package audio

import (
	"testing"
)

func TestApplyFmtpConfiguresEncoder(t *testing.T) {
	// Verify the encoder's libopus state actually reflects the requested
	// settings, not just that ApplyTo returned nil.
	cases := []struct {
		name string
		in   string
		// checks accept the encoder and report any mismatches.
		check func(t *testing.T, e *Encoder)
	}{
		{
			"default bitrate when missing",
			"",
			func(t *testing.T, e *Encoder) {
				br, err := e.Bitrate()
				if err != nil {
					t.Fatalf("Bitrate: %v", err)
				}
				if br != DefaultBitrate {
					t.Errorf("Bitrate=%d, want %d", br, DefaultBitrate)
				}
			},
		},
		{
			"useinbandfec sets FEC and loss perc",
			"useinbandfec=1",
			func(t *testing.T, e *Encoder) {
				fec, err := e.InBandFEC()
				if err != nil {
					t.Fatalf("InBandFEC: %v", err)
				}
				if !fec {
					t.Error("InBandFEC=false, want true")
				}
				lp, err := e.PacketLossPerc()
				if err != nil {
					t.Fatalf("PacketLossPerc: %v", err)
				}
				if lp != 5 {
					t.Errorf("PacketLossPerc=%d, want 5", lp)
				}
			},
		},
		{
			"usedtx sets DTX",
			"usedtx=1",
			func(t *testing.T, e *Encoder) {
				dtx, err := e.DTX()
				if err != nil {
					t.Fatalf("DTX: %v", err)
				}
				if !dtx {
					t.Error("DTX=false, want true")
				}
			},
		},
		{
			"maxaveragebitrate sets bitrate",
			"maxaveragebitrate=20000",
			func(t *testing.T, e *Encoder) {
				br, err := e.Bitrate()
				if err != nil {
					t.Fatalf("Bitrate: %v", err)
				}
				if br != 20000 {
					t.Errorf("Bitrate=%d, want 20000", br)
				}
			},
		},
	}
	for _, tc := range cases {
		t.Run(tc.name, func(t *testing.T) {
			enc, err := NewEncoder()
			if err != nil {
				t.Fatalf("NewEncoder: %v", err)
			}
			if err := ParseFmtp(tc.in).ApplyTo(enc); err != nil {
				t.Fatalf("Apply(%q): %v", tc.in, err)
			}
			tc.check(t, enc)
		})
	}
}

func TestExtractOpusFmtp(t *testing.T) {
	cases := []struct {
		name string
		sdp  string
		want string
	}{
		{
			"matched opus pt",
			"v=0\r\nm=audio 9 UDP/TLS/RTP/SAVPF 111\r\na=rtpmap:111 opus/48000/2\r\na=fmtp:111 minptime=10;useinbandfec=1\r\n",
			"minptime=10;useinbandfec=1",
		},
		{
			"rtpmap after fmtp",
			"a=fmtp:111 minptime=10;useinbandfec=1\r\na=rtpmap:111 opus/48000/2\r\n",
			"minptime=10;useinbandfec=1",
		},
		{
			"multiple codecs, opus matched",
			"a=rtpmap:0 PCMU/8000\r\na=rtpmap:111 opus/48000/2\r\na=fmtp:111 stereo=1;sprop-stereo=1\r\na=fmtp:0 unrelated=1\r\n",
			"stereo=1;sprop-stereo=1",
		},
		{
			"no opus -> empty",
			"a=rtpmap:0 PCMU/8000\r\na=fmtp:0 unrelated=1\r\n",
			"",
		},
		{
			"opus without fmtp -> empty",
			"a=rtpmap:111 opus/48000/2\r\n",
			"",
		},
	}
	for _, tc := range cases {
		t.Run(tc.name, func(t *testing.T) {
			got := ExtractOpusFmtp(tc.sdp)
			if got != tc.want {
				t.Errorf("ExtractOpusFmtp:\n got %q\nwant %q", got, tc.want)
			}
		})
	}
}