package docker

import (
	"fmt"
	"sort"
	"strings"

	"github.com/caarlos0/log"
	"github.com/goreleaser/goreleaser/internal/artifact"
	"github.com/goreleaser/goreleaser/internal/ids"
	"github.com/goreleaser/goreleaser/internal/pipe"
	"github.com/goreleaser/goreleaser/internal/semerrgroup"
	"github.com/goreleaser/goreleaser/internal/tmpl"
	"github.com/goreleaser/goreleaser/pkg/config"
	"github.com/goreleaser/goreleaser/pkg/context"
)

// ManifestPipe is an implementation for the docker manifest feature,
// allowing to publish multi-arch docker images.
type ManifestPipe struct{}

func (ManifestPipe) String() string { return "docker manifests" }
func (ManifestPipe) Skip(ctx *context.Context) bool {
	return len(ctx.Config.DockerManifests) == 0 || ctx.SkipDocker
}

// Default sets the pipe defaults.
func (ManifestPipe) Default(ctx *context.Context) error {
	ids := ids.New("docker_manifests")
	for i := range ctx.Config.DockerManifests {
		manifest := &ctx.Config.DockerManifests[i]
		if manifest.ID != "" {
			ids.Inc(manifest.ID)
		}
		if manifest.Use == "" {
			manifest.Use = useDocker
		}
		if err := validateManifester(manifest.Use); err != nil {
			return err
		}
	}
	return ids.Validate()
}

// Publish the docker manifests.
func (ManifestPipe) Publish(ctx *context.Context) error {
	g := semerrgroup.NewSkipAware(semerrgroup.New(1))
	for _, manifest := range ctx.Config.DockerManifests {
		manifest := manifest
		g.Go(func() error {
			if strings.TrimSpace(manifest.SkipPush) == "true" {
				return pipe.Skip("docker_manifest.skip_push is set")
			}

			if strings.TrimSpace(manifest.SkipPush) == "auto" && ctx.Semver.Prerelease != "" {
				return pipe.Skip("prerelease detected with 'auto' push, skipping docker manifest")
			}

			name, err := manifestName(ctx, manifest)
			if err != nil {
				return err
			}

			images, err := manifestImages(ctx, manifest)
			if err != nil {
				return err
			}

			manifester := manifesters[manifest.Use]

			log.WithField("manifest", name).WithField("images", images).Info("creating")
			if err := manifester.Create(ctx, name, images, manifest.CreateFlags); err != nil {
				return err
			}
			art := &artifact.Artifact{
				Type:  artifact.DockerManifest,
				Name:  name,
				Path:  name,
				Extra: map[string]interface{}{},
			}
			if manifest.ID != "" {
				art.Extra[artifact.ExtraID] = manifest.ID
			}

			log.WithField("manifest", name).Info("pushing")
			digest, err := manifester.Push(ctx, name, manifest.PushFlags)
			if err != nil {
				return err
			}
			art.Extra[artifact.ExtraDigest] = digest
			ctx.Artifacts.Add(art)
			return nil
		})
	}
	return g.Wait()
}

func validateManifester(use string) error {
	valid := make([]string, 0, len(manifesters))
	for k := range manifesters {
		valid = append(valid, k)
	}
	for _, s := range valid {
		if s == use {
			return nil
		}
	}
	sort.Strings(valid)
	return fmt.Errorf("docker manifest: invalid use: %s, valid options are %v", use, valid)
}

func manifestName(ctx *context.Context, manifest config.DockerManifest) (string, error) {
	name, err := tmpl.New(ctx).Apply(manifest.NameTemplate)
	if err != nil {
		return name, err
	}
	if strings.TrimSpace(name) == "" {
		return name, pipe.Skip("manifest name is empty")
	}
	return name, nil
}

func manifestImages(ctx *context.Context, manifest config.DockerManifest) ([]string, error) {
	artifacts := ctx.Artifacts.Filter(artifact.ByType(artifact.DockerImage)).List()
	imgs := make([]string, 0, len(manifest.ImageTemplates))
	for _, img := range manifest.ImageTemplates {
		str, err := tmpl.New(ctx).Apply(img)
		if err != nil {
			return []string{}, err
		}
		imgs = append(imgs, withDigest(manifest.Use, str, artifacts))
	}
	if strings.TrimSpace(strings.Join(manifest.ImageTemplates, "")) == "" {
		return imgs, pipe.Skip("manifest has no images")
	}
	return imgs, nil
}

func withDigest(use, name string, images []*artifact.Artifact) string {
	for _, art := range images {
		if art.Name == name {
			if digest := artifact.ExtraOr(*art, artifact.ExtraDigest, ""); digest != "" {
				return name + "@" + digest
			}
			break
		}
	}
	log.Warnf("did not find the digest for %s using %s, defaulting to insecure mode", name, use)
	return name
}
