package main

import (
	"context"
	"encoding/base64"
	"encoding/json"
	"strings"
	"testing"
	"time"

	"github.com/nats-io/nats.go"

	"github.com/novox/mesh-controller/internal/inventory"
	"github.com/novox/mesh-controller/internal/link"
	"github.com/novox/mesh-controller/internal/testbus"
)

// echoEnvironment makes the test binary, run as a command line, say the verb and caller it was given (TestMain).
const echoEnvironment = "MESH_TEST_ECHO_ENVIRONMENT"

var cliNodes = []inventory.Node{
	{Name: "control", Account: "operator"},
	{Name: "laptop", Account: "operator"},
	{Name: "unnamed"},
}

func cliAsked(account string, uid uint32, line ...string) link.CLIAsked {
	return link.CLIAsked{Line: line, Account: account, UID: uid, Session: "session-1.scope"}
}

// Who is the controller's terminal, and who is an ordinary call or refused (novox/hq ADR 0272 §4).
func TestMeshCLIIsTheTerminalOnlyForTheControlNodesOperator(t *testing.T) {
	control := []string{"control"}
	cases := []struct {
		name, node string
		asked      link.CLIAsked
		control    []string
		terminal   bool
		refused    string
		why        string
	}{
		{"the control-node's operator", "control", cliAsked("operator", 1000, "status"), control, true, "", "the controller's terminal"},
		{"another node's operator", "laptop", cliAsked("operator", 1000, "status"), control, false, "", "agents on laptop may run as operator"},
		{"another account", "control", cliAsked("agent", 1001, "status"), control, false, "operator account (operator) only", ""},
		{"root", "control", cliAsked("root", 0, "status"), control, false, "never root", ""},
		{"a node with no operator account", "unnamed", cliAsked("operator", 1000, "status"), control, false, "does not know unnamed's operator account", ""},
		{"a node the mesh does not know", "elsewhere", cliAsked("operator", 1000, "status"), control, false, "not a node this mesh knows", ""},
		{"two control-nodes", "control", cliAsked("operator", 1000, "status"), []string{"control", "laptop"}, false, "", "2 control-nodes"},
	}
	for _, c := range cases {
		v := judgeCLI(c.node, c.asked, cliNodes, c.control)
		if v.terminal != c.terminal {
			t.Errorf("%s: terminal %v, want %v (%+v)", c.name, v.terminal, c.terminal, v)
		}
		if c.refused == "" && v.refused != "" || c.refused != "" && !strings.Contains(v.refused, c.refused) {
			t.Errorf("%s: refused %q, want %q", c.name, v.refused, c.refused)
		}
		if c.why != "" && !strings.Contains(v.why, c.why) {
			t.Errorf("%s: why %q, want %q", c.name, v.why, c.why)
		}
	}
}

// The terminal runs its line without MESH_VERB, even where this process carries one; an ordinary call names
// mesh-cli; both record who asked through mesh-cli.
func TestTheTerminalRunsWithoutAVerbAndAnOrdinaryCallNamesMeshCLI(t *testing.T) {
	t.Setenv(echoEnvironment, "1")
	t.Setenv("MESH_VERB", "leaked-from-the-serving-process")
	// The serving controller marks itself (ADR 0266); its terminal line for mesh-cli is still the terminal's.
	t.Setenv(servedVar, "1")
	ctx := context.Background()

	a := runForMeshCLI(ctx, "control", cliAsked("operator", 1000, "status"), cliVerdict{terminal: true, why: "the terminal"})
	if a.Exit != 0 || a.Refused != "" || !a.Terminal {
		t.Fatalf("the terminal's line did not run: %+v", a)
	}
	if got := string(a.Stdout); !strings.Contains(got, `verb=""`) || !strings.Contains(got, "operator through mesh-cli on control") ||
		!strings.Contains(got, "terminal=true") {
		t.Fatalf("the terminal's line ran with %s", got)
	}

	a = runForMeshCLI(ctx, "laptop", cliAsked("operator", 1000, "status"), cliVerdict{why: "not the terminal"})
	if a.Exit != 0 || a.Terminal || a.Why != "not the terminal" {
		t.Fatalf("an ordinary line did not run as one: %+v", a)
	}
	if got := string(a.Stdout); !strings.Contains(got, `verb="mesh-cli"`) || !strings.Contains(got, "terminal=false") {
		t.Fatalf("an ordinary line ran with %s", got)
	}
}

// An ordinary call meets every refusal of the generic command verb, and nothing runs; a server is never run.
func TestAnOrdinaryCallMeetsTheCommandVerbsRefusals(t *testing.T) {
	t.Setenv(echoEnvironment, "1")
	ctx := context.Background()
	ordinary := cliVerdict{why: "not the terminal"}
	a := runForMeshCLI(ctx, "laptop", cliAsked("operator", 1000, "cleanup", "delete", "x"), ordinary)
	if a.Refused == "" || len(a.Stdout) != 0 || a.Exit != 1 || a.Why != "not the terminal" {
		t.Fatalf("a repair without --why ran as an ordinary call: %+v", a)
	}
	a = runForMeshCLI(ctx, "laptop", cliAsked("operator", 1000, "settings", "set", "claude-code", "{}"), ordinary)
	if a.Refused != "" || !strings.Contains(string(a.Stdout), `verb="mesh-cli"`) {
		t.Fatalf("an ordinary settings set did not run through the settings verb's path with MESH_VERB set: %+v", a)
	}
	for _, server := range []string{"serve", "api", "board"} {
		a := runForMeshCLI(ctx, "control", cliAsked("operator", 1000, server), cliVerdict{terminal: true})
		if a.Refused == "" || len(a.Stdout) != 0 {
			t.Fatalf("%s was run for mesh-cli: %+v", server, a)
		}
	}
	a = runForMeshCLI(ctx, "control", cliAsked("agent", 1001, "status"), cliVerdict{refused: "agent is not answered"})
	if a.Refused != "agent is not answered" || len(a.Stdout) != 0 {
		t.Fatalf("a refused line ran: %+v", a)
	}
}

// **Which node is the terminal does not follow a verb** (review of ADR 0272): the controller's module is assigned
// and unassigned at the terminal alone, so no caller of `assign` can move the terminal to a node of its choosing.
// Asked through the acts themselves, as the verbs ask them; refused before any store is touched (none is given).
func TestTheControllersModuleIsMovedAtTheTerminalAlone(t *testing.T) {
	t.Setenv("MESH_VERB", "assign")
	ctx := context.Background()
	if _, err := assignWith(ctx, nil, "laptop", assignOptions{}, "zsh", "mesh-controller"); err == nil ||
		!strings.Contains(err.Error(), "terminal") {
		t.Fatalf("assigning the controller through a verb was not refused: %v", err)
	}
	if _, err := assign(ctx, nil, "laptop", "mesh-controller"); err == nil || !strings.Contains(err.Error(), "terminal") {
		t.Fatalf("assigning the controller through a verb was not refused: %v", err)
	}
	t.Setenv("MESH_VERB", "unassign")
	if _, err := unassign(ctx, nil, "control", "mesh-controller"); err == nil || !strings.Contains(err.Error(), "terminal") {
		t.Fatalf("unassigning the controller through a verb was not refused: %v", err)
	}
	// Another module through a verb, and the controller's at the terminal, are not refused for it.
	if err := refusedMovingTheController([]string{"zsh"}); err != nil {
		t.Fatalf("another module was refused: %v", err)
	}
	t.Setenv("MESH_VERB", "")
	if err := refusedMovingTheController([]string{"mesh-controller"}); err != nil {
		t.Fatalf("the terminal was refused: %v", err)
	}
}

// An ordinary `settings set|clear` goes down the settings verb's own path: composed as that verb composes it, and
// run with MESH_VERB set, so its refusals — the terminal-only keys among them — are the settings command's own,
// not a blanket refusal of the generic command (review of ADR 0272).
func TestAnOrdinarySettingsLineTakesTheSettingsVerbsPath(t *testing.T) {
	cases := []struct {
		line []string
		want string
		err  string
	}{
		{[]string{"settings", "set", "zsh", `{"execute":"withhold"}`, "--node", "laptop"}, `settings set zsh {"execute":"withhold"} --node laptop`, ""},
		{[]string{"settings", "set", "zsh", "{}", "--replace"}, "settings set zsh {} --replace", ""},
		{[]string{"settings", "clear", "zsh", "--node", "laptop"}, "settings clear zsh --node laptop", ""},
		{[]string{"settings", "show", "zsh", "--history"}, "settings show zsh --history", ""},
		{[]string{"settings", "preferences"}, "settings preferences", ""},
		{[]string{"settings", "set", "zsh"}, "", "settings"},
		{[]string{"settings", "set", "zsh", "{}", "--sideways"}, "", "--sideways"},
	}
	for _, c := range cases {
		argv, err := ordinaryLine(c.line)
		if c.err != "" {
			if err == nil || !strings.Contains(err.Error(), c.err) {
				t.Errorf("%q: refused with %v, want %q", c.line, err, c.err)
			}
			continue
		}
		if err != nil || strings.Join(argv, " ") != c.want {
			t.Errorf("%q: composed %q (%v), want %q", c.line, argv, err, c.want)
		}
	}
	// Anything else still meets the generic command verb's refusals.
	if _, err := ordinaryLine([]string{"retire", "delete", "x"}); err == nil {
		t.Error("a repair composed as an ordinary line")
	}
}

// Every line is said in the controller's journal, with its call, who asked where and how it ran — its command word
// only, never the rest of the line (review of ADR 0272).
func TestEveryMeshCLILineIsSaidInTheJournal(t *testing.T) {
	t.Setenv(echoEnvironment, "1")
	var said []string
	was := cliJournal
	cliJournal = func(line string) { said = append(said, line) }
	t.Cleanup(func() { cliJournal = was })
	ctx := link.WithCallID(context.Background(), "call-1")
	runForMeshCLI(ctx, "control", cliAsked("operator", 1000, "settings", "set", "x", `{"password":"s3cret"}`),
		cliVerdict{terminal: true, why: "the terminal"})
	runForMeshCLI(ctx, "control", cliAsked("agent", 1001, "status"), cliVerdict{refused: "agent is not answered"})
	all := strings.Join(said, "\n")
	if len(said) != 2 || !strings.Contains(all, "call-1") || !strings.Contains(all, "operator on control") ||
		!strings.Contains(all, "as the controller's terminal") || !strings.Contains(all, "refused") {
		t.Fatalf("the journal said %q", said)
	}
	if strings.Contains(all, "s3cret") {
		t.Fatalf("the journal carries the line's values: %q", said)
	}
}

// **An ordinary line runs only what the generic command verb would** (review of ADR 0272, ADR 0266): its reading
// forms, and never a command that is the terminal's alone. Each of these, from another node's operator, is refused
// and runs nothing.
func TestAnOrdinaryLineRunsNothingTheCommandVerbWouldRefuse(t *testing.T) {
	t.Setenv(echoEnvironment, "1")
	for _, line := range [][]string{
		{"node", "account", "control", "x"},
		{"node", "agent-account", "control", "x", "--clear"},
		{"token", "issue", "laptop"},
		{"secret", "export", "x"},
		{"operator", "key", "set", "x"},
		{"assign", "laptop", "zsh"},
	} {
		if _, err := ordinaryLine(line); err == nil {
			t.Errorf("%q composed as an ordinary line", line)
		}
		a := runForMeshCLI(context.Background(), "laptop", cliAsked("operator", 1000, line...), cliVerdict{why: "not the terminal"})
		if a.Refused == "" || len(a.Stdout) != 0 {
			t.Errorf("%q ran as an ordinary line: %+v", line, a)
		}
	}
	if argv, err := ordinaryLine([]string{"status"}); err != nil || argv[0] != "status" {
		t.Fatalf("a read was refused: %v", err)
	}
}

// **`calls` never shows a mesh-cli line's answer** (review of ADR 0272): the verb's own answer is read for a line
// served over a bus, and neither the answer's text nor the base64 JSON writes its bytes in is there.
func TestTheCallsVerbNeverShowsAMeshCLILinesAnswer(t *testing.T) {
	conn, err := nats.Connect(testbus.URL(t))
	if err != nil {
		t.Fatal(err)
	}
	defer conn.Close()
	stop, err := link.OverNATS{Conn: conn}.ServeCLI(func(context.Context, string, link.CLIAsked) link.CLIAnswer {
		return link.CLIAnswer{Stdout: []byte("s3cret-join")}
	}, nil)
	if err != nil {
		t.Fatal(err)
	}
	defer stop()
	body, _ := json.Marshal(link.CLIAsked{Line: []string{"token", "issue", "x"}, Account: "operator"})
	msg, err := conn.Request(link.CLISubject("control"), body, 5*time.Second)
	if err != nil {
		t.Fatal(err)
	}
	if !strings.Contains(string(msg.Data), base64.StdEncoding.EncodeToString([]byte("s3cret-join"))) {
		t.Fatalf("the asker was not given its answer: %s", msg.Data)
	}
	recent, _ := link.Calls.Recent()
	var id string
	for _, c := range recent {
		if c.Seat == link.CLISeat {
			id = c.ID
			break
		}
	}
	shown, err := callsAnswer(link.Calls, id)
	if err != nil {
		t.Fatal(err)
	}
	said, _ := json.Marshal(shown)
	if strings.Contains(string(said), "s3cret-join") ||
		strings.Contains(string(said), base64.StdEncoding.EncodeToString([]byte("s3cret-join"))) {
		t.Fatalf("calls showed a mesh-cli line's answer: %s", said)
	}
}

// **Only the terminal's line carries the terminal's mark** (review of ADR 0272): a mark the serving controller's
// environment holds — leaked, or set by anything — is stripped from every other command line it runs, a verb's and
// an ordinary mesh-cli line alike, so neither reads as the terminal.
func TestTheTerminalsMarkIsStrippedFromEveryOtherLine(t *testing.T) {
	t.Setenv(echoEnvironment, "1")
	t.Setenv(cliTerminalVar, "1")
	t.Setenv(servedVar, "1")
	for _, env := range [][]string{commandEnvironment("someone", "status", false)} {
		for _, kv := range env {
			if strings.HasPrefix(kv, cliTerminalVar+"=") {
				t.Fatalf("a verb's line carries the terminal's mark: %s", kv)
			}
		}
	}
	a := runForMeshCLI(context.Background(), "laptop", cliAsked("operator", 1000, "status"), cliVerdict{why: "not the terminal"})
	if got := string(a.Stdout); !strings.Contains(got, "terminal=false") || !strings.Contains(got, `verb="mesh-cli"`) {
		t.Fatalf("an ordinary line with the mark in the serving environment ran as %s", got)
	}
	a = runForMeshCLI(context.Background(), "control", cliAsked("operator", 1000, "status"), cliVerdict{terminal: true})
	if got := string(a.Stdout); !strings.Contains(got, "terminal=true") {
		t.Fatalf("the terminal's line ran as %s", got)
	}
}

// **Only a login session is the terminal** (review of ADR 0272): the operator's account on the control-node, asking
// from a service — the tool runner, a user unit — and not a login session, is an ordinary call.
func TestOnlyALoginSessionIsTheTerminal(t *testing.T) {
	control := []string{"control"}
	v := judgeCLI("control", link.CLIAsked{Line: []string{"status"}, Account: "operator", UID: 1000}, cliNodes, control)
	if v.terminal || v.refused != "" || !strings.Contains(v.why, "login session") {
		t.Fatalf("a line from no login session reads %+v", v)
	}
	v = judgeCLI("control", link.CLIAsked{Line: []string{"status"}, Account: "operator", UID: 1000, Session: "session-3.scope"},
		cliNodes, control)
	if !v.terminal {
		t.Fatalf("a line from a login session on the control-node reads %+v", v)
	}
}