package tracectx

import "testing"

func TestResolveLoopbackHopAndDuplicates(t *testing.T) {
	// outer nginx (public client) -> inner nginx (loopback) -> app span; the
	// same 401 is recorded at every hop.
	spans := []Span{
		{TraceID: "t", SpanID: "outer", Service: "nginx", Edge: true, PeerIP: "203.0.113.9", IsError: true, StatusCode: 401},
		{TraceID: "t", SpanID: "inner", ParentID: "outer", Service: "nginx", Edge: true, PeerIP: "127.0.0.1", IsError: true, StatusCode: 401},
		{TraceID: "t", SpanID: "app", ParentID: "inner", Service: "orchestrator", PeerIP: "10.244.4.195", IsError: true, StatusCode: 401},
	}
	got := Resolve(spans)
	inner := got[Key{"t", "inner"}]
	if inner.ClientIP != "203.0.113.9" || inner.ClientHops != 1 {
		t.Fatalf("inner client = %+v", inner)
	}
	app := got[Key{"t", "app"}]
	if app.ClientIP != "203.0.113.9" || app.ClientHops != 2 || app.EdgePeer != "203.0.113.9" {
		t.Fatalf("app client = %+v", app)
	}
	if got[Key{"t", "outer"}].IsDuplicate || !got[Key{"t", "inner"}].IsDuplicate || !got[Key{"t", "app"}].IsDuplicate {
		t.Fatal("only the outermost error may own the request")
	}
	if !app.IsRootCause || got[Key{"t", "outer"}].IsRootCause {
		t.Fatal("root cause is the deepest error")
	}
	if outer := got[Key{"t", "outer"}]; outer.Children != 1 || outer.UpstreamChildren != 0 || outer.Depth != 0 {
		t.Fatalf("outer = %+v", outer)
	}
	if inner.UpstreamChildren != 1 {
		t.Fatalf("inner should have one upstream (other service) child: %+v", inner)
	}
}

func TestResolveDifferentStatusIsNotDuplicate(t *testing.T) {
	got := Resolve([]Span{
		{TraceID: "t", SpanID: "a", Service: "nginx", Edge: true, PeerIP: "203.0.113.9", IsError: true, StatusCode: 502},
		{TraceID: "t", SpanID: "b", ParentID: "a", Service: "api", IsError: true, StatusCode: 500},
	})
	if got[Key{"t", "b"}].IsDuplicate {
		t.Fatal("a 500 under a 502 is a distinct failure")
	}
}

func TestResolveMissingParentAndCycle(t *testing.T) {
	got := Resolve([]Span{
		{TraceID: "t", SpanID: "x", ParentID: "gone", Service: "nginx", PeerIP: "198.51.100.7"},
		{TraceID: "t", SpanID: "c1", ParentID: "c2", Service: "s", IsError: true},
		{TraceID: "t", SpanID: "c2", ParentID: "c1", Service: "s", IsError: true},
	})
	if !got[Key{"t", "x"}].ParentMissing || got[Key{"t", "x"}].ClientIP != "198.51.100.7" {
		t.Fatalf("x = %+v", got[Key{"t", "x"}])
	}
	if _, ok := got[Key{"t", "c1"}]; !ok { // must terminate
		t.Fatal("cycle dropped a span")
	}
}