package runtime

import (
	"context"
	"encoding/json"
	"errors"
	"sort"
	"strings"
	"testing"

	"git.novox.be/novox/mesh-sdk/go/buscalls"
	"git.novox.be/novox/mesh-sdk/go/catalogue"
	"git.novox.be/novox/mesh-sdk/go/membership"
	"github.com/nats-io/nats.go"
	"github.com/nats-io/nats.go/jetstream"

	"github.com/novox/mesh-tools/node-tools/internal/bus"
	mt "github.com/novox/mesh-tools/node-tools/internal/meshtest"
)

// 1966/AC16: given a module with a ledger binding, when the runner lists its tools, then the four repair tools are
// among them, marked acts or reads; a module without one has none, and a binding written later brings them.
func TestTheLedgerRepairsAreToolsOfEveryLedgerOwner(t *testing.T) {
	mesh := mt.New(t)
	owner := mt.MembershipOf("owner", "anchor", true, nil)
	owner.Bindings = []membership.BusBinding{{Local: "records", Storage: catalogue.StorageLedger, Template: catalogue.TemplateLedger,
		History: "LEDGER_owner_records", Subject: "mesh.ledger.owner.records.history", State: "owner_records",
		Snapshot: "mesh.ledger.owner.records.snapshot"}}
	plain := mt.MembershipOf("plain", "anchor", true, nil)
	mesh.Issue(t, owner)
	mesh.Issue(t, plain)
	nodeTools := connect(t, "node-tools", "anchor")
	stop, err := Run(nodeTools, []Served{{"owner", []string{mt.Fixture("caller-echo.py")}},
		{"plain", []string{mt.Fixture("caller-echo.py")}}}, nil, func(string, ...any) {})
	if err != nil {
		t.Fatal(err)
	}
	defer stop()
	asker := connect(t, "console", "workstation")
	listed := func(module string) (string, error) {
		answered, err := asker.Ask(module+"."+ToolsVerb, map[string]any{}, "")
		if err != nil {
			return "", err
		}
		var got ToolsAnswer
		if err := json.Unmarshal(answered.Result, &got); err != nil {
			return "", err
		}
		var names []string
		for _, tool := range got.Tools {
			names = append(names, tool.Name+":"+tool.Effect)
		}
		sort.Strings(names)
		return strings.Join(names, " "), nil
	}
	for _, c := range []struct{ name, module, want string }{
		{"a ledger owner lists the four repairs", "owner", "ledger_lag:reads ledger_rebuild:acts ledger_reindex:acts ledger_snapshot:acts who:"},
		{"a module with no ledger has none", "plain", "who:"},
	} {
		t.Run(c.name, func(t *testing.T) {
			var got string
			mt.Until(t, func() (err error) { got, err = listed(c.module); return })
			if got != c.want {
				t.Fatalf("%s lists %q, want %q", c.module, got, c.want)
			}
		})
	}
	t.Run("a ledger bound later brings them", func(t *testing.T) {
		plain.Bindings = owner.Bindings
		mesh.Issue(t, plain)
		mt.Until(t, func() error {
			got, err := listed("plain")
			if err == nil && !strings.Contains(got, "ledger_rebuild:acts") {
				err = errors.New("listed " + got)
			}
			return err
		})
	})
}

// aLedger raises one ledger of module m on the bus as the bus module would create it, binds it in m's membership, and
// answers the runtime's buses for m and for other; its types travel on its binding, and a second binding carries none.
func aLedger(t *testing.T) (m, other *moduleBus, mesh *mt.Mesh) {
	t.Helper()
	mesh = mt.New(t)
	nc, err := nats.Connect(mt.URL(t))
	if err != nil {
		t.Fatal(err)
	}
	t.Cleanup(nc.Close)
	js, _ := jetstream.New(nc)
	ctx := context.Background()
	for _, cfg := range []jetstream.StreamConfig{
		{Name: "LEDGER_m_records", Subjects: []string{"mesh.ledger.m.records.history.>"}},
		{Name: "SNAPSHOT_m_records", Subjects: []string{"mesh.ledger.m.records.snapshot.>"}, MaxMsgsPerSubject: 1},
	} {
		if _, err := js.CreateStream(ctx, cfg); err != nil {
			t.Fatal(err)
		}
	}
	if _, err := js.CreateKeyValue(ctx, jetstream.KeyValueConfig{Bucket: "m_records"}); err != nil {
		t.Fatal(err)
	}
	mem := mt.MembershipOf("m", "anchor", false, nil)
	mem.Bindings = []membership.BusBinding{{Local: "records", Storage: catalogue.StorageLedger, Template: catalogue.TemplateLedger,
		History: "LEDGER_m_records", Subject: "mesh.ledger.m.records.history", State: "m_records", Snapshot: "mesh.ledger.m.records.snapshot",
		Types: []catalogue.LedgerType{{Name: "decision", Schema: map[string]catalogue.LedgerField{"title": {Type: "string"}},
			Operations: []catalogue.LedgerOperation{{Name: "title", Effect: catalogue.EffectSetFields, Fields: []string{"title"}, Author: true}}}}},
		{Local: "untyped", Storage: catalogue.StorageLedger, Template: catalogue.TemplateLedger, History: "LEDGER_m_records",
			State: "m_records"},
		{Local: "elsewhere", Storage: catalogue.StorageLedger, Template: catalogue.TemplateLedger, History: "LEDGER_m_records",
			Subject: "mesh.ledger.m.records.history", State: "m_records", Types: []catalogue.LedgerType{{Name: "decision"}}}}
	mesh.Issue(t, mem)
	mesh.Issue(t, mt.MembershipOf("other", "anchor", false, nil))
	conn := connect(t, "node-tools", "anchor")
	conn.Follow("m")
	conn.Follow("other")
	mt.Until(t, func() error {
		if conn.Membership("m") == nil || conn.Membership("other") == nil {
			return errors.New("not issued yet")
		}
		return nil
	})
	all := &consumers{conn: conn, logf: t.Logf, of: map[string]*moduleEvents{}, ledgers: ledgerSource{
		writer: func(string) (*bus.Conn, error) { return conn, nil },
	}}
	return all.forModule("m").(*moduleBus), all.forModule("other").(*moduleBus), mesh
}

// 1966/AC17, 1966/AC18: the author an apply is stamped with is the caller the runtime proved for the call in flight it
// names, whatever author the bundle wrote; another module's call, or one not in flight, is refused naming it (ADR 0597 §7).
func TestAnApplyIsStampedWithTheCallerTheRuntimeProved(t *testing.T) {
	m, other, _ := aLedger(t)
	call, end := m.Begin("op@shanks")
	defer end()
	theirs, endTheirs := other.Begin("op@shanks")
	defer endTheirs()
	forged := `"body":{"title":"T","author":{"account":"x","caller":"forged"}}`
	for _, c := range []struct{ name, params, caller, refusal string }{
		{"1966/AC17 a call in flight stamps its proven caller", `{"ledger":"records","instance":"decision/1","operation":"title",` + forged + `,"call":"` + call + `","author":"forged"}`, "op@shanks", ""},
		{"naming no call stamps the account alone", `{"ledger":"records","instance":"decision/2","operation":"title",` + forged + `}`, "", ""},
		{"1966/AC18 another module's call is refused, naming it", `{"ledger":"records","instance":"decision/3","operation":"title",` + forged + `,"call":"` + theirs + `"}`, "", "the call " + theirs + ", which is another module's"},
		{"a ledger bound with no types is refused, naming it", `{"ledger":"untyped","instance":"decision/3","operation":"title",` + forged + `}`, "", `m's ledger "untyped" is bound with no types`},
		{"a binding naming subjects its account is not granted is refused, naming both", `{"ledger":"elsewhere","instance":"decision/3","operation":"title",` + forged + `}`, "", "bound with the history subject mesh.ledger.m.records.history, and its ledger account is granted mesh.ledger.m.elsewhere.history alone"},
		{"a call not in flight is refused, naming it", `{"ledger":"records","instance":"decision/3","operation":"title",` + forged + `,"call":"c0ffee"}`, "", "the call c0ffee, which is not a tool call in flight"},
	} {
		t.Run(c.name, func(t *testing.T) {
			var req struct {
				Instance string `json:"instance"`
			}
			_ = json.Unmarshal([]byte(c.params), &req)
			_, err := m.BusState(buscalls.LedgerApply, json.RawMessage(c.params))
			if c.refusal != "" {
				if err == nil || !strings.Contains(err.Error(), c.refusal) {
					t.Fatalf("applied with %v, want refused with %q", err, c.refusal)
				}
				return
			}
			if err != nil {
				t.Fatal(err)
			}
			raw, err := m.BusState(buscalls.LedgerHistory, json.RawMessage(`{"ledger":"records","instance":"`+req.Instance+`"}`))
			if err != nil {
				t.Fatal(err)
			}
			var page buscalls.HistoryPage
			_ = json.Unmarshal(raw, &page)
			if len(page.Operations) != 1 || page.Operations[0].Author != (buscalls.Author{Account: "m", Caller: c.caller}) {
				t.Fatalf("the history holds %+v, want the author {m %s}", page.Operations, c.caller)
			}
			state, _ := m.BusState(buscalls.LedgerGet, json.RawMessage(`{"ledger":"records","instance":"`+req.Instance+`"}`))
			if !strings.Contains(string(state), `"author":{"account":"m"`) || strings.Contains(string(state), "forged") {
				t.Fatalf("the state took the bundle's author: %s", state)
			}
		})
	}
	end()
	if _, err := m.BusState(buscalls.LedgerApply, json.RawMessage(`{"ledger":"records","instance":"decision/4","operation":"title","call":"`+call+`"}`)); err == nil {
		t.Fatal("a call that ended was still taken as in flight")
	}
}