package mqtt

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

	"gitea.lab.audasmedia.com.au/sam/internet_use_control/internal/store"
)

func TestTopicHelpers(t *testing.T) {
	const config = "restrict/harry_phone_2/config"
	if got := StatusTopic(config); got != "restrict/harry_phone_2/status" {
		t.Errorf("StatusTopic = %q", got)
	}
	if got := TelemetryTopic(config); got != "restrict/harry_phone_2/telemetry" {
		t.Errorf("TelemetryTopic = %q", got)
	}

	for _, tc := range []struct {
		topic  string
		suffix string
		want   string
		ok     bool
	}{
		{"restrict/harry_phone_2/status", SuffixStatus, config, true},
		{"restrict/harry_phone_2/telemetry", SuffixTelemetry, config, true},
		{"restrict/harry_phone_2/config", SuffixStatus, "", false},
		{"restrict/status", SuffixStatus, "", false},
		{"restrict/a/b/status", SuffixStatus, "", false},
		{"other/harry_phone_2/status", SuffixStatus, "", false},
	} {
		got, ok := deviceFromTopic(tc.topic, tc.suffix)
		if ok != tc.ok || got != tc.want {
			t.Errorf("deviceFromTopic(%q, %q) = (%q, %v), want (%q, %v)",
				tc.topic, tc.suffix, got, ok, tc.want, tc.ok)
		}
	}
}

func TestConfigMarshal(t *testing.T) {
	until := time.Date(2026, 10, 13, 21, 0, 0, 0, time.UTC)
	b, err := Config{
		V:           ConfigVersion,
		DeviceID:    2,
		Name:        "harry_phone",
		Platform:    store.PlatformAndroid,
		Locked:      true,
		Until:       &until,
		GeneratedAt: time.Date(2026, 10, 13, 3, 0, 0, 0, time.UTC),
	}.Marshal()
	if err != nil {
		t.Fatalf("Marshal: %v", err)
	}

	// The lists must be present as arrays, never null, so a client can parse
	// this without null checks.
	if !strings.Contains(string(b), `"allow":[]`) || !strings.Contains(string(b), `"block":[]`) {
		t.Errorf("payload has null lists: %s", b)
	}

	var back Config
	if err := json.Unmarshal(b, &back); err != nil {
		t.Fatalf("Unmarshal: %v", err)
	}
	if !back.Locked || back.Until == nil || !back.Until.Equal(until) {
		t.Errorf("round trip lost the lock: %+v", back)
	}
	if back.V != ConfigVersion || back.DeviceID != 2 {
		t.Errorf("round trip lost the identity: %+v", back)
	}
}

func TestParseStatus(t *testing.T) {
	if _, err := ParseStatus(nil); err == nil {
		t.Error("expected an error for an empty payload")
	}
	if _, err := ParseStatus([]byte("{oops")); err == nil {
		t.Error("expected an error for malformed JSON")
	}

	// An explicit offline (the will payload the broker publishes on a dropped
	// connection) must read as offline.
	off, err := ParseStatus([]byte(`{"online":false}`))
	if err != nil {
		t.Fatalf("ParseStatus: %v", err)
	}
	if off.IsOnline() {
		t.Error(`{"online":false} read as online`)
	}

	// A report with no "online" field means the device is talking.
	on, err := ParseStatus([]byte(`{"app":"com.spotify.music"}`))
	if err != nil {
		t.Fatalf("ParseStatus: %v", err)
	}
	if !on.IsOnline() {
		t.Error("a report with no online field read as offline")
	}
	if on.App != "com.spotify.music" {
		t.Errorf("App = %q", on.App)
	}

	at := on.Timestamp(time.Date(2026, 1, 1, 0, 0, 0, 0, time.UTC))
	if !at.Equal(time.Date(2026, 1, 1, 0, 0, 0, 0, time.UTC)) {
		t.Errorf("Timestamp with no at field = %v, want the fallback", at)
	}
	at = Status{At: "2026-10-13T07:30:00Z"}.Timestamp(time.Now())
	if at.UTC().Format(time.RFC3339) != "2026-10-13T07:30:00Z" {
		t.Errorf("Timestamp = %v", at)
	}
}

func TestTelemetryRows(t *testing.T) {
	payload := []byte(`{
		"day": "2026-10-13",
		"apps":    [{"name": "com.spotify.music", "seconds": 600}, {"name": "", "seconds": 5}],
		"domains": [{"name": "youtube.com", "seconds": 120}]
	}`)
	report, err := ParseTelemetry(payload)
	if err != nil {
		t.Fatalf("ParseTelemetry: %v", err)
	}
	rows := report.Rows()
	if len(rows) != 2 {
		t.Fatalf("Rows = %+v, want 2 rows", rows)
	}
	// Apps first, then domains.
	if rows[0].App != "com.spotify.music" || rows[0].Seconds != 600 {
		t.Errorf("rows[0] = %+v", rows[0])
	}
	if rows[1].Domain != "youtube.com" || rows[1].Seconds != 120 {
		t.Errorf("rows[1] = %+v", rows[1])
	}
	if got := report.DayOrDefault(time.Now()); got != "2026-10-13" {
		t.Errorf("DayOrDefault = %q, want the reported day", got)
	}

	// The flat single-row form, and a bad day falling back to today.
	flat, err := ParseTelemetry([]byte(`{"app":"roblox","seconds":60,"day":"yesterday"}`))
	if err != nil {
		t.Fatalf("ParseTelemetry flat: %v", err)
	}
	flatRows := flat.Rows()
	if len(flatRows) != 1 || flatRows[0].App != "roblox" {
		t.Fatalf("flat Rows = %+v", flatRows)
	}
	now := time.Date(2026, 3, 4, 12, 0, 0, 0, time.UTC)
	if got := flat.DayOrDefault(now); got != "2026-03-04" {
		t.Errorf("DayOrDefault with a bad day = %q, want 2026-03-04", got)
	}

	// Negative totals are dropped, not stored.
	bad, err := ParseTelemetry([]byte(`{"apps":[{"name":"x","seconds":-1}]}`))
	if err != nil {
		t.Fatalf("ParseTelemetry: %v", err)
	}
	if len(bad.Rows()) != 0 {
		t.Errorf("negative usage stored: %+v", bad.Rows())
	}

	if _, err := ParseTelemetry([]byte("not json")); err == nil {
		t.Error("expected an error for malformed JSON")
	}
}

func TestNewRejectsIncompleteOptions(t *testing.T) {
	if _, err := New(Options{Broker: "tcp://127.0.0.1:1883"}); err == nil {
		t.Error("expected an error without a device lookup, source and sink")
	}
	_, err := New(Options{
		Broker:  "tls://broker:8883",
		CAFile:  "/nonexistent/ca.crt",
		Devices: stubLookup{},
		Source:  stubSource{},
		Reports: stubSink{},
	})
	if err == nil {
		t.Fatal("expected an error for a missing CA bundle")
	}
	if !strings.Contains(err.Error(), "ca.crt") {
		t.Errorf("error = %v, want it to name the CA file", err)
	}
}

type stubLookup struct{}

func (stubLookup) DeviceByConfigTopic(ctx context.Context, topic string) (*store.Device, error) {
	return nil, errors.New("not implemented")
}

type stubSource struct{}

func (stubSource) ListDevices(ctx context.Context) ([]store.Device, error) { return nil, nil }

func (stubSource) EffectiveState(ctx context.Context, dev store.Device, now time.Time) (store.EffectiveState, error) {
	return store.EffectiveState{DeviceID: dev.ID, Allow: []string{}, Block: []string{}}, nil
}

type stubSink struct{}

func (stubSink) SetPresence(ctx context.Context, id int64, online bool, at time.Time, actor string) (bool, error) {
	return false, nil
}

func (stubSink) InsertTelemetry(ctx context.Context, id int64, day string, e []store.TelemetryEntry) (int, error) {
	return 0, nil
}

// stateSource returns a fixed effective state, to prove the published payload
// without a broker.
type stateSource struct {
	eff store.EffectiveState
}

func (s stateSource) ListDevices(ctx context.Context) ([]store.Device, error) { return nil, nil }

func (s stateSource) EffectiveState(ctx context.Context, dev store.Device, now time.Time) (store.EffectiveState, error) {
	eff := s.eff
	eff.DeviceID = dev.ID
	return eff, nil
}

// TestBuildConfigAllowlistIsolation is the Phase 6 definition of done: with
// Spotify allowlisted while other apps are blocked during an active schedule
// window, the retained payload says Spotify is allowed and the others are
// blocked.
func TestBuildConfigAllowlistIsolation(t *testing.T) {
	until := time.Date(2026, 10, 13, 21, 0, 0, 0, time.UTC)
	link, err := New(Options{
		Broker: "tcp://127.0.0.1:1883",
		Source: stateSource{eff: store.EffectiveState{
			Locked: true,
			Until:  &until,
			Reason: "schedule",
			Allow:  []string{"com.spotify.music"},
			Block:  []string{"com.youtube.android", "roblox.exe"},
		}},
		Devices: stubLookup{},
		Reports: stubSink{},
	})
	if err != nil {
		t.Fatalf("New: %v", err)
	}

	payload, err := link.buildConfig(context.Background(), store.Device{
		ID: 7, Name: "Harry's phone", Platform: store.PlatformAndroid,
	})
	if err != nil {
		t.Fatalf("buildConfig: %v", err)
	}

	var cfg Config
	if err := json.Unmarshal(payload, &cfg); err != nil {
		t.Fatalf("Unmarshal: %v", err)
	}
	if !cfg.Locked || cfg.Reason != "schedule" {
		t.Errorf("payload = %s, want locked by schedule", payload)
	}
	if cfg.Until == nil || !cfg.Until.Equal(until) {
		t.Errorf("until = %v, want %v", cfg.Until, until)
	}
	if len(cfg.Allow) != 1 || cfg.Allow[0] != "com.spotify.music" {
		t.Errorf("allow = %v, want Spotify allowed", cfg.Allow)
	}
	if len(cfg.Block) != 2 {
		t.Errorf("block = %v, want the other apps blocked", cfg.Block)
	}
	// The JSON is the contract the kids' clients read.
	for _, want := range []string{
		`"locked":true`, `"reason":"schedule"`,
		`"allow":["com.spotify.music"]`,
	} {
		if !strings.Contains(string(payload), want) {
			t.Errorf("payload %s missing %s", payload, want)
		}
	}
}

func TestParseStatusTamper(t *testing.T) {
	payload := []byte(`{"online":true,"app":"com.android.settings",` +
		`"tamper":{"kind":"accessibility_disabled","detail":"service turned off",` +
		`"at":"2026-10-13T08:00:00Z"},"at":"2026-10-13T08:00:01Z"}`)
	st, err := ParseStatus(payload)
	if err != nil {
		t.Fatalf("ParseStatus: %v", err)
	}
	if !st.HasTamper() {
		t.Fatal("HasTamper = false, want true")
	}
	if st.Tamper.Kind != "accessibility_disabled" {
		t.Errorf("kind = %q", st.Tamper.Kind)
	}
	if st.Tamper.Detail != "service turned off" {
		t.Errorf("detail = %q", st.Tamper.Detail)
	}

	plain, err := ParseStatus([]byte(`{"online":false}`))
	if err != nil {
		t.Fatalf("ParseStatus plain: %v", err)
	}
	if plain.HasTamper() {
		t.Error("plain status reported a tamper")
	}
}