConfig.backupPaths = strings.Split(paths, ",")
					}

					if preHookCmd, ok := service.Deploy.Labels["backupbot.backup.pre-hook"]; ok {
						logrus.Debugf("detected pre-hook command for %s: %s", fullServiceName, preHookCmd)
						bkConfig.preHookCmd = preHookCmd
					}

					if postHookCmd, ok := service.Deploy.Labels["backupbot.backup.post-hook"]; ok {
						logrus.Debugf("detected post-hook command for %s: %s", fullServiceName, postHookCmd)
						bkConfig.postHookCmd = postHookCmd
					}

					backupConfigs[service.Name] = bkConfig
				}
			}
		}

		serviceName := c.Args().Get(1)
		if serviceName != "" {
			backupConfig, ok := backupConfigs[serviceName]
			if !ok {
				logrus.Fatalf("no backup config for %s? does %s exist?", serviceName, serviceName)
			}
			if err := runBackup(app, serviceName, backupConfig); err != nil {
				logrus.Fatal(err)
			}
		} else {
			for serviceName, backupConfig := range backupConfigs {
				if err := runBackup(app, serviceName, backupConfig); err != nil {
					logrus.Fatal(err)
				}
			}
		}

		return nil
	},
}

// runBackup does the actual backup logic.
func runBackup(app config.App, serviceName string, bkConfig backupConfig) error {
	if len(bkConfig.backupPaths) == 0 {
		return fmt.Errorf("backup paths are empty for %s?", serviceName)
	}

	cl, err := client.New(app.Server)
	if err != nil {
		return err
	}

	// FIXME: avoid instantiating a new CLI
	dcli, err := command.NewDockerCli()
	if err != nil {
		return err
	}

	filters := filters.NewArgs()
	filters.Add("name", fmt.Sprintf("^%s_%s", app.StackName(), serviceName))

	targetContainer, err := containerPkg.GetContainer(context.Background(), cl, filters, true)
	if err != nil {
		return err
	}

	fullServiceName := fmt.Sprintf("%s_%s", app.StackName(), serviceName)
	if bkConfig.preHookCmd != "" {
		splitCmd := internal.SafeSplit(bkConfig.preHookCmd)

		logrus.Debugf("split pre-hook command for %s into %s", fullServiceName, splitCmd)

		preHookExecOpts := types.ExecConfig{
			AttachStderr: true,
			AttachStdin:  true,
			AttachStdout: true,
			Cmd:          splitCmd,
			Detach:       false,
			Tty:          true,
		}

		if err := container.RunExec(dcli, cl, targetContainer.ID, &preHookExecOpts); err != nil {
			return err
		}

		logrus.Infof("succesfully ran %s pre-hook command: %s", fullServiceName, bkConfig.preHookCmd)
	}

	for _, remoteBackupPath := range bkConfig.backupPaths {
		timestamp := strconv.Itoa(time.Now().Nanosecond())
		sanitisedPath := strings.ReplaceAll(remoteBackupPath, "/", "_")
		localBackupPath := filepath.Join(config.BACKUP_DIR, fmt.Sprintf("%s%s_%s.tar.gz", fullServiceName, sanitisedPath, timestamp))
		logrus.Debugf("backing up %s:%s to %s", fullServiceName, remoteBackupPath, localBackupPath)

		content, _, err := cl.CopyFromContainer(context.Background(), targetContainer.ID, remoteBackupPath)
		if err != nil {
			return err
		}
		defer content.Close()

		body, err := ioutil.ReadAll(content)
		if err != nil {
			return err
		}

		if err := ioutil.WriteFile(localBackupPath, body, 0644); err != nil {
			return err
		}

		logrus.Infof("backed up %s:%s to %s", fullServiceName, remoteBackupPath, localBackupPath)
	}

	if bkConfig.postHookCmd != "" {
		splitCmd := internal.SafeSplit(bkConfig.postHookCmd)

		logrus.Debugf("split post-hook command for %s into %s", fullServiceName, splitCmd)

		postHookExecOpts := types.ExecConfig{
			AttachStderr: true,
			AttachStdin:  true,
			AttachStdout: true,
			Cmd:          splitCmd,
			Detach:       false,
			Tty:          true,
		}

		if err := container.RunExec(dcli, cl, targetContainer.ID, &postHookExecOpts); err != nil {
			return err
		}

		logrus.Infof("succesfully ran %s post-hook command: %s", fullServiceName, bkConfig.postHookCmd)
	}

	return nil
}