package inventory

import (
	"context"
	"encoding/json"
	"fmt"
	"reflect"
	"testing"
	"time"

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

	"github.com/novox/mesh-controller/internal/chain"
)

// **A build keeps its reuse key and what it published, and comes back whole from the bucket** (novox/hq ADR 0408 §1,
// issue 1090): an artifact by the digest of what it made, a package release by name and version.
func TestABuildKeepsItsReuseKeyAndWhatItPublishedWhenKeptOnTheBus(t *testing.T) {
	at := time.Date(2026, 10, 18, 3, 0, 0, 0, time.UTC)
	b := Build{ID: "build-1", Repository: "novox/notes", Ref: "main", Module: "notes", Commit: "c1", On: "ace", Path: "modules/notes",
		Manifest: []byte(`{"module":"notes"}`), Against: []string{"artifact-store://base@sha256:aa"},
		Read:              []ReadRepository{{Repository: "novox/other", Ref: "main"}},
		Sources:           []BuildSource{{Paths: []string{"modules/notes/module.json"}}},
		SourceFingerprint: "fp", Asked: at, At: at.Add(time.Minute), ReuseKey: "rk-1",
		Made: []Artifact{{Name: "notes", Kind: "image", Reference: "artifact-store://notes@sha256:bb"},
			{Name: "sdk", Kind: "package", Reference: "mesh-sdk@1.4.0"}}}
	kept := toChainBuild(b)
	if kept.ReuseKey != "rk-1" {
		t.Errorf("the reuse key is %q", kept.ReuseKey)
	}
	if kept.Published == nil || kept.Published.Artifact != "sha256:bb" || kept.Published.Package == nil ||
		kept.Published.Package.Name != "mesh-sdk" || kept.Published.Package.Version != "1.4.0" {
		t.Errorf("it published %+v", kept.Published)
	}
	// Through the bucket's bytes and back: nothing is lost.
	raw, err := json.Marshal(kept)
	if err != nil {
		t.Fatal(err)
	}
	var back chain.Build
	if err := json.Unmarshal(raw, &back); err != nil {
		t.Fatal(err)
	}
	got := fromChainBuild(back)
	b.Published = kept.Published
	if !reflect.DeepEqual(got, b) {
		t.Fatalf("the build came back as\n %+v\nnot\n %+v", got, b)
	}
}

func TestWhatABuildPublishedIsReadFromWhatItMade(t *testing.T) {
	for name, tc := range map[string]struct {
		made []Artifact
		want *chain.Published
	}{
		"nothing":                   {nil, nil},
		"an archive with no digest": {[]Artifact{{Name: "config", Kind: "archive", Reference: "…/blobs/sha256:…"}}, nil},
		"an image": {[]Artifact{{Name: "a", Kind: "image", Reference: "artifact-store://a@sha256:11"}},
			&chain.Published{Artifact: "sha256:11"}},
		"the first digest stands": {[]Artifact{{Kind: "image", Reference: "x@sha256:11"}, {Kind: "archive", Reference: "y@sha256:22"}},
			&chain.Published{Artifact: "sha256:11"}},
		"a package": {[]Artifact{{Name: "sdk", Kind: "package", Reference: "mesh-sdk@2.0.1"}},
			&chain.Published{Package: &chain.Package{Name: "mesh-sdk", Version: "2.0.1"}}},
		"a package with no version": {[]Artifact{{Name: "sdk", Kind: "package", Reference: "mesh-sdk"}}, nil},
	} {
		if got := publishedOf(tc.made); !reflect.DeepEqual(got, tc.want) {
			t.Errorf("%s: published %+v, not %+v", name, got, tc.want)
		}
	}
}

// **The same content hashes alike, however the record spells it** (issue 280's fingerprints, now over the bucket's bytes
// and not the store's jsonb text): key order and white space of a manifest change nothing.
func TestTheSameBuildHashesAlikeWhateverTheSpellingOfItsRecord(t *testing.T) {
	a := Build{Manifest: []byte(`{"module": "notes", "version": "1"}`), Made: []Artifact{{Name: "n", Kind: "image", Reference: "r"}}}
	b := Build{Manifest: []byte("{\"version\":\"1\",\n \"module\":\"notes\"}"), Made: []Artifact{{Name: "n", Kind: "image", Reference: "r"}}}
	if chainFingerprint(a) != chainFingerprint(b) {
		t.Fatal("two spellings of one manifest hash apart")
	}
	b.Made[0].Reference = "other"
	if chainFingerprint(a) == chainFingerprint(b) {
		t.Fatal("two artifacts hash alike")
	}
}

// **Newest request first, as the store's ordering was**: the newest ask, then the newest record, then the newest id.
func TestBuildsAreOrderedNewestRequestFirst(t *testing.T) {
	t0 := time.Date(2026, 10, 18, 3, 0, 0, 0, time.UTC)
	builds := []Build{
		{ID: "old", Asked: t0, At: t0.Add(time.Hour)},
		{ID: "unasked", At: t0.Add(2 * time.Hour)},
		{ID: "new", Asked: t0.Add(3 * time.Hour), At: t0.Add(3*time.Hour + time.Minute)},
		{ID: "same-a", Asked: t0.Add(4 * time.Hour), At: t0.Add(5 * time.Hour)},
		{ID: "same-b", Asked: t0.Add(4 * time.Hour), At: t0.Add(5 * time.Hour)},
	}
	newestRequestOrder(builds)
	var got []string
	for _, b := range builds {
		got = append(got, b.ID)
	}
	if want := []string{"same-b", "same-a", "new", "unasked", "old"}; !reflect.DeepEqual(got, want) {
		t.Fatalf("ordered %v, not %v", got, want)
	}
}

// **A bus that does not answer, a lease lost and a key written first are "not now"** (issue 1092): a merge or a report whose
// write failed so is held and handed over again, as it is for a store that is away.
func TestTheBusBeingAwayIsNotNowLikeTheStoreBeingAway(t *testing.T) {
	for name, err := range map[string]error{
		"a timeout":      fmt.Errorf("the plan is not written: %w", nats.ErrTimeout),
		"no responders":  fmt.Errorf("build 1: %w", nats.ErrNoResponders),
		"a closed bus":   nats.ErrConnectionClosed,
		"the lease lost": fmt.Errorf("%w: another controller holds it", chain.ErrNotHeld),
		"a key moved":    chain.ErrMoved,
		"a deadline":     context.DeadlineExceeded,
	} {
		if !Unreachable(err) {
			t.Errorf("%s is read as an answer", name)
		}
	}
	for name, err := range map[string]error{
		"a value too large": chain.ErrTooLarge,
		"a key not taken":   chain.ErrBadKey,
		"a plan moved":      ErrPlanMoved,
		"a key that exists": chain.ErrExists,
	} {
		if Unreachable(err) {
			t.Errorf("%s is read as a bus being away: asking again gets the same answer", name)
		}
	}
}