package nodeengineclient

import (
	"errors"
	"fmt"
	"reflect"
	"strings"
	"testing"

	seat "git.novox.be/novox/mesh-contracts/go/seats/nodeengine"
	"git.novox.be/novox/mesh-sdk/go/delivery"
)

// The verb compose-candidate's ask and answer (ADR 0593 §7, §9): each round-trips, and a reader refuses what it could
// not take, naming it.
func TestComposeCandidateRoundTripsAndRefuses(t *testing.T) {
	key, err := delivery.CompositionKey("mesh-sdk#7", "0123456789ab")
	if err != nil {
		t.Fatal(err)
	}
	raw, err := EncodeAsk(seat.ComposeCandidateInput{Candidate: key, Input: true})
	if err != nil {
		t.Fatal(err)
	}
	if a, err := DecodeAsk(raw); err != nil || a.Candidate != key || !a.Input {
		t.Fatalf("ask round trip: %v, %+v", err, a)
	}
	if _, err := DecodeAsk([]byte(`{"candidate":"` + key + `","other":1}`)); err == nil {
		t.Error("an ask with an unknown key was read")
	}
	if _, err := EncodeAsk(seat.ComposeCandidateInput{Candidate: "nope"}); err == nil {
		t.Error("an ask naming no candidate key was encoded")
	}

	good := seat.ComposeCandidateAnswer{Node: "ace", Candidate: key, Verdict: Refused, Took: 812,
		Own: seat.Module{Module: Own, State: ModuleComposed, Digest: "sha256:00"},
		Modules: []seat.Module{
			{Module: "netcheck", Fp: "src2:x", State: ModuleComposed, Digest: "sha256:01", Changed: true},
			{Module: "route-proxy", State: ModuleRefused, Words: "the setting domain has no value"},
			{Module: "zz", State: ModuleHeld, Words: "held before"},
		}, Input: map[string]any{"machines": []any{"ace"}}}
	raw, err = EncodeAnswer(good)
	if err != nil {
		t.Fatal(err)
	}
	back, err := DecodeAnswer(raw)
	if err != nil || back.Verdict != Refused || len(back.Modules) != 3 || !reflect.DeepEqual(back.Input, good.Input) {
		t.Fatalf("answer round trip: %v, %+v", err, back)
	}
	if _, err := DecodeAnswer([]byte(strings.Replace(string(raw), `"took"`, `"other":1,"took"`, 1))); err == nil {
		t.Error("an answer with an unknown key was read")
	}
	if _, err := DecodeAnswer([]byte(strings.Replace(string(raw), `"v":1`, `"v":2`, 1))); !errors.Is(err, ErrUnknownVersion) {
		t.Errorf("an answer at another version read as %v", err)
	}
	numbered := strings.Replace(string(raw), `"machines":["ace"]`, `"bound":12345678901234567890`, 1)
	if back, err := DecodeAnswer([]byte(numbered)); err != nil || fmt.Sprint(back.Input["bound"]) != "12345678901234567890" {
		t.Errorf("an open input's number did not keep its digits: %v, %+v", err, back.Input)
	}

	whole := seat.ComposeCandidateAnswer{Node: "ace", Candidate: key, Verdict: Refused, Refused: "the bound passed"}
	unready := seat.ComposeCandidateAnswer{Node: "ace", Candidate: key, Verdict: Unready, Refused: "the agent is starting"}
	notJudged := seat.ComposeCandidateAnswer{Node: "ace", Candidate: key, Verdict: NotJudged, Refused: "its node-engine sends no running state"}
	for _, a := range []seat.ComposeCandidateAnswer{whole, unready, notJudged} {
		if raw, err := EncodeAnswer(a); err != nil {
			t.Errorf("a %s answer was not encoded: %v", a.Verdict, err)
		} else if back, err := DecodeAnswer(raw); err != nil || back.Verdict != a.Verdict {
			t.Errorf("a %s answer read back as %+v, %v", a.Verdict, back, err)
		}
	}

	for name, c := range map[string]struct {
		from   seat.ComposeCandidateAnswer
		mutate func(a *seat.ComposeCandidateAnswer)
	}{
		"verdict not the modules'":   {good, func(a *seat.ComposeCandidateAnswer) { a.Verdict = Composed }},
		"unknown state":              {good, func(a *seat.ComposeCandidateAnswer) { a.Modules[0].State = "fine" }},
		"composed without digest":    {good, func(a *seat.ComposeCandidateAnswer) { a.Modules[0].Digest = "" }},
		"refused without words":      {good, func(a *seat.ComposeCandidateAnswer) { a.Modules[1].Words = "" }},
		"unsorted":                   {good, func(a *seat.ComposeCandidateAnswer) { a.Modules[0], a.Modules[1] = a.Modules[1], a.Modules[0] }},
		"own misnamed":               {good, func(a *seat.ComposeCandidateAnswer) { a.Own.Module = "ace" }},
		"whole refusal with modules": {good, func(a *seat.ComposeCandidateAnswer) { a.Refused = "the bound passed" }},
		"node with a dot":            {good, func(a *seat.ComposeCandidateAnswer) { a.Node = "a.b" }},
		"negative took":              {good, func(a *seat.ComposeCandidateAnswer) { a.Took = -1 }},
		"unready saying no why":      {unready, func(a *seat.ComposeCandidateAnswer) { a.Refused = "" }},
		"unready naming modules":     {unready, func(a *seat.ComposeCandidateAnswer) { a.Modules = good.Modules }},
		"not judged saying no why":   {notJudged, func(a *seat.ComposeCandidateAnswer) { a.Refused = "" }},
		"not judged naming modules":  {notJudged, func(a *seat.ComposeCandidateAnswer) { a.Modules = good.Modules }},
	} {
		a := c.from
		a.Modules = append([]seat.Module(nil), c.from.Modules...)
		c.mutate(&a)
		if _, err := EncodeAnswer(a); err == nil {
			t.Errorf("%s: encoded", name)
		}
	}
}