package nntp

import (
	"bufio"
	"bytes"
	"testing"
)

func TestNewClient(t *testing.T) {
	c := NewClient(Config{Host: "news.example.com", Port: 563, SSL: true})
	if c.cfg.MaxConnections != 10 {
		t.Errorf("default MaxConnections = %d, want 10", c.cfg.MaxConnections)
	}
	if c.cfg.Host != "news.example.com" {
		t.Errorf("Host = %q", c.cfg.Host)
	}
}

func TestNewClientCustomConnections(t *testing.T) {
	c := NewClient(Config{Host: "news.example.com", Port: 563, MaxConnections: 20})
	if c.cfg.MaxConnections != 20 {
		t.Errorf("MaxConnections = %d, want 20", c.cfg.MaxConnections)
	}
}

func TestNewClientZeroConnections(t *testing.T) {
	c := NewClient(Config{Host: "news.example.com", Port: 563, MaxConnections: 0})
	if c.cfg.MaxConnections != 10 {
		t.Errorf("MaxConnections should default to 10, got %d", c.cfg.MaxConnections)
	}
}

func TestNewClientNegativeConnections(t *testing.T) {
	c := NewClient(Config{MaxConnections: -5})
	if c.cfg.MaxConnections != 10 {
		t.Errorf("MaxConnections should default to 10 for negative, got %d", c.cfg.MaxConnections)
	}
}

func TestActiveConnections(t *testing.T) {
	c := NewClient(Config{Host: "localhost", Port: 119})
	if c.ActiveConnections() != 0 {
		t.Errorf("ActiveConnections = %d, want 0", c.ActiveConnections())
	}
}

func TestStatus(t *testing.T) {
	c := NewClient(Config{Host: "news.example.com", Port: 563})
	s := c.Status()
	if s != "0 connections (0 pooled) to news.example.com:563" {
		t.Errorf("Status = %q", s)
	}
}

func TestCloseIdempotent(t *testing.T) {
	c := NewClient(Config{Host: "localhost", Port: 119})
	// Close should be idempotent
	if err := c.Close(); err != nil {
		t.Errorf("first Close: %v", err)
	}
	if err := c.Close(); err != nil {
		t.Errorf("second Close: %v", err)
	}
}

func TestArticleNotFoundError(t *testing.T) {
	err := &ArticleNotFoundError{MessageID: "abc123@news.example.com"}
	msg := err.Error()
	if msg != "nntp: article not found: abc123@news.example.com" {
		t.Errorf("Error() = %q", msg)
	}
}

func TestReadDotBody(t *testing.T) {
	tests := []struct {
		name  string
		input string
		want  string
	}{
		{
			"simple body",
			"Hello World\r\n.\r\n",
			"Hello World\n",
		},
		{
			"multiline",
			"Line 1\r\nLine 2\r\nLine 3\r\n.\r\n",
			"Line 1\nLine 2\nLine 3\n",
		},
		{
			"dot-stuffed line",
			"..This starts with a dot\r\n.\r\n",
			".This starts with a dot\n",
		},
		{
			"empty body",
			".\r\n",
			"",
		},
		{
			"binary-like data",
			"=ybegin line=128 size=1024 name=test.bin\r\nsome encoded data\r\n=yend\r\n.\r\n",
			"=ybegin line=128 size=1024 name=test.bin\nsome encoded data\n=yend\n",
		},
	}

	for _, tt := range tests {
		t.Run(tt.name, func(t *testing.T) {
			r := bufio.NewReader(bytes.NewBufferString(tt.input))
			got, err := readDotBody(r)
			if err != nil {
				t.Fatalf("readDotBody: %v", err)
			}
			if string(got) != tt.want {
				t.Errorf("readDotBody = %q, want %q", string(got), tt.want)
			}
		})
	}
}

func TestReadDotBodyEOF(t *testing.T) {
	// No dot terminator — should read until EOF
	r := bufio.NewReader(bytes.NewBufferString("partial data\r\n"))
	got, err := readDotBody(r)
	if err != nil {
		t.Fatalf("readDotBody EOF: %v", err)
	}
	if string(got) != "partial data\n" {
		t.Errorf("readDotBody EOF = %q", string(got))
	}
}