package builder

import (
	"context"
	"errors"
	"reflect"
	"strings"
	"testing"
)

// A build killed by hand (novox/hq ADR 0219) ends every command it started: the context's end kills
// the command's whole process group, not the one process the context knows about.

// Every `docker run` a build starts carries its id as a label; nothing else is touched.
func TestEveryContainerABuildStartsCarriesItsID(t *testing.T) {
	got := LabelledArgs("docker", []string{"run", "--rm", "img", "sh"}, "build-1")
	if want := []string{"run", "--label", "mesh.build=build-1", "--rm", "img", "sh"}; !reflect.DeepEqual(got, want) {
		t.Errorf("docker run became %v", got)
	}
	for _, c := range []struct {
		name string
		args []string
	}{{"docker", []string{"build", "."}}, {"git", []string{"run"}}, {"docker", nil}} {
		if got := LabelledArgs(c.name, c.args, "build-1"); !reflect.DeepEqual(got, c.args) {
			t.Errorf("%s %v became %v", c.name, c.args, got)
		}
	}
	var ran [][]string
	run := Labelled(func(_ context.Context, _ string, name string, args ...string) (string, error) {
		ran = append(ran, append([]string{name}, args...))
		return "", nil
	}, "build-2")
	_, _ = run(context.Background(), "", "docker", "run", "img")
	if want := [][]string{{"docker", "run", "--label", "mesh.build=build-2", "img"}}; !reflect.DeepEqual(ran, want) {
		t.Errorf("ran %v", ran)
	}
}

// What a kill removes is found by the label, and only what it finds.
func TestAKillRemovesTheContainersLabelledWithTheBuild(t *testing.T) {
	var ran []string
	run := func(_ context.Context, _ string, name string, args ...string) (string, error) {
		ran = append(ran, name+" "+strings.Join(args, " "))
		if args[0] == "ps" {
			return "c1\nc2\n", nil
		}
		return "", nil
	}
	n, err := RemoveContainersOf(context.Background(), run, "build-3")
	if err != nil || n != 2 {
		t.Fatalf("%d %v", n, err)
	}
	if want := []string{"docker ps -aq --filter label=mesh.build=build-3", "docker inspect --format " + MountedVolumes + " c1 c2",
		"docker rm -f -v c1 c2"}; !reflect.DeepEqual(ran, want) {
		t.Errorf("ran %v", ran)
	}
}

// **Issue 306**: a holder starting removes what earlier holders on its machine left — every container
// labelled with an ask of the seat — and nothing labelled otherwise.
func TestAStartingHolderRemovesWhatEarlierHoldersLeftAndNothingElse(t *testing.T) {
	var ran [][]string
	run := func(_ context.Context, _ string, name string, args ...string) (string, error) {
		ran = append(ran, append([]string{name}, args...))
		if args[0] == "ps" {
			return "c1 build-1791418000320743455\nc2 build-1791418000320743455\n" +
				"c3 check-here-1791418000320743455\nc4 check-test-17\nc5 build-x\nc6 build-\n\nc7 build-1791319895953076871\n", nil
		}
		return "", nil
	}
	n, err := RemoveLeftBehind(context.Background(), run)
	if err != nil {
		t.Fatal(err)
	}
	if n != 3 {
		t.Errorf("removed %d", n)
	}
	if len(ran) != 3 || !reflect.DeepEqual(ran[2], []string{"docker", "rm", "-f", "-v", "c1", "c2", "c7"}) {
		t.Fatalf("ran %v", ran)
	}
	if !strings.Contains(strings.Join(ran[0], " "), "--filter label=mesh.build") {
		t.Errorf("listed with %v", ran[0])
	}

	// Nothing left behind: nothing removed, and no rm asked.
	ran = nil
	quiet := func(_ context.Context, _ string, name string, args ...string) (string, error) {
		ran = append(ran, append([]string{name}, args...))
		return "c3 check-here-1\n", nil
	}
	if n, err := RemoveLeftBehind(context.Background(), quiet); err != nil || n != 0 || len(ran) != 1 {
		t.Errorf("with nothing of the seat's: %d %v %v", n, err, ran)
	}
}

// **Issue 1772**: a throwaway store declares its data directory a VOLUME, so docker makes an anonymous volume for
// it, and `docker rm -f` without -v leaves that volume behind (1,629 of them, 107 GB, on one build node). Every
// container a build or check removes is removed with its anonymous volumes (-v), and any volume the container
// mounted that is still there afterwards is removed by name — those, and only those, never a named volume.
func TestARemovedContainerTakesItsAnonymousVolumesWithIt(t *testing.T) {
	anon := strings.Repeat("a", 64)
	other := strings.Repeat("b", 64)
	var ran []string
	run := func(_ context.Context, _ string, name string, args ...string) (string, error) {
		ran = append(ran, name+" "+strings.Join(args, " "))
		switch args[0] {
		case "ps":
			return "c1\n", nil
		case "inspect":
			return anon + "\n" + "compose_data\n" + other + "\n", nil
		}
		return "", nil
	}
	if n, err := RemoveContainersOf(context.Background(), run, "build-4"); err != nil || n != 1 {
		t.Fatalf("%d %v", n, err)
	}
	last := ran[len(ran)-1]
	if want := "docker volume rm " + anon + " " + other; last != want {
		t.Errorf("last command %q, want %q", last, want)
	}
	if !strings.Contains(strings.Join(ran, "\n"), "docker rm -f -v c1") {
		t.Errorf("ran %v", ran)
	}
	if strings.Contains(last, "compose_data") {
		t.Errorf("a named volume was removed: %q", last)
	}
}

// A volume already gone when the sweep looks (rm -v took it) is no failure.
func TestAVolumeAlreadyGoneIsNoFailure(t *testing.T) {
	run := func(_ context.Context, _ string, name string, args ...string) (string, error) {
		switch args[0] {
		case "ps":
			return "c1\n", nil
		case "inspect":
			return strings.Repeat("c", 64) + "\n", nil
		case "volume":
			return "", errors.New("no such volume")
		}
		return "", nil
	}
	if n, err := RemoveContainersOf(context.Background(), run, "build-5"); err != nil || n != 1 {
		t.Fatalf("%d %v", n, err)
	}
}

// A node's build slice limits everything a build or check starts (novox/hq issue 1798): with a parent
// set, every `docker run` joins it, so the node's CPU and IO weights and memory cap bind the container;
// with none set the arguments are as they always were.
func TestEveryContainerJoinsTheNodesBuildSlice(t *testing.T) {
	was := CgroupParent
	defer func() { CgroupParent = was }()
	CgroupParent = "meshbuild.slice"
	got := LabelledArgs("docker", []string{"run", "--rm", "img", "sh"}, "build-1")
	want := []string{"run", "--label", "mesh.build=build-1", "--cgroup-parent", "meshbuild.slice", "--rm", "img", "sh"}
	if !reflect.DeepEqual(got, want) {
		t.Errorf("1798/AC1: docker run became %v", got)
	}
	if got := LabelledArgs("docker", []string{"build", "."}, "build-1"); !reflect.DeepEqual(got, []string{"build", "."}) {
		t.Errorf("a docker build became %v", got)
	}
	CgroupParent = ""
	if got := LabelledArgs("docker", []string{"run", "img"}, "build-1"); !reflect.DeepEqual(got, []string{"run", "--label", "mesh.build=build-1", "img"}) {
		t.Errorf("1798/AC1: with no slice, docker run became %v", got)
	}
}