//go:build linux || freebsd
// +build linux freebsd

package ftp

import (
	"errors"
	"net/url"
	"strings"
	"testing"
	"time"
)

// ---------- Protocol tests ----------

func TestNewProtocol(t *testing.T) {
	p := NewProtocol()
	if p == nil {
		t.Fatal("NewProtocol() returned nil")
	}
}

func TestScheme(t *testing.T) {
	p := &Protocol{}
	if got := p.Scheme(); got != "ftp" {
		t.Errorf("Scheme() = %q, want %q", got, "ftp")
	}
}

func TestCanHandle(t *testing.T) {
	tests := []struct {
		name string
		raw  string
		want bool
	}{
		{"ftp scheme", "ftp://ftp.example.com/file.txt", true},
		{"ftps scheme", "ftps://ftp.example.com/file.txt", true},
		{"http scheme", "http://example.com/file.txt", false},
		{"https scheme", "https://example.com/file.txt", false},
		{"sftp scheme", "sftp://example.com/file.txt", false},
		{"empty scheme", "file.txt", false},
		{"nil URL", "", false},
	}

	p := &Protocol{}
	for _, tt := range tests {
		t.Run(tt.name, func(t *testing.T) {
			var u *url.URL
			if tt.raw != "" {
				var err error
				u, err = url.Parse(tt.raw)
				if err != nil {
					t.Fatalf("failed to parse URL %q: %v", tt.raw, err)
				}
			}
			if got := p.CanHandle(u); got != tt.want {
				t.Errorf("CanHandle(%q) = %v, want %v", tt.raw, got, tt.want)
			}
		})
	}
}

func TestCanHandleCaseInsensitive(t *testing.T) {
	p := &Protocol{}
	u, _ := url.Parse("FTP://example.com/file.txt")
	if !p.CanHandle(u) {
		t.Errorf("CanHandle should be case-insensitive for FTP")
	}
	u, _ = url.Parse("FTPS://example.com/file.txt")
	if !p.CanHandle(u) {
		t.Errorf("CanHandle should be case-insensitive for FTPS")
	}
}

func TestCapabilities(t *testing.T) {
	p := &Protocol{}
	caps := p.Capabilities()
	if caps == nil {
		t.Fatal("Capabilities() returned nil")
	}

	expected := map[string]bool{
		"download":  true,
		"resume":    true,
		"recursive": true,
		"tls":       true,
	}

	if len(caps) != len(expected) {
		t.Errorf("Capabilities() length = %d, want %d", len(caps), len(expected))
	}

	for _, cap := range caps {
		if !expected[cap] {
			t.Errorf("unexpected capability: %q", cap)
		}
	}
}

func TestSupportsResume(t *testing.T) {
	p := &Protocol{}
	if !p.SupportsResume() {
		t.Errorf("SupportsResume() should return true")
	}
}

func TestSupportsCompression(t *testing.T) {
	p := &Protocol{}
	if p.SupportsCompression() {
		t.Errorf("SupportsCompression() should return false")
	}
}

func TestSupportsParallel(t *testing.T) {
	p := &Protocol{}
	if p.SupportsParallel() {
		t.Errorf("SupportsParallel() should return false")
	}
}

func TestSupportsRecursive(t *testing.T) {
	p := &Protocol{}
	if !p.SupportsRecursive() {
		t.Errorf("SupportsRecursive() should return true")
	}
}

func TestReadAll(t *testing.T) {
	t.Run("normal content", func(t *testing.T) {
		input := "Hello, FTP world!"
		r := strings.NewReader(input)
		data, err := readAll(r)
		if err != nil {
			t.Fatalf("readAll() returned error: %v", err)
		}
		if string(data) != input {
			t.Errorf("readAll() = %q, want %q", string(data), input)
		}
	})

	t.Run("empty reader", func(t *testing.T) {
		r := strings.NewReader("")
		data, err := readAll(r)
		if err != nil {
			t.Fatalf("readAll() returned error: %v", err)
		}
		if len(data) != 0 {
			t.Errorf("readAll() returned %d bytes, want 0", len(data))
		}
	})

	t.Run("large content", func(t *testing.T) {
		// Create content larger than the 32KB buffer to ensure multiple reads
		content := strings.Repeat("A", 100*1024)
		r := strings.NewReader(content)
		data, err := readAll(r)
		if err != nil {
			t.Fatalf("readAll() returned error: %v", err)
		}
		if len(data) != len(content) {
			t.Errorf("readAll() returned %d bytes, want %d", len(data), len(content))
		}
	})

	t.Run("reader error", func(t *testing.T) {
		expectedErr := errors.New("read error")
		r := &errorReader{err: expectedErr}
		_, err := readAll(r)
		if err == nil {
			t.Fatal("readAll() should return error")
		}
		if !strings.Contains(err.Error(), expectedErr.Error()) {
			t.Errorf("readAll() error = %v, want %v", err, expectedErr)
		}
	})
}

// errorReader implements io.Reader that always returns an error
type errorReader struct {
	err error
}

func (r *errorReader) Read(p []byte) (n int, err error) {
	return 0, r.err
}

// ---------- Client tests ----------

func TestNewClient(t *testing.T) {
	tests := []struct {
		name    string
		rawURL  string
		wantErr bool
	}{
		{"basic FTP URL", "ftp://ftp.example.com/pub/file.txt", false},
		{"FTP URL with path", "ftp://ftp.example.com/pub/", false},
		{"FTP URL root", "ftp://ftp.example.com", false},
		{"FTP URL with trailing slash", "ftp://ftp.example.com/", false},
	}

	for _, tt := range tests {
		t.Run(tt.name, func(t *testing.T) {
			client, err := NewClient(tt.rawURL, 30*time.Second)
			if tt.wantErr {
				if err == nil {
					t.Errorf("NewClient(%q) expected error", tt.rawURL)
				}
				return
			}
			if err != nil {
				t.Fatalf("NewClient(%q) returned error: %v", tt.rawURL, err)
			}
			if client == nil {
				t.Fatal("NewClient() returned nil")
			}
		})
	}
}

func TestNewClientWithAuth(t *testing.T) {
	client, err := NewClient("ftp://user:password@ftp.example.com/file.txt", 30*time.Second)
	if err != nil {
		t.Fatalf("NewClient() returned error: %v", err)
	}
	if client.user != "user" {
		t.Errorf("client.user = %q, want %q", client.user, "user")
	}
	if client.password != "password" {
		t.Errorf("client.password = %q, want %q", client.password, "password")
	}
}

func TestNewClientWithUserOnly(t *testing.T) {
	client, err := NewClient("ftp://user@ftp.example.com/file.txt", 30*time.Second)
	if err != nil {
		t.Fatalf("NewClient() returned error: %v", err)
	}
	if client.user != "user" {
		t.Errorf("client.user = %q, want %q", client.user, "user")
	}
	if client.password != "anonymous@" {
		t.Errorf("client.password should default to %q when only username is provided, got %q", "anonymous@", client.password)
	}
}

func TestNewClientFTPS(t *testing.T) {
	client, err := NewClient("ftps://ftp.example.com/file.txt", 30*time.Second)
	if err != nil {
		t.Fatalf("NewClient() returned error: %v", err)
	}
	if !client.useTLS {
		t.Errorf("client.useTLS should be true for ftps:// scheme")
	}
}

func TestNewClientFTPSWithAuth(t *testing.T) {
	client, err := NewClient("ftps://alice:secret@ftp.example.com/file.txt", 30*time.Second)
	if err != nil {
		t.Fatalf("NewClient() returned error: %v", err)
	}
	if !client.useTLS {
		t.Errorf("client.useTLS should be true for ftps:// scheme")
	}
	if client.user != "alice" {
		t.Errorf("client.user = %q, want %q", client.user, "alice")
	}
	if client.password != "secret" {
		t.Errorf("client.password = %q, want %q", client.password, "secret")
	}
}

func TestNewClientInvalidURL(t *testing.T) {
	// Only inputs where url.Parse itself fails
	_, err := NewClient("://invalid", 30*time.Second)
	if err == nil {
		t.Errorf("NewClient(%q) expected error", "://invalid")
	}
}

func TestNewClientEmptyURL(t *testing.T) {
	client, err := NewClient("", 30*time.Second)
	if err != nil {
		t.Fatalf("NewClient(\"\") returned error: %v", err)
	}
	// url.Parse("") returns an empty URL struct, so host will be empty
	if client.host != "" {
		t.Errorf("client.host = %q, want empty", client.host)
	}
	if client.port != 21 {
		t.Errorf("client.port = %d, want %d", client.port, 21)
	}
}

func TestNewClientNoScheme(t *testing.T) {
	client, err := NewClient("not-a-url", 30*time.Second)
	if err != nil {
		t.Fatalf("NewClient(\"not-a-url\") returned error: %v", err)
	}
	// url.Parse("not-a-url") parses it as a path with empty host
	if client.host != "" {
		t.Errorf("client.host = %q, want empty", client.host)
	}
	if client.port != 21 {
		t.Errorf("client.port = %d, want %d", client.port, 21)
	}
}

func TestNewClientDefaultPort(t *testing.T) {
	client, err := NewClient("ftp://ftp.example.com/file.txt", 30*time.Second)
	if err != nil {
		t.Fatalf("NewClient() returned error: %v", err)
	}
	if client.port != 21 {
		t.Errorf("client.port = %d, want %d", client.port, 21)
	}
}

func TestNewClientCustomPort(t *testing.T) {
	client, err := NewClient("ftp://ftp.example.com:2121/file.txt", 30*time.Second)
	if err != nil {
		t.Fatalf("NewClient() returned error: %v", err)
	}
	if client.port != 2121 {
		t.Errorf("client.port = %d, want %d", client.port, 2121)
	}
}

func TestNewClientInvalidPort(t *testing.T) {
	_, err := NewClient("ftp://ftp.example.com:invalid/file.txt", 30*time.Second)
	if err == nil {
		t.Errorf("NewClient() expected error for invalid port")
	}
}

func TestNewClientDefaultCredentials(t *testing.T) {
	client, err := NewClient("ftp://ftp.example.com/file.txt", 30*time.Second)
	if err != nil {
		t.Fatalf("NewClient() returned error: %v", err)
	}
	if client.user != "anonymous" {
		t.Errorf("default user = %q, want %q", client.user, "anonymous")
	}
	if client.password != "anonymous@" {
		t.Errorf("default password = %q, want %q", client.password, "anonymous@")
	}
}

func TestNewClientHostParsing(t *testing.T) {
	client, err := NewClient("ftp://ftp.example.com/path/to/file.txt", 30*time.Second)
	if err != nil {
		t.Fatalf("NewClient() returned error: %v", err)
	}
	if client.host != "ftp.example.com" {
		t.Errorf("client.host = %q, want %q", client.host, "ftp.example.com")
	}
}

func TestNewClientPassiveModeDefault(t *testing.T) {
	client, err := NewClient("ftp://ftp.example.com/file.txt", 30*time.Second)
	if err != nil {
		t.Fatalf("NewClient() returned error: %v", err)
	}
	if !client.passive {
		t.Errorf("client.passive should default to true")
	}
}

func TestNewClientTLSConfig(t *testing.T) {
	client, err := NewClient("ftps://secure.example.com/file.txt", 30*time.Second)
	if err != nil {
		t.Fatalf("NewClient() returned error: %v", err)
	}
	if client.tlsConfig == nil {
		t.Fatal("client.tlsConfig should not be nil")
	}
	if client.tlsConfig.ServerName != "secure.example.com" {
		t.Errorf("tlsConfig.ServerName = %q, want %q", client.tlsConfig.ServerName, "secure.example.com")
	}
	if client.tlsConfig.InsecureSkipVerify {
		t.Errorf("tlsConfig.InsecureSkipVerify should be false by default")
	}
}

func TestSetPinnedCert(t *testing.T) {
	client, err := NewClient("ftps://secure.example.com/file.txt", 30*time.Second)
	if err != nil {
		t.Fatalf("NewClient() returned error: %v", err)
	}

	// Pinning is off by default.
	if client.pinnedCertHash != "" {
		t.Errorf("pinnedCertHash should default to empty, got %q", client.pinnedCertHash)
	}

	// SetPinnedCert normalises to lowercase and trims whitespace.
	client.SetPinnedCert("  ABCDEF0123456789  ")
	if client.pinnedCertHash != "abcdef0123456789" {
		t.Errorf("pinnedCertHash = %q, want %q", client.pinnedCertHash, "abcdef0123456789")
	}
}