package auth

import (
	"testing"

	"github.com/perfect-panel/server/internal/config"
	"github.com/stretchr/testify/assert"
)

func TestNormalizeEmail(t *testing.T) {
	tests := []struct {
		input string
		want  string
	}{
		// Gmail dot trick
		{"a.v.x.xx@gmail.com", "avxxx@gmail.com"},
		{"john.doe@gmail.com", "johndoe@gmail.com"},
		{"a.b.c.d.e@gmail.com", "abcde@gmail.com"},
		// Gmail + alias
		{"user+tag@gmail.com", "user@gmail.com"},
		{"a.b+tag@gmail.com", "ab@gmail.com"},
		// Googlemail
		{"a.b@googlemail.com", "ab@googlemail.com"},
		// Non-Gmail: dots preserved
		{"john.doe@outlook.com", "john.doe@outlook.com"},
		{"john.doe@qq.com", "john.doe@qq.com"},
		// + alias stripped for all providers
		{"user+spam@outlook.com", "user@outlook.com"},
		{"user+spam@qq.com", "user@qq.com"},
		// Case insensitive
		{"User@Gmail.COM", "user@gmail.com"},
		{"A.B@Gmail.com", "ab@gmail.com"},
		// No change for normal non-gmail email
		{"abc@163.com", "abc@163.com"},
	}

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

func TestNormalizeEmail_NoChangeSkipsCheck(t *testing.T) {
	// These emails should NOT trigger cross-user check (normalized == original)
	noChangeCases := []string{
		"abc@163.com",
		"john.doe@outlook.com",
		"user@qq.com",
	}
	for _, email := range noChangeCases {
		normalized := NormalizeEmail(email)
		lower := email
		if normalized == lower {
			// correct: no normalization change, NormalizedEmailHasTrial would return false early
		}
	}
}

func TestShouldGrantTrialForEmail(t *testing.T) {
	// 模拟线上配置：白名单开启，gmail.com 也在名单里
	rcWithGmail := config.RegisterConfig{
		EnableTrial:               true,
		EnableTrialEmailWhitelist: true,
		TrialEmailDomainWhitelist: "hifastapp.com,hifastvpn.com,126.com,139.com,163.com,gmail.com",
	}
	// 白名单关闭
	rcNoWhitelist := config.RegisterConfig{
		EnableTrial:               true,
		EnableTrialEmailWhitelist: false,
	}

	tests := []struct {
		name   string
		rc     config.RegisterConfig
		email  string
		want   bool
		reason string
	}{
		{
			name:   "gmail dot trick - blocked even if gmail.com in whitelist",
			rc:     rcWithGmail,
			email:  "s.m.s.n.fsmbt.d.ndny@gmail.com",
			want:   false,
			reason: "gmail 泛域名（含点号）应拒绝",
		},
		{
			name:   "gmail plus alias - blocked",
			rc:     rcWithGmail,
			email:  "user+tag@gmail.com",
			want:   false,
			reason: "gmail +别名应拒绝",
		},
		{
			name:   "clean gmail - allowed",
			rc:     rcWithGmail,
			email:  "normaluser@gmail.com",
			want:   true,
			reason: "干净的 gmail 应放行",
		},
		{
			name:   "163 with dot - allowed (non-gmail dot is ok)",
			rc:     rcWithGmail,
			email:  "s.m.s.n@163.com",
			want:   true,
			reason: "非 gmail 域点号不拦截",
		},
		{
			name:   "163 plus alias - blocked",
			rc:     rcWithGmail,
			email:  "user+spam@163.com",
			want:   false,
			reason: "所有域名的 +别名都拦截",
		},
		{
			name:   "gmail typo squatting domain - blocked even if accidentally whitelisted",
			rc:     config.RegisterConfig{EnableTrial: true, EnableTrialEmailWhitelist: true, TrialEmailDomainWhitelist: "gmail.com,gmaial.com"},
			email:  "1.2.3.4xxx@gmaial.com",
			want:   false,
			reason: "易混淆 Gmail 域名不应发放试用",
		},
		{
			name:   "invalid empty local - blocked",
			rc:     rcWithGmail,
			email:  "@gmail.com",
			want:   false,
			reason: "邮箱 local 为空应拒绝",
		},
		{
			name:   "subdomain spoof - blocked",
			rc:     rcWithGmail,
			email:  "user@fake.gmail.com",
			want:   false,
			reason: "白名单必须精确匹配域名，不匹配子域",
		},
		{
			name:   "whitelist disabled - gmail dot trick still blocked",
			rc:     rcNoWhitelist,
			email:  "s.m.s.n.fsmbt.d.ndny@gmail.com",
			want:   false,
			reason: "白名单未启用，但泛域名仍应拒绝",
		},
		{
			name:   "trial disabled - always blocked",
			rc:     config.RegisterConfig{EnableTrial: false},
			email:  "user@163.com",
			want:   false,
			reason: "试用未开启",
		},
	}

	for _, tt := range tests {
		t.Run(tt.name, func(t *testing.T) {
			got := ShouldGrantTrialForEmail(tt.rc, tt.email)
			if got != tt.want {
				t.Errorf("ShouldGrantTrialForEmail(%q) = %v, want %v | reason: %s",
					tt.email, got, tt.want, tt.reason)
			}
		})
	}
}

func TestShouldAutoGrantTrialOnPublicEmailFlows(t *testing.T) {
	assert.False(t, ShouldAutoGrantTrialOnPublicEmailFlows(config.RegisterConfig{}))
	assert.False(t, ShouldAutoGrantTrialOnPublicEmailFlows(config.RegisterConfig{
		EnableTrial:               true,
		EnableTrialEmailWhitelist: true,
		TrialEmailDomainWhitelist: "gmail.com,example.com",
	}))
}

func TestIsEmailDomainWhitelisted(t *testing.T) {
	whitelist := "gmail.com,edu.cn,outlook.com"
	tests := []struct {
		email string
		want  bool
	}{
		{"user@gmail.com", true},
		{"user@edu.cn", true},
		{"User@Gmail.COM", true},
		{"user@yahoo.com", false},
		{"user@fake.gmail.com", false}, // subdomain not matched
		{"user@", false},
		{"notanemail", false},
		{"@gmail.com", false},
	}
	for _, tt := range tests {
		t.Run(tt.email, func(t *testing.T) {
			got := IsEmailDomainWhitelisted(tt.email, whitelist)
			if got != tt.want {
				t.Errorf("IsEmailDomainWhitelisted(%q) = %v, want %v", tt.email, got, tt.want)
			}
		})
	}
}