package server

import (
	"context"
	"net/url"
	"strings"
	"sync"
	"testing"
	"time"

	"github.com/alicebob/miniredis/v2"

	"migadu_counters/internal/store"
)

// Real CDB: yagolivas.com has A/o=20 and O/o=20, so 80% is 16.
func TestOut_WarnsAt80PercentOnceAndBreachesOnce(t *testing.T) {
	h := newHarness(t, options{warnPercent: 80})
	for i := 0; i < 22; i++ {
		h.accept("/out", `{"trace_id":"w","auth_user":"a@yagolivas.com","recipient":"x@gmail.com"}`)
	}
	if err := h.notifier.Shutdown(context.Background()); err != nil {
		t.Fatal(err)
	}
	if h.warnAddr.count() != 1 || h.warnOrg.count() != 1 {
		t.Errorf("warnings addr=%d org=%d, want 1 each", h.warnAddr.count(), h.warnOrg.count())
	}
	if h.addrURL.count() != 1 || h.orgURL.count() != 1 {
		t.Errorf("breaches addr=%d org=%d, want 1 each", h.addrURL.count(), h.orgURL.count())
	}
	u, err := url.Parse(h.warnAddr.urls[0])
	if err != nil {
		t.Fatal(err)
	}
	q := u.Query()
	if u.Path != "/api/limits/warning" || q.Get("count") != "16" || q.Get("limit") != "20" || q.Get("percent") != "80" || q.Get("id") != "a@yagolivas.com" {
		t.Errorf("warning url = %s", h.warnAddr.urls[0])
	}
	if h.metric(h.m.WarningReached.WithLabelValues("A", "o")) != 1 {
		t.Error("warning_reached_total not recorded")
	}
	if h.metric(h.m.Notifications.WithLabelValues("warning", "A", "sent")) != 1 {
		t.Error("notifications_total{warning,A,sent} not recorded")
	}
	if !strings.Contains(h.tx.String(), "warning reached (level=[A] id=[a@yagolivas.com] flow=[o] by=[a@yagolivas.com]) => notifying warn_address_url") {
		t.Errorf("transaction log:\n%s", h.tx.String())
	}
}

func TestOut_ConcurrentIncrementsNotifyOnce(t *testing.T) {
	h := newHarness(t, options{warnPercent: 80, workers: 8})
	var wg sync.WaitGroup
	for i := 0; i < 40; i++ {
		wg.Add(1)
		go func() {
			defer wg.Done()
			h.post("/out", `{"trace_id":"c","auth_user":"a@yagolivas.com","recipient":"x@gmail.com"}`)
		}()
	}
	wg.Wait()
	h.settle()
	if err := h.notifier.Shutdown(context.Background()); err != nil {
		t.Fatal(err)
	}
	if h.redisInt(store.Key("A", "a@yagolivas.com", day, "o")) != 40 {
		t.Fatalf("counter = %d, want 40", h.redisInt(store.Key("A", "a@yagolivas.com", day, "o")))
	}
	if h.warnAddr.count() != 1 || h.addrURL.count() != 1 {
		t.Errorf("warnings=%d breaches=%d, want 1 each", h.warnAddr.count(), h.addrURL.count())
	}
}

func TestOut_WarningsOffSendsNone(t *testing.T) {
	h := newHarness(t, options{})
	for i := 0; i < 20; i++ {
		h.accept("/out", `{"trace_id":"w","auth_user":"a@yagolivas.com","recipient":"x@gmail.com"}`)
	}
	h.notifier.Shutdown(context.Background())
	if h.warnAddr.count() != 0 || h.addrURL.count() != 1 {
		t.Errorf("warnings=%d breaches=%d, want 0 and 1", h.warnAddr.count(), h.addrURL.count())
	}
	if strings.Contains(h.tx.String(), "warning reached") {
		t.Errorf("transaction log mentions a warning:\n%s", h.tx.String())
	}
}

// Once a breach was notified, a lost EXEC reply on a later message sends nothing.
func TestLostReplyAfterBreachSendsNothing(t *testing.T) {
	backend := miniredis.RunT(t)
	proxy := delayProxy(t, backend.Addr(), 3*time.Second)
	h := newHarness(t, options{writeAddr: proxy})
	key := store.Key("A", "a@yagolivas.com", day, "o") // A/o=20
	backend.Set(key, "40")
	backend.Set(store.MarkerKey("A", "a@yagolivas.com", day, "o", store.MarkerLimit), "1")
	h.accept("/out", `{"trace_id":"lost2","auth_user":"a@yagolivas.com","recipient":"x@gmail.com"}`)
	if err := h.notifier.Shutdown(context.Background()); err != nil {
		t.Fatal(err)
	}
	if h.addrURL.count() != 0 {
		t.Errorf("address notifications = %d, want 0", h.addrURL.count())
	}
	if !strings.Contains(h.tx.String(), "count=41 limit=20 reached=false (re-read)") {
		t.Errorf("transaction log:\n%s", h.tx.String())
	}
}

// --- review round 2 ------------------------------------------------------------

func TestOut_LoginSuffixNeverLogged(t *testing.T) {
	h := newHarness(t, options{})
	h.accept("/out", `{"trace_id":"m2","auth_user":"x@yagolivas.com@SECRET\\nFORGED LINE","recipient":"y@yagolivas.com"}`)
	h.accept("/out", `{"trace_id":"m3","auth_user":"x@yagolivas.com@SECRET\nFORGED LINE","recipient":"y@yagolivas.com"}`)
	if tx := h.tx.String(); strings.Contains(tx, "SECRET") || strings.Contains(tx, "FORGED") {
		t.Errorf("transaction log contains the login suffix:\n%s", tx)
	}
}

func TestReject_LeavesTraceInBothLogs(t *testing.T) {
	h := newHarness(t, options{})
	if st, _ := h.post("/in", `{"trace_id":"TRACE-XYZ","recipient":"nobody"}`); st != 400 {
		t.Fatal(st)
	}
	if !strings.Contains(h.log.String(), "TRACE-XYZ") {
		t.Errorf("app log lacks the trace id:\n%s", h.log.String())
	}
	if !strings.Contains(h.tx.String(), "<TRACE-XYZ> in; rejected: 400 ") {
		t.Errorf("counting log lacks the rejection:\n%s", h.tx.String())
	}
}

func TestErrors_DoNotExposeInternals(t *testing.T) {
	h := newHarness(t, options{})
	readAddr, writeAddr := h.read.Addr(), h.write.Addr()
	h.read.Close()
	st, body := h.get("/counters?address=a@yagolivas.com")
	if st != 503 || strings.Contains(body, readAddr) || strings.Contains(body, "dial") {
		t.Errorf("/counters = %d %s", st, body)
	}
	if !strings.Contains(h.log.String(), readAddr) {
		t.Errorf("detail should stay in the app log:\n%s", h.log.String())
	}
	h.write.Close()
	st, body = h.adminGet("/health")
	if st != 503 || strings.Contains(body, writeAddr) || strings.Contains(body, "dial") {
		t.Errorf("/health = %d %s", st, body)
	}
}

func TestPanic_CountedInRequestMetrics(t *testing.T) {
	h := newHarness(t, options{})
	h.srv.panicHook = func() { panic("boom") }
	if st, _ := h.post("/in", `{"recipient":"b@yagolivas.com"}`); st != 500 {
		t.Fatal(st)
	}
	if got := h.metric(h.m.Requests.WithLabelValues("/in", "500")); got != 1 {
		t.Errorf("requests_total{/in,500} = %v, want 1", got)
	}
}

// Real CDB: xn-- domains are hosted under their punycode key.
func TestCounters_UnicodeDomainIsNormalised(t *testing.T) {
	h := newHarness(t, options{})
	if st, _ := h.get("/counters?domain=host_name.example.com"); st != 400 {
		t.Errorf("invalid domain status = %d, want 400", st)
	}
	st, body := h.get("/counters?domain=" + url.QueryEscape("Bücher.example."))
	if st != 200 {
		t.Fatalf("status %d: %s", st, body)
	}
	if r := decodeCounters(t, body); r.Query != "xn--bcher-kva.example" {
		t.Errorf("query = %q, want the punycode form", r.Query)
	}
}