package inspect

import (
	"context"
	"fmt"
	"os"
	"regexp"
	"strings"
	"text/tabwriter"
	"text/template"

	"github.com/containers/podman/v2/cmd/podman/parse"
	"github.com/containers/podman/v2/cmd/podman/registry"
	"github.com/containers/podman/v2/cmd/podman/report"
	"github.com/containers/podman/v2/cmd/podman/validate"
	"github.com/containers/podman/v2/pkg/domain/entities"
	"github.com/pkg/errors"
	"github.com/sirupsen/logrus"
	"github.com/spf13/cobra"
)

const (
	// ImageType is the image type.
	ImageType = "image"
	// ContainerType is the container type.
	ContainerType = "container"
	// AllType can be of type ImageType or ContainerType.
	AllType = "all"
)

// Pull in configured json library
var json = registry.JSONLibrary()

// AddInspectFlagSet takes a command and adds the inspect flags and returns an
// InspectOptions object.
func AddInspectFlagSet(cmd *cobra.Command) *entities.InspectOptions {
	opts := entities.InspectOptions{}

	flags := cmd.Flags()
	flags.BoolVarP(&opts.Size, "size", "s", false, "Display total file size")
	flags.StringVarP(&opts.Format, "format", "f", "json", "Format the output to a Go template or json")
	flags.StringVarP(&opts.Type, "type", "t", AllType, fmt.Sprintf("Specify inspect-oject type (%q, %q or %q)", ImageType, ContainerType, AllType))

	validate.AddLatestFlag(cmd, &opts.Latest)
	return &opts
}

// Inspect inspects the specified container/image names or IDs.
func Inspect(namesOrIDs []string, options entities.InspectOptions) error {
	inspector, err := newInspector(options)
	if err != nil {
		return err
	}
	return inspector.inspect(namesOrIDs)
}

// inspector allows for inspecting images and containers.
type inspector struct {
	containerEngine entities.ContainerEngine
	imageEngine     entities.ImageEngine
	options         entities.InspectOptions
}

// newInspector creates a new inspector based on the specified options.
func newInspector(options entities.InspectOptions) (*inspector, error) {
	switch options.Type {
	case ImageType, ContainerType, AllType:
		// Valid types.
	default:
		return nil, errors.Errorf("invalid type %q: must be %q, %q or %q", options.Type, ImageType, ContainerType, AllType)
	}
	if options.Type == ImageType {
		if options.Latest {
			return nil, errors.Errorf("latest is not supported for type %q", ImageType)
		}
		if options.Size {
			return nil, errors.Errorf("size is not supported for type %q", ImageType)
		}
	}
	return &inspector{
		containerEngine: registry.ContainerEngine(),
		imageEngine:     registry.ImageEngine(),
		options:         options,
	}, nil
}

// inspect inspects the specified container/image names or IDs.
func (i *inspector) inspect(namesOrIDs []string) error {
	// data - dumping place for inspection results.
	var data []interface{} // nolint
	var errs []error
	ctx := context.Background()

	if len(namesOrIDs) == 0 {
		if !i.options.Latest {
			return errors.New("no containers or images specified")
		}
	}

	tmpType := i.options.Type
	if i.options.Latest {
		if len(namesOrIDs) > 0 {
			return errors.New("--latest and containers cannot be used together")
		}
		tmpType = ContainerType // -l works with --type=all
	}

	// Inspect - note that AllType requires us to expensively query one-by-one.
	switch tmpType {
	case AllType:
		allData, allErrs, err := i.inspectAll(ctx, namesOrIDs)
		if err != nil {
			return err
		}
		data = allData
		errs = allErrs
	case ImageType:
		imgData, allErrs, err := i.imageEngine.Inspect(ctx, namesOrIDs, i.options)
		if err != nil {
			return err
		}
		errs = allErrs
		for i := range imgData {
			data = append(data, imgData[i])
		}
	case ContainerType:
		ctrData, allErrs, err := i.containerEngine.ContainerInspect(ctx, namesOrIDs, i.options)
		if err != nil {
			return err
		}
		errs = allErrs
		for i := range ctrData {
			data = append(data, ctrData[i])
		}
	default:
		return errors.Errorf("invalid type %q: must be %q, %q or %q", i.options.Type, ImageType, ContainerType, AllType)
	}

	// Always print an empty array
	if data == nil {
		data = []interface{}{}
	}

	var err error
	switch {
	case parse.MatchesJSONFormat(i.options.Format) || i.options.Format == "":
		err = printJSON(data)
	default:
		row := inspectNormalize(i.options.Format)
		row = "{{range . }}" + report.NormalizeFormat(row) + "{{end}}"
		err = printTmpl(tmpType, row, data)
	}
	if err != nil {
		logrus.Errorf("Error printing inspect output: %v", err)
	}

	if len(errs) > 0 {
		if len(errs) > 1 {
			for _, err := range errs[1:] {
				fmt.Fprintf(os.Stderr, "error inspecting object: %v\n", err)
			}
		}
		return errors.Errorf("error inspecting object: %v", errs[0])
	}
	return nil
}

func printJSON(data []interface{}) error {
	enc := json.NewEncoder(os.Stdout)
	enc.SetIndent("", "     ")
	return enc.Encode(data)
}

func printTmpl(typ, row string, data []interface{}) error {
	t, err := template.New(typ + " inspect").Parse(row)
	if err != nil {
		return err
	}
	w := tabwriter.NewWriter(os.Stdout, 8, 2, 2, ' ', 0)
	return t.Execute(w, data)
}

func (i *inspector) inspectAll(ctx context.Context, namesOrIDs []string) ([]interface{}, []error, error) {
	var data []interface{} // nolint
	allErrs := []error{}
	for _, name := range namesOrIDs {
		ctrData, errs, err := i.containerEngine.ContainerInspect(ctx, []string{name}, i.options)
		if err != nil {
			return nil, nil, err
		}
		if len(errs) == 0 {
			data = append(data, ctrData[0])
			continue
		}
		imgData, errs, err := i.imageEngine.Inspect(ctx, []string{name}, i.options)
		if err != nil {
			return nil, nil, err
		}
		if len(errs) > 0 {
			allErrs = append(allErrs, errors.Errorf("no such object: %q", name))
			continue
		}
		data = append(data, imgData[0])
	}
	return data, allErrs, nil
}

func inspectNormalize(row string) string {
	m := regexp.MustCompile(`{{\s*\.Id\s*}}`)
	row = m.ReplaceAllString(row, "{{.ID}}")

	r := strings.NewReplacer(
		".Src", ".Source",
		".Dst", ".Destination",
		".ImageID", ".Image",
	)
	return r.Replace(row)
}