package security

import (
	"bufio"
	"context"
	"crypto/hmac"
	"crypto/sha256"
	"encoding/base64"
	"encoding/hex"
	"fmt"
	"net"
	"net/http"
	"net/http/httptest"
	"net/url"
	"strings"
	"sync/atomic"
	"testing"
	"time"

	"github.com/stretchr/testify/assert"
	"github.com/stretchr/testify/require"
)

// --- Encryption Tests ---

func TestDefaultEncryptionConfig(t *testing.T) {
	cfg := DefaultEncryptionConfig()
	assert.False(t, cfg.Enabled)
	assert.Equal(t, "", cfg.AESKey)
	assert.Equal(t, 1, cfg.KeyVersion)
}

func TestNewEncryptor_Disabled(t *testing.T) {
	e, err := NewEncryptor(DefaultEncryptionConfig())
	require.NoError(t, err)
	require.NotNil(t, e)
	assert.False(t, e.IsEnabled())
	assert.Equal(t, 1, e.KeyVersion())
}

func TestNewEncryptor_Enabled_ValidKey(t *testing.T) {
	key := base64.StdEncoding.EncodeToString(make([]byte, 32))
	cfg := EncryptionConfig{AESKey: key, KeyVersion: 2, Enabled: true}
	e, err := NewEncryptor(cfg)
	require.NoError(t, err)
	require.NotNil(t, e)
	assert.True(t, e.IsEnabled())
	assert.Equal(t, 2, e.KeyVersion())
}

func TestNewEncryptor_InvalidBase64(t *testing.T) {
	cfg := EncryptionConfig{AESKey: "!!!invalid-base64!!!", Enabled: true}
	_, err := NewEncryptor(cfg)
	require.Error(t, err)
	assert.Contains(t, err.Error(), "decode base64")
}

func TestNewEncryptor_WrongKeySize(t *testing.T) {
	cfg := EncryptionConfig{AESKey: base64.StdEncoding.EncodeToString([]byte("short")), Enabled: true}
	_, err := NewEncryptor(cfg)
	require.Error(t, err)
	assert.Contains(t, err.Error(), "32 bytes")
}

func TestEncryptor_EncryptDecrypt_RoundTrip(t *testing.T) {
	key := base64.StdEncoding.EncodeToString(make([]byte, 32))
	e, err := NewEncryptor(EncryptionConfig{AESKey: key, KeyVersion: 1, Enabled: true})
	require.NoError(t, err)

	plaintext := "my-secret-token"
	encrypted, err := e.Encrypt(plaintext)
	require.NoError(t, err)
	assert.NotEqual(t, plaintext, encrypted)
	assert.True(t, strings.HasPrefix(encrypted, "enc:v1:"))

	decrypted, err := e.Decrypt(encrypted)
	require.NoError(t, err)
	assert.Equal(t, plaintext, decrypted)
}

func TestEncryptor_EncryptDisabled_ReturnsPlaintext(t *testing.T) {
	e, err := NewEncryptor(DefaultEncryptionConfig())
	require.NoError(t, err)

	encrypted, err := e.Encrypt("secret")
	require.NoError(t, err)
	assert.Equal(t, "secret", encrypted)
}

func TestEncryptor_DecryptDisabled_ReturnsCiphertext(t *testing.T) {
	e, err := NewEncryptor(DefaultEncryptionConfig())
	require.NoError(t, err)

	decrypted, err := e.Decrypt("some-ciphertext")
	require.NoError(t, err)
	assert.Equal(t, "some-ciphertext", decrypted)
}

func TestEncryptor_EncryptEmptyString(t *testing.T) {
	key := base64.StdEncoding.EncodeToString(make([]byte, 32))
	e, err := NewEncryptor(EncryptionConfig{AESKey: key, Enabled: true})
	require.NoError(t, err)

	encrypted, err := e.Encrypt("")
	require.NoError(t, err)
	assert.Equal(t, "", encrypted)
}

func TestEncryptor_DecryptEmptyString(t *testing.T) {
	key := base64.StdEncoding.EncodeToString(make([]byte, 32))
	e, err := NewEncryptor(EncryptionConfig{AESKey: key, Enabled: true})
	require.NoError(t, err)

	decrypted, err := e.Decrypt("")
	require.NoError(t, err)
	assert.Equal(t, "", decrypted)
}

func TestEncryptor_Decrypt_InvalidBase64(t *testing.T) {
	key := base64.StdEncoding.EncodeToString(make([]byte, 32))
	e, err := NewEncryptor(EncryptionConfig{AESKey: key, Enabled: true})
	require.NoError(t, err)

	_, err = e.Decrypt("enc:v1:!!!invalid!!!")
	require.Error(t, err)
	assert.Contains(t, err.Error(), "base64")
}

func TestEncryptor_Decrypt_CorruptedData(t *testing.T) {
	key := base64.StdEncoding.EncodeToString(make([]byte, 32))
	e, err := NewEncryptor(EncryptionConfig{AESKey: key, Enabled: true})
	require.NoError(t, err)

	// Create a too-short ciphertext (less than nonce size)
	shortData := base64.StdEncoding.EncodeToString([]byte("short"))
	_, err = e.Decrypt(shortData)
	require.Error(t, err)
	assert.Contains(t, err.Error(), "too short")
}

func TestEncryptor_Decrypt_TamperedData(t *testing.T) {
	key := base64.StdEncoding.EncodeToString(make([]byte, 32))
	e, err := NewEncryptor(EncryptionConfig{AESKey: key, Enabled: true})
	require.NoError(t, err)

	encrypted, err := e.Encrypt("secret-data")
	require.NoError(t, err)

	// Tamper with the encrypted data
	tampered := encrypted[:len(encrypted)-2] + "XX"

	_, err = e.Decrypt(tampered)
	require.Error(t, err)
	assert.Contains(t, err.Error(), "decryption failed")
}

func TestEncryptField_DecryptField_RoundTrip(t *testing.T) {
	key := base64.StdEncoding.EncodeToString(make([]byte, 32))
	e, err := NewEncryptor(EncryptionConfig{AESKey: key, Enabled: true})
	require.NoError(t, err)

	encrypted, err := e.EncryptField("my-api-key", FieldTypeAPIKey)
	require.NoError(t, err)

	decrypted, err := e.DecryptField(encrypted, FieldTypeAPIKey)
	require.NoError(t, err)
	assert.Equal(t, "my-api-key", decrypted)
}

func TestIsEncrypted(t *testing.T) {
	assert.True(t, IsEncrypted("enc:v1:somedata"))
	assert.True(t, IsEncrypted("enc:v2:abcdef"))
	assert.False(t, IsEncrypted("plaintext"))
	assert.False(t, IsEncrypted("enc:"))
	assert.False(t, IsEncrypted(""))
}

func TestStripEncryptedPrefix(t *testing.T) {
	assert.Equal(t, "payload", stripEncryptedPrefix("enc:v1:payload"))
	assert.Equal(t, "data", stripEncryptedPrefix("enc:v10:data"))
	// Malformed prefix (no colon after version)
	assert.Equal(t, "enc:v1nopayload", stripEncryptedPrefix("enc:v1nopayload"))
}

func TestGenerateAESKey(t *testing.T) {
	key, err := GenerateAESKey()
	require.NoError(t, err)
	assert.NotEmpty(t, key)

	decoded, err := base64.StdEncoding.DecodeString(key)
	require.NoError(t, err)
	assert.Len(t, decoded, 32)

	// Generate another key — should be different
	key2, err := GenerateAESKey()
	require.NoError(t, err)
	assert.NotEqual(t, key, key2)
}

func TestEncryptor_DifferentKeyVersions(t *testing.T) {
	key := base64.StdEncoding.EncodeToString(make([]byte, 32))

	e1, _ := NewEncryptor(EncryptionConfig{AESKey: key, KeyVersion: 1, Enabled: true})
	e2, _ := NewEncryptor(EncryptionConfig{AESKey: key, KeyVersion: 2, Enabled: true})

	enc1, _ := e1.Encrypt("test")
	enc2, _ := e2.Encrypt("test")

	assert.True(t, strings.HasPrefix(enc1, "enc:v1:"))
	assert.True(t, strings.HasPrefix(enc2, "enc:v2:"))

	// Both should decrypt with the same key
	dec1, _ := e1.Decrypt(enc1)
	dec2, _ := e2.Decrypt(enc2)
	assert.Equal(t, "test", dec1)
	assert.Equal(t, "test", dec2)
}

// --- JWT Security Tests ---

func TestHashToken(t *testing.T) {
	hash1 := hashToken("token1")
	hash2 := hashToken("token2")
	hash1Again := hashToken("token1")

	assert.NotEqual(t, hash1, hash2)
	assert.Equal(t, hash1, hash1Again)
	assert.Len(t, hash1, 64) // SHA-256 hex = 64 chars
}

func TestParseUnixTimestamp(t *testing.T) {
	ts, err := parseUnixTimestamp("1700000000")
	require.NoError(t, err)
	assert.Equal(t, int64(1700000000), ts.Unix())
}

func TestParseUnixTimestamp_Invalid(t *testing.T) {
	_, err := parseUnixTimestamp("not-a-number")
	assert.Error(t, err)
}

func TestClaims_StructFields(t *testing.T) {
	c := Claims{
		UserID:    1,
		AccountID: 2,
		Role:      "admin",
	}
	assert.Equal(t, uint(1), c.UserID)
	assert.Equal(t, uint(2), c.AccountID)
	assert.Equal(t, "admin", c.Role)
}

// --- SQL Safety Tests ---

func TestDefaultColumnWhitelists(t *testing.T) {
	wl := DefaultColumnWhitelists()
	assert.NotEmpty(t, wl)

	// Check some known tables exist
	tableMap := make(map[string]bool)
	for _, w := range wl {
		tableMap[w.Table] = true
	}
	assert.True(t, tableMap["conversations"])
	assert.True(t, tableMap["messages"])
	assert.True(t, tableMap["contacts"])
	assert.True(t, tableMap["accounts"])
	assert.True(t, tableMap["users"])
}

func TestNewSQLInjectionValidator_NilWhitelists(t *testing.T) {
	v := NewSQLInjectionValidator(nil)
	require.NotNil(t, v)
	// Should use default whitelists
	assert.NotEmpty(t, v.whitelists)
}

func TestNewSQLInjectionValidator_CustomWhitelists(t *testing.T) {
	custom := []ColumnWhitelist{
		{Table: "custom_table", Columns: []string{"id", "name"}},
	}
	v := NewSQLInjectionValidator(custom)
	require.NotNil(t, v)

	// Should use custom whitelist
	_, err := v.ValidateSortColumn("custom_table", "id")
	assert.NoError(t, err)

	// Default tables should not be whitelisted
	_, err = v.ValidateSortColumn("conversations", "id")
	assert.Error(t, err)
}

func TestValidateSortColumn_ValidColumn(t *testing.T) {
	v := NewSQLInjectionValidator(nil)

	col, err := v.ValidateSortColumn("conversations", "id")
	require.NoError(t, err)
	assert.Equal(t, "id", col)

	col, err = v.ValidateSortColumn("conversations", "created_at DESC")
	require.NoError(t, err)
	assert.Equal(t, "created_at DESC", col)

	col, err = v.ValidateSortColumn("conversations", "status ASC")
	require.NoError(t, err)
	assert.Equal(t, "status ASC", col)
}

func TestValidateSortColumn_EmptyInput(t *testing.T) {
	v := NewSQLInjectionValidator(nil)
	col, err := v.ValidateSortColumn("conversations", "")
	require.NoError(t, err)
	assert.Equal(t, "", col)
}

func TestValidateSortColumn_NotWhitelisted(t *testing.T) {
	v := NewSQLInjectionValidator(nil)
	_, err := v.ValidateSortColumn("conversations", "password_hash")
	assert.Error(t, err)
	assert.Contains(t, err.Error(), "not allowed")
}

func TestValidateSortColumn_UnknownTable(t *testing.T) {
	v := NewSQLInjectionValidator(nil)
	_, err := v.ValidateSortColumn("unknown_table", "id")
	assert.Error(t, err)
}

func TestValidateSortColumn_InvalidDirection(t *testing.T) {
	v := NewSQLInjectionValidator(nil)
	_, err := v.ValidateSortColumn("conversations", "id RANDOM")
	assert.Error(t, err)
	assert.Contains(t, err.Error(), "invalid sort direction")
}

func TestValidateColumnName_Valid(t *testing.T) {
	v := NewSQLInjectionValidator(nil)
	err := v.ValidateColumnName("conversations", "id")
	assert.NoError(t, err)

	err = v.ValidateColumnName("messages", "conversation_id")
	assert.NoError(t, err)
}

func TestValidateColumnName_Empty(t *testing.T) {
	v := NewSQLInjectionValidator(nil)
	err := v.ValidateColumnName("conversations", "")
	assert.Error(t, err)
}

func TestValidateColumnName_InvalidChars(t *testing.T) {
	v := NewSQLInjectionValidator(nil)
	err := v.ValidateColumnName("conversations", "id; DROP TABLE")
	assert.Error(t, err)
	assert.Contains(t, err.Error(), "invalid characters")
}

func TestValidateColumnName_NotWhitelisted(t *testing.T) {
	v := NewSQLInjectionValidator(nil)
	err := v.ValidateColumnName("conversations", "some_random_col")
	assert.Error(t, err)
}

func TestValidateTableName_Valid(t *testing.T) {
	err := ValidateTableName("conversations")
	assert.NoError(t, err)

	err = ValidateTableName("messages_2024")
	assert.NoError(t, err)
}

func TestValidateTableName_Empty(t *testing.T) {
	err := ValidateTableName("")
	assert.Error(t, err)
}

func TestValidateTableName_InvalidChars(t *testing.T) {
	err := ValidateTableName("conversations; DROP TABLE users")
	assert.Error(t, err)
	assert.Contains(t, err.Error(), "invalid characters")
}

func TestEscapeLikeWildcards(t *testing.T) {
	input := "test%value_here"
	result := EscapeLikeWildcards(input)
	assert.Equal(t, `test\%value\_here`, result)
}

func TestEscapeLikeWildcards_Backslash(t *testing.T) {
	input := `test\value`
	result := EscapeLikeWildcards(input)
	assert.Equal(t, `test\\value`, result)
}

func TestEscapeLikeWildcards_Empty(t *testing.T) {
	result := EscapeLikeWildcards("")
	assert.Equal(t, "", result)
}

func TestEscapeLikeWildcards_NoWildcards(t *testing.T) {
	result := EscapeLikeWildcards("plain-text")
	assert.Equal(t, "plain-text", result)
}

func TestValidateIDParameter_Valid(t *testing.T) {
	id, err := ValidateIDParameter("123")
	require.NoError(t, err)
	assert.Equal(t, int64(123), id)
}

func TestValidateIDParameter_Empty(t *testing.T) {
	_, err := ValidateIDParameter("")
	assert.Error(t, err)
}

func TestValidateIDParameter_NonDigit(t *testing.T) {
	_, err := ValidateIDParameter("12a3")
	assert.Error(t, err)
	assert.Contains(t, err.Error(), "non-digit")
}

func TestValidateIDParameter_Zero(t *testing.T) {
	_, err := ValidateIDParameter("0")
	assert.Error(t, err)
	assert.Contains(t, err.Error(), "positive integer")
}

func TestValidateIDParameter_Negative(t *testing.T) {
	_, err := ValidateIDParameter("-1")
	assert.Error(t, err)
}

func TestValidateInClauseValues_Empty(t *testing.T) {
	err := ValidateInClauseValues("users", []interface{}{}, 100)
	assert.Error(t, err)
	assert.Contains(t, err.Error(), "cannot be empty")
}

func TestValidateInClauseValues_ValidSize(t *testing.T) {
	err := ValidateInClauseValues("users", []interface{}{1, 2, 3}, 100)
	assert.NoError(t, err)
}

func TestValidateInClauseValues_ExceedsMax(t *testing.T) {
	values := make([]interface{}, 101)
	for i := range values {
		values[i] = i
	}
	err := ValidateInClauseValues("users", values, 100)
	assert.Error(t, err)
	assert.Contains(t, err.Error(), "exceeds maximum")
}

func TestValidateInClauseValues_DefaultMax(t *testing.T) {
	values := make([]interface{}, 10)
	for i := range values {
		values[i] = i
	}
	err := ValidateInClauseValues("users", values, 0) // default max = 1000
	assert.NoError(t, err)
}

func TestAuditRawQuery_NoIssues(t *testing.T) {
	warnings := AuditRawQuery("SELECT * FROM users WHERE id = ?")
	assert.Empty(t, warnings)
}

func TestAuditRawQuery_SprintfPattern(t *testing.T) {
	warnings := AuditRawQuery("SELECT * FROM users WHERE name = '%s'")
	assert.NotEmpty(t, warnings)
	assert.Contains(t, warnings[0], "CRITICAL")
}

func TestAuditRawQuery_SQLKeywordsWithoutPlaceholder(t *testing.T) {
	warnings := AuditRawQuery("DELETE FROM users WHERE name = 'test'")
	assert.NotEmpty(t, warnings)
}

func TestAuditRawQuery_Semicolon(t *testing.T) {
	warnings := AuditRawQuery("SELECT * FROM users; DROP TABLE users")
	assert.NotEmpty(t, warnings)
	found := false
	for _, w := range warnings {
		if strings.Contains(w, "Semicolon") {
			found = true
		}
	}
	assert.True(t, found)
}

func TestAuditRawQuery_CommentPattern(t *testing.T) {
	warnings := AuditRawQuery("SELECT * FROM users -- comment")
	assert.NotEmpty(t, warnings)
}

func TestGORMSafePattern_NotEmpty(t *testing.T) {
	assert.NotEmpty(t, GORMSafePattern)
	var safeCount, unsafeCount int
	for _, p := range GORMSafePattern {
		if p.Safe {
			safeCount++
		} else {
			unsafeCount++
		}
	}
	assert.True(t, safeCount > 0)
	assert.True(t, unsafeCount > 0)
}

func TestSafeQueryBuilder_SafeWhere_Valid(t *testing.T) {
	v := NewSQLInjectionValidator(nil)
	b := NewSafeQueryBuilder(nil, v)
	b.SafeWhere("column = ?", "value")
	assert.False(t, b.HasErrors())
}

func TestSafeQueryBuilder_SafeWhere_Unsafe(t *testing.T) {
	v := NewSQLInjectionValidator(nil)
	b := NewSafeQueryBuilder(nil, v)
	b.SafeWhere("column = 'value'")
	assert.True(t, b.HasErrors())
	errs := b.GetErrors()
	assert.NotEmpty(t, errs)
}

func TestSafeQueryBuilder_SafeOrder_Valid(t *testing.T) {
	v := NewSQLInjectionValidator(nil)
	b := NewSafeQueryBuilder(nil, v)
	b.SafeOrder("conversations", "id")
	assert.False(t, b.HasErrors())
}

func TestSafeQueryBuilder_SafeOrder_Invalid(t *testing.T) {
	v := NewSQLInjectionValidator(nil)
	b := NewSafeQueryBuilder(nil, v)
	b.SafeOrder("conversations", "malicious_column")
	assert.True(t, b.HasErrors())
}

func TestSafeQueryBuilder_GetErrors(t *testing.T) {
	v := NewSQLInjectionValidator(nil)
	b := NewSafeQueryBuilder(nil, v)
	b.SafeWhere("bad = 'value'")
	b.SafeOrder("conversations", "bad_col")
	errs := b.GetErrors()
	assert.Len(t, errs, 2)
}

// --- SSRF Protection Tests ---

func TestDefaultSSRFConfig(t *testing.T) {
	cfg := DefaultSSRFConfig()
	assert.NotEmpty(t, cfg.AllowedDomains)
	assert.NotEmpty(t, cfg.BlockedCIDRs)
	assert.Equal(t, 3, cfg.MaxRedirects)
	assert.False(t, cfg.RequireTLS)

	assert.Contains(t, cfg.BlockedCIDRs, "10.0.0.0/8")
	assert.Contains(t, cfg.BlockedCIDRs, "127.0.0.0/8")
	assert.Contains(t, cfg.BlockedCIDRs, "192.168.0.0/16")
}

func TestIsBlockedIP_PrivateIPs(t *testing.T) {
	cfg := DefaultSSRFConfig()
	blocked := []string{"10.0.0.1", "172.16.0.1", "192.168.1.1", "127.0.0.1", "0.0.0.0", "169.254.1.1"}
	for _, ip := range blocked {
		assert.True(t, isBlockedIP(net.ParseIP(ip), cfg.BlockedCIDRs), "expected %s to be blocked", ip)
	}
}

func TestIsBlockedIP_PublicIPs(t *testing.T) {
	cfg := DefaultSSRFConfig()
	assert.False(t, isBlockedIP(net.ParseIP("8.8.8.8"), cfg.BlockedCIDRs), "expected 8.8.8.8 to NOT be blocked")
	assert.False(t, isBlockedIP(net.ParseIP("1.1.1.1"), cfg.BlockedCIDRs), "expected 1.1.1.1 to NOT be blocked")
}

func TestIsBlockedIP_InvalidCIDR(t *testing.T) {
	assert.False(t, isBlockedIP(net.ParseIP("8.8.8.8"), []string{"invalid-cidr"}))
}

func TestSafeRedirectCheck(t *testing.T) {
	check := safeRedirectCheck(2)

	// Under redirect limit — should pass (non-IP host)
	req, _ := http.NewRequest("GET", "https://example.com", nil)
	err := check(req, nil)
	assert.NoError(t, err)

	// At redirect limit — should fail
	via := []*http.Request{req, req}
	err = check(req, via)
	assert.Error(t, err)
	assert.Contains(t, err.Error(), "stopped after")
}

func TestSafeRedirectCheck_IPLiteral(t *testing.T) {
	check := safeRedirectCheck(3)
	req, _ := http.NewRequest("GET", "http://10.0.0.1", nil)
	err := check(req, nil)
	assert.Error(t, err)
	assert.Contains(t, err.Error(), "IP literal")
}

func TestSafeRedirectCheckConfig_BlocksPrivateAndNonHTTPRedirects(t *testing.T) {
	check := safeRedirectCheckConfig(DefaultSSRFConfig())
	for _, target := range []string{
		"http://169.254.169.254/latest/meta-data/",
		"http://10.0.0.1/admin",
		"ftp://example.com/file",
		"https://example.com:8443/file",
	} {
		req, err := http.NewRequest(http.MethodGet, target, nil)
		require.NoError(t, err)
		assert.Error(t, check(req, nil), target)
	}
}

func TestSafeHTTPClient_RevalidatesEveryRealRedirect(t *testing.T) {
	var firstHits, secondHits, privateHits atomic.Int32
	private := httptest.NewServer(http.HandlerFunc(func(http.ResponseWriter, *http.Request) {
		privateHits.Add(1)
	}))
	defer private.Close()
	second := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
		secondHits.Add(1)
		http.Redirect(w, r, "http://169.254.169.254/latest/meta-data/", http.StatusFound)
	}))
	defer second.Close()
	first := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
		firstHits.Add(1)
		http.Redirect(w, r, "http://second.example/next", http.StatusFound)
	}))
	defer first.Close()

	addresses := map[string]string{
		"first.example":   first.Listener.Addr().String(),
		"second.example":  second.Listener.Addr().String(),
		"169.254.169.254": private.Listener.Addr().String(),
	}
	client := NewSafeHTTPClient(DefaultSSRFConfig())
	client.client.Transport = &http.Transport{DialContext: func(ctx context.Context, network, addr string) (net.Conn, error) {
		host, _, err := net.SplitHostPort(addr)
		if err != nil {
			return nil, err
		}
		return (&net.Dialer{}).DialContext(ctx, network, addresses[host])
	}}

	req, err := http.NewRequest(http.MethodGet, "http://first.example/start", nil)
	require.NoError(t, err)
	resp, err := client.Do(req)
	if resp != nil {
		resp.Body.Close()
	}
	require.ErrorContains(t, err, "private/reserved")
	assert.Equal(t, int32(1), firstHits.Load())
	assert.Equal(t, int32(1), secondHits.Load())
	assert.Zero(t, privateHits.Load())
}

func TestSafeHTTPClient_DialsFirstValidatedDNSResult(t *testing.T) {
	serverConn, clientConn := net.Pipe()
	defer serverConn.Close()
	serverDone := make(chan error, 1)
	go func() {
		request, err := http.ReadRequest(bufio.NewReader(serverConn))
		if err == nil {
			request.Body.Close()
			_, err = serverConn.Write([]byte("HTTP/1.1 200 OK\r\nContent-Length: 2\r\nConnection: close\r\n\r\nok"))
		}
		serverDone <- err
	}()

	lookups := 0
	dialedAddress := ""
	client := newSafeHTTPClient(DefaultSSRFConfig(),
		func(context.Context, string) ([]net.IPAddr, error) {
			lookups++
			if lookups == 1 {
				return []net.IPAddr{{IP: net.ParseIP("93.184.216.34")}}, nil
			}
			return []net.IPAddr{{IP: net.ParseIP("127.0.0.1")}}, nil
		},
		func(_ context.Context, _, addr string) (net.Conn, error) {
			dialedAddress = addr
			return clientConn, nil
		},
	)

	resp, err := client.SafeFetchURL(context.Background(), "http://rebind.example/file")
	require.NoError(t, err)
	defer resp.Body.Close()
	assert.Equal(t, 1, lookups)
	assert.Equal(t, "93.184.216.34:80", dialedAddress)
	require.NoError(t, <-serverDone)
}

func TestValidateURL_Empty(t *testing.T) {
	err := ValidateURL("", DefaultSSRFConfig())
	assert.Error(t, err)
	assert.Contains(t, err.Error(), "empty")
}

func TestValidateURL_AllowedDomain(t *testing.T) {
	err := ValidateURL("https://api.telegram.org/bot123/sendMessage", DefaultSSRFConfig())
	assert.NoError(t, err)
}

func TestValidateURL_AllowedDomainSubdomain(t *testing.T) {
	err := ValidateURL("https://sub.api.telegram.org/test", DefaultSSRFConfig())
	assert.NoError(t, err)
}

func TestValidateURL_PublicDomain(t *testing.T) {
	err := ValidateURL("https://example.com/test", DefaultSSRFConfig())
	assert.NoError(t, err)
}

func TestValidateURL_PrivateIP(t *testing.T) {
	err := ValidateURL("http://10.0.0.1/admin", DefaultSSRFConfig())
	assert.Error(t, err)
	assert.Contains(t, err.Error(), "private/reserved")
}

func TestValidateURL_LoopbackIP(t *testing.T) {
	err := ValidateURL("http://127.0.0.1/admin", DefaultSSRFConfig())
	assert.Error(t, err)
}

func TestValidateURL_InvalidURL(t *testing.T) {
	err := ValidateURL("://invalid-url", DefaultSSRFConfig())
	assert.Error(t, err)
}

func TestNewSafeHTTPClient(t *testing.T) {
	cfg := DefaultSSRFConfig()
	client := NewSafeHTTPClient(cfg)
	require.NotNil(t, client)
	require.NotNil(t, client.client)
	assert.Equal(t, cfg, client.cfg)
}

func TestSafeHTTPClient_Do_AllowedDomain(t *testing.T) {
	srv := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
		w.WriteHeader(http.StatusOK)
		_, err := w.Write([]byte("hello"))
		require.NoError(t, err)
	}))
	defer srv.Close()

	parsed, _ := url.Parse(srv.URL)
	host := parsed.Hostname()

	// httptest.NewServer runs on 127.0.0.1 which SSRF blocks.
	// Use empty BlockedCIDRs to allow localhost for testing.
	cfg := SSRFConfig{
		AllowedDomains: []string{host},
		BlockedCIDRs:   []string{},
		MaxRedirects:   3,
	}
	client := NewSafeHTTPClient(cfg)

	req, _ := http.NewRequest("GET", srv.URL, nil)
	resp, err := client.Do(req)
	require.NoError(t, err)
	defer resp.Body.Close()
	assert.Equal(t, 200, resp.StatusCode)
}

func TestSafeHTTPClient_Do_RequireTLS(t *testing.T) {
	srv := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
		w.WriteHeader(http.StatusOK)
	}))
	defer srv.Close()

	cfg := SSRFConfig{
		AllowedDomains: nil,
		BlockedCIDRs:   DefaultSSRFConfig().BlockedCIDRs,
		MaxRedirects:   3,
		RequireTLS:     true,
	}
	client := NewSafeHTTPClient(cfg)

	req, _ := http.NewRequest("GET", srv.URL, nil)
	_, err := client.Do(req)
	assert.Error(t, err)
	assert.Contains(t, err.Error(), "non-HTTPS")
}

func TestSafeHTTPClient_Do_BlocksResolvedLoopback(t *testing.T) {
	srv := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
		t.Fatal("blocked target must not receive a request")
	}))
	defer srv.Close()

	cfg := DefaultSSRFConfig()
	cfg.AllowedPorts = nil
	client := NewSafeHTTPClient(cfg)
	req, _ := http.NewRequest(http.MethodGet, srv.URL, nil)
	_, err := client.Do(req)
	require.Error(t, err)
	assert.Contains(t, err.Error(), "SSRF")
}

func TestSafeHTTPClient_SafeFetchURL(t *testing.T) {
	srv := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
		w.WriteHeader(http.StatusOK)
		_, err := w.Write([]byte("fetched"))
		require.NoError(t, err)
	}))
	defer srv.Close()

	parsed, _ := url.Parse(srv.URL)
	host := parsed.Hostname()

	// httptest.NewServer runs on 127.0.0.1 which SSRF blocks.
	// Use empty BlockedCIDRs to allow localhost for testing.
	cfg := SSRFConfig{
		AllowedDomains: []string{host},
		BlockedCIDRs:   []string{},
		MaxRedirects:   3,
	}
	client := NewSafeHTTPClient(cfg)

	resp, err := client.SafeFetchURL(context.Background(), srv.URL)
	require.NoError(t, err)
	defer resp.Body.Close()
	assert.Equal(t, 200, resp.StatusCode)
}

func TestSafeHTTPClient_SafeFetchURL_InvalidURL(t *testing.T) {
	cfg := DefaultSSRFConfig()
	client := NewSafeHTTPClient(cfg)

	_, err := client.SafeFetchURL(context.Background(), "://invalid")
	assert.Error(t, err)
}

func TestTestWrite(t *testing.T) {
	TestWrite()
}

// --- Webhook Signing Tests ---

func TestDefaultWebhookSignatureConfig(t *testing.T) {
	cfg := DefaultWebhookSignatureConfig()
	assert.Equal(t, int64(300), cfg.MaxAgeSeconds)
	assert.Equal(t, int64(30), cfg.ClockSkewSeconds)
	assert.NotEmpty(t, cfg.ChannelConfigs)

	_, ok := cfg.ChannelConfigs["meta"]
	assert.True(t, ok)
	_, ok = cfg.ChannelConfigs["telegram"]
	assert.True(t, ok)
	_, ok = cfg.ChannelConfigs["api"]
	assert.True(t, ok)
}

func TestNewWebhookSignatureService_DefaultConfig(t *testing.T) {
	svc := NewWebhookSignatureService(WebhookSignatureConfig{})
	assert.NotNil(t, svc)
	assert.Equal(t, int64(300), svc.config.MaxAgeSeconds)
}

func TestNewWebhookSignatureService_CustomMaxAge(t *testing.T) {
	svc := NewWebhookSignatureService(WebhookSignatureConfig{MaxAgeSeconds: 600, ClockSkewSeconds: 10})
	assert.NotNil(t, svc)
	assert.Equal(t, int64(600), svc.config.MaxAgeSeconds)
	assert.Equal(t, int64(10), svc.config.ClockSkewSeconds)
}

func TestGenerateSignature_Success(t *testing.T) {
	svc := NewWebhookSignatureService(DefaultWebhookSignatureConfig())
	payload := []byte(`{"event":"test"}`)
	ts := int64(1700000000)

	result, err := svc.GenerateSignature("meta", "my-secret", payload, ts)
	require.NoError(t, err)
	require.NotNil(t, result)
	assert.Equal(t, ts, result.Timestamp)
	assert.Equal(t, "X-Hub-Signature-256", result.HeaderName)
	assert.True(t, strings.HasPrefix(result.HeaderValue, "sha256="))
	assert.NotEmpty(t, result.Signature)

	// Verify the signature is correct
	expectedMsg := fmt.Sprintf("%d.%s", ts, string(payload))
	mac := hmac.New(sha256.New, []byte("my-secret"))
	mac.Write([]byte(expectedMsg))
	expectedSig := hex.EncodeToString(mac.Sum(nil))
	assert.Equal(t, expectedSig, result.Signature)
	assert.Equal(t, "sha256="+expectedSig, result.HeaderValue)
}

func TestGenerateSignature_EmptySecret(t *testing.T) {
	svc := NewWebhookSignatureService(DefaultWebhookSignatureConfig())
	_, err := svc.GenerateSignature("meta", "", []byte("payload"), 0)
	assert.Error(t, err)
	assert.Contains(t, err.Error(), "secret cannot be empty")
}

func TestGenerateSignature_EmptyPayload(t *testing.T) {
	svc := NewWebhookSignatureService(DefaultWebhookSignatureConfig())
	_, err := svc.GenerateSignature("meta", "secret", []byte{}, 0)
	assert.Error(t, err)
	assert.Contains(t, err.Error(), "payload cannot be empty")
}

func TestGenerateSignature_UnknownChannel(t *testing.T) {
	svc := NewWebhookSignatureService(DefaultWebhookSignatureConfig())
	_, err := svc.GenerateSignature("unknown_channel", "secret", []byte("payload"), 0)
	assert.Error(t, err)
	assert.Contains(t, err.Error(), "unknown channel type")
}

func TestGenerateSignature_DefaultTimestamp(t *testing.T) {
	svc := NewWebhookSignatureService(DefaultWebhookSignatureConfig())
	before := time.Now().Unix()
	result, err := svc.GenerateSignature("api", "secret", []byte("payload"), 0)
	require.NoError(t, err)
	after := time.Now().Unix()
	assert.True(t, result.Timestamp >= before && result.Timestamp <= after)
}

func TestGenerateSignature_Telegram(t *testing.T) {
	svc := NewWebhookSignatureService(DefaultWebhookSignatureConfig())
	result, err := svc.GenerateSignature("telegram", "secret", []byte("payload"), 1700000000)
	require.NoError(t, err)
	assert.Equal(t, "X-Telegram-Bot-Api-Secret-Token", result.HeaderName)
	// Telegram has empty prefix, so HeaderValue is the raw hex HMAC signature
	assert.NotEmpty(t, result.HeaderValue)
	assert.True(t, strings.HasPrefix(result.HeaderValue, "") == true)
}

func TestVerifySignature_Success(t *testing.T) {
	svc := NewWebhookSignatureService(DefaultWebhookSignatureConfig())
	payload := []byte(`{"event":"test"}`)
	ts := time.Now().Unix()

	result, err := svc.GenerateSignature("api", "my-secret", payload, ts)
	require.NoError(t, err)

	err = svc.VerifySignature("api", "my-secret", payload, result.HeaderValue, fmt.Sprintf("%d", ts))
	assert.NoError(t, err)
}

func TestVerifySignature_WrongSecret(t *testing.T) {
	svc := NewWebhookSignatureService(DefaultWebhookSignatureConfig())
	payload := []byte(`{"event":"test"}`)
	ts := time.Now().Unix()

	result, err := svc.GenerateSignature("api", "correct-secret", payload, ts)
	require.NoError(t, err)

	err = svc.VerifySignature("api", "wrong-secret", payload, result.HeaderValue, fmt.Sprintf("%d", ts))
	assert.Error(t, err)
	assert.Contains(t, err.Error(), "verification failed")
}

func TestVerifySignature_EmptySecret(t *testing.T) {
	svc := NewWebhookSignatureService(DefaultWebhookSignatureConfig())
	err := svc.VerifySignature("api", "", []byte("payload"), "sig", "123")
	assert.Error(t, err)
}

func TestVerifySignature_EmptyPayload(t *testing.T) {
	svc := NewWebhookSignatureService(DefaultWebhookSignatureConfig())
	err := svc.VerifySignature("api", "secret", []byte{}, "sig", "123")
	assert.Error(t, err)
}

func TestVerifySignature_EmptySignature(t *testing.T) {
	svc := NewWebhookSignatureService(DefaultWebhookSignatureConfig())
	err := svc.VerifySignature("api", "secret", []byte("payload"), "", "123")
	assert.Error(t, err)
}

func TestVerifySignature_UnknownChannel(t *testing.T) {
	svc := NewWebhookSignatureService(DefaultWebhookSignatureConfig())
	err := svc.VerifySignature("unknown", "secret", []byte("payload"), "sig", "123")
	assert.Error(t, err)
}

func TestVerifySignature_Telegram_SecretToken(t *testing.T) {
	svc := NewWebhookSignatureService(DefaultWebhookSignatureConfig())
	err := svc.VerifySignature("telegram", "my-secret-token", []byte{}, "my-secret-token", "")
	assert.NoError(t, err)
}

func TestVerifySignature_Telegram_WrongToken(t *testing.T) {
	svc := NewWebhookSignatureService(DefaultWebhookSignatureConfig())
	err := svc.VerifySignature("telegram", "correct-token", []byte{}, "wrong-token", "")
	assert.Error(t, err)
	assert.Contains(t, err.Error(), "verification failed")
}

func TestVerifySignature_Telegram_WithTimestamp(t *testing.T) {
	svc := NewWebhookSignatureService(DefaultWebhookSignatureConfig())
	ts := time.Now().Unix()
	err := svc.VerifySignature("telegram", "my-token", []byte{}, "my-token", fmt.Sprintf("%d", ts))
	assert.NoError(t, err)
}

func TestVerifySignature_Telegram_ExpiredTimestamp(t *testing.T) {
	svc := NewWebhookSignatureService(DefaultWebhookSignatureConfig())
	oldTs := time.Now().Unix() - 600

	err := svc.VerifySignature("telegram", "my-token", []byte{}, "my-token", fmt.Sprintf("%d", oldTs))
	assert.Error(t, err)
}

func TestVerifySignature_ExpiredTimestamp(t *testing.T) {
	svc := NewWebhookSignatureService(DefaultWebhookSignatureConfig())
	payload := []byte(`{"event":"test"}`)
	oldTs := time.Now().Unix() - 600

	result, err := svc.GenerateSignature("api", "secret", payload, oldTs)
	require.NoError(t, err)

	err = svc.VerifySignature("api", "secret", payload, result.HeaderValue, fmt.Sprintf("%d", oldTs))
	assert.Error(t, err)
	assert.Contains(t, err.Error(), "expired")
}

func TestVerifySignature_FutureTimestamp(t *testing.T) {
	svc := NewWebhookSignatureService(DefaultWebhookSignatureConfig())
	futureTs := time.Now().Unix() + 120

	err := svc.VerifySignature("api", "secret", []byte("payload"), "some-sig", fmt.Sprintf("%d", futureTs))
	assert.Error(t, err)
	assert.Contains(t, err.Error(), "future")
}

func TestVerifySignature_InvalidTimestamp(t *testing.T) {
	svc := NewWebhookSignatureService(DefaultWebhookSignatureConfig())
	err := svc.VerifySignature("api", "secret", []byte("payload"), "some-sig", "not-a-number")
	assert.Error(t, err)
	assert.Contains(t, err.Error(), "invalid timestamp")
}

func TestVerifySignature_Meta_PrefixMissing(t *testing.T) {
	svc := NewWebhookSignatureService(DefaultWebhookSignatureConfig())
	err := svc.VerifySignature("meta", "secret", []byte("payload"), "rawhexwithoutprefix", fmt.Sprintf("%d", time.Now().Unix()))
	assert.Error(t, err)
	assert.Contains(t, err.Error(), "prefix")
}

func TestVerifyTelegramWebhook(t *testing.T) {
	svc := NewWebhookSignatureService(DefaultWebhookSignatureConfig())
	err := svc.VerifyTelegramWebhook("my-token", "my-token", "")
	assert.NoError(t, err)
}

func TestVerifyTelegramWebhook_WrongToken(t *testing.T) {
	svc := NewWebhookSignatureService(DefaultWebhookSignatureConfig())
	err := svc.VerifyTelegramWebhook("correct", "wrong", "")
	assert.Error(t, err)
}

func TestVerifyAPIWebhook(t *testing.T) {
	svc := NewWebhookSignatureService(DefaultWebhookSignatureConfig())
	payload := []byte(`{"event":"test"}`)
	ts := time.Now().Unix()

	result, err := svc.GenerateSignature("api", "my-secret", payload, ts)
	require.NoError(t, err)

	err = svc.VerifyAPIWebhook("my-secret", payload, result.HeaderValue, fmt.Sprintf("%d", ts))
	assert.NoError(t, err)
}

func TestVerifyWebWidgetWebhook(t *testing.T) {
	svc := NewWebhookSignatureService(DefaultWebhookSignatureConfig())
	payload := []byte(`{"event":"test"}`)
	ts := time.Now().Unix()

	result, err := svc.GenerateSignature("web_widget", "my-secret", payload, ts)
	require.NoError(t, err)

	err = svc.VerifyWebWidgetWebhook("my-secret", payload, result.HeaderValue, fmt.Sprintf("%d", ts))
	assert.NoError(t, err)
}

func TestExtractSignature_WithPrefix(t *testing.T) {
	sig, err := extractSignature("sha256=abcdef", "sha256=", false)
	require.NoError(t, err)
	assert.Equal(t, "abcdef", sig)
}

func TestExtractSignature_PrefixMissing(t *testing.T) {
	_, err := extractSignature("rawhex", "sha256=", false)
	assert.Error(t, err)
}

func TestExtractSignature_NoPrefix(t *testing.T) {
	sig, err := extractSignature("rawhex", "", false)
	require.NoError(t, err)
	assert.Equal(t, "rawhex", sig)
}

func TestExtractSignature_SecretToken(t *testing.T) {
	sig, err := extractSignature("my-secret-token", "", true)
	require.NoError(t, err)
	assert.Equal(t, "my-secret-token", sig)
}

func TestExtractSignature_WithWhitespace(t *testing.T) {
	// extractSignature does not trim whitespace before checking prefix,
	// so input with leading whitespace before the prefix will fail.
	sig, err := extractSignature("sha256=abcdef  ", "sha256=", false)
	require.NoError(t, err)
	assert.Equal(t, "abcdef", sig)
}

func TestComputeHMAC_WithTimestamp(t *testing.T) {
	svc := NewWebhookSignatureService(DefaultWebhookSignatureConfig())
	sig, err := svc.computeHMAC("secret", []byte("payload"), 1700000000)
	require.NoError(t, err)
	assert.NotEmpty(t, sig)

	expectedMsg := "1700000000.payload"
	mac := hmac.New(sha256.New, []byte("secret"))
	mac.Write([]byte(expectedMsg))
	expectedSig := hex.EncodeToString(mac.Sum(nil))
	assert.Equal(t, expectedSig, sig)
}

func TestComputeHMAC_WithoutTimestamp(t *testing.T) {
	svc := NewWebhookSignatureService(DefaultWebhookSignatureConfig())
	sig, err := svc.computeHMAC("secret", []byte("payload"), 0)
	require.NoError(t, err)
	assert.NotEmpty(t, sig)

	mac := hmac.New(sha256.New, []byte("secret"))
	mac.Write([]byte("payload"))
	expectedSig := hex.EncodeToString(mac.Sum(nil))
	assert.Equal(t, expectedSig, sig)
}

func TestValidateTimestamp_Valid(t *testing.T) {
	svc := NewWebhookSignatureService(DefaultWebhookSignatureConfig())
	ts := time.Now().Unix()
	err := svc.validateTimestamp(fmt.Sprintf("%d", ts))
	assert.NoError(t, err)
}

func TestValidateTimestamp_Invalid(t *testing.T) {
	svc := NewWebhookSignatureService(DefaultWebhookSignatureConfig())
	err := svc.validateTimestamp("not-a-number")
	assert.Error(t, err)
}