package service

import (
	"context"
	"testing"
	"time"
)

// =============================================================================
// Auth Service Unit Tests
// =============================================================================

func TestPasswordStrength(t *testing.T) {
	tests := []struct {
		name     string
		password string
		wantInfo PasswordStrengthInfo
	}{
		{
			name:     "empty_password",
			password: "",
			wantInfo: PasswordStrengthInfo{Score: 0, Length: 0, HasUpper: false, HasLower: false, HasDigit: false, HasSpecial: false},
		},
		{
			name:     "lowercase_only",
			password: "abcdefgh",
			wantInfo: PasswordStrengthInfo{Score: 1, Length: 8, HasUpper: false, HasLower: true, HasDigit: false, HasSpecial: false},
		},
		{
			name:     "uppercase_only",
			password: "ABCDEFGH",
			wantInfo: PasswordStrengthInfo{Score: 1, Length: 8, HasUpper: true, HasLower: false, HasDigit: false, HasSpecial: false},
		},
		{
			name:     "digits_only",
			password: "12345678",
			wantInfo: PasswordStrengthInfo{Score: 1, Length: 8, HasUpper: false, HasLower: false, HasDigit: true, HasSpecial: false},
		},
		{
			name:     "mixed_case_with_digits",
			password: "Abcd1234",
			wantInfo: PasswordStrengthInfo{Score: 3, Length: 8, HasUpper: true, HasLower: true, HasDigit: true, HasSpecial: false},
		},
		{
			name:     "mixed_with_special",
			password: "Abcd1234!",
			wantInfo: PasswordStrengthInfo{Score: 4, Length: 9, HasUpper: true, HasLower: true, HasDigit: true, HasSpecial: true},
		},
		{
			name:     "chinese_characters",
			password: "密码123456",
			wantInfo: PasswordStrengthInfo{Score: 1, Length: 8, HasUpper: false, HasLower: false, HasDigit: true, HasSpecial: false},
		},
	}

	for _, tt := range tests {
		t.Run(tt.name, func(t *testing.T) {
			info := GetPasswordStrength(tt.password)
			if info.Score != tt.wantInfo.Score {
				t.Errorf("Score: got %d, want %d", info.Score, tt.wantInfo.Score)
			}
			if info.Length != tt.wantInfo.Length {
				t.Errorf("Length: got %d, want %d", info.Length, tt.wantInfo.Length)
			}
			if info.HasUpper != tt.wantInfo.HasUpper {
				t.Errorf("HasUpper: got %v, want %v", info.HasUpper, tt.wantInfo.HasUpper)
			}
			if info.HasLower != tt.wantInfo.HasLower {
				t.Errorf("HasLower: got %v, want %v", info.HasLower, tt.wantInfo.HasLower)
			}
			if info.HasDigit != tt.wantInfo.HasDigit {
				t.Errorf("HasDigit: got %v, want %v", info.HasDigit, tt.wantInfo.HasDigit)
			}
			if info.HasSpecial != tt.wantInfo.HasSpecial {
				t.Errorf("HasSpecial: got %v, want %v", info.HasSpecial, tt.wantInfo.HasSpecial)
			}
		})
	}
}

func TestValidatePasswordStrength(t *testing.T) {
	tests := []struct {
		name      string
		password  string
		minLength int
		strict    bool
		wantErr   bool
	}{
		{
			name:      "valid_password_strict",
			password:  "Abcd1234!",
			minLength: 8,
			strict:    true,
			wantErr:   false,
		},
		{
			name:      "too_short",
			password:  "Ab1!",
			minLength: 8,
			strict:    false,
			wantErr:   true,
		},
		{
			name:      "weak_password",
			password:  "abcdefgh",
			minLength: 8,
			strict:    false,
			wantErr:   true,
		},
		{
			name:      "strict_missing_uppercase",
			password:  "abcd1234!",
			minLength: 8,
			strict:    true,
			wantErr:   true,
		},
		{
			name:      "strict_missing_lowercase",
			password:  "ABCD1234!",
			minLength: 8,
			strict:    true,
			wantErr:   true,
		},
		{
			name:      "strict_missing_digit",
			password:  "Abcdefgh!",
			minLength: 8,
			strict:    true,
			wantErr:   true,
		},
		{
			name:      "valid_weak_password_non_strict",
			password:  "Abcd1234",
			minLength: 8,
			strict:    false,
			wantErr:   false,
		},
	}

	for _, tt := range tests {
		t.Run(tt.name, func(t *testing.T) {
			err := validatePasswordStrength(tt.password, tt.minLength, tt.strict)
			if (err != nil) != tt.wantErr {
				t.Errorf("validatePasswordStrength() error = %v, wantErr %v", err, tt.wantErr)
			}
		})
	}
}

func TestSanitizeUsername(t *testing.T) {
	tests := []struct {
		name  string
		input string
		want  string
	}{
		{
			name:  "normal_username",
			input: "john_doe",
			want:  "john_doe",
		},
		{
			name:  "username_with_spaces",
			input: "john doe",
			want:  "john_doe",
		},
		{
			name:  "username_with_uppercase",
			input: "JohnDoe",
			want:  "johndoe",
		},
		{
			name:  "username_with_special_chars",
			input: "john@doe",
			want:  "johndoe",
		},
		{
			name:  "empty_username",
			input: "",
			want:  "user",
		},
		{
			name:  "whitespace_only",
			input: "   ",
			want:  "user",
		},
		{
			name:  "username_with_emoji",
			input: "john😀doe",
			want:  "johndoe", // emoji is filtered out as it's not letter/digit/./-/_
		},
		{
			name:  "username_with_leading_underscore",
			input: "_john_",
			want:  "john", // leading and trailing _ are trimmed
		},
		{
			name:  "username_with_trailing_dots",
			input: "john..doe...",
			want:  "john..doe", // trailing dots trimmed
		},
		{
			name:  "long_username_truncated",
			input: "this_is_a_very_long_username_that_exceeds_fifty_characters_limit",
			want:  "this_is_a_very_long_username_that_exceeds_fifty_ch", // 50 chars max, cuts off "acters_limit"
		},
	}

	for _, tt := range tests {
		t.Run(tt.name, func(t *testing.T) {
			got := sanitizeUsername(tt.input)
			if got != tt.want {
				t.Errorf("sanitizeUsername() = %q (len=%d), want %q (len=%d)", got, len(got), tt.want, len(tt.want))
			}
		})
	}
}

func TestIsValidPhoneSimple(t *testing.T) {
	tests := []struct {
		phone string
		want  bool
	}{
		{"13800138000", true},
		{"+8613800138000", true},  // Valid: +86 prefix with 11 digit mobile
		{"8613800138000", true},   // Valid: 86 prefix with 11 digit mobile
		{"1234567890", false},
		{"abcdefghij", false},
		{"", false},
		{"138001380001", false}, // 12 digits
		{"1380013800", false},   // 10 digits
		{"19800138000", true},   // 98 prefix
		// +[1-9]\d{6,14} allows international numbers like +16171234567
		{"+16171234567", true},    // 11 digits international, valid for \d{6,14}
		{"+112345678901", true},   // 11 digits international, valid for \d{6,14}
	}

	for _, tt := range tests {
		t.Run(tt.phone, func(t *testing.T) {
			got := isValidPhoneSimple(tt.phone)
			if got != tt.want {
				t.Errorf("isValidPhoneSimple(%q) = %v, want %v", tt.phone, got, tt.want)
			}
		})
	}
}

func TestLoginRequestGetAccount(t *testing.T) {
	tests := []struct {
		name string
		req  *LoginRequest
		want string
	}{
		{
			name: "account_field",
			req:  &LoginRequest{Account: "john", Username: "jane", Email: "jane@test.com"},
			want: "john",
		},
		{
			name: "username_field",
			req:  &LoginRequest{Username: "jane", Email: "jane@test.com"},
			want: "jane",
		},
		{
			name: "email_field",
			req:  &LoginRequest{Email: "jane@test.com"},
			want: "jane@test.com",
		},
		{
			name: "phone_field",
			req:  &LoginRequest{Phone: "13800138000"},
			want: "13800138000",
		},
		{
			name: "all_fields_with_whitespace",
			req:  &LoginRequest{Account: "  john  ", Username: "  jane  ", Email: "  jane@test.com  "},
			want: "john",
		},
		{
			name: "empty_request",
			req:  &LoginRequest{},
			want: "",
		},
		{
			name: "nil_request",
			req:  nil,
			want: "",
		},
	}

	for _, tt := range tests {
		t.Run(tt.name, func(t *testing.T) {
			got := tt.req.GetAccount()
			if got != tt.want {
				t.Errorf("GetAccount() = %q, want %q", got, tt.want)
			}
		})
	}
}

func TestBuildDeviceFingerprint(t *testing.T) {
	tests := []struct {
		name string
		req  *LoginRequest
		want string
	}{
		{
			name: "full_device_info",
			req: &LoginRequest{
				DeviceID:      "device123",
				DeviceName:    "iPhone 15",
				DeviceBrowser: "Safari",
				DeviceOS:      "iOS 17",
			},
			want: "device123|iPhone 15|Safari|iOS 17",
		},
		{
			name: "partial_device_info",
			req: &LoginRequest{
				DeviceID:   "device123",
				DeviceName: "iPhone 15",
			},
			want: "device123|iPhone 15",
		},
		{
			name: "only_device_id",
			req: &LoginRequest{
				DeviceID: "device123",
			},
			want: "device123",
		},
		{
			name: "empty_device_info",
			req:  &LoginRequest{},
			want: "",
		},
		{
			name: "nil_request",
			req:  nil,
			want: "",
		},
	}

	for _, tt := range tests {
		t.Run(tt.name, func(t *testing.T) {
			got := buildDeviceFingerprint(tt.req)
			if got != tt.want {
				t.Errorf("buildDeviceFingerprint() = %q, want %q", got, tt.want)
			}
		})
	}
}

func TestAuthServiceDefaultConfig(t *testing.T) {
	// Test that default configuration is applied correctly
	svc := NewAuthService(nil, nil, nil, nil, 0, 0, 0)

	if svc == nil {
		t.Fatal("NewAuthService returned nil")
	}

	// Check default password minimum length
	if svc.passwordMinLength != defaultPasswordMinLen {
		t.Errorf("passwordMinLength: got %d, want %d", svc.passwordMinLength, defaultPasswordMinLen)
	}

	// Check default max login attempts
	if svc.maxLoginAttempts != 5 {
		t.Errorf("maxLoginAttempts: got %d, want %d", svc.maxLoginAttempts, 5)
	}

	// Check default login lock duration
	if svc.loginLockDuration != 15*time.Minute {
		t.Errorf("loginLockDuration: got %v, want %v", svc.loginLockDuration, 15*time.Minute)
	}
}

func TestAuthServiceNilSafety(t *testing.T) {
	t.Run("validatePassword_nil_service", func(t *testing.T) {
		var svc *AuthService
		err := svc.validatePassword("Abcd1234!")
		if err != nil {
			t.Errorf("nil service should not error: %v", err)
		}
	})

	t.Run("accessTokenTTL_nil_service", func(t *testing.T) {
		var svc *AuthService
		ttl := svc.accessTokenTTLSeconds()
		if ttl != 0 {
			t.Errorf("nil service should return 0: got %d", ttl)
		}
	})

	t.Run("RefreshTokenTTL_nil_service", func(t *testing.T) {
		var svc *AuthService
		ttl := svc.RefreshTokenTTLSeconds()
		if ttl != 0 {
			t.Errorf("nil service should return 0: got %d", ttl)
		}
	})

	t.Run("generateUniqueUsername_nil_service", func(t *testing.T) {
		var svc *AuthService
		username, err := svc.generateUniqueUsername(context.Background(), "testuser")
		if err != nil {
			t.Errorf("nil service should return username: %v", err)
		}
		if username != "testuser" {
			t.Errorf("username: got %q, want %q", username, "testuser")
		}
	})

	t.Run("buildUserInfo_nil_user", func(t *testing.T) {
		var svc *AuthService
		info := svc.buildUserInfo(nil)
		if info != nil {
			t.Errorf("nil user should return nil info: got %v", info)
		}
	})

	t.Run("ensureUserActive_nil_user", func(t *testing.T) {
		var svc *AuthService
		err := svc.ensureUserActive(nil)
		if err == nil {
			t.Error("nil user should return error")
		}
	})

	t.Run("blacklistToken_nil_service", func(t *testing.T) {
		var svc *AuthService
		err := svc.blacklistTokenClaims(context.Background(), "token", nil)
		if err != nil {
			t.Errorf("nil service should not error: %v", err)
		}
	})

	t.Run("Logout_nil_service", func(t *testing.T) {
		var svc *AuthService
		err := svc.Logout(context.Background(), "user", nil)
		if err != nil {
			t.Errorf("nil service should not error: %v", err)
		}
	})

	t.Run("IsTokenBlacklisted_nil_service", func(t *testing.T) {
		var svc *AuthService
		blacklisted := svc.IsTokenBlacklisted(context.Background(), "jti")
		if blacklisted {
			t.Error("nil service should not blacklist tokens")
		}
	})
}

func TestUserInfoFromCacheValue(t *testing.T) {
	t.Run("valid_UserInfo_pointer", func(t *testing.T) {
		info := &UserInfo{ID: 1, Username: "testuser"}
		got, ok := userInfoFromCacheValue(info)
		if !ok {
			t.Error("should parse *UserInfo")
		}
		if got.ID != 1 || got.Username != "testuser" {
			t.Errorf("got %+v, want %+v", got, info)
		}
	})

	t.Run("valid_UserInfo_value", func(t *testing.T) {
		info := UserInfo{ID: 2, Username: "testuser2"}
		got, ok := userInfoFromCacheValue(info)
		if !ok {
			t.Error("should parse UserInfo value")
		}
		if got.ID != 2 || got.Username != "testuser2" {
			t.Errorf("got %+v, want %+v", got, info)
		}
	})

	t.Run("invalid_type", func(t *testing.T) {
		got, ok := userInfoFromCacheValue("invalid string")
		if ok || got != nil {
			t.Errorf("should not parse string: ok=%v, got=%+v", ok, got)
		}
	})
}

func TestEnsureUserActive(t *testing.T) {
	t.Run("nil_user", func(t *testing.T) {
		var svc *AuthService
		err := svc.ensureUserActive(nil)
		if err == nil {
			t.Error("nil user should error")
		}
	})
}

func TestAttemptCount(t *testing.T) {
	tests := []struct {
		name  string
		value interface{}
		want  int
	}{
		{"int_value", 5, 5},
		{"int64_value", int64(3), 3},
		{"float64_value", float64(4.0), 4},
		{"string_int", "3", 0}, // strings are not converted
		{"invalid_type", "abc", 0},
		{"nil", nil, 0},
	}

	for _, tt := range tests {
		t.Run(tt.name, func(t *testing.T) {
			got := attemptCount(tt.value)
			if got != tt.want {
				t.Errorf("attemptCount(%v) = %d, want %d", tt.value, got, tt.want)
			}
		})
	}
}

func TestIncrementFailAttempts(t *testing.T) {
	t.Run("nil_service", func(t *testing.T) {
		var svc *AuthService
		count := svc.incrementFailAttempts(context.Background(), "key")
		if count != 0 {
			t.Errorf("nil service should return 0, got %d", count)
		}
	})

	t.Run("empty_key", func(t *testing.T) {
		svc := NewAuthService(nil, nil, nil, nil, 8, 5, 15*time.Minute)
		count := svc.incrementFailAttempts(context.Background(), "")
		if count != 0 {
			t.Errorf("empty key should return 0, got %d", count)
		}
	})
}