// Copyright 2023 The Go Authors. All rights reserved.
// Use of this source code is governed by a BSD-style
// license that can be found in the LICENSE file.

//go:build go1.21

package quic

import "testing"

func TestConnInflowReturnOnRead(t *testing.T) {
	ctx := canceledContext()
	tc, s := newTestConnAndRemoteStream(t, serverSide, uniStream, func(c *Config) {
		c.MaxConnReadBufferSize = 64
	})
	tc.writeFrames(packetType1RTT, debugFrameStream{
		id:   s.id,
		data: make([]byte, 64),
	})
	const readSize = 8
	if n, err := s.ReadContext(ctx, make([]byte, readSize)); n != readSize || err != nil {
		t.Fatalf("s.Read() = %v, %v; want %v, nil", n, err, readSize)
	}
	tc.wantFrame("available window increases, send a MAX_DATA",
		packetType1RTT, debugFrameMaxData{
			max: 64 + readSize,
		})
	if n, err := s.ReadContext(ctx, make([]byte, 64)); n != 64-readSize || err != nil {
		t.Fatalf("s.Read() = %v, %v; want %v, nil", n, err, 64-readSize)
	}
	tc.wantFrame("available window increases, send a MAX_DATA",
		packetType1RTT, debugFrameMaxData{
			max: 128,
		})
}

func TestConnInflowReturnOnClose(t *testing.T) {
	tc, s := newTestConnAndRemoteStream(t, serverSide, uniStream, func(c *Config) {
		c.MaxConnReadBufferSize = 64
	})
	tc.ignoreFrame(frameTypeStopSending)
	tc.writeFrames(packetType1RTT, debugFrameStream{
		id:   s.id,
		data: make([]byte, 64),
	})
	s.CloseRead()
	tc.wantFrame("closing stream updates connection-level flow control",
		packetType1RTT, debugFrameMaxData{
			max: 128,
		})
}

func TestConnInflowReturnOnReset(t *testing.T) {
	tc, s := newTestConnAndRemoteStream(t, serverSide, uniStream, func(c *Config) {
		c.MaxConnReadBufferSize = 64
	})
	tc.ignoreFrame(frameTypeStopSending)
	tc.writeFrames(packetType1RTT, debugFrameStream{
		id:   s.id,
		data: make([]byte, 32),
	})
	tc.writeFrames(packetType1RTT, debugFrameResetStream{
		id:        s.id,
		finalSize: 64,
	})
	s.CloseRead()
	tc.wantFrame("receiving stream reseet updates connection-level flow control",
		packetType1RTT, debugFrameMaxData{
			max: 128,
		})
}

func TestConnInflowStreamViolation(t *testing.T) {
	tc := newTestConn(t, serverSide, func(c *Config) {
		c.MaxConnReadBufferSize = 100
	})
	tc.handshake()
	tc.ignoreFrame(frameTypeAck)
	// Total MAX_DATA consumed: 50
	tc.writeFrames(packetType1RTT, debugFrameStream{
		id:   newStreamID(clientSide, bidiStream, 0),
		data: make([]byte, 50),
	})
	// Total MAX_DATA consumed: 80
	tc.writeFrames(packetType1RTT, debugFrameStream{
		id:   newStreamID(clientSide, uniStream, 0),
		off:  20,
		data: make([]byte, 10),
	})
	// Total MAX_DATA consumed: 100
	tc.writeFrames(packetType1RTT, debugFrameStream{
		id:  newStreamID(clientSide, bidiStream, 0),
		off: 70,
		fin: true,
	})
	// This stream has already consumed quota for these bytes.
	// Total MAX_DATA consumed: 100
	tc.writeFrames(packetType1RTT, debugFrameStream{
		id:   newStreamID(clientSide, uniStream, 0),
		data: make([]byte, 20),
	})
	tc.wantIdle("peer has consumed all MAX_DATA quota")

	// Total MAX_DATA consumed: 101
	tc.writeFrames(packetType1RTT, debugFrameStream{
		id:   newStreamID(clientSide, bidiStream, 2),
		data: make([]byte, 1),
	})
	tc.wantFrame("peer violates MAX_DATA limit",
		packetType1RTT, debugFrameConnectionCloseTransport{
			code: errFlowControl,
		})
}

func TestConnInflowResetViolation(t *testing.T) {
	tc := newTestConn(t, serverSide, func(c *Config) {
		c.MaxConnReadBufferSize = 100
	})
	tc.handshake()
	tc.ignoreFrame(frameTypeAck)
	tc.writeFrames(packetType1RTT, debugFrameStream{
		id:   newStreamID(clientSide, bidiStream, 0),
		data: make([]byte, 100),
	})
	tc.wantIdle("peer has consumed all MAX_DATA quota")

	tc.writeFrames(packetType1RTT, debugFrameResetStream{
		id:        newStreamID(clientSide, uniStream, 0),
		finalSize: 0,
	})
	tc.wantIdle("stream reset does not consume MAX_DATA quota, no error")

	tc.writeFrames(packetType1RTT, debugFrameResetStream{
		id:        newStreamID(clientSide, uniStream, 1),
		finalSize: 1,
	})
	tc.wantFrame("RESET_STREAM final size violates MAX_DATA limit",
		packetType1RTT, debugFrameConnectionCloseTransport{
			code: errFlowControl,
		})
}

func TestConnInflowMultipleStreams(t *testing.T) {
	ctx := canceledContext()
	tc := newTestConn(t, serverSide, func(c *Config) {
		c.MaxConnReadBufferSize = 128
	})
	tc.handshake()
	tc.ignoreFrame(frameTypeAck)

	var streams []*Stream
	for _, id := range []streamID{
		newStreamID(clientSide, uniStream, 0),
		newStreamID(clientSide, uniStream, 1),
		newStreamID(clientSide, bidiStream, 0),
		newStreamID(clientSide, bidiStream, 1),
	} {
		tc.writeFrames(packetType1RTT, debugFrameStream{
			id:   id,
			data: make([]byte, 32),
		})
		s, err := tc.conn.AcceptStream(ctx)
		if err != nil {
			t.Fatalf("AcceptStream() = %v", err)
		}
		streams = append(streams, s)
		if n, err := s.ReadContext(ctx, make([]byte, 1)); err != nil || n != 1 {
			t.Fatalf("s.Read() = %v, %v; want 1, nil", n, err)
		}
	}
	tc.wantIdle("streams have read data, but not enough to update MAX_DATA")

	if n, err := streams[0].ReadContext(ctx, make([]byte, 32)); err != nil || n != 31 {
		t.Fatalf("s.Read() = %v, %v; want 31, nil", n, err)
	}
	tc.wantFrame("read enough data to trigger a MAX_DATA update",
		packetType1RTT, debugFrameMaxData{
			max: 128 + 32 + 1 + 1 + 1,
		})

	streams[2].CloseRead()
	tc.wantFrame("closed stream triggers another MAX_DATA update",
		packetType1RTT, debugFrameMaxData{
			max: 128 + 32 + 1 + 32 + 1,
		})
}