package versions

import (
	"context"
	"encoding/json"
	"errors"
	"reflect"
	"strings"
	"sync"
	"testing"
	"time"
)

// mem is a Store in memory; before runs once before the next Create, to stage a race.
type mem struct {
	mu     sync.Mutex
	vals   map[string][]byte
	revs   map[string]uint64
	rev    uint64
	before func()
}

func newMem() *mem { return &mem{vals: map[string][]byte{}, revs: map[string]uint64{}} }

func (m *mem) Get(_ context.Context, key string) ([]byte, uint64, bool, error) {
	m.mu.Lock()
	defer m.mu.Unlock()
	v, ok := m.vals[key]
	return v, m.revs[key], ok, nil
}

func (m *mem) Create(ctx context.Context, key string, value []byte) (uint64, error) {
	if f := m.before; f != nil {
		m.before = nil
		f()
	}
	m.mu.Lock()
	defer m.mu.Unlock()
	if _, ok := m.vals[key]; ok {
		return 0, ErrConflict
	}
	m.rev++
	m.vals[key], m.revs[key] = value, m.rev
	return m.rev, nil
}

func (m *mem) Update(_ context.Context, key string, value []byte, revision uint64) (uint64, error) {
	m.mu.Lock()
	defer m.mu.Unlock()
	if m.revs[key] != revision {
		return 0, ErrConflict
	}
	m.rev++
	m.vals[key], m.revs[key] = value, m.rev
	return m.rev, nil
}

func (m *mem) KeysOf(_ context.Context, filter string) ([]string, error) {
	m.mu.Lock()
	defer m.mu.Unlock()
	prefix := strings.TrimSuffix(filter, "*")
	var out []string
	for k := range m.vals {
		if strings.HasPrefix(k, prefix) && !strings.Contains(k[len(prefix):], ".") {
			out = append(out, k)
		}
	}
	return out, nil
}

func known(seat, tags, reqs []string) Floor { return Floor{Seat: seat, Tags: tags, Requirements: reqs} }

// TestTheBuildersVersions holds design 51 *The versions*, *The floor* and *Tagged versions* (DLV-B1, DLV-B2, DLV-B3):
// one table per rule, the unit cases of the builder's numbering.
func TestTheBuildersVersions(t *testing.T) {
	t.Run("keys", func(t *testing.T) {
		names := []string{"@novox/mesh-sdk", "git.novox.be/novox/mesh-sdk/go", "git.novox.be/novox/mesh-sdk", "a=40b", "a@b"}
		seen := map[string]string{}
		for _, n := range names {
			k := Key(n, "0.1.14")
			if strings.Count(k, ".") != 1 {
				t.Errorf("Key(%q) = %q, want two tokens", n, k)
			}
			if o, dup := seen[k]; dup {
				t.Errorf("%q and %q escape alike: %q", n, o, k)
			}
			seen[k] = n
			if !strings.HasPrefix(k, strings.TrimSuffix(NameFilter(n), "*")) {
				t.Errorf("Key(%q) = %q is not under NameFilter %q", n, k, NameFilter(n))
			}
		}
	})
	t.Run("floor", func(t *testing.T) {
		for _, c := range []struct {
			name  string
			floor Floor
			want  string
		}{
			{"none starts at 0", known(nil, nil, nil), "0.1.0"},
			{"the Go tag of today gives v0.1.14", known(nil, []string{"go/v0.1.13"}, []string{"v0.1.14-0.20261103221822-85ba0a9a70d8"}), "0.1.14"},
			{"npm's 0.1.17 on the seat gives 0.1.18", known([]string{"0.1.17", "0.1.3"}, nil, nil), "0.1.18"},
			{"another series and a tagged version count nothing", known([]string{"0.2.40", "0.1.9-feat-x.1"}, nil, nil), "0.1.0"},
			{"the highest of the three", known([]string{"0.1.4"}, []string{"v0.1.9"}, []string{"v0.1.7"}), "0.1.10"},
		} {
			if got := Next(nil, "0.1", c.floor); got != c.want {
				t.Errorf("%s: Next = %s, want %s", c.name, got, c.want)
			}
		}
		if got := Next([]Entry{{Version: "0.1.20", Series: "0.1"}, {Version: "0.1.21-x.1", Series: "0.1", Tag: "x"}}, "0.1", known([]string{"0.1.3"}, nil, nil)); got != "0.1.21" {
			t.Errorf("Next above the state's own = %s, want 0.1.21", got)
		}
	})
	t.Run("decide", func(t *testing.T) {
		pub := Entry{Name: "n", Kind: KindPackage, Series: "0.1", Version: "0.1.5", Revision: "r1", Fingerprint: "fA", State: Published}
		ref := pub
		ref.State, ref.Version, ref.Revision = Refused, "0.1.6", "r2"
		img := Entry{Name: "i", Kind: KindBundle, Series: "0.1", Version: "0.1.2", Fingerprint: "fB", State: Published}
		silent := Floor{Silent: []string{SourceSeat}}
		for _, c := range []struct {
			name                 string
			entries              []Entry
			kind, fp, rev        string
			floor                Floor
			version              string
			keep, publish, unnum bool
			wait                 bool
		}{
			{"a package's revision held published keeps its version and publishes nothing", []Entry{pub}, KindPackage, "fX", "r1", silent, "0.1.5", true, false, false, false},
			{"a revision numbered but refused is published by its second build under the same version", []Entry{pub, ref}, KindPackage, "fY", "r2", known(nil, nil, nil), "0.1.6", true, true, false, false},
			{"a new revision takes the next", []Entry{pub, ref}, KindPackage, "fZ", "r3", known(nil, nil, nil), "0.1.7", false, true, false, false},
			{"a bundle's fingerprint keeps its number", []Entry{img}, KindBundle, "fB", "", silent, "0.1.2", true, false, false, false},
			{"an unknown floor builds a bundle unnumbered", nil, KindBundle, "fC", "", silent, "", false, true, true, false},
			{"an unknown floor builds an image unnumbered", nil, KindImage, "fC", "", silent, "", false, true, true, false},
			{"an unknown floor makes a package wait", nil, KindPackage, "fC", "r9", silent, "", false, false, false, true},
		} {
			d := Decide(c.entries, c.kind, "0.1", c.fp, c.rev, c.floor)
			if d.Version != c.version || d.Keep != c.keep || d.Publish != c.publish || d.Unnumbered != c.unnum || d.Wait != c.wait || d.Why == "" {
				t.Errorf("%s: Decide = %+v", c.name, d)
			}
		}
	})
	t.Run("two claims never one number", func(t *testing.T) {
		st := newMem()
		v := Versions{Store: st, Now: func() time.Time { return time.Unix(0, 0) }}
		ctx := context.Background()
		st.before = func() { // a second claim takes 0.1.0 between the first's read and its create
			if _, _, err := (Versions{Store: st}).Number(ctx, Claim{Name: "n", Kind: KindBundle, Fingerprint: "f2"}); err != nil {
				t.Error(err)
			}
		}
		d, e, err := v.Number(ctx, Claim{Name: "n", Kind: KindBundle, Fingerprint: "f1"})
		if err != nil || d.Version != "0.1.1" || e.State != Numbered || e.Series != DefaultSeries {
			t.Fatalf("Number = %+v, %+v, %v, want 0.1.1 after the other claim's 0.1.0", d, e, err)
		}
		if d, _, _ := v.Number(ctx, Claim{Name: "n", Kind: KindBundle, Fingerprint: "f1"}); !d.Keep || d.Version != "0.1.1" {
			t.Errorf("a numbered fingerprint claimed again = %+v, want it kept", d)
		}
		got, err := v.Mark(ctx, "n", "0.1.1", func(e *Entry) { e.State = Published })
		if err != nil || got.State != Published {
			t.Errorf("Mark = %+v, %v", got, err)
		}
		if _, err := v.Mark(ctx, "n", "0.9.9", func(*Entry) {}); err == nil {
			t.Error("marking a version never numbered is no error")
		}
	})
	t.Run("recorded", func(t *testing.T) {
		st := newMem()
		v := Versions{Store: st}
		ctx := context.Background()
		if _, _, err := v.Number(ctx, Claim{Name: "n", Kind: KindImage, Fingerprint: "f", Digest: "sha256:aa", Floor: known(nil, nil, nil)}); err != nil {
			t.Fatal(err)
		}
		for _, c := range []struct {
			version, digest string
			ok              bool
		}{{"0.1.0", "sha256:aa", true}, {"0.1.0", "sha256:bb", false}, {"0.1.7", "sha256:aa", false}} {
			if _, ok, why, err := v.Recorded(ctx, "n", c.version, c.digest); err != nil || ok != c.ok || (!ok && why == "") {
				t.Errorf("Recorded(%s, %s) = %v, %q, %v; want %v", c.version, c.digest, ok, why, err, c.ok)
			}
		}
		// builder_versions answers the same through the tools bundle's read-only view.
		r := Reader{Keys: func() ([]string, error) {
			var all []string
			for k := range st.vals {
				all = append(all, k)
			}
			return all, nil
		}, Get: func(k string) (json.RawMessage, bool, error) {
			v, _, ok, err := st.Get(ctx, k)
			return v, ok, err
		}}
		a, err := AnswerVersions(ctx, r, "n", "0.1.0", "sha256:bb")
		if err != nil || len(a.Versions) != 1 || a.Recorded == nil || *a.Recorded || a.Why == "" {
			t.Errorf("builder_versions = %+v, %v; want one version and not recorded for another digest", a, err)
		}
		if _, err := AnswerVersions(ctx, r, " ", "", ""); err == nil {
			t.Error("builder_versions with no name answered")
		}
	})
	t.Run("tagged", func(t *testing.T) {
		es := []Entry{{Version: "0.1.14", Series: "0.1"}, {Version: "0.1.15-feat-x.1", Series: "0.1", Tag: "feat-x"}}
		if got := Tagged(es, "0.1", "feat/X", known(nil, nil, nil)); got != "0.1.15-feat-x.2" {
			t.Errorf("Tagged = %s, want 0.1.15-feat-x.2", got)
		}
		if got := Tagged(nil, "0.1", "feat-x", known(nil, nil, nil)); got != "0.1.0-feat-x.1" {
			t.Errorf("a package new in a group = %s, want 0.1.0-feat-x.1", got)
		}
		if got := CleanTag("--Fix/ä_1965--"); got != "fix-1965" {
			t.Errorf("CleanTag = %s", got)
		}
	})
	t.Run("merge order", func(t *testing.T) {
		es := []Entry{{Fingerprint: "f1", Version: "0.1.0", Series: "0.1"}}
		for _, c := range []struct {
			name  string
			merge uint64
			held  map[string]uint64
			want  uint64
		}{
			{"an earlier merge numbered waits on nothing", 5, map[string]uint64{"f1": 3}, 0},
			{"an earlier merge not numbered is waited on", 5, map[string]uint64{"f1": 3, "f2": 4}, 4},
			{"a replaced fingerprint the indexer no longer holds is skipped", 5, map[string]uint64{}, 0},
			{"a later merge is not waited on", 5, map[string]uint64{"f3": 7}, 0},
		} {
			if got := WaitsOn(es, c.merge, c.held); got != c.want {
				t.Errorf("%s: WaitsOn = %d, want %d", c.name, got, c.want)
			}
		}
	})
	t.Run("the floor wakes on its silent source, never a timer", func(t *testing.T) {
		ctx := context.Background()
		src := FloorSources{
			Seat:         func(context.Context, string, string) ([]string, error) { return []string{"0.1.3"}, nil },
			Tags:         func(context.Context, string, string) ([]string, error) { return nil, errors.New("no answer") },
			Requirements: func(context.Context, string) ([]string, error) { return nil, nil },
		}
		f, why := src.Ask(ctx, FloorOf{Seat: "oci-artifact-registry", Name: "m/program"})
		if f.Known() || !reflect.DeepEqual(f.Silent, []string{SourceTags}) || why[SourceTags] != "no answer" {
			t.Fatalf("Ask = %+v, %v; want bridge_tags silent", f, why)
		}
		var fw FloorWaits
		w := fw.Wait("m/program", "oci-artifact-registry", "distribution", f, why, time.Unix(0, 0))
		if !strings.Contains(w.Finding(), "bridge_tags (no answer)") {
			t.Errorf("finding = %q", w.Finding())
		}
		for _, c := range []struct {
			kind, seat, module, name string
			want                     []string
		}{
			{WakePublished, "oci-artifact-registry", "", "", nil}, // the seat answered already: a publish wakes nothing
			{WakeAccepted, "", "", "", nil},
			{WakeForge, "", "", "", []string{"m/program"}},
			{WakeCleared, "", "mesh-delivery-forge-bridge", "", []string{"m/program"}}, // recovered with nothing to say
			{WakeCleared, "", "mesh-delivery-indexer", "", nil},
			{WakeByHand, "", "", "m/program", []string{"m/program"}},
			{WakeByHand, "", "", "other", nil},
		} {
			if got := fw.Wake(c.kind, c.seat, c.module, c.name); !reflect.DeepEqual(got, c.want) {
				t.Errorf("Wake(%s %s %s %s) = %v, want %v", c.kind, c.seat, c.module, c.name, got, c.want)
			}
		}
		seatDown := Floor{Silent: []string{SourceSeat}}
		fw.Wait("distribution/program", "container-image-registry", "distribution", seatDown, nil, time.Unix(0, 0))
		if got := fw.Wake(WakePublished, "container-image-registry", "", ""); !reflect.DeepEqual(got, []string{"distribution/program"}) {
			t.Errorf("the holder's published woke %v, want its own image's name", got)
		}
		if got := fw.Wake(WakeCleared, "", "distribution", ""); !reflect.DeepEqual(got, []string{"distribution/program"}) {
			t.Errorf("the holder's clear woke %v", got)
		}
		if !fw.Answered("m/program") || fw.Answered("m/program") || len(fw.Waiting()) != 1 {
			t.Error("Answered drops the wait once")
		}
	})
	t.Run("old form", func(t *testing.T) {
		forms := []string{"ref:artifact-store", "ref:registry"}
		base := []string{"ref:artifact-store"}
		both := []string{"ref:artifact-store", "ref:registry"}
		for _, c := range []struct {
			name    string
			nodes   []NodeReads
			dropped map[string]bool
			want    FormsAnswer
		}{
			{"one present node lacking it keeps the old form alone",
				[]NodeReads{{Node: "a", Present: true, Serves: true, Stated: both}, {Node: "b", Present: true, Serves: true, Stated: base}}, nil,
				FormsAnswer{Single: "ref:artifact-store", Open: true, Holding: []string{"b"}}},
			{"a node not serving manifest-reads counts as the baseline",
				[]NodeReads{{Node: "a", Present: true, Serves: true, Stated: both}, {Node: "b", Present: true, Stated: both}}, nil,
				FormsAnswer{Single: "ref:artifact-store", Open: true, Holding: []string{"b"}}},
			{"every present node states it: the new form beside the old, an away old node keeping the old in the single reference",
				[]NodeReads{{Node: "a", Present: true, Serves: true, Stated: both}, {Node: "c", Serves: true, Stated: base}}, nil,
				FormsAnswer{Single: "ref:artifact-store", Beside: []string{"ref:registry"}, Open: true, Holding: []string{"c"}}},
			{"the away node back with the new engine closes the window",
				[]NodeReads{{Node: "a", Present: true, Serves: true, Stated: both}, {Node: "c", Present: true, Serves: true, Stated: []string{"ref:registry"}}}, nil,
				FormsAnswer{Single: "ref:registry"}},
			{"a retired node dropped by hand counts no more",
				[]NodeReads{{Node: "a", Present: true, Serves: true, Stated: []string{"ref:registry"}}, {Node: "c", Serves: true, Stated: base}}, map[string]bool{"c": true},
				FormsAnswer{Single: "ref:registry"}},
		} {
			if got := Forms(forms, base, c.nodes, c.dropped); !reflect.DeepEqual(got, c.want) {
				t.Errorf("%s: Forms = %+v, want %+v", c.name, got, c.want)
			}
		}
		t0 := time.Unix(0, 0)
		w, closed, overdue := OldFormWindow{}.Step(FormsAnswer{Open: true, Holding: []string{"c"}}, t0)
		if closed || len(overdue) != 0 || !w.Open {
			t.Fatalf("Step = %+v %v %v", w, closed, overdue)
		}
		w, _, overdue = w.Step(FormsAnswer{Open: true, Holding: []string{"c"}}, t0.Add(FindingAfter))
		if !reflect.DeepEqual(overdue, []string{"c"}) {
			t.Errorf("seven days held: overdue %v, want c", overdue)
		}
		w, closed, _ = w.Step(FormsAnswer{}, t0.Add(FindingAfter+time.Hour))
		if !closed || w.Open || !reflect.DeepEqual(w.LastHolding, []string{"c"}) {
			t.Errorf("closing: %+v closed=%v", w, closed)
		}
		if _, again, _ := w.Step(FormsAnswer{}, t0.Add(FindingAfter+2*time.Hour)); again {
			t.Error("a closed window closes again: old-form-closed would be said twice")
		}
	})
	t.Run("at the claim", func(t *testing.T) {
		ctx := context.Background()
		tagsUp := false
		var asked []string
		src := FloorSources{
			Seat: func(context.Context, string, string) ([]string, error) { return []string{"0.1.3"}, nil },
			Tags: func(_ context.Context, repo, prefix string) ([]string, error) {
				asked = append(asked, repo+" "+prefix)
				if !tagsUp {
					return nil, errors.New("no answer")
				}
				return []string{"go/v0.1.13"}, nil
			},
			Requirements: func(context.Context, string) ([]string, error) { return nil, nil },
		}
		var said []NumberedBody
		fw := &FloorWaits{}
		n := &Numberer{Versions: Versions{Store: newMem()}, Floor: src, Waits: fw, Said: func(b NumberedBody) { said = append(said, b) }}
		c := BuildClaim{Module: "m", Path: "go", Repository: "novox/m", Fingerprint: "fp1", Commit: "c1", Revision: "7", Merge: 7,
			Artifacts: []ClaimArtifact{{Artifact: "program", Kind: KindBundle, Language: "go"}, {Artifact: "base", Kind: "upstream"}}}
		got, err := n.Number(ctx, c)
		if err != nil || len(got.Versions) != 0 || !reflect.DeepEqual(got.Unnumbered, []string{"program"}) || got.Wait != "" {
			t.Fatalf("silent floor: %+v, %v; want program unnumbered, the upstream copy left out", got, err)
		}
		if !reflect.DeepEqual(asked, []string{"novox/m go/v"}) || len(fw.Waiting()) != 1 || len(said) != 0 {
			t.Fatalf("asked %v, waits %+v, said %v", asked, fw.Waiting(), said)
		}
		pkg := c
		pkg.Artifacts = []ClaimArtifact{{Artifact: "lib", Kind: KindPackage, Language: "go"}}
		if got, _ := n.Number(ctx, pkg); got.Wait == "" || len(got.Versions) != 0 {
			t.Fatalf("a package with no floor = %+v; want it to wait", got)
		}
		tagsUp = true
		got, err = n.Number(ctx, c)
		if err != nil || got.Versions["program"] != "0.1.14" || len(said) != 1 || said[0].Version != "0.1.14" || len(fw.Waiting()) != 1 {
			t.Fatalf("floor answered: %+v, %v, said %v, waits %+v; want 0.1.14 said once, lib still waiting", got, err, said, fw.Waiting())
		}
		if err := n.Built(ctx, c, got, map[string]string{"program": "sha256:aa"}); err != nil {
			t.Fatal(err)
		}
		again, _ := n.Number(ctx, c)
		if again.Versions["program"] != "0.1.14" || len(said) != 1 || len(asked) != 3 {
			t.Fatalf("again: %+v, said %d, asked %v; want the number kept, nothing said, the floor not asked", again, len(said), asked)
		}
		if _, ok, why, _ := n.Versions.Recorded(ctx, "m/program", "0.1.14", "sha256:bb"); ok {
			t.Fatalf("another digest recorded: %s", why)
		}
		// DLV-B4: the seat's events move the entry; a published wakes the names waiting on that seat.
		if wake, err := n.Heard(ctx, SeatArtifacts, HeardPublished, "e1", Outcome{Name: "m/other", Digest: "sha256:cc"}); err != nil || len(wake) != 0 {
			t.Fatalf("a by-digest publish of another seat's wait: %v, %v", wake, err)
		}
		n.Waits.Wait("m/lib", SeatGoPackages, "", Floor{Silent: []string{SourceSeat}}, nil, time.Unix(0, 0))
		if wake, _ := n.Heard(ctx, SeatGoPackages, HeardPublished, "e2", Outcome{Name: "m/x", Digest: "sha256:dd"}); !reflect.DeepEqual(wake, []string{"m/lib"}) {
			t.Fatalf("a published on the Go seat woke %v, want m/lib, whose seat was silent", wake)
		}
		for _, h := range []struct{ event, state, reason string }{{HeardRefused, Refused, "bytes differ"}, {HeardPublished, Published, ""}, {HeardRefused, Published, ""}, {HeardRemoved, Removed, "retention"}} {
			if _, err := n.Heard(ctx, SeatArtifacts, h.event, "e3", Outcome{Name: "m/program", Version: "0.1.14", Digest: "sha256:aa", Reason: h.reason}); err != nil {
				t.Fatal(err)
			}
			all, _ := n.Versions.Of(ctx, "m/program")
			if all[0].State != h.state {
				t.Fatalf("after %s: %+v, want %s", h.event, all[0], h.state)
			}
		}
		if _, err := n.Heard(ctx, SeatArtifacts, HeardPublished, "e4", Outcome{Name: "m/none", Version: "0.1.0"}); err == nil {
			t.Fatal("a published of a version the builder never numbered is not said")
		}
	})
	t.Run("fill", func(t *testing.T) {
		if _, full := Fill(Cap*79/100, Cap); full {
			t.Error("79 % is full")
		}
		if _, full := Fill((Cap*80+99)/100, Cap); !full {
			t.Error("80 % is not full")
		}
	})
}