package main

import (
	"fmt"
	"os/exec"
	"strings"

	"github.com/docker/docker/pkg/integration/checker"
	"github.com/go-check/check"
)

// TestPullImageWithAliases pulls a specific image tag and verifies that any aliases (i.e., other
// tags for the same image) are not also pulled down.
//
// Ref: docker/docker#8141
func (s *DockerRegistrySuite) TestPullImageWithAliases(c *check.C) {
	repoName := fmt.Sprintf("%v/dockercli/busybox", privateRegistryURL)

	repos := []string{}
	for _, tag := range []string{"recent", "fresh"} {
		repos = append(repos, fmt.Sprintf("%v:%v", repoName, tag))
	}

	// Tag and push the same image multiple times.
	for _, repo := range repos {
		dockerCmd(c, "tag", "busybox", repo)
		dockerCmd(c, "push", repo)
	}

	// Clear local images store.
	args := append([]string{"rmi"}, repos...)
	dockerCmd(c, args...)

	// Pull a single tag and verify it doesn't bring down all aliases.
	dockerCmd(c, "pull", repos[0])
	dockerCmd(c, "inspect", repos[0])
	for _, repo := range repos[1:] {
		_, _, err := dockerCmdWithError("inspect", repo)
		c.Assert(err, checker.NotNil, check.Commentf("Image %v shouldn't have been pulled down", repo))
	}
}

// TestConcurrentPullWholeRepo pulls the same repo concurrently.
func (s *DockerRegistrySuite) TestConcurrentPullWholeRepo(c *check.C) {
	repoName := fmt.Sprintf("%v/dockercli/busybox", privateRegistryURL)

	repos := []string{}
	for _, tag := range []string{"recent", "fresh", "todays"} {
		repo := fmt.Sprintf("%v:%v", repoName, tag)
		_, err := buildImage(repo, fmt.Sprintf(`
		    FROM busybox
		    ENTRYPOINT ["/bin/echo"]
		    ENV FOO foo
		    ENV BAR bar
		    CMD echo %s
		`, repo), true)
		c.Assert(err, checker.IsNil)
		dockerCmd(c, "push", repo)
		repos = append(repos, repo)
	}

	// Clear local images store.
	args := append([]string{"rmi"}, repos...)
	dockerCmd(c, args...)

	// Run multiple re-pulls concurrently
	results := make(chan error)
	numPulls := 3

	for i := 0; i != numPulls; i++ {
		go func() {
			_, _, err := runCommandWithOutput(exec.Command(dockerBinary, "pull", "-a", repoName))
			results <- err
		}()
	}

	// These checks are separate from the loop above because the check
	// package is not goroutine-safe.
	for i := 0; i != numPulls; i++ {
		err := <-results
		c.Assert(err, checker.IsNil, check.Commentf("concurrent pull failed with error: %v", err))
	}

	// Ensure all tags were pulled successfully
	for _, repo := range repos {
		dockerCmd(c, "inspect", repo)
		out, _ := dockerCmd(c, "run", "--rm", repo)
		c.Assert(strings.TrimSpace(out), checker.Equals, "/bin/sh -c echo "+repo)
	}
}

// TestConcurrentFailingPull tries a concurrent pull that doesn't succeed.
func (s *DockerRegistrySuite) TestConcurrentFailingPull(c *check.C) {
	repoName := fmt.Sprintf("%v/dockercli/busybox", privateRegistryURL)

	// Run multiple pulls concurrently
	results := make(chan error)
	numPulls := 3

	for i := 0; i != numPulls; i++ {
		go func() {
			_, _, err := runCommandWithOutput(exec.Command(dockerBinary, "pull", repoName+":asdfasdf"))
			results <- err
		}()
	}

	// These checks are separate from the loop above because the check
	// package is not goroutine-safe.
	for i := 0; i != numPulls; i++ {
		err := <-results
		c.Assert(err, checker.NotNil, check.Commentf("expected pull to fail"))
	}
}

// TestConcurrentPullMultipleTags pulls multiple tags from the same repo
// concurrently.
func (s *DockerRegistrySuite) TestConcurrentPullMultipleTags(c *check.C) {
	repoName := fmt.Sprintf("%v/dockercli/busybox", privateRegistryURL)

	repos := []string{}
	for _, tag := range []string{"recent", "fresh", "todays"} {
		repo := fmt.Sprintf("%v:%v", repoName, tag)
		_, err := buildImage(repo, fmt.Sprintf(`
		    FROM busybox
		    ENTRYPOINT ["/bin/echo"]
		    ENV FOO foo
		    ENV BAR bar
		    CMD echo %s
		`, repo), true)
		c.Assert(err, checker.IsNil)
		dockerCmd(c, "push", repo)
		repos = append(repos, repo)
	}

	// Clear local images store.
	args := append([]string{"rmi"}, repos...)
	dockerCmd(c, args...)

	// Re-pull individual tags, in parallel
	results := make(chan error)

	for _, repo := range repos {
		go func(repo string) {
			_, _, err := runCommandWithOutput(exec.Command(dockerBinary, "pull", repo))
			results <- err
		}(repo)
	}

	// These checks are separate from the loop above because the check
	// package is not goroutine-safe.
	for range repos {
		err := <-results
		c.Assert(err, checker.IsNil, check.Commentf("concurrent pull failed with error: %v", err))
	}

	// Ensure all tags were pulled successfully
	for _, repo := range repos {
		dockerCmd(c, "inspect", repo)
		out, _ := dockerCmd(c, "run", "--rm", repo)
		c.Assert(strings.TrimSpace(out), checker.Equals, "/bin/sh -c echo "+repo)
	}
}

// TestPullIDStability verifies that pushing an image and pulling it back
// preserves the image ID.
func (s *DockerRegistrySuite) TestPullIDStability(c *check.C) {
	derivedImage := privateRegistryURL + "/dockercli/id-stability"
	baseImage := "busybox"

	_, err := buildImage(derivedImage, fmt.Sprintf(`
	    FROM %s
	    ENV derived true
	    ENV asdf true
	    RUN dd if=/dev/zero of=/file bs=1024 count=1024
	    CMD echo %s
	`, baseImage, derivedImage), true)
	if err != nil {
		c.Fatal(err)
	}

	originalID, err := getIDByName(derivedImage)
	if err != nil {
		c.Fatalf("error inspecting: %v", err)
	}
	dockerCmd(c, "push", derivedImage)

	// Pull
	out, _ := dockerCmd(c, "pull", derivedImage)
	if strings.Contains(out, "Pull complete") {
		c.Fatalf("repull redownloaded a layer: %s", out)
	}

	derivedIDAfterPull, err := getIDByName(derivedImage)
	if err != nil {
		c.Fatalf("error inspecting: %v", err)
	}

	if derivedIDAfterPull != originalID {
		c.Fatal("image's ID unexpectedly changed after a repush/repull")
	}

	// Make sure the image runs correctly
	out, _ = dockerCmd(c, "run", "--rm", derivedImage)
	if strings.TrimSpace(out) != derivedImage {
		c.Fatalf("expected %s; got %s", derivedImage, out)
	}

	// Confirm that repushing and repulling does not change the computed ID
	dockerCmd(c, "push", derivedImage)
	dockerCmd(c, "rmi", derivedImage)
	dockerCmd(c, "pull", derivedImage)

	derivedIDAfterPull, err = getIDByName(derivedImage)
	if err != nil {
		c.Fatalf("error inspecting: %v", err)
	}

	if derivedIDAfterPull != originalID {
		c.Fatal("image's ID unexpectedly changed after a repush/repull")
	}
	if err != nil {
		c.Fatalf("error inspecting: %v", err)
	}

	// Make sure the image still runs
	out, _ = dockerCmd(c, "run", "--rm", derivedImage)
	if strings.TrimSpace(out) != derivedImage {
		c.Fatalf("expected %s; got %s", derivedImage, out)
	}
}