package delivery

import (
	"encoding/json"
	"errors"
	"strings"
	"testing"
	"time"
)

// 1131/AC1: the have key forms and parses back; bad names are refused, naming them.
func TestHaveKey(t *testing.T) {
	if HaveBucket != "node-engine_have" {
		t.Fatalf("HaveBucket = %q", HaveBucket)
	}
	key, err := HaveKey("ace", "plex")
	if err != nil || key != "ace.plex" {
		t.Fatalf("HaveKey = %q, %v", key, err)
	}
	node, module, isNode, err := ParseHaveKey(key)
	if err != nil || node != "ace" || module != "plex" || isNode {
		t.Fatalf("ParseHaveKey = %q %q %v %v", node, module, isNode, err)
	}
	if got, err := HaveNodeKey("ace"); err != nil || got != "ace.node" {
		t.Fatalf("HaveNodeKey = %q, %v", got, err)
	}
	if _, err := HaveNodeKey("a b"); err == nil {
		t.Error("HaveNodeKey with a space accepted")
	}
	node, module, isNode, err = ParseHaveKey("ace.node")
	if err != nil || node != "ace" || module != "" || !isNode {
		t.Fatalf("ParseHaveKey node = %q %q %v %v", node, module, isNode, err)
	}
	for _, c := range []struct{ node, module, named string }{
		{"ace", "node", "node"},
		{"ace", "", "module"},
		{"", "plex", "node"},
		{"a.b", "plex", "a.b"},
		{"ace", "p*", "p*"},
		{"ace", "p>", "p>"},
		{"ace", "p x", "p x"},
		{"ace", "p\tx", "module"},
	} {
		_, err := HaveKey(c.node, c.module)
		if err == nil || !strings.Contains(err.Error(), c.named) {
			t.Errorf("HaveKey(%q, %q) = %v, want an error naming %q", c.node, c.module, err, c.named)
		}
	}
	for _, bad := range []string{"", "ace", "ace.", ".plex", "ace.plex.x", "ace.p x"} {
		if _, _, _, err := ParseHaveKey(bad); err == nil {
			t.Errorf("ParseHaveKey(%q) accepted", bad)
		}
	}
}

// 1131/AC2: the presence keys form and parse back; a node named part is refused.
func TestPresenceKey(t *testing.T) {
	if PresenceBucket != "mesh-delivery-watchman_presence" {
		t.Fatalf("PresenceBucket = %q", PresenceBucket)
	}
	key, err := PresenceNodeKey("ace")
	if err != nil || key != "ace" {
		t.Fatalf("PresenceNodeKey = %q, %v", key, err)
	}
	node, part, instance, err := ParsePresenceKey(key)
	if err != nil || node != "ace" || part != "" || instance != "" {
		t.Fatalf("ParsePresenceKey node = %q %q %q %v", node, part, instance, err)
	}
	key, err = PresencePartKey("view", "novox")
	if err != nil || key != "part.view.novox" {
		t.Fatalf("PresencePartKey = %q, %v", key, err)
	}
	node, part, instance, err = ParsePresenceKey(key)
	if err != nil || node != "" || part != "view" || instance != "novox" {
		t.Fatalf("ParsePresenceKey part = %q %q %q %v", node, part, instance, err)
	}
	if _, err := PresenceNodeKey("part"); err == nil || !strings.Contains(err.Error(), "part") {
		t.Errorf("PresenceNodeKey(part) = %v", err)
	}
	if _, err := PresenceNodeKey("a.b"); err == nil {
		t.Error("PresenceNodeKey(a.b) accepted")
	}
	if _, err := PresencePartKey("", "x"); err == nil {
		t.Error("PresencePartKey with empty part accepted")
	}
	if _, err := PresencePartKey("view", "x y"); err == nil {
		t.Error("PresencePartKey with a space accepted")
	}
	for _, bad := range []string{"", "part", "part.view", "part.view.a.b", "a.b", "part..x"} {
		if _, _, _, err := ParsePresenceKey(bad); err == nil {
			t.Errorf("ParsePresenceKey(%q) accepted", bad)
		}
	}
}

// 1131/AC3: the pulse key splits at the first dot, the key holding dots.
func TestPulseKey(t *testing.T) {
	if PulseBucket != "mesh-delivery-watchman_pulse" {
		t.Fatalf("PulseBucket = %q", PulseBucket)
	}
	key, err := PulseKey("node-engine_have", "ace.plex")
	if err != nil || key != "node-engine_have.ace.plex" {
		t.Fatalf("PulseKey = %q, %v", key, err)
	}
	bucket, rest, err := ParsePulseKey(key)
	if err != nil || bucket != "node-engine_have" || rest != "ace.plex" {
		t.Fatalf("ParsePulseKey = %q %q %v", bucket, rest, err)
	}
	for _, c := range [][2]string{{"", "k"}, {"a.b", "k"}, {"b", ""}, {"b", "k x"}, {"b", ".k"}, {"b", "k."}, {"b", "k*"}} {
		if _, err := PulseKey(c[0], c[1]); err == nil {
			t.Errorf("PulseKey(%q, %q) accepted", c[0], c[1])
		}
	}
	for _, bad := range []string{"", "nodot", ".k", "b."} {
		if _, _, err := ParsePulseKey(bad); err == nil {
			t.Errorf("ParsePulseKey(%q) accepted", bad)
		}
	}
}

// 1131/AC4: each value encodes, decodes equal, and carries "v":1.
func TestRoundTrip(t *testing.T) {
	hasV1 := func(t *testing.T, b []byte) {
		t.Helper()
		var m map[string]any
		if err := json.Unmarshal(b, &m); err != nil {
			t.Fatal(err)
		}
		if m["v"] != float64(1) {
			t.Fatalf("v = %v in %s", m["v"], b)
		}
		if len(b) > 500 {
			t.Fatalf("value is %d bytes", len(b))
		}
	}
	t.Run("have", func(t *testing.T) {
		in := Have{Build: "b1", FP: "f1", Phase: PhaseRunning, Health: HealthOK, Detail: "up"}
		b, err := EncodeHave(in)
		if err != nil {
			t.Fatal(err)
		}
		hasV1(t, b)
		out, err := DecodeHave(b)
		if err != nil {
			t.Fatal(err)
		}
		in.V = Version
		if out != in {
			t.Fatalf("got %+v want %+v", out, in)
		}
	})
	t.Run("have node", func(t *testing.T) {
		in := HaveNode{Windows: json.RawMessage(`{"a":1}`), Busy: json.RawMessage(`true`)}
		b, err := EncodeHaveNode(in)
		if err != nil {
			t.Fatal(err)
		}
		hasV1(t, b)
		out, err := DecodeHaveNode(b)
		if err != nil {
			t.Fatal(err)
		}
		if !SameHaveNode(out, HaveNode{V: Version, Windows: in.Windows, Busy: in.Busy}) {
			t.Fatalf("got %+v", out)
		}
	})
	t.Run("presence", func(t *testing.T) {
		b, err := EncodePresence(Presence{Online: true})
		if err != nil {
			t.Fatal(err)
		}
		hasV1(t, b)
		out, err := DecodePresence(b)
		if err != nil || out != (Presence{V: Version, Online: true}) {
			t.Fatalf("got %+v %v", out, err)
		}
	})
	t.Run("pulse", func(t *testing.T) {
		in := Pulse{Bucket: "node-engine_have", Key: "ace.plex", Revision: 7, Owes: "ace"}
		b, err := EncodePulse(in)
		if err != nil {
			t.Fatal(err)
		}
		hasV1(t, b)
		out, err := DecodePulse(b)
		in.V = Version
		if err != nil || out != in {
			t.Fatalf("got %+v %v", out, err)
		}
	})
}

// 1131/AC5: a missing or unknown version is refused as ErrUnknownVersion, naming both versions.
func TestUnknownVersion(t *testing.T) {
	decoders := map[string]func([]byte) error{
		"have":      func(b []byte) error { _, err := DecodeHave(b); return err },
		"have node": func(b []byte) error { _, err := DecodeHaveNode(b); return err },
		"presence":  func(b []byte) error { _, err := DecodePresence(b); return err },
		"pulse":     func(b []byte) error { _, err := DecodePulse(b); return err },
	}
	for name, dec := range decoders {
		t.Run(name, func(t *testing.T) {
			err := dec([]byte(`{"v":2,"phase":"running","health":"ok"}`))
			if !errors.Is(err, ErrUnknownVersion) || !strings.Contains(err.Error(), "2") || !strings.Contains(err.Error(), "1") {
				t.Errorf("v 2: %v", err)
			}
			err = dec([]byte(`{"phase":"running","health":"ok"}`))
			if !errors.Is(err, ErrUnknownVersion) {
				t.Errorf("missing v: %v", err)
			}
			if err := dec([]byte(`not json`)); err == nil || errors.Is(err, ErrUnknownVersion) {
				t.Errorf("garbage: %v", err)
			}
		})
	}
}

// 1131/AC6: a phase or health outside the lists is refused on encode and decode.
func TestPhaseHealthRefused(t *testing.T) {
	for _, p := range []Phase{PhaseBackingUp, PhaseApplying, PhaseChecking, PhaseRunning, PhaseFailed} {
		for _, h := range []Health{HealthOK, HealthFailed, HealthWaits, HealthUnknown} {
			if _, err := EncodeHave(Have{Phase: p, Health: h}); err != nil {
				t.Errorf("%s/%s refused: %v", p, h, err)
			}
		}
	}
	if _, err := EncodeHave(Have{Phase: "sleeping", Health: HealthOK}); err == nil || !strings.Contains(err.Error(), "sleeping") {
		t.Errorf("bad phase encoded: %v", err)
	}
	if _, err := EncodeHave(Have{Phase: PhaseRunning, Health: "fine"}); err == nil || !strings.Contains(err.Error(), "fine") {
		t.Errorf("bad health encoded: %v", err)
	}
	if _, err := EncodeHave(Have{Phase: PhaseRunning}); err == nil {
		t.Error("empty health encoded")
	}
	if _, err := DecodeHave([]byte(`{"v":1,"phase":"sleeping","health":"ok"}`)); err == nil {
		t.Error("bad phase decoded")
	}
	if _, err := DecodeHave([]byte(`{"v":1,"phase":"running","health":"fine"}`)); err == nil {
		t.Error("bad health decoded")
	}
}

// 1131/AC7: the pulse's time to live is 120 seconds minus the move's age; at the bound the move is stalled.
func TestPulseTTL(t *testing.T) {
	for _, c := range []struct {
		age     time.Duration
		ttl     time.Duration
		stalled bool
	}{
		{0, 120 * time.Second, false},
		{30 * time.Second, 90 * time.Second, false},
		{119 * time.Second, time.Second, false},
		{120 * time.Second, 0, true},
		{200 * time.Second, 0, true},
	} {
		ttl, stalled := PulseTTL(c.age)
		if ttl != c.ttl || stalled != c.stalled {
			t.Errorf("PulseTTL(%v) = %v, %v; want %v, %v", c.age, ttl, stalled, c.ttl, c.stalled)
		}
	}
	if PulseMoveBound != 120*time.Second || HaveHistory != 20 || PresenceHistory != 20 {
		t.Error("constants")
	}
}

// 1131/AC8: equal values say same, different ones do not.
func TestSame(t *testing.T) {
	a := Have{V: 1, Build: "b", Phase: PhaseRunning, Health: HealthOK}
	b := a
	if !SameHave(a, b) {
		t.Error("equal haves differ")
	}
	b.Detail = "x"
	if SameHave(a, b) {
		t.Error("different haves same")
	}
	n := HaveNode{V: 1, Busy: json.RawMessage(`true`)}
	if !SameHaveNode(n, HaveNode{V: 1, Busy: json.RawMessage(`true`)}) || SameHaveNode(n, HaveNode{V: 1}) {
		t.Error("have node")
	}
	if !SamePresence(Presence{V: 1, Online: true}, Presence{V: 1, Online: true}) || SamePresence(Presence{V: 1}, Presence{V: 1, Online: true}) {
		t.Error("presence")
	}
	p := Pulse{V: 1, Bucket: "b", Key: "k", Revision: 1, Owes: "ace"}
	q := p
	if !SamePulse(p, q) {
		t.Error("equal pulses differ")
	}
	q.Revision = 2
	if SamePulse(p, q) {
		t.Error("different pulses same")
	}
}