package server

import (
	"testing"

	protocolnnet "git.noahlan.cn/noahlan/nnet/v2/internal/protocol/nnet"
	internalunpacker "git.noahlan.cn/noahlan/nnet/v2/internal/unpacker"
	unpackerpkg "git.noahlan.cn/noahlan/nnet/v2/pkg/unpacker"
)

func TestProcessDataWithUnpackerConsumesIncompleteInput(t *testing.T) {
	unpacker := internalunpacker.NewLengthFieldUnpacker(unpackerpkg.LengthFieldUnpacker{
		LengthFieldOffset:   0,
		LengthFieldLength:   1,
		LengthAdjustment:    0,
		InitialBytesToStrip: 0,
	})

	messages, consumed, hasRemaining, err := processDataWithUnpacker([]byte{3, 'a'}, unpacker)
	if err != nil {
		t.Fatalf("processDataWithUnpacker error: %v", err)
	}
	if len(messages) != 0 {
		t.Fatalf("messages=%d, want 0", len(messages))
	}
	if consumed != 2 {
		t.Fatalf("consumed=%d, want 2", consumed)
	}
	if !hasRemaining {
		t.Fatal("hasRemaining=false, want true")
	}

	messages, consumed, hasRemaining, err = processDataWithUnpacker([]byte{'b', 'c'}, unpacker)
	if err != nil {
		t.Fatalf("processDataWithUnpacker second error: %v", err)
	}
	if consumed != 2 {
		t.Fatalf("second consumed=%d, want 2", consumed)
	}
	if hasRemaining {
		t.Fatal("second hasRemaining=true, want false")
	}
	if len(messages) != 1 {
		t.Fatalf("second messages=%d, want 1", len(messages))
	}
	if string(messages[0]) != "\x03abc" {
		t.Fatalf("message=%q, want %q", string(messages[0]), "\x03abc")
	}
}

func TestProcessDataWithUnpackerIsolatesConnectionBuffers(t *testing.T) {
	u1 := internalunpacker.NewLengthFieldUnpacker(unpackerpkg.LengthFieldUnpacker{
		LengthFieldOffset:   0,
		LengthFieldLength:   1,
		LengthAdjustment:    0,
		InitialBytesToStrip: 0,
	})
	u2 := internalunpacker.NewLengthFieldUnpacker(unpackerpkg.LengthFieldUnpacker{
		LengthFieldOffset:   0,
		LengthFieldLength:   1,
		LengthAdjustment:    0,
		InitialBytesToStrip: 0,
	})

	messages, _, hasRemaining, err := processDataWithUnpacker([]byte{3, 'a'}, u1)
	if err != nil {
		t.Fatalf("first connection partial error: %v", err)
	}
	if len(messages) != 0 || !hasRemaining {
		t.Fatalf("first connection messages=%d hasRemaining=%v, want 0/true", len(messages), hasRemaining)
	}

	messages, _, hasRemaining, err = processDataWithUnpacker([]byte{1, 'z'}, u2)
	if err != nil {
		t.Fatalf("second connection complete error: %v", err)
	}
	if hasRemaining || len(messages) != 1 || string(messages[0]) != "\x01z" {
		t.Fatalf("second connection messages=%q hasRemaining=%v, want isolated complete frame", messages, hasRemaining)
	}

	messages, _, hasRemaining, err = processDataWithUnpacker([]byte{'b', 'c'}, u1)
	if err != nil {
		t.Fatalf("first connection completion error: %v", err)
	}
	if hasRemaining || len(messages) != 1 || string(messages[0]) != "\x03abc" {
		t.Fatalf("first connection messages=%q hasRemaining=%v, want original buffered frame", messages, hasRemaining)
	}
}

func TestSplitWebSocketMessagesKeepsPartialFrameState(t *testing.T) {
	protocol := protocolnnet.NewNNetProtocol("1.0")
	provider, ok := protocol.(interface{ Unpacker() unpackerpkg.Unpacker })
	if !ok {
		t.Fatal("protocol should provide an unpacker")
	}
	unpacker := provider.Unpacker()
	packet, err := protocol.Encode([]byte("hello"), nil)
	if err != nil {
		t.Fatalf("encode error: %v", err)
	}

	messages, err := splitWebSocketMessages(packet[:6], unpacker)
	if err != nil {
		t.Fatalf("partial split error: %v", err)
	}
	if len(messages) != 0 {
		t.Fatalf("partial messages=%d, want 0", len(messages))
	}

	messages, err = splitWebSocketMessages(packet[6:], unpacker)
	if err != nil {
		t.Fatalf("completion split error: %v", err)
	}
	if len(messages) != 1 || string(messages[0]) != string(packet) {
		t.Fatalf("messages=%q, want complete packet", messages)
	}
}