Merge pull request #10 from zyh001/fix/quiz-ui-improvements

Fix/quiz UI improvements

Author: zyh001

assets/static/sw.js

@@ -1,5 +1,5 @@
 // Service Worker for 医考练习 PWA
-const CACHE_NAME = 'med-quiz-v2.11.0';
+const CACHE_NAME = 'med-quiz-v2.12.0';
 
 const STATIC_ASSETS = [
     '/static/common.css',

internal/progress/progress.go

@@ -90,7 +90,16 @@ CREATE TABLE IF NOT EXISTS ai_chat_logs (
     provider    TEXT    DEFAULT '',
     created_at  INTEGER NOT NULL
 );
-CREATE INDEX IF NOT EXISTS idx_acl_created ON ai_chat_logs(created_at);`
+CREATE INDEX IF NOT EXISTS idx_acl_created ON ai_chat_logs(created_at);
+
+CREATE TABLE IF NOT EXISTS exam_sessions (
+    id           TEXT    PRIMARY KEY,
+    answers_json TEXT    NOT NULL DEFAULT '{}',
+    ts           INTEGER NOT NULL,
+    started_at   INTEGER NOT NULL DEFAULT 0,
+    time_limit   INTEGER NOT NULL DEFAULT 0,
+    revealed_at  INTEGER NOT NULL DEFAULT 0
+);`
 
 	if _, err = db.Exec(ddl); err != nil {
 		return nil, fmt.Errorf("progress: init schema: %w", err)

internal/server/exam_persist.go

@@ -0,0 +1,312 @@
+package server
+
+// exam_persist.go — 考试会话持久化
+//
+// 不再写 JSON 文件，改为存入已有数据库（SQLite 或 PostgreSQL）。
+// 表结构非常简单，与 sessions / attempts 等表共处一个 DB。
+//
+// SQLite：直接用 b.DB（*sql.DB）
+// Postgres：通过 b.PgStore，要求其实现 examSessionStorer 接口
+//
+// 降级策略：
+//   - 若所有 bank 均无可用 DB，退回到旧的 JSON 文件（exam-sessions.json），
+//     并打印一条警告，保证数据永远不会丢。
+
+import (
+	"context"
+	"database/sql"
+	"encoding/json"
+	"fmt"
+	"os"
+	"path/filepath"
+	"time"
+
+	"github.com/zyh001/med-exam-kit/internal/logger"
+	"github.com/zyh001/med-exam-kit/internal/store"
+)
+
+// ────────────────────────────────────────────────────────────────
+// Postgres interface (implemented in store/postgres/postgres.go)
+// ────────────────────────────────────────────────────────────────
+
+// examSessionStorer is the subset of PgStore used here.
+// postgres.Store implements this; noop.Store returns empty/nil.
+type examSessionStorer interface {
+	SaveExamSession(ctx context.Context, id string, answersJSON []byte, ts, startedAt int64, timeLimit int, revealedAt int64) error
+	LoadExamSessions(ctx context.Context) ([]store.ExamSessionRow, error)
+	DeleteExamSession(ctx context.Context, id string) error
+}
+
+// ────────────────────────────────────────────────────────────────
+// SQLite DDL (one-time migration, called from progress.InitDB)
+// ────────────────────────────────────────────────────────────────
+
+const examSessionsDDL = `
+CREATE TABLE IF NOT EXISTS exam_sessions (
+    id           TEXT    PRIMARY KEY,
+    answers_json TEXT    NOT NULL DEFAULT '{}',
+    ts           INTEGER NOT NULL,
+    started_at   INTEGER NOT NULL DEFAULT 0,
+    time_limit   INTEGER NOT NULL DEFAULT 0,
+    revealed_at  INTEGER NOT NULL DEFAULT 0
+);`
+
+// initExamSessionsTable ensures the SQLite table exists.
+func initExamSessionsTable(db *sql.DB) error {
+	_, err := db.Exec(examSessionsDDL)
+	return err
+}
+
+// ────────────────────────────────────────────────────────────────
+// dbOrNil returns (sqliteDB, pgStorer) for the first available bank.
+// Caller must check which is non-nil.
+// ────────────────────────────────────────────────────────────────
+func (s *Server) dbOrNil() (*sql.DB, examSessionStorer) {
+	for i := range s.cfg.Banks {
+		b := &s.cfg.Banks[i]
+		if b.PgStore != nil {
+			if st, ok := b.PgStore.(examSessionStorer); ok {
+				return nil, st
+			}
+		}
+		if b.DB != nil {
+			return b.DB, nil
+		}
+	}
+	return nil, nil
+}
+
+// ────────────────────────────────────────────────────────────────
+// Public helpers (called from server.go)
+// ────────────────────────────────────────────────────────────────
+
+// persistExamSessions writes all current sessions to the DB (best-effort).
+// Run in a goroutine for non-blocking writes; call synchronously before shutdown.
+func (s *Server) persistExamSessions() {
+	s.examMu.Lock()
+	snap := make(map[string]*examSession, len(s.examSessions))
+	for id, sess := range s.examSessions {
+		snap[id] = sess
+	}
+	s.examMu.Unlock()
+
+	sqlDB, pgSt := s.dbOrNil()
+
+	if sqlDB == nil && pgSt == nil {
+		// No DB available — fall back to JSON file
+		s.persistExamSessionsFile(snap)
+		return
+	}
+
+	ctx := context.Background()
+	for id, sess := range snap {
+		raw, err := json.Marshal(sess.answers)
+		if err != nil {
+			logger.Errorf("[exam-persist] 序列化 session %s 失败: %v", id, err)
+			continue
+		}
+		if pgSt != nil {
+			if err := pgSt.SaveExamSession(ctx, id, raw, sess.ts, sess.startedAt, sess.timeLimit, sess.revealedAt); err != nil {
+				logger.Errorf("[exam-persist] PG 写入 session %s 失败: %v", id, err)
+			}
+		} else {
+			if err := sqliteSaveExamSession(sqlDB, id, raw, sess.ts, sess.startedAt, sess.timeLimit, sess.revealedAt); err != nil {
+				logger.Errorf("[exam-persist] SQLite 写入 session %s 失败: %v", id, err)
+			}
+		}
+	}
+}
+
+// loadExamSessions reads persisted sessions into memory on startup,
+// pruning stale sessions.
+func (s *Server) loadExamSessions() {
+	sqlDB, pgSt := s.dbOrNil()
+
+	var rows []store.ExamSessionRow
+	if pgSt != nil {
+		ctx := context.Background()
+		// Ensure table exists (Postgres schema migration is idempotent)
+		var err error
+		rows, err = pgSt.LoadExamSessions(ctx)
+		if err != nil {
+			logger.Warnf("[exam-persist] PG 读取 exam_sessions 失败: %v", err)
+			return
+		}
+	} else if sqlDB != nil {
+		// Ensure SQLite table exists
+		if err := initExamSessionsTable(sqlDB); err != nil {
+			logger.Warnf("[exam-persist] SQLite 建表失败: %v", err)
+			return
+		}
+		var err error
+		rows, err = sqliteLoadExamSessions(sqlDB)
+		if err != nil {
+			logger.Warnf("[exam-persist] SQLite 读取 exam_sessions 失败: %v", err)
+			return
+		}
+	} else {
+		// Fallback: try the JSON file written by an older version
+		s.loadExamSessionsFile()
+		return
+	}
+
+	nowS := time.Now().Unix()
+	loaded := 0
+	s.examMu.Lock()
+	for _, row := range rows {
+		if nowS-row.Ts > 86400 {
+			continue
+		}
+		if row.RevealedAt != 0 && nowS-row.RevealedAt > int64(revealGraceWindow) {
+			continue
+		}
+		var answers map[string]examAnswer
+		if err := json.Unmarshal(row.AnswersJSON, &answers); err != nil {
+			logger.Warnf("[exam-persist] 反序列化 session %s 失败: %v", row.ID, err)
+			continue
+		}
+		s.examSessions[row.ID] = &examSession{
+			answers:    answers,
+			ts:         row.Ts,
+			startedAt:  row.StartedAt,
+			timeLimit:  row.TimeLimit,
+			revealedAt: row.RevealedAt,
+		}
+		loaded++
+	}
+	s.examMu.Unlock()
+
+	if loaded > 0 {
+		logger.Infof("[exam-persist] 从数据库恢复 %d 个考试会话", loaded)
+	}
+}
+
+// activeExamCount returns the number of in-progress (not yet revealed) sessions.
+func (s *Server) activeExamCount() int {
+	s.examMu.Lock()
+	defer s.examMu.Unlock()
+	n := 0
+	for _, sess := range s.examSessions {
+		if sess.revealedAt == 0 {
+			n++
+		}
+	}
+	return n
+}
+
+// examSessionsSummary returns a human-readable summary for the shutdown warning.
+func (s *Server) examSessionsSummary() string {
+	s.examMu.Lock()
+	defer s.examMu.Unlock()
+	active := 0
+	for _, sess := range s.examSessions {
+		if sess.revealedAt == 0 {
+			active++
+		}
+	}
+	return fmt.Sprintf("%d 场考试正在进行中（答案已持久化到数据库，重启后可恢复）", active)
+}
+
+// ────────────────────────────────────────────────────────────────
+// SQLite helpers
+// ────────────────────────────────────────────────────────────────
+
+func sqliteSaveExamSession(db *sql.DB, id string, answersJSON []byte, ts, startedAt int64, timeLimit int, revealedAt int64) error {
+	_, err := db.Exec(`
+		INSERT INTO exam_sessions(id, answers_json, ts, started_at, time_limit, revealed_at)
+		VALUES (?, ?, ?, ?, ?, ?)
+		ON CONFLICT(id) DO UPDATE SET
+			answers_json = excluded.answers_json,
+			ts           = excluded.ts,
+			started_at   = excluded.started_at,
+			time_limit   = excluded.time_limit,
+			revealed_at  = excluded.revealed_at`,
+		id, string(answersJSON), ts, startedAt, timeLimit, revealedAt)
+	return err
+}
+
+func sqliteLoadExamSessions(db *sql.DB) ([]store.ExamSessionRow, error) {
+	rows, err := db.Query(`
+		SELECT id, answers_json, ts, started_at, time_limit, revealed_at
+		FROM exam_sessions`)
+	if err != nil {
+		return nil, err
+	}
+	defer rows.Close()
+	var out []store.ExamSessionRow
+	for rows.Next() {
+		var r store.ExamSessionRow
+		var answersStr string
+		if err := rows.Scan(&r.ID, &answersStr, &r.Ts, &r.StartedAt, &r.TimeLimit, &r.RevealedAt); err != nil {
+			continue
+		}
+		r.AnswersJSON = []byte(answersStr)
+		out = append(out, r)
+	}
+	return out, rows.Err()
+}
+
+// ────────────────────────────────────────────────────────────────
+// JSON-file fallback (no DB available — shouldn't normally happen)
+// ────────────────────────────────────────────────────────────────
+
+func (s *Server) examSessionsFilePath() string {
+	base := "exam-sessions.json"
+	if s.configPath != "" {
+		return filepath.Join(filepath.Dir(s.configPath), base)
+	}
+	return base
+}
+
+func (s *Server) persistExamSessionsFile(snap map[string]*examSession) {
+	logger.Warnf("[exam-persist] 无可用数据库，降级写 JSON 文件")
+	type diskEntry struct {
+		Answers    map[string]examAnswer `json:"answers"`
+		Ts         int64                 `json:"ts"`
+		StartedAt  int64                 `json:"started_at"`
+		TimeLimit  int                   `json:"time_limit"`
+		RevealedAt int64                 `json:"revealed_at"`
+	}
+	m := make(map[string]diskEntry, len(snap))
+	for id, sess := range snap {
+		m[id] = diskEntry{sess.answers, sess.ts, sess.startedAt, sess.timeLimit, sess.revealedAt}
+	}
+	data, _ := json.MarshalIndent(m, "", "  ")
+	path := s.examSessionsFilePath()
+	tmp := path + ".tmp"
+	_ = os.WriteFile(tmp, data, 0600)
+	_ = os.Rename(tmp, path)
+}
+
+func (s *Server) loadExamSessionsFile() {
+	path := s.examSessionsFilePath()
+	data, err := os.ReadFile(path)
+	if err != nil {
+		return
+	}
+	type diskEntry struct {
+		Answers    map[string]examAnswer `json:"answers"`
+		Ts         int64                 `json:"ts"`
+		StartedAt  int64                 `json:"started_at"`
+		TimeLimit  int                   `json:"time_limit"`
+		RevealedAt int64                 `json:"revealed_at"`
+	}
+	var m map[string]diskEntry
+	if err := json.Unmarshal(data, &m); err != nil {
+		return
+	}
+	nowS := time.Now().Unix()
+	loaded := 0
+	s.examMu.Lock()
+	for id, d := range m {
+		if nowS-d.Ts > 86400 || (d.RevealedAt != 0 && nowS-d.RevealedAt > int64(revealGraceWindow)) {
+			continue
+		}
+		s.examSessions[id] = &examSession{answers: d.Answers, ts: d.Ts, startedAt: d.StartedAt, timeLimit: d.TimeLimit, revealedAt: d.RevealedAt}
+		loaded++
+	}
+	s.examMu.Unlock()
+	if loaded > 0 {
+		logger.Infof("[exam-persist] 从 JSON 文件恢复 %d 个考试会话（旧格式）", loaded)
+	}
+}