feat(email): 初始化自建邮箱 MVP

- 新增 Go + SQLite 后端，支持登录、域名、邮箱、别名、联系人、规则、统计与邮件收发。 - 新增 Webmail 前端，支持多邮箱切换、邮件列表/阅读/写信、附件、搜索、主题切换与个人中心。 - 新增 Docker Compose 部署骨架，补充 Postfix、Dovecot、OpenDKIM、Nginx 配置与部署说明。
2026-06-14 01:07:48 +08:00
commit 3ef8caa319
85 changed files with 13649 additions and 0 deletions
@@ -0,0 +1,199 @@
+package app
+
+import (
+	"crypto/rand"
+	"crypto/sha256"
+	"database/sql"
+	"encoding/base64"
+	"encoding/hex"
+	"encoding/json"
+	"errors"
+	"fmt"
+	"net/http"
+	"regexp"
+	"strings"
+	"time"
+	"unicode"
+
+	"github.com/microcosm-cc/bluemonday"
+)
+
+type HTMLPolicy struct{ policy *bluemonday.Policy }
+
+func NewHTMLPolicy() *HTMLPolicy {
+	p := bluemonday.UGCPolicy()
+	p.AllowAttrs("style").OnElements("p", "span", "div", "table", "td", "th")
+	return &HTMLPolicy{policy: p}
+}
+
+func (p *HTMLPolicy) Sanitize(s string) string {
+	if p == nil || p.policy == nil {
+		return s
+	}
+	return p.policy.Sanitize(s)
+}
+
+func newID(prefix string) string {
+	buf := make([]byte, 16)
+	_, _ = rand.Read(buf)
+	return prefix + "_" + base64.RawURLEncoding.EncodeToString(buf)
+}
+
+func randomToken() string {
+	buf := make([]byte, 32)
+	_, _ = rand.Read(buf)
+	return base64.RawURLEncoding.EncodeToString(buf)
+}
+
+func hashToken(token string) string {
+	sum := sha256.Sum256([]byte(token))
+	return hex.EncodeToString(sum[:])
+}
+
+func normalizeDomain(s string) string {
+	s = strings.ToLower(strings.TrimSpace(s))
+	s = strings.TrimSuffix(s, ".")
+	return s
+}
+
+var localPartRe = regexp.MustCompile(`[^a-z0-9._%+\-]`)
+
+func normalizeLocalPart(s string) string {
+	s = strings.ToLower(strings.TrimSpace(s))
+	s = localPartRe.ReplaceAllString(s, "")
+	s = strings.Trim(s, ".")
+	return s
+}
+
+func normalizeEmail(s string) string {
+	s = strings.ToLower(strings.TrimSpace(s))
+	if !strings.Contains(s, "@") {
+		return s
+	}
+	parts := strings.SplitN(s, "@", 2)
+	return normalizeLocalPart(parts[0]) + "@" + normalizeDomain(parts[1])
+}
+
+func dedupeEmails(items []string) []string {
+	seen := map[string]bool{}
+	out := make([]string, 0, len(items))
+	for _, item := range items {
+		email := normalizeEmail(item)
+		if email == "" || !strings.Contains(email, "@") || seen[email] {
+			continue
+		}
+		seen[email] = true
+		out = append(out, email)
+	}
+	return out
+}
+
+func jsonEncode(v any) string {
+	b, _ := json.Marshal(v)
+	return string(b)
+}
+
+func jsonDecodeSlice(s string) []string {
+	if s == "" {
+		return nil
+	}
+	var out []string
+	if err := json.Unmarshal([]byte(s), &out); err != nil {
+		return nil
+	}
+	return out
+}
+
+func respondJSON(w http.ResponseWriter, status int, payload any) {
+	w.Header().Set("Content-Type", "application/json; charset=utf-8")
+	w.WriteHeader(status)
+	_ = json.NewEncoder(w).Encode(payload)
+}
+
+func respondError(w http.ResponseWriter, status int, msg string) {
+	respondJSON(w, status, map[string]any{"error": msg})
+}
+
+func decodeJSON(r *http.Request, dst any) error {
+	defer r.Body.Close()
+	dec := json.NewDecoder(r.Body)
+	dec.DisallowUnknownFields()
+	if err := dec.Decode(dst); err != nil {
+		return err
+	}
+	return nil
+}
+
+func boolInt(v bool) int {
+	if v {
+		return 1
+	}
+	return 0
+}
+
+func intBool(v int) bool { return v != 0 }
+
+func parseTime(v string) time.Time {
+	t, _ := time.Parse(time.RFC3339Nano, v)
+	return t
+}
+
+func nullableTime(v sql.NullString) *time.Time {
+	if !v.Valid || v.String == "" {
+		return nil
+	}
+	t := parseTime(v.String)
+	return &t
+}
+
+func snippetFrom(text, html string) string {
+	s := text
+	if strings.TrimSpace(s) == "" {
+		s = stripTags(html)
+	}
+	s = strings.Join(strings.Fields(s), " ")
+	if len([]rune(s)) > 160 {
+		r := []rune(s)
+		s = string(r[:160]) + "…"
+	}
+	return s
+}
+
+func stripTags(s string) string {
+	var b strings.Builder
+	inTag := false
+	for _, r := range s {
+		switch r {
+		case '<':
+			inTag = true
+		case '>':
+			inTag = false
+		default:
+			if !inTag {
+				if unicode.IsSpace(r) {
+					b.WriteRune(' ')
+				} else {
+					b.WriteRune(r)
+				}
+			}
+		}
+	}
+	return strings.Join(strings.Fields(b.String()), " ")
+}
+
+func badRequest(w http.ResponseWriter, err error) {
+	msg := "bad request"
+	if err != nil {
+		msg = err.Error()
+	}
+	respondError(w, http.StatusBadRequest, msg)
+}
+
+func requireString(name, value string) error {
+	if strings.TrimSpace(value) == "" {
+		return fmt.Errorf("%s is required", name)
+	}
+	return nil
+}
+
+var errNotFound = errors.New("not found")