package git

import (
	"bytes"
	"strings"
	"testing"
)

func TestPacketReader(t *testing.T) {
	// Test single packet
	t.Run("single packet", func(t *testing.T) {
		input := "0010hello world\n"
		reader := NewPacketReader(strings.NewReader(input))
		
		packet, err := reader.ReadPacket()
		if err != nil {
			t.Fatalf("unexpected error: %v", err)
		}
		
		expected := "hello world\n"
		if string(packet) != expected {
			t.Errorf("expected %q, got %q", expected, string(packet))
		}
	})
	
	// Test flush packet
	t.Run("flush packet", func(t *testing.T) {
		input := "0000"
		reader := NewPacketReader(strings.NewReader(input))
		
		packet, err := reader.ReadPacket()
		if err != nil {
			t.Fatalf("unexpected error: %v", err)
		}
		
		if packet != nil {
			t.Errorf("expected nil for flush packet, got %q", string(packet))
		}
	})
}

func TestPacketWriter(t *testing.T) {
	var buf bytes.Buffer
	writer := NewPacketWriter(&buf)
	
	err := writer.WritePacket([]byte("hello world\n"))
	if err != nil {
		t.Fatalf("unexpected error: %v", err)
	}
	
	err = writer.WriteFlush()
	if err != nil {
		t.Fatalf("unexpected error: %v", err)
	}
	
	expected := "0010hello world\n0000"
	if buf.String() != expected {
		t.Errorf("expected %q, got %q", expected, buf.String())
	}
}

func TestParseUploadPackRequest(t *testing.T) {
	input := "0032want 1234567890abcdef1234567890abcdef12345678\n" +
		"0032want abcdef1234567890abcdef1234567890abcdef12\n" +
		"0032have fedcba0987654321fedcba0987654321fedcba09\n" +
		"0000"
	
	req, err := ParseUploadPackRequest(strings.NewReader(input))
	if err != nil {
		t.Fatalf("unexpected error: %v", err)
	}
	
	expectedWants := []string{
		"1234567890abcdef1234567890abcdef12345678",
		"abcdef1234567890abcdef1234567890abcdef12",
	}
	expectedHaves := []string{
		"fedcba0987654321fedcba0987654321fedcba09",
	}
	
	if len(req.Wants) != len(expectedWants) {
		t.Fatalf("expected %d wants, got %d", len(expectedWants), len(req.Wants))
	}
	
	for i, want := range expectedWants {
		if req.Wants[i] != want {
			t.Errorf("want %d: expected %q, got %q", i, want, req.Wants[i])
		}
	}
	
	if len(req.Haves) != len(expectedHaves) {
		t.Fatalf("expected %d haves, got %d", len(expectedHaves), len(req.Haves))
	}
	
	for i, have := range expectedHaves {
		if req.Haves[i] != have {
			t.Errorf("have %d: expected %q, got %q", i, have, req.Haves[i])
		}
	}
}