package main

import (
	"context"
	"encoding/json"
	"errors"
	"io/fs"
	"os"
	"reflect"
	"strings"
	"testing"
	"time"
)

type call struct {
	name string
	args []string
}

// fake answers each command by the first rule whose prefix matches "name arg arg…".
type fake struct {
	rules []rule
	calls []call
}

type rule struct {
	prefix string
	ran    Ran
}

func (f *fake) on(prefix string, r Ran) *fake { f.rules = append(f.rules, rule{prefix, r}); return f }

func (f *fake) run(_ context.Context, name string, args ...string) Ran {
	f.calls = append(f.calls, call{name, args})
	line := strings.Join(append([]string{name}, args...), " ")
	for _, r := range f.rules {
		if strings.HasPrefix(line, r.prefix) {
			return r.ran
		}
	}
	return Ran{Status: 1, Stderr: "unexpected: " + line}
}

func (f *fake) ran(prefix string) bool {
	for _, c := range f.calls {
		if strings.HasPrefix(strings.Join(append([]string{c.name}, c.args...), " "), prefix) {
			return true
		}
	}
	return false
}

func client(f *fake, uid int) *Client {
	return &Client{Run: f.run, UID: uid, ReadFile: func(string) ([]byte, error) { return nil, fs.ErrNotExist },
		Now: func() time.Time { return time.Date(2026, 10, 4, 12, 0, 0, 0, time.UTC) }}
}

const held = `{"Id":"aaaaaaaaaaaaaaaa","Name":"/mesh-web","Created":"2026-10-01T00:00:00Z","Image":"sha256:img1",
 "Config":{"Image":"web:1","Labels":{"mesh-host.id":"hello-web.server","mesh-host.spec":"x"},"Env":["PASSWORD=hunter2","PATH=/bin"]},
 "State":{"Status":"running","Running":true,"StartedAt":"2026-10-01T00:00:01Z","FinishedAt":"0001-01-01T00:00:00Z","Health":{"Status":"healthy"}},
 "HostConfig":{"RestartPolicy":{"Name":"unless-stopped"},"NetworkMode":"bridge"},
 "NetworkSettings":{"Ports":{"80/tcp":[{"HostIp":"0.0.0.0","HostPort":"8080"}]}},
 "Mounts":[{"Type":"volume","Name":"webdata","Destination":"/data","RW":true}]}`

const stray = `{"Id":"bbbbbbbbbbbbbbbb","Name":"/dev-db","Created":"2026-09-01T00:00:00Z","Image":"sha256:img2",
 "Config":{"Image":"postgres:16","Labels":{"com.docker.compose.project":"dev","com.docker.compose.project.working_dir":"/home/op/dev"}},
 "State":{"Status":"exited","ExitCode":1,"FinishedAt":"2026-09-02T00:00:00Z"},
 "HostConfig":{"RestartPolicy":{"Name":"no"}},"NetworkSettings":{"Ports":{}},
 "Mounts":[{"Type":"volume","Name":"dbdata","Destination":"/var/lib/postgresql/data","RW":true}]}`

func machine() *fake {
	return (&fake{}).
		on("docker ps --all --quiet --no-trunc", Ran{Stdout: "aaaaaaaaaaaaaaaa\nbbbbbbbbbbbbbbbb\n"}).
		on("docker container inspect aaaaaaaaaaaaaaaa bbbbbbbbbbbbbbbb", Ran{Stdout: "[" + held + "," + stray + "]"}).
		on("docker container inspect mesh-web", Ran{Stdout: "[" + held + "]"}).
		on("docker container inspect dev-db", Ran{Stdout: "[" + stray + "]"})
}

func TestARefusedSocketIsAskedAgainThroughSudoWithoutAPromptUnlessThisIsRoot(t *testing.T) {
	denied := Ran{Status: 1, Stderr: "permission denied while trying to connect to the Docker daemon socket at unix:///var/run/docker.sock: Get ...: dial unix /var/run/docker.sock: connect: permission denied\n"}
	f := (&fake{}).on("docker ", denied).on("sudo -n docker info", Ran{Stdout: "{}"})
	if _, err := client(f, 1000).docker(context.Background(), "info", "--format", "{{json .}}"); err != nil {
		t.Fatal(err)
	}
	if !f.ran("sudo -n docker info --format") {
		t.Fatalf("not escalated: %+v", f.calls)
	}
	f = (&fake{}).on("docker ", denied)
	if _, err := client(f, 0).docker(context.Background(), "info"); err == nil || f.ran("sudo") {
		t.Fatalf("root escalated or answered: %v %+v", err, f.calls)
	}
}

func TestFailuresAreNamedByHowTheyFailed(t *testing.T) {
	denied := Ran{Status: 1, Stderr: "permission denied while trying to connect to the Docker daemon socket at unix:///var/run/docker.sock\n"}
	cases := map[string]*fake{
		"may not escalate without a prompt": (&fake{}).on("docker ", denied).on("sudo ", Ran{Status: 1, Stderr: "sudo: a password is required\n"}),
		"sudo is not installed":             (&fake{}).on("docker ", denied).on("sudo ", Ran{Status: 127, Err: "ENOENT"}),
		"docker is not installed":           (&fake{}).on("docker ", Ran{Status: 127, Err: "ENOENT"}),
		"daemon is not answering":           (&fake{}).on("docker ", Ran{Status: 1, Stderr: "Cannot connect to the Docker daemon at unix:///var/run/docker.sock. Is the docker daemon running?\n"}),
		"did not answer: no answer within":  (&fake{}).on("docker ", Ran{Status: 124, Err: "no answer within 20 s"}),
		"docker info failed (3): boom":      (&fake{}).on("docker ", Ran{Status: 3, Stderr: "boom\n"}),
	}
	for want, f := range cases {
		_, err := client(f, 1000).docker(context.Background(), "info")
		if err == nil || !strings.Contains(err.Error(), want) {
			t.Errorf("want %q, got %v", want, err)
		}
	}
}

func TestANameIsNeverAnOption(t *testing.T) {
	for _, bad := range []string{"--help", "-v", "", "a b", "x;y"} {
		if _, err := Ref(bad); err == nil {
			t.Errorf("%q accepted", bad)
		}
	}
	for _, good := range []string{"mesh-web", "aaaaaaaaaaaa", "registry.mesh.internal:5100/x@sha256:abc", "dev_db.1"} {
		if _, err := Ref(good); err != nil {
			t.Errorf("%q refused: %v", good, err)
		}
	}
	f := machine()
	for _, verb := range []string{"start", "stop", "restart"} {
		if _, err := client(f, 1000).Act(context.Background(), verb, "--rm"); err == nil {
			t.Errorf("%s took an option", verb)
		}
	}
	if len(f.calls) != 0 {
		t.Fatalf("docker was called: %+v", f.calls)
	}
}

func TestEveryContainerIsListedAndTheMeshsAreMarked(t *testing.T) {
	c := client(machine(), 1000)
	all, err := c.Containers(context.Background(), "", "", "")
	if err != nil || len(all) != 2 {
		t.Fatalf("%v %+v", err, all)
	}
	web, db := all[1], all[0]
	if !web.MeshHeld || web.HeldBy != "hello-web.server" || web.Module != "hello-web" || web.Health != "healthy" {
		t.Errorf("held: %+v", web)
	}
	if !reflect.DeepEqual(web.Ports, []string{"0.0.0.0:8080->80/tcp"}) || web.Mounts[0].Name != "webdata" {
		t.Errorf("ports/mounts: %+v", web)
	}
	if db.MeshHeld || db.Compose != "dev" || db.ComposeDir != "/home/op/dev" || db.FinishedAt == "" {
		t.Errorf("stray: %+v", db)
	}
	mesh, _ := c.Containers(context.Background(), "mesh", "", "")
	other, _ := c.Containers(context.Background(), "other", "", "")
	if len(mesh) != 1 || mesh[0].Name != "mesh-web" || len(other) != 1 || other[0].Name != "dev-db" {
		t.Errorf("held filter: %+v / %+v", mesh, other)
	}
	if _, err := c.Containers(context.Background(), "mine", "", ""); err == nil {
		t.Error("an unknown held filter was accepted")
	}
}

func TestNoContainersIsAnEmptyListAndAFailureIsAnError(t *testing.T) {
	got, err := client((&fake{}).on("docker ps", Ran{}), 1000).Containers(context.Background(), "", "", "")
	if err != nil || got == nil || len(got) != 0 {
		t.Fatalf("%v %v", got, err)
	}
	if _, err := client((&fake{}).on("docker ps", Ran{Status: 1, Stderr: "Cannot connect to the Docker daemon\n"}), 1000).Containers(context.Background(), "", "", ""); err == nil {
		t.Fatal("a daemon that does not answer read as no containers")
	}
}

func TestInspectLeavesTheEnvironmentsValuesOut(t *testing.T) {
	got, err := client(machine(), 1000).Inspect(context.Background(), "mesh-web")
	if err != nil {
		t.Fatal(err)
	}
	b, _ := json.Marshal(got)
	if strings.Contains(string(b), "hunter2") || !strings.Contains(string(b), `"PASSWORD"`) || got["mesh_held"] != true {
		t.Fatalf("%s", b)
	}
}

func TestActingOnAMeshContainerSaysTheHostRestoresIt(t *testing.T) {
	f := machine().on("docker stop", Ran{}).on("docker start", Ran{})
	got, err := client(f, 1000).Act(context.Background(), "stop", "mesh-web")
	if err != nil {
		t.Fatal(err)
	}
	if !f.ran("docker stop --time 10 mesh-web") || got["mesh_held"] != true || !strings.Contains(got["note"].(string), "host restores") {
		t.Fatalf("%v %+v", got, f.calls)
	}
	got, _ = client(f, 1000).Act(context.Background(), "start", "dev-db")
	if _, noted := got["note"]; noted || got["mesh_held"] != false {
		t.Fatalf("a stray was noted: %v", got)
	}
}

func TestPruneIsADryRunByDefaultAndNeverTouchesAVolumeOrAMeshContainer(t *testing.T) {
	f := machine().
		on("docker image ls --no-trunc --filter dangling=true", Ran{Stdout: `{"ID":"sha256:dead","Size":"1.5GB"}` + "\n"}).
		on("docker system df --format", Ran{Stdout: `{"Type":"Build Cache","TotalCount":"3","Size":"2GB","Reclaimable":"1GB"}` + "\n"}).
		on("docker image prune", Ran{Stdout: "Deleted Images:\nx\n\nTotal reclaimed space: 1.5GB\n"}).
		on("docker builder prune", Ran{Stdout: "Total:\t1GB\n"}).
		on("docker container rm", Ran{})
	c := client(f, 1000)
	got, err := c.Prune(context.Background(), PruneAsk{Images: true, BuildCache: true, Containers: true, DryRun: true})
	if err != nil {
		t.Fatal(err)
	}
	if f.ran("docker image prune") || f.ran("docker builder prune") || f.ran("docker container rm") {
		t.Fatalf("a dry run removed something: %+v", f.calls)
	}
	if got["images"].(map[string]any)["dangling"] != 1 || !reflect.DeepEqual(got["containers"].(map[string]any)["stopped_not_held"], []string{"dev-db"}) {
		t.Fatalf("%v", got)
	}
	got, err = c.Prune(context.Background(), PruneAsk{Images: true, BuildCache: true, Containers: true, OlderThanH: 24})
	if err != nil {
		t.Fatal(err)
	}
	if !f.ran("docker image prune --force --filter until=24h") || !f.ran("docker builder prune --force --filter until=24h") || !f.ran("docker container rm dev-db") {
		t.Fatalf("not pruned: %+v", f.calls)
	}
	for _, c := range f.calls {
		line := strings.Join(c.args, " ")
		if strings.Contains(line, "volume") || strings.Contains(line, "mesh-web") && c.args[0] != "container" || strings.Contains(line, "--volumes") || strings.Contains(line, "--all") && c.args[0] != "ps" {
			t.Errorf("prune reached too far: %s", line)
		}
	}
	if got["images"].(map[string]any)["reclaimed"] != "1.5GB" || got["build_cache"].(map[string]any)["reclaimed"] != "1GB" {
		t.Errorf("reclaimed: %v", got)
	}
}

func TestLogsMergeBothStreamsInOrderAndKeepTheTail(t *testing.T) {
	f := (&fake{}).on("docker logs", Ran{Stdout: "2026-10-04T10:00:01Z out one\n2026-10-04T10:00:03Z out two\n", Stderr: "2026-10-04T10:00:02Z err one\n"})
	got, err := client(f, 1000).Logs(context.Background(), "web", 2, "30m")
	if err != nil {
		t.Fatal(err)
	}
	if !reflect.DeepEqual(got["lines"], []string{"2026-10-04T10:00:02Z err one", "2026-10-04T10:00:03Z out two"}) {
		t.Fatalf("%v", got["lines"])
	}
	if !f.ran("docker logs --timestamps --tail 2 --since 30m web") {
		t.Fatalf("%+v", f.calls)
	}
	if _, err := client(f, 1000).Logs(context.Background(), "web", 2, "--follow"); err == nil {
		t.Fatal("since took an option")
	}
	f = (&fake{}).on("docker logs", Ran{Status: 1, Stderr: "Error response from daemon: No such container: nope\n"})
	if _, err := client(f, 1000).Logs(context.Background(), "nope", 2, ""); err == nil {
		t.Fatal("a missing container read as no lines")
	}
}

func TestSizesAreReadAsDockerPrintsThem(t *testing.T) {
	for in, want := range map[string]int64{"0B": 0, "55.63GB": 55630000000, "33.2MiB": 34812723, "1.5kB": 1500, "12MB (34%)": 12000000, "N/A": -1} {
		if got := Bytes(in); got != want {
			t.Errorf("%s: %d, want %d", in, got, want)
		}
	}
}

func TestDaemonConfigSaysWhatTheDaemonHasNotTakenYet(t *testing.T) {
	f := (&fake{}).on("docker info", Ran{Stdout: `{"ServerVersion":"29.8.2","LiveRestoreEnabled":false,"LoggingDriver":"json-file","RegistryConfig":{"IndexConfigs":{"docker.io":{"Secure":true},"registry.mesh.internal:5100":{"Secure":false}}}}`})
	c := client(f, 1000)
	c.ReadFile = func(string) ([]byte, error) {
		return []byte(`{"live-restore": true, "dns": ["10.0.0.1"], "log-driver": "local"}`), nil
	}
	got, err := c.DaemonConfig(context.Background())
	if err != nil {
		t.Fatal(err)
	}
	pending := strings.Join(got["pending"].([]string), "\n")
	if !strings.Contains(pending, "live-restore is true in the file and false") || !strings.Contains(pending, "log-driver is local") {
		t.Errorf("pending: %s", pending)
	}
	if !reflect.DeepEqual(got["daemon"].(map[string]any)["InsecureRegistries"], []string{"registry.mesh.internal:5100"}) {
		t.Errorf("registries: %v", got["daemon"])
	}
	if !reflect.DeepEqual(got["read_only_at_start"], []string{"dns", "log-driver"}) {
		t.Errorf("start-only: %v", got["read_only_at_start"])
	}
	c.ReadFile = func(string) ([]byte, error) { return nil, os.ErrNotExist }
	got, _ = c.DaemonConfig(context.Background())
	if !strings.HasPrefix(got["file_state"].(string), "absent") {
		t.Errorf("absent: %v", got["file_state"])
	}
	c.ReadFile = func(string) ([]byte, error) { return nil, errors.New("permission denied") }
	got, _ = c.DaemonConfig(context.Background())
	if !strings.HasPrefix(got["file_state"].(string), "unreadable") {
		t.Errorf("unreadable: %v", got["file_state"])
	}
}

func TestEventsAreABoundedWindowWithoutExecNoise(t *testing.T) {
	out := `{"Type":"container","Action":"exec_start: pg_isready","Actor":{"ID":"aaaaaaaaaaaaaaaa","Attributes":{"name":"db"}},"timeNano":1}
{"Type":"container","Action":"die","Actor":{"ID":"aaaaaaaaaaaaaaaa","Attributes":{"name":"web","mesh-host.id":"hello-web.server","exitCode":"137"}},"timeNano":2}
`
	f := (&fake{}).on("docker events", Ran{Stdout: out})
	got, err := client(f, 1000).Events(context.Background(), 30, "container", 10, false)
	if err != nil {
		t.Fatal(err)
	}
	evs := got["events"].([]map[string]any)
	if len(evs) != 1 || evs[0]["action"] != "die" || evs[0]["mesh_held"] != true || evs[0]["exit_code"] != "137" {
		t.Fatalf("%v", evs)
	}
	if !f.ran("docker events --since 30m --until 0s --format {{json .}} --filter type=container") {
		t.Fatalf("%+v", f.calls)
	}
	if _, err := client(f, 1000).Events(context.Background(), 30, "secret", 10, false); err == nil {
		t.Fatal("an unknown type was accepted")
	}
}

func TestVolumesSayWhoMountsThemAndWhetherTheMeshDoes(t *testing.T) {
	f := machine().
		on("docker volume ls --quiet", Ran{Stdout: "webdata\ndbdata\nloose\n"}).
		on("docker volume inspect", Ran{Stdout: `[{"Name":"webdata","Driver":"local"},{"Name":"dbdata","Driver":"local"},{"Name":"loose","Driver":"local","Labels":{"com.docker.volume.anonymous":""}}]`})
	got, err := client(f, 1000).Volumes(context.Background(), false, false)
	if err != nil {
		t.Fatal(err)
	}
	vols := got["volumes"].([]map[string]any)
	if vols[0]["mesh_held"] != true || vols[1]["mesh_held"] != false || len(vols[2]["mounted_by"].([]map[string]any)) != 0 || vols[2]["anonymous"] != true {
		t.Fatalf("%v", vols)
	}
	got, _ = client(f, 1000).Volumes(context.Background(), true, false)
	if got["count"] != 1 {
		t.Fatalf("unmounted: %v", got)
	}
}

func TestImagesNameTheirUsers(t *testing.T) {
	f := machine().on("docker image ls", Ran{Stdout: `{"ID":"sha256:img1","Repository":"web","Tag":"1","Size":"100MB"}
{"ID":"sha256:img3","Repository":"<none>","Tag":"<none>","Size":"2GB"}
`})
	got, err := client(f, 1000).Images(context.Background(), "", "", 10)
	if err != nil {
		t.Fatal(err)
	}
	imgs := got["images"].([]Image)
	if imgs[0].ID != "sha256:img3" || !imgs[0].Dangling || imgs[1].UsedBy[0] != "mesh-web" || !imgs[1].MeshUsed {
		t.Fatalf("%+v", imgs)
	}
	got, _ = client(f, 1000).Images(context.Background(), "unused", "", 10)
	if got["count"] != 1 {
		t.Fatalf("unused: %v", got)
	}
}

func TestProblemsNameWhyAndUnlabelledIsTheCleanupList(t *testing.T) {
	c := client(machine(), 1000)
	p, err := c.Problems(context.Background())
	if err != nil || len(p) != 1 || p[0]["name"] != "dev-db" || p[0]["why"].([]string)[0] != "exited 1" {
		t.Fatalf("%v %v", p, err)
	}
	u, err := c.Unlabelled(context.Background())
	if err != nil || u["count"] != 1 {
		t.Fatalf("%v %v", u, err)
	}
}