Scoreboard/server/internal/httpapi/live_events.go

package httpapi

import (
	"context"
	"database/sql"
	"errors"
	"net/http"
	"sort"
	"strings"
	"time"

	"git.yeij.top/AskaEth/Scoreboard/server/internal/dto"
)

// 「实时赛况」大屏页的当前项目判定。
//
// 现场节奏：一个项目跑完一批就发布一批，下一场开始前大屏要一直显示上一场。
// 判定顺序（display.live_source=auto 时）：
//  1. 人工指定了 display.live_events → 用人工指定的（最多 2 个）；
//  2. 否则取 scheduled_at 落在「现在 ± liveEventWindow」内的小项，按离现在多近排序，最多 2 个；
//  3. 都没有 → 取最近一次发布过成绩的小项（用户要求的「下一场开始前持续显示上一场」）。
//
// manual 时只认人工指定，不做任何回退。
const (
	// liveEventWindow 是排期窗口的半径：项目开始时间前后各 30 分钟都算「正在进行」。
	// 取 30 分钟是因为一个田径小项（含多轮次）通常不会超过一小时；
	// 想更精确可以后续做成设置项，这里先给一个现场够用的固定值。
	liveEventWindow = 30 * time.Minute

	liveReasonManual    = "manual"
	liveReasonScheduled = "scheduled"
	liveReasonRecent    = "recent"
)

// liveScheduledCandidate 是排期命中的候选小项。
type liveScheduledCandidate struct {
	ID        int64
	At        time.Time
	SortOrder int
}

// liveSelection 是判定结果：id 列表与每个 id 的入选原因。
type liveSelection struct {
	Source  string
	IDs     []int64
	Reasons map[int64]string
}

// pickLiveEvents 是纯函数形式的回退链，方便单测覆盖各种组合。
// scheduled 传入的候选必须已经按窗口筛过。
func pickLiveEvents(source string, manual []int64, scheduled []liveScheduledCandidate, recent int64, now time.Time) liveSelection {
	out := liveSelection{Source: source, IDs: make([]int64, 0, dto.MaxLiveEvents), Reasons: map[int64]string{}}
	take := func(ids []int64, reason string) {
		for _, id := range ids {
			if id <= 0 || len(out.IDs) >= dto.MaxLiveEvents {
				return
			}
			if _, ok := out.Reasons[id]; ok {
				continue
			}
			out.IDs = append(out.IDs, id)
			out.Reasons[id] = reason
		}
	}

	if source == dto.LiveSourceManual {
		take(manual, liveReasonManual)
		return out
	}
	if len(manual) > 0 {
		take(manual, liveReasonManual)
		return out
	}

	if len(scheduled) > 0 {
		sort.SliceStable(scheduled, func(i, j int) bool {
			di := absDuration(scheduled[i].At.Sub(now))
			dj := absDuration(scheduled[j].At.Sub(now))
			if di != dj {
				return di < dj
			}
			if scheduled[i].SortOrder != scheduled[j].SortOrder {
				return scheduled[i].SortOrder < scheduled[j].SortOrder
			}
			return scheduled[i].ID < scheduled[j].ID
		})
		ids := make([]int64, 0, len(scheduled))
		for _, c := range scheduled {
			ids = append(ids, c.ID)
		}
		take(ids, liveReasonScheduled)
		return out
	}

	if recent > 0 {
		take([]int64{recent}, liveReasonRecent)
	}
	return out
}

func absDuration(d time.Duration) time.Duration {
	if d < 0 {
		return -d
	}
	return d
}

// resolveLiveEvents 读取设置与赛事库，判定当前项目。
func (s *server) resolveLiveEvents(ctx context.Context, now time.Time) (liveSelection, error) {
	values, err := loadSettingsMap(ctx, s.ev)
	if err != nil {
		return liveSelection{}, err
	}
	source := dto.NormalizeLiveSource(values[dto.SettingKeyLiveSource])

	manual, err := s.existingEventIDs(ctx, dto.ParseLiveEventIDs(values[dto.SettingKeyLiveEvents]))
	if err != nil {
		return liveSelection{}, err
	}
	// manual 模式不必查排期与最近发布，省掉两次查询。
	if source == dto.LiveSourceManual {
		return pickLiveEvents(source, manual, nil, 0, now), nil
	}
	scheduled, err := s.scheduledLiveCandidates(ctx, now)
	if err != nil {
		return liveSelection{}, err
	}
	recent, err := s.mostRecentPublishedEvent(ctx)
	if err != nil {
		return liveSelection{}, err
	}
	return pickLiveEvents(source, manual, scheduled, recent, now), nil
}

// existingEventIDs 丢掉已不存在的小项 id：人工指定的小项被删除后，
// 大屏不该因为一个残留 id 报错或整块空白。
func (s *server) existingEventIDs(ctx context.Context, ids []int64) ([]int64, error) {
	out := make([]int64, 0, len(ids))
	for _, id := range ids {
		var one int
		err := s.ev.QueryRowContext(ctx, `SELECT 1 FROM events WHERE id = ?`, id).Scan(&one)
		switch {
		case errors.Is(err, sql.ErrNoRows):
			continue
		case err != nil:
			return nil, internal(err)
		default:
			out = append(out, id)
		}
	}
	return out, nil
}

// scheduledLiveCandidates 取 scheduled_at 落在当前窗口内的小项。
func (s *server) scheduledLiveCandidates(ctx context.Context, now time.Time) ([]liveScheduledCandidate, error) {
	rows, err := s.ev.QueryContext(ctx,
		`SELECT id, scheduled_at, sort_order FROM events
		  WHERE scheduled_at IS NOT NULL AND TRIM(scheduled_at) <> ''`)
	if err != nil {
		return nil, internal(err)
	}
	defer func() { _ = rows.Close() }()

	out := make([]liveScheduledCandidate, 0)
	for rows.Next() {
		var (
			c       liveScheduledCandidate
			raw     string
			sortOrd int64
		)
		if err := rows.Scan(&c.ID, &raw, &sortOrd); err != nil {
			return nil, internal(err)
		}
		at, ok := parseScheduledAt(raw)
		if !ok || absDuration(at.Sub(now)) > liveEventWindow {
			continue
		}
		c.At = at
		c.SortOrder = int(sortOrd)
		out = append(out, c)
	}
	return out, rows.Err()
}

// mostRecentPublishedEvent 取最近一次发布过成绩的小项，取不到时返回 0（全新赛事）。
func (s *server) mostRecentPublishedEvent(ctx context.Context) (int64, error) {
	var id int64
	err := s.ev.QueryRowContext(ctx, `
		SELECT r.event_id
		  FROM results r
		  JOIN events ev ON ev.id = r.event_id
		 WHERE r.state = 'published' AND r.status <> 'withdrawn'
		 ORDER BY COALESCE(r.verified_at, r.recorded_at, r.updated_at, r.created_at) DESC, r.id DESC
		 LIMIT 1`).Scan(&id)
	if errors.Is(err, sql.ErrNoRows) {
		return 0, nil
	}
	if err != nil {
		return 0, internal(err)
	}
	return id, nil
}

// parseScheduledAt 解析 events.scheduled_at。
//
// 管理端存的是 datetime-local 转出的 RFC3339（UTC），但手工改库或早期数据可能是
// 其它几种常见写法；认不出来的一律当成「没有排期」，不让一个大屏因为格式怪就整块不显示。
func parseScheduledAt(raw string) (time.Time, bool) {
	v := strings.TrimSpace(raw)
	if v == "" {
		return time.Time{}, false
	}
	layouts := []string{
		time.RFC3339Nano,
		time.RFC3339,
		"2006-01-02T15:04:05.999999999",
		"2006-01-02T15:04:05",
		"2006-01-02T15:04",
		"2006-01-02 15:04:05",
		"2006-01-02 15:04",
		"2006-01-02",
	}
	for _, layout := range layouts {
		if at, err := time.Parse(layout, v); err == nil {
			return at, true
		}
	}
	return time.Time{}, false
}

// dedupeIDs 去重并丢掉非法 id（0 / 负数），保持原顺序。
func dedupeIDs(ids []int64) []int64 {
	out := make([]int64, 0, len(ids))
	seen := make(map[int64]bool, len(ids))
	for _, id := range ids {
		if id <= 0 || seen[id] {
			continue
		}
		seen[id] = true
		out = append(out, id)
	}
	return out
}

// ---------- 接口 ----------

// liveEventsHandler 是 GET /api/display/live：大屏「实时赛况」页拉当前项目与已发布成绩。
// 同样对 guest 开放——局域网大屏不带会话，判定结论本身不含任何管理配置。
func (s *server) liveEventsHandler(w http.ResponseWriter, r *http.Request) (any, error) {
	ctx := r.Context()
	sel, err := s.resolveLiveEvents(ctx, time.Now())
	if err != nil {
		return nil, err
	}
	out := dto.LiveEvents{Source: sel.Source, EventIDs: sel.IDs, Events: make([]dto.LiveEvent, 0, len(sel.IDs))}
	for _, id := range sel.IDs {
		ev, err := loadEventQ(ctx, s.ev, id)
		if err != nil {
			return nil, err
		}
		groups, err := s.liveResultGroups(ctx, id)
		if err != nil {
			return nil, err
		}
		out.Events = append(out.Events, dto.LiveEvent{
			Event:  dto.EventFromDomain(ev),
			Reason: sel.Reasons[id],
			Groups: groups,
		})
	}
	return out, nil
}

// liveResultGroups 取某个小项已发布的成绩，按「小项 + 组别」聚合成组。
//
// 与实时层 snapshot.latestResults 的口径一致（排除 withdrawn、组内按名次排序），
// 但范围固定在这一个小项、且不设条数上限——当前项目要显示完整名单，不能被 20 条截断。
func (s *server) liveResultGroups(ctx context.Context, eventID int64) ([]dto.EventResultGroup, error) {
	rows, err := s.ev.QueryContext(ctx, `
		SELECT COALESCE(ev.code, ''), COALESCE(ev.name, ''),
		       e.category_id, COALESCE(cat.name, ''),
		       COALESCE(r.verified_at, r.recorded_at, r.updated_at, r.created_at, ''),
		       r.entry_id, r.rank, e.team_id,
		       COALESCE(t.code, ''), COALESCE(t.name, ''), COALESCE(t.short_name, ''), t.logo_path,
		       e.athlete_id, COALESCE(a.name, ''), COALESCE(e.member_names, ''),
		       COALESCE(r.result_text, ''), r.result_value, COALESCE(r.unit, ''), r.is_tie, r.status
		  FROM results r
		  JOIN entries e ON e.id = r.entry_id
		  JOIN events ev ON ev.id = r.event_id
		  LEFT JOIN event_categories cat ON cat.id = e.category_id
		  LEFT JOIN teams t ON t.id = e.team_id
		  LEFT JOIN athletes a ON a.id = e.athlete_id
		 WHERE r.event_id = ? AND r.state = 'published' AND r.status <> 'withdrawn'
		 ORDER BY COALESCE(r.verified_at, r.recorded_at, r.updated_at, r.created_at) DESC, r.id DESC`, eventID)
	if err != nil {
		return nil, internal(err)
	}
	defer func() { _ = rows.Close() }()

	index := make(map[int64]int)
	out := make([]dto.EventResultGroup, 0)
	for rows.Next() {
		var (
			eventCode, eventName string
			categoryID           int64
			categoryName         string
			publishedAt          string
			row                  dto.EventResultRow
			rank                 sql.NullInt64
			value                sql.NullFloat64
			athleteID            sql.NullInt64
			athleteName          string
			shortName            string
			logoPath             sql.NullString
			memberNames          sql.NullString
			isTie                int
		)
		if err := rows.Scan(&eventCode, &eventName, &categoryID, &categoryName, &publishedAt,
			&row.EntryID, &rank, &row.TeamID, &row.TeamCode, &row.TeamName, &shortName, &logoPath,
			&athleteID, &athleteName, &memberNames,
			&row.ResultText, &value, &row.Unit, &isTie, &row.Status); err != nil {
			return nil, internal(err)
		}
		if rank.Valid {
			v := int(rank.Int64)
			row.Rank = &v
		}
		if value.Valid {
			v := value.Float64
			row.ResultValue = &v
		}
		if athleteID.Valid && athleteID.Int64 != 0 {
			v := athleteID.Int64
			row.AthleteID = &v
		}
		row.AthleteName = nilIfEmpty(athleteName)
		row.ShortName = nilIfEmpty(shortName)
		row.LogoPath = nilIfEmpty(logoPath.String)
		row.MemberNames = parseNames(memberNames)
		row.IsTie = isTie != 0

		key := categoryID
		i, ok := index[key]
		if !ok {
			i = len(out)
			index[key] = i
			out = append(out, dto.EventResultGroup{
				EventID:      eventID,
				EventCode:    eventCode,
				EventName:    eventName,
				CategoryID:   categoryID,
				CategoryName: categoryName,
				PublishedAt:  nilIfEmpty(publishedAt),
				Rows:         []dto.EventResultRow{},
			})
		}
		out[i].Rows = append(out[i].Rows, row)
	}
	if err := rows.Err(); err != nil {
		return nil, internal(err)
	}

	// 行是按发布时间倒序取回的，组内要改回名次顺序；无名次的排最后。
	for i := range out {
		sort.SliceStable(out[i].Rows, func(a, b int) bool {
			ra, rb := out[i].Rows[a], out[i].Rows[b]
			switch {
			case ra.Rank == nil && rb.Rank == nil:
				return ra.EntryID < rb.EntryID
			case ra.Rank == nil:
				return false
			case rb.Rank == nil:
				return true
			default:
				return *ra.Rank < *rb.Rank
			}
		})
	}
	return out, nil
}