package main

import (
	"fmt"
	"regexp"
	"strings"
	"time"

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

// TestPullFromCentralRegistry pulls an image from the central registry and verifies that the client
// prints all expected output.
func (s *DockerHubPullSuite) TestPullFromCentralRegistry(c *check.C) {
	testRequires(c, DaemonIsLinux)
	out := s.Cmd(c, "pull", "hello-world")
	defer deleteImages("hello-world")

	c.Assert(out, checker.Contains, "Using default tag: latest", check.Commentf("expected the 'latest' tag to be automatically assumed"))
	c.Assert(out, checker.Contains, "Pulling from library/hello-world", check.Commentf("expected the 'library/' prefix to be automatically assumed"))
	c.Assert(out, checker.Contains, "Downloaded newer image for hello-world:latest")

	matches := regexp.MustCompile(`Digest: (.+)\n`).FindAllStringSubmatch(out, -1)
	c.Assert(len(matches), checker.Equals, 1, check.Commentf("expected exactly one image digest in the output"))
	c.Assert(len(matches[0]), checker.Equals, 2, check.Commentf("unexpected number of submatches for the digest"))
	_, err := digest.ParseDigest(matches[0][1])
	c.Check(err, checker.IsNil, check.Commentf("invalid digest %q in output", matches[0][1]))

	// We should have a single entry in images.
	img := strings.TrimSpace(s.Cmd(c, "images"))
	splitImg := strings.Split(img, "\n")
	c.Assert(splitImg, checker.HasLen, 2)
	c.Assert(splitImg[1], checker.Matches, `hello-world\s+latest.*?`, check.Commentf("invalid output for `docker images` (expected image and tag name"))
}

// TestPullNonExistingImage pulls non-existing images from the central registry, with different
// combinations of implicit tag and library prefix.
func (s *DockerHubPullSuite) TestPullNonExistingImage(c *check.C) {
	testRequires(c, DaemonIsLinux)
	for _, e := range []struct {
		Repo  string
		Alias string
	}{
		{"library/asdfasdf", "asdfasdf:foobar"},
		{"library/asdfasdf", "library/asdfasdf:foobar"},
		{"library/asdfasdf", "asdfasdf"},
		{"library/asdfasdf", "asdfasdf:latest"},
		{"library/asdfasdf", "library/asdfasdf"},
		{"library/asdfasdf", "library/asdfasdf:latest"},
	} {
		out, err := s.CmdWithError("pull", e.Alias)
		c.Assert(err, checker.NotNil, check.Commentf("expected non-zero exit status when pulling non-existing image: %s", out))
		// Hub returns 401 rather than 404 for nonexistent repos over
		// the v2 protocol - but we should end up falling back to v1,
		// which does return a 404.
		c.Assert(out, checker.Contains, fmt.Sprintf("Error: image %s not found", e.Repo), check.Commentf("expected image not found error messages"))

		// pull -a on a nonexistent registry should fall back as well
		if !strings.ContainsRune(e.Alias, ':') {
			out, err := s.CmdWithError("pull", "-a", e.Alias)
			c.Assert(err, checker.NotNil, check.Commentf("expected non-zero exit status when pulling non-existing image: %s", out))
			c.Assert(out, checker.Contains, fmt.Sprintf("Error: image %s not found", e.Repo), check.Commentf("expected image not found error messages"))
			c.Assert(out, checker.Not(checker.Contains), "unauthorized", check.Commentf(`message should not contain "unauthorized"`))
		}
	}

}

// TestPullFromCentralRegistryImplicitRefParts pulls an image from the central registry and verifies
// that pulling the same image with different combinations of implicit elements of the the image
// reference (tag, repository, central registry url, ...) doesn't trigger a new pull nor leads to
// multiple images.
func (s *DockerHubPullSuite) TestPullFromCentralRegistryImplicitRefParts(c *check.C) {
	testRequires(c, DaemonIsLinux)
	s.Cmd(c, "pull", "hello-world")
	defer deleteImages("hello-world")

	for _, i := range []string{
		"hello-world",
		"hello-world:latest",
		"library/hello-world",
		"library/hello-world:latest",
		"docker.io/library/hello-world",
		"index.docker.io/library/hello-world",
	} {
		out := s.Cmd(c, "pull", i)
		v1Retries := 0
		for strings.Contains(out, "this image was pulled from a legacy registry") {
			// Some network errors may cause fallbacks to the v1
			// protocol, which would violate the test's assumption
			// that it will get the same images. To make the test
			// more robust against these network glitches, allow a
			// few retries if we end up with a v1 pull.

			if v1Retries > 2 {
				c.Fatalf("too many v1 fallback incidents when pulling %s", i)
			}

			s.Cmd(c, "rmi", i)
			out = s.Cmd(c, "pull", i)

			v1Retries++
		}
		c.Assert(out, checker.Contains, "Image is up to date for hello-world:latest")
	}

	// We should have a single entry in images.
	img := strings.TrimSpace(s.Cmd(c, "images"))
	splitImg := strings.Split(img, "\n")
	c.Assert(splitImg, checker.HasLen, 2)
	c.Assert(splitImg[1], checker.Matches, `hello-world\s+latest.*?`, check.Commentf("invalid output for `docker images` (expected image and tag name"))
}

// TestPullScratchNotAllowed verifies that pulling 'scratch' is rejected.
func (s *DockerHubPullSuite) TestPullScratchNotAllowed(c *check.C) {
	testRequires(c, DaemonIsLinux)
	out, err := s.CmdWithError("pull", "scratch")
	c.Assert(err, checker.NotNil, check.Commentf("expected pull of scratch to fail"))
	c.Assert(out, checker.Contains, "'scratch' is a reserved name")
	c.Assert(out, checker.Not(checker.Contains), "Pulling repository scratch")
}

// TestPullAllTagsFromCentralRegistry pulls using `all-tags` for a given image and verifies that it
// results in more images than a naked pull.
func (s *DockerHubPullSuite) TestPullAllTagsFromCentralRegistry(c *check.C) {
	testRequires(c, DaemonIsLinux)
	s.Cmd(c, "pull", "busybox")
	outImageCmd := s.Cmd(c, "images", "busybox")
	splitOutImageCmd := strings.Split(strings.TrimSpace(outImageCmd), "\n")
	c.Assert(splitOutImageCmd, checker.HasLen, 2)

	s.Cmd(c, "pull", "--all-tags=true", "busybox")
	outImageAllTagCmd := s.Cmd(c, "images", "busybox")
	linesCount := strings.Count(outImageAllTagCmd, "\n")
	c.Assert(linesCount, checker.GreaterThan, 2, check.Commentf("pulling all tags should provide more than two images, got %s", outImageAllTagCmd))

	// Verify that the line for 'busybox:latest' is left unchanged.
	var latestLine string
	for _, line := range strings.Split(outImageAllTagCmd, "\n") {
		if strings.HasPrefix(line, "busybox") && strings.Contains(line, "latest") {
			latestLine = line
			break
		}
	}
	c.Assert(latestLine, checker.Not(checker.Equals), "", check.Commentf("no entry for busybox:latest found after pulling all tags"))
	splitLatest := strings.Fields(latestLine)
	splitCurrent := strings.Fields(splitOutImageCmd[1])

	// Clear relative creation times, since these can easily change between
	// two invocations of "docker images". Without this, the test can fail
	// like this:
	// ... obtained []string = []string{"busybox", "latest", "d9551b4026f0", "27", "minutes", "ago", "1.113", "MB"}
	// ... expected []string = []string{"busybox", "latest", "d9551b4026f0", "26", "minutes", "ago", "1.113", "MB"}
	splitLatest[3] = ""
	splitLatest[4] = ""
	splitLatest[5] = ""
	splitCurrent[3] = ""
	splitCurrent[4] = ""
	splitCurrent[5] = ""

	c.Assert(splitLatest, checker.DeepEquals, splitCurrent, check.Commentf("busybox:latest was changed after pulling all tags"))
}

// TestPullClientDisconnect kills the client during a pull operation and verifies that the operation
// gets cancelled.
//
// Ref: docker/docker#15589
func (s *DockerHubPullSuite) TestPullClientDisconnect(c *check.C) {
	testRequires(c, DaemonIsLinux)
	repoName := "hello-world:latest"

	pullCmd := s.MakeCmd("pull", repoName)
	stdout, err := pullCmd.StdoutPipe()
	c.Assert(err, checker.IsNil)
	err = pullCmd.Start()
	c.Assert(err, checker.IsNil)

	// Cancel as soon as we get some output.
	buf := make([]byte, 10)
	_, err = stdout.Read(buf)
	c.Assert(err, checker.IsNil)

	err = pullCmd.Process.Kill()
	c.Assert(err, checker.IsNil)

	time.Sleep(2 * time.Second)
	_, err = s.CmdWithError("inspect", repoName)
	c.Assert(err, checker.NotNil, check.Commentf("image was pulled after client disconnected"))
}