package httpapi

import (
	"context"
	"database/sql"
	"errors"
	"fmt"
	"os"
	"path/filepath"
	"strconv"
	"strings"
	"time"

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

// ---------- settings ----------

func loadSettingsMap(ctx context.Context, q queryer) (map[string]string, error) {
	rows, err := q.QueryContext(ctx, `SELECT key, value FROM settings`)
	if err != nil {
		return nil, internal(err)
	}
	defer func() { _ = rows.Close() }()

	out := make(map[string]string)
	for rows.Next() {
		var k, v string
		if err := rows.Scan(&k, &v); err != nil {
			return nil, internal(err)
		}
		out[k] = v
	}
	return out, rows.Err()
}

func (s *server) getSettings(ctx context.Context) (eventSettingsDTO, error) {
	values, err := loadSettingsMap(ctx, s.ev)
	if err != nil {
		return eventSettingsDTO{}, err
	}

	var out eventSettingsDTO
	out.Event.Name = orDefault(values["event.name"], "未命名赛事")
	out.Event.Subtitle = nilIfEmpty(values["event.subtitle"])
	out.Event.Host = nilIfEmpty(values["event.organizer"])
	out.Event.LogoPath = nilIfEmpty(values["event.logo_path"])
	out.Event.PrimaryColor = nilIfEmpty(values["display.theme_color"])

	out.Display.Background = nilIfEmpty(values["display.background"])
	out.Display.Logo = nilIfEmpty(values["display.logo"])
	if out.Display.Logo == nil {
		out.Display.Logo = out.Event.LogoPath
	}
	out.Display.Title = orDefault(values["display.title"], out.Event.Name)
	out.Display.Subtitle = nilIfEmpty(values["display.subtitle"])
	if out.Display.Subtitle == nil {
		out.Display.Subtitle = out.Event.Subtitle
	}
	out.Display.PrimaryColor = out.Event.PrimaryColor
	out.Display.RotateSecond = atoiDefault(values["display.rotate_seconds"], 15)

	out.Standings.IndividualToTeamWeight = atofDefault(values["standings.individual_to_team_weight"], 1)
	out.Standings.RankingMode = orDefault(values["standings.mode"], "points")
	out.Standings.ShowIndividualBoard = boolDefault(
		firstNonEmpty(values["standings.show_individual_board"], values["standings.show_individual_medals"]), true)

	out.RequireApproval = boolDefault(values["results.review_required"], false)

	if code := values["scoring.default_profile"]; code != "" {
		var id int64
		err := s.ev.QueryRowContext(ctx, `SELECT id FROM scoring_profiles WHERE code = ?`, code).Scan(&id)
		switch {
		case errors.Is(err, sql.ErrNoRows):
			// 配置引用的模板已被删除：返回 null，由管理端提示重新选择。
		case err != nil:
			return eventSettingsDTO{}, internal(err)
		default:
			out.DefaultProfileID = &id
		}
	}
	return out, nil
}

func (s *server) updateSettings(ctx context.Context, patch settingsPatch) (eventSettingsDTO, error) {
	tx, err := s.ev.BeginTx(ctx, nil)
	if err != nil {
		return eventSettingsDTO{}, internal(err)
	}
	defer func() { _ = tx.Rollback() }()

	set := func(key, value string) error {
		_, err := tx.ExecContext(ctx,
			`INSERT INTO settings (key, value, updated_at) VALUES (?, ?, datetime('now'))
			 ON CONFLICT(key) DO UPDATE SET value = excluded.value, updated_at = datetime('now')`,
			key, value)
		if err != nil {
			return internal(err)
		}
		return nil
	}
	setPtr := func(key string, v *string) error {
		if v == nil {
			return nil
		}
		return set(key, *v)
	}

	if p := patch.Event; p != nil {
		if err := setPtr("event.name", p.Name); err != nil {
			return eventSettingsDTO{}, err
		}
		if err := setPtr("event.subtitle", p.Subtitle); err != nil {
			return eventSettingsDTO{}, err
		}
		if err := setPtr("event.organizer", p.Host); err != nil {
			return eventSettingsDTO{}, err
		}
		if err := setPtr("event.logo_path", p.LogoPath); err != nil {
			return eventSettingsDTO{}, err
		}
		if err := setPtr("display.theme_color", p.PrimaryColor); err != nil {
			return eventSettingsDTO{}, err
		}
	}
	if p := patch.Display; p != nil {
		if err := setPtr("display.background", p.Background); err != nil {
			return eventSettingsDTO{}, err
		}
		if err := setPtr("display.logo", p.Logo); err != nil {
			return eventSettingsDTO{}, err
		}
		if err := setPtr("display.title", p.Title); err != nil {
			return eventSettingsDTO{}, err
		}
		if err := setPtr("display.subtitle", p.Subtitle); err != nil {
			return eventSettingsDTO{}, err
		}
		if err := setPtr("display.theme_color", p.PrimaryColor); err != nil {
			return eventSettingsDTO{}, err
		}
		if p.RotateSeconds != nil {
			if err := set("display.rotate_seconds", strconv.FormatFloat(*p.RotateSeconds, 'f', -1, 64)); err != nil {
				return eventSettingsDTO{}, err
			}
		}
	}
	if p := patch.Standings; p != nil {
		if p.IndividualToTeamWeight != nil {
			if err := set("standings.individual_to_team_weight",
				strconv.FormatFloat(*p.IndividualToTeamWeight, 'f', -1, 64)); err != nil {
				return eventSettingsDTO{}, err
			}
		}
		if err := setPtr("standings.mode", p.RankingMode); err != nil {
			return eventSettingsDTO{}, err
		}
		if p.ShowIndividualBoard != nil {
			if err := set("standings.show_individual_board", strconv.FormatBool(*p.ShowIndividualBoard)); err != nil {
				return eventSettingsDTO{}, err
			}
		}
	}
	if patch.DefaultProfileID != nil {
		code := ""
		if *patch.DefaultProfileID != 0 {
			if err := tx.QueryRowContext(ctx, `SELECT code FROM scoring_profiles WHERE id = ?`, *patch.DefaultProfileID).Scan(&code); err != nil {
				if errors.Is(err, sql.ErrNoRows) {
					return eventSettingsDTO{}, badRequest("defaultProfileId 不存在", nil)
				}
				return eventSettingsDTO{}, internal(err)
			}
		}
		if err := set("scoring.default_profile", code); err != nil {
			return eventSettingsDTO{}, err
		}
	}
	if patch.RequireApproval != nil {
		if err := set("results.review_required", strconv.FormatBool(*patch.RequireApproval)); err != nil {
			return eventSettingsDTO{}, err
		}
	}

	if err := tx.Commit(); err != nil {
		return eventSettingsDTO{}, internal(err)
	}
	return s.getSettings(ctx)
}

func firstNonEmpty(values ...string) string {
	for _, v := range values {
		if strings.TrimSpace(v) != "" {
			return v
		}
	}
	return ""
}

func atoiDefault(v string, def int) int {
	n, err := strconv.Atoi(strings.TrimSpace(v))
	if err != nil {
		return def
	}
	return n
}

func atofDefault(v string, def float64) float64 {
	n, err := strconv.ParseFloat(strings.TrimSpace(v), 64)
	if err != nil {
		return def
	}
	return n
}

func boolDefault(v string, def bool) bool {
	switch strings.ToLower(strings.TrimSpace(v)) {
	case "true", "1", "yes":
		return true
	case "false", "0", "no":
		return false
	default:
		return def
	}
}

// ---------- standings ----------

func (s *server) loadStandingsInput(ctx context.Context, q queryer) (domain.StandingsInput, error) {
	teams, err := s.domainTeams(ctx, q)
	if err != nil {
		return domain.StandingsInput{}, err
	}
	athletes, err := s.domainAthletes(ctx, q)
	if err != nil {
		return domain.StandingsInput{}, err
	}
	ledger, err := s.activeLedger(ctx, q)
	if err != nil {
		return domain.StandingsInput{}, err
	}
	ranked, err := s.buildRanked(ctx, q)
	if err != nil {
		return domain.StandingsInput{}, err
	}
	values, err := loadSettingsMap(ctx, q)
	if err != nil {
		return domain.StandingsInput{}, err
	}
	weight := atofDefault(values["standings.individual_to_team_weight"], 1)
	exclude := !boolDefault(values["standings.medal_counts_team_events"], true)

	return domain.StandingsInput{
		Teams:                  teams,
		Athletes:               athletes,
		Ledger:                 ledger,
		Ranked:                 ranked,
		IndividualToTeamWeight: weight,
		ExcludeTeamEventMedals: exclude,
	}, nil
}

// standingsSnapshot 构造与 GET /api/standings 完全同构的整张榜单，
// 供 change_log 的 standings replace 载荷使用（契约要求 data 是榜单数组）。
func (s *server) standingsSnapshot(ctx context.Context, q queryer) ([]standingRowDTO, error) {
	in, err := s.loadStandingsInput(ctx, q)
	if err != nil {
		return nil, err
	}
	teams, err := teamMapQ(ctx, q)
	if err != nil {
		return nil, err
	}
	return standingRowsDTO(domain.BuildTeamStandings(in), teams), nil
}

// bumpStandings 在写事务内把整张榜单写入 change_log；榜单变化后必须调用，否则大屏不会刷新。
func (s *server) bumpStandings(ctx context.Context, tx *sql.Tx, actorID int64) error {
	snapshot, err := s.standingsSnapshot(ctx, tx)
	if err != nil {
		return err
	}
	return bumpVersion(ctx, tx, "standings", 0, "replace", snapshot, actorID)
}

func (s *server) domainTeams(ctx context.Context, q queryer) ([]domain.Team, error) {
	rows, err := q.QueryContext(ctx,
		`SELECT id, code, name, short_name, color, sort_order, active FROM teams WHERE active = 1`)
	if err != nil {
		return nil, internal(err)
	}
	defer func() { _ = rows.Close() }()

	out := make([]domain.Team, 0)
	for rows.Next() {
		var (
			t         domain.Team
			shortName sql.NullString
			color     sql.NullString
		)
		if err := rows.Scan(&t.ID, &t.Code, &t.Name, &shortName, &color, &t.SortOrder, &t.Active); err != nil {
			return nil, internal(err)
		}
		t.ShortName = shortName.String
		t.Color = color.String
		out = append(out, t)
	}
	return out, rows.Err()
}

func (s *server) domainAthletes(ctx context.Context, q queryer) ([]domain.Athlete, error) {
	rows, err := q.QueryContext(ctx, `SELECT id, name, gender, team_id FROM athletes WHERE active = 1`)
	if err != nil {
		return nil, internal(err)
	}
	defer func() { _ = rows.Close() }()

	out := make([]domain.Athlete, 0)
	for rows.Next() {
		var (
			a      domain.Athlete
			gender sql.NullString
			teamID sql.NullInt64
		)
		if err := rows.Scan(&a.ID, &a.Name, &gender, &teamID); err != nil {
			return nil, internal(err)
		}
		a.Gender = gender.String
		a.TeamID = teamID.Int64
		out = append(out, a)
	}
	return out, rows.Err()
}

// buildRanked 从已发布成绩重建名次明细（用于奖牌统计与个人榜）。
// 一条成绩在每个通道下各产出一条明细，与计分引擎的口径一致。
func (s *server) buildRanked(ctx context.Context, q queryer) ([]domain.RankedResult, error) {
	rows, err := q.QueryContext(ctx,
		`SELECT r.id, r.event_id, e.category_id, r.rank, r.result_value, r.status,
		        e.id, e.team_id, e.athlete_id, COALESCE(a.name, ''), c.scope, c.id
		   FROM results r
		   JOIN entries e ON e.id = r.entry_id
		   JOIN event_score_channels c ON c.event_id = r.event_id
		   LEFT JOIN athletes a ON a.id = e.athlete_id
		  WHERE r.state = 'published' AND r.rank IS NOT NULL AND r.rank > 0 AND r.status = 'ok'
		    AND (c.scope = 'team' OR e.athlete_id IS NOT NULL)`)
	if err != nil {
		return nil, internal(err)
	}
	defer func() { _ = rows.Close() }()

	out := make([]domain.RankedResult, 0)
	for rows.Next() {
		var (
			rr        domain.RankedResult
			value     sql.NullFloat64
			athleteID sql.NullInt64
			rank      int
		)
		if err := rows.Scan(&rr.ResultID, &rr.EventID, &rr.CategoryID, &rank, &value, &rr.Status,
			&rr.EntryID, &rr.TeamID, &athleteID, &rr.AthleteName, &rr.Scope, &rr.ChannelID); err != nil {
			return nil, internal(err)
		}
		rr.Rank = rank
		if value.Valid {
			v := value.Float64
			rr.ResultValue = &v
		}
		rr.AthleteID = athleteID.Int64
		rr.Shares = []domain.TeamShare{{TeamID: rr.TeamID, Weight: 1}}
		out = append(out, rr)
	}
	return out, rows.Err()
}

func (s *server) teamBreakdown(ctx context.Context, teamID int64) (teamBreakdownDTO, error) {
	team, err := s.getTeam(ctx, teamID)
	if err != nil {
		return teamBreakdownDTO{}, err
	}
	rows, err := s.ev.QueryContext(ctx,
		`SELECT l.id, l.source_type, l.event_id, ev.code, ev.name, cat.name,
		        l.athlete_id, a.name, r.rank, r.result_text, l.points, COALESCE(l.created_at, '')
		   FROM score_ledger l
		   LEFT JOIN events ev ON ev.id = l.event_id
		   LEFT JOIN entries e ON e.id = l.entry_id
		   LEFT JOIN event_categories cat ON cat.id = e.category_id
		   LEFT JOIN athletes a ON a.id = l.athlete_id
		   LEFT JOIN results r ON r.id = l.result_id
		  WHERE l.team_id = ? AND l.voided = 0
		  ORDER BY l.id DESC`, teamID)
	if err != nil {
		return teamBreakdownDTO{}, internal(err)
	}
	defer func() { _ = rows.Close() }()

	out := teamBreakdownDTO{TeamID: team.ID, TeamCode: team.Code, TeamName: team.Name, Items: []breakdownItemDTO{}}
	for rows.Next() {
		var (
			item                      breakdownItemDTO
			eventID, athleteID        sql.NullInt64
			eventCode, eventName      sql.NullString
			categoryName, athleteName sql.NullString
			rank                      sql.NullInt64
			resultText                sql.NullString
		)
		if err := rows.Scan(&item.LedgerID, &item.SourceType, &eventID, &eventCode, &eventName,
			&categoryName, &athleteID, &athleteName, &rank, &resultText, &item.Points, &item.CreatedAt); err != nil {
			return teamBreakdownDTO{}, internal(err)
		}
		item.EventID = i64Ptr(eventID)
		item.EventCode = strPtr(eventCode)
		item.EventName = strPtr(eventName)
		item.CategoryName = strPtr(categoryName)
		item.AthleteID = i64Ptr(athleteID)
		item.AthleteName = strPtr(athleteName)
		item.Rank = intPtr(rank)
		item.ResultText = strPtr(resultText)
		out.Items = append(out.Items, item)
		out.TotalPoints += item.Points
	}
	return out, rows.Err()
}

// ---------- records ----------

func (s *server) listRecords(ctx context.Context, eventID int64) ([]recordEntryDTO, error) {
	query := `SELECT id, event_id, level, COALESCE(result_value, 0), COALESCE(result_text, ''),
	                 holder_name, holder_team_id, achieved_at, is_current, source
	            FROM records WHERE is_current = 1`
	args := []any{}
	if eventID > 0 {
		query += ` AND event_id = ?`
		args = append(args, eventID)
	}
	query += ` ORDER BY event_id, level`

	rows, err := s.ev.QueryContext(ctx, query, args...)
	if err != nil {
		return nil, internal(err)
	}
	defer func() { _ = rows.Close() }()

	out := make([]recordEntryDTO, 0)
	for rows.Next() {
		var (
			r            recordEntryDTO
			holderName   sql.NullString
			holderTeamID sql.NullInt64
			achievedAt   sql.NullString
		)
		if err := rows.Scan(&r.ID, &r.EventID, &r.Level, &r.ResultValue, &r.ResultText,
			&holderName, &holderTeamID, &achievedAt, &r.IsCurrent, &r.Source); err != nil {
			return nil, internal(err)
		}
		r.HolderName = strPtr(holderName)
		r.HolderTeamID = i64Ptr(holderTeamID)
		r.AchievedAt = strPtr(achievedAt)
		out = append(out, r)
	}
	return out, rows.Err()
}

func (s *server) createRecordBreak(ctx context.Context, in recordBreakInput, userID int64) (recordBreakDTO, error) {
	if in.EventID == 0 || in.EntryID == 0 || in.Level == "" {
		return recordBreakDTO{}, badRequest("eventId、entryId、level 必填", nil)
	}
	switch in.Level {
	case "meet", "city", "province", "national":
	default:
		return recordBreakDTO{}, badRequest("level 非法", in.Level)
	}
	res, err := s.ev.ExecContext(ctx,
		`INSERT INTO record_breaks (event_id, entry_id, level, result_value, result_text, bonus_points, state)
		 VALUES (?, ?, ?, ?, ?, 0, 'pending')`,
		in.EventID, in.EntryID, in.Level, in.ResultValue, in.ResultText)
	if isForeignKeyViolation(err) {
		return recordBreakDTO{}, badRequest("eventId/entryId 不存在", nil)
	}
	if err != nil {
		return recordBreakDTO{}, internal(err)
	}
	id, err := lastInsertID(res)
	if err != nil {
		return recordBreakDTO{}, internal(err)
	}
	return s.getRecordBreak(ctx, id)
}

func (s *server) getRecordBreak(ctx context.Context, id int64) (recordBreakDTO, error) {
	var (
		b          recordBreakDTO
		value      sql.NullFloat64
		text       sql.NullString
		approvedBy sql.NullInt64
		approvedAt sql.NullString
	)
	err := s.ev.QueryRowContext(ctx,
		`SELECT id, event_id, entry_id, level, result_value, result_text, bonus_points, state, approved_by, approved_at
		   FROM record_breaks WHERE id = ?`, id).
		Scan(&b.ID, &b.EventID, &b.EntryID, &b.Level, &value, &text, &b.BonusPoints, &b.State, &approvedBy, &approvedAt)
	if errors.Is(err, sql.ErrNoRows) {
		return recordBreakDTO{}, notFound("破纪录登记不存在")
	}
	if err != nil {
		return recordBreakDTO{}, internal(err)
	}
	b.ResultValue = value.Float64
	b.ResultText = text.String
	b.ApprovedBy = i64Ptr(approvedBy)
	b.ApprovedAt = strPtr(approvedAt)
	return b, nil
}

func (s *server) approveRecordBreak(ctx context.Context, id, userID int64) (recordBreakDTO, error) {
	tx, err := s.ev.BeginTx(ctx, nil)
	if err != nil {
		return recordBreakDTO{}, internal(err)
	}
	defer func() { _ = tx.Rollback() }()

	var (
		state      string
		eventID    int64
		entryID    int64
		level      string
		resultVal  sql.NullFloat64
		resultText sql.NullString
	)
	if err := tx.QueryRowContext(ctx,
		`SELECT state, event_id, entry_id, level, result_value, result_text FROM record_breaks WHERE id = ?`, id).
		Scan(&state, &eventID, &entryID, &level, &resultVal, &resultText); err != nil {
		if errors.Is(err, sql.ErrNoRows) {
			return recordBreakDTO{}, notFound("破纪录登记不存在")
		}
		return recordBreakDTO{}, internal(err)
	}
	if state != "pending" {
		return recordBreakDTO{}, stateInvalid("该破纪录登记已处理")
	}
	if _, err := tx.ExecContext(ctx,
		`UPDATE record_breaks SET state = 'approved', approved_by = ?, approved_at = datetime('now') WHERE id = ?`,
		nullID(userID), id); err != nil {
		return recordBreakDTO{}, internal(err)
	}
	if _, err := recomputeLedgerTx(ctx, tx, eventID, 0, userID, "确认破纪录加分"); err != nil {
		return recordBreakDTO{}, err
	}
	// 确认即更新纪录库，并把引擎算出的加分回填到登记上（devdocs/02 第 3 节）。
	if err := upsertCurrentRecord(ctx, tx, eventID, entryID, level, resultVal, resultText); err != nil {
		return recordBreakDTO{}, err
	}
	if _, err := tx.ExecContext(ctx,
		`UPDATE record_breaks SET bonus_points = COALESCE((
		     SELECT SUM(points) FROM score_ledger
		      WHERE source_type = 'record_bonus' AND event_id = ? AND entry_id = ? AND voided = 0), 0)
		  WHERE id = ?`, eventID, entryID, id); err != nil {
		return recordBreakDTO{}, internal(err)
	}
	if err := bumpVersion(ctx, tx, "record", id, "upsert", map[string]any{"id": id}, userID); err != nil {
		return recordBreakDTO{}, err
	}
	if err := s.bumpStandings(ctx, tx, userID); err != nil {
		return recordBreakDTO{}, err
	}
	if err := tx.Commit(); err != nil {
		return recordBreakDTO{}, internal(err)
	}
	s.audit(ctx, "record_break.approve", "record_break", id, map[string]any{"state": state}, map[string]any{"state": "approved"})
	return s.getRecordBreak(ctx, id)
}

// upsertCurrentRecord 把确认后的破纪录写入 records：同小项同档位的旧纪录改为非当前，
// 新纪录标为 current（devdocs/04 records 表；source=current 表示本届产生）。
func upsertCurrentRecord(ctx context.Context, tx *sql.Tx, eventID, entryID int64, level string, value sql.NullFloat64, text sql.NullString) error {
	var (
		teamID      int64
		athleteID   sql.NullInt64
		athleteName sql.NullString
		teamName    sql.NullString
	)
	if err := tx.QueryRowContext(ctx,
		`SELECT e.team_id, e.athlete_id, a.name, t.name
		   FROM entries e
		   LEFT JOIN athletes a ON a.id = e.athlete_id
		   LEFT JOIN teams t ON t.id = e.team_id
		  WHERE e.id = ?`, entryID).Scan(&teamID, &athleteID, &athleteName, &teamName); err != nil {
		if errors.Is(err, sql.ErrNoRows) {
			return notFound("报名项不存在")
		}
		return internal(err)
	}
	holder := teamName.String
	if athleteID.Valid && athleteName.String != "" {
		holder = athleteName.String
	}
	if _, err := tx.ExecContext(ctx,
		`UPDATE records SET is_current = 0 WHERE event_id = ? AND level = ? AND is_current = 1`,
		eventID, level); err != nil {
		return internal(err)
	}
	if _, err := tx.ExecContext(ctx,
		`INSERT INTO records (event_id, level, result_value, result_text, holder_name, holder_team_id, achieved_at, is_current, source)
		 VALUES (?, ?, ?, ?, ?, ?, datetime('now'), 1, 'current')`,
		eventID, level, value, text, nullStr(&holder), nullID(teamID)); err != nil {
		return internal(err)
	}
	return nil
}

// ---------- adjustments ----------

func (s *server) listAdjustments(ctx context.Context, teamID int64, page, size int) (pageResult[adjustmentDTO], error) {
	where := []string{"1 = 1"}
	args := []any{}
	if teamID > 0 {
		where = append(where, "team_id = ?")
		args = append(args, teamID)
	}
	clause := " WHERE " + joinAnd(where)

	var total int
	if err := s.ev.QueryRowContext(ctx, `SELECT COUNT(*) FROM point_adjustments`+clause, args...).Scan(&total); err != nil {
		return pageResult[adjustmentDTO]{}, internal(err)
	}
	query := `SELECT id, team_id, delta, category, reason, event_id, voided, created_by, created_at
	            FROM point_adjustments` + clause + ` ORDER BY id DESC LIMIT ? OFFSET ?`
	args = append(args, size, (page-1)*size)

	rows, err := s.ev.QueryContext(ctx, query, args...)
	if err != nil {
		return pageResult[adjustmentDTO]{}, internal(err)
	}
	defer func() { _ = rows.Close() }()

	items := make([]adjustmentDTO, 0)
	for rows.Next() {
		var (
			a                  adjustmentDTO
			eventID, createdBy sql.NullInt64
		)
		if err := rows.Scan(&a.ID, &a.TeamID, &a.Delta, &a.Category, &a.Reason, &eventID, &a.Voided, &createdBy, &a.CreatedAt); err != nil {
			return pageResult[adjustmentDTO]{}, internal(err)
		}
		a.EventID = i64Ptr(eventID)
		a.CreatedBy = i64Ptr(createdBy)
		items = append(items, a)
	}
	if err := rows.Err(); err != nil {
		return pageResult[adjustmentDTO]{}, internal(err)
	}
	return pageResult[adjustmentDTO]{Items: items, Total: total, Page: page, Size: size}, nil
}

func (s *server) createAdjustment(ctx context.Context, in adjustmentInput, userID int64) (adjustmentDTO, error) {
	values, err := loadSettingsMap(ctx, s.ev)
	if err != nil {
		return adjustmentDTO{}, err
	}
	if !boolDefault(values["manual_adjustment.enabled"], false) {
		return adjustmentDTO{}, stateInvalid("人工调整当前未启用")
	}
	if boolDefault(values["manual_adjustment.reason_required"], true) && strings.TrimSpace(in.Reason) == "" {
		return adjustmentDTO{}, badRequest("reason 必填", nil)
	}
	switch in.Category {
	case "penalty", "bonus", "correction":
	default:
		return adjustmentDTO{}, badRequest("category 非法", in.Category)
	}
	if in.TeamID == 0 {
		return adjustmentDTO{}, badRequest("teamId 必填", nil)
	}

	tx, err := s.ev.BeginTx(ctx, nil)
	if err != nil {
		return adjustmentDTO{}, internal(err)
	}
	defer func() { _ = tx.Rollback() }()

	res, err := tx.ExecContext(ctx,
		`INSERT INTO point_adjustments (team_id, delta, category, reason, event_id, created_by)
		 VALUES (?, ?, ?, ?, ?, ?)`,
		in.TeamID, in.Delta, in.Category, in.Reason, nullI64(in.EventID), nullID(userID))
	if isForeignKeyViolation(err) {
		return adjustmentDTO{}, badRequest("teamId/eventId 不存在", nil)
	}
	if err != nil {
		return adjustmentDTO{}, internal(err)
	}
	id, err := lastInsertID(res)
	if err != nil {
		return adjustmentDTO{}, internal(err)
	}
	if _, err := tx.ExecContext(ctx,
		`INSERT INTO score_ledger (team_id, event_id, source_type, source_id, points, created_by)
		 VALUES (?, ?, 'adjustment', ?, ?, ?)`,
		in.TeamID, nullI64(in.EventID), id, in.Delta, nullID(userID)); err != nil {
		return adjustmentDTO{}, internal(err)
	}
	// 调整分进积分榜，必须写版本号，否则大屏不会刷新。
	if err := s.bumpStandings(ctx, tx, userID); err != nil {
		return adjustmentDTO{}, err
	}
	if err := tx.Commit(); err != nil {
		return adjustmentDTO{}, internal(err)
	}
	s.audit(ctx, "adjustment.create", "adjustment", id, nil, in)
	return s.getAdjustment(ctx, id)
}

func (s *server) getAdjustment(ctx context.Context, id int64) (adjustmentDTO, error) {
	var (
		a                  adjustmentDTO
		eventID, createdBy sql.NullInt64
	)
	err := s.ev.QueryRowContext(ctx,
		`SELECT id, team_id, delta, category, reason, event_id, voided, created_by, created_at
		   FROM point_adjustments WHERE id = ?`, id).
		Scan(&a.ID, &a.TeamID, &a.Delta, &a.Category, &a.Reason, &eventID, &a.Voided, &createdBy, &a.CreatedAt)
	if errors.Is(err, sql.ErrNoRows) {
		return adjustmentDTO{}, notFound("人工调整不存在")
	}
	if err != nil {
		return adjustmentDTO{}, internal(err)
	}
	a.EventID = i64Ptr(eventID)
	a.CreatedBy = i64Ptr(createdBy)
	return a, nil
}

func (s *server) voidAdjustment(ctx context.Context, id, userID int64, reason string) (adjustmentDTO, error) {
	tx, err := s.ev.BeginTx(ctx, nil)
	if err != nil {
		return adjustmentDTO{}, internal(err)
	}
	defer func() { _ = tx.Rollback() }()

	var voided bool
	if err := tx.QueryRowContext(ctx, `SELECT voided FROM point_adjustments WHERE id = ?`, id).Scan(&voided); err != nil {
		if errors.Is(err, sql.ErrNoRows) {
			return adjustmentDTO{}, notFound("人工调整不存在")
		}
		return adjustmentDTO{}, internal(err)
	}
	if voided {
		return adjustmentDTO{}, stateInvalid("该人工调整已作废")
	}
	if _, err := tx.ExecContext(ctx,
		`UPDATE point_adjustments SET voided = 1, voided_by = ?, voided_at = datetime('now') WHERE id = ?`,
		nullID(userID), id); err != nil {
		return adjustmentDTO{}, internal(err)
	}
	if _, err := tx.ExecContext(ctx,
		`UPDATE score_ledger SET voided = 1, voided_by = ?, voided_at = datetime('now'), void_reason = ?
		  WHERE source_type = 'adjustment' AND source_id = ? AND voided = 0`,
		nullID(userID), reason, id); err != nil {
		return adjustmentDTO{}, internal(err)
	}
	if err := s.bumpStandings(ctx, tx, userID); err != nil {
		return adjustmentDTO{}, err
	}
	if err := tx.Commit(); err != nil {
		return adjustmentDTO{}, internal(err)
	}
	s.audit(ctx, "adjustment.void", "adjustment", id, map[string]any{"voided": false}, map[string]any{"voided": true, "reason": reason})
	return s.getAdjustment(ctx, id)
}

// ---------- audit logs ----------

func (s *server) listAuditLogs(ctx context.Context, page, size int, entityType string, userID int64) (pageResult[auditLogDTO], error) {
	where := []string{"1 = 1"}
	args := []any{}
	if entityType != "" {
		where = append(where, "entity_type = ?")
		args = append(args, entityType)
	}
	if userID > 0 {
		where = append(where, "user_id = ?")
		args = append(args, userID)
	}
	clause := " WHERE " + joinAnd(where)

	var total int
	if err := s.ev.QueryRowContext(ctx, `SELECT COUNT(*) FROM audit_logs`+clause, args...).Scan(&total); err != nil {
		return pageResult[auditLogDTO]{}, internal(err)
	}
	query := `SELECT id, user_id, action, COALESCE(entity_type, ''), entity_id, before_json, after_json, ip, request_id, created_at
	            FROM audit_logs` + clause + ` ORDER BY id DESC LIMIT ? OFFSET ?`
	args = append(args, size, (page-1)*size)

	rows, err := s.ev.QueryContext(ctx, query, args...)
	if err != nil {
		return pageResult[auditLogDTO]{}, internal(err)
	}
	defer func() { _ = rows.Close() }()

	items := make([]auditLogDTO, 0)
	for rows.Next() {
		var (
			a         auditLogDTO
			uid, eid  sql.NullInt64
			before    sql.NullString
			after     sql.NullString
			ip, reqID sql.NullString
		)
		if err := rows.Scan(&a.ID, &uid, &a.Action, &a.EntityType, &eid, &before, &after, &ip, &reqID, &a.CreatedAt); err != nil {
			return pageResult[auditLogDTO]{}, internal(err)
		}
		a.UserID = i64Ptr(uid)
		a.EntityID = i64Ptr(eid)
		a.BeforeJSON = strPtr(before)
		a.AfterJSON = strPtr(after)
		a.IP = strPtr(ip)
		a.RequestID = strPtr(reqID)
		items = append(items, a)
	}
	if err := rows.Err(); err != nil {
		return pageResult[auditLogDTO]{}, internal(err)
	}
	return pageResult[auditLogDTO]{Items: items, Total: total, Page: page, Size: size}, nil
}

// ---------- backup ----------

// backup 用 VACUUM INTO 生成一致性快照（见 devdocs/08 第 6 节）。
func (s *server) backup(ctx context.Context) (backupResultDTO, error) {
	if strings.TrimSpace(s.dataDir) == "" {
		return backupResultDTO{}, internal(errors.New("未配置数据目录"))
	}
	dir := filepath.Join(s.dataDir, "backups")
	if err := os.MkdirAll(dir, 0o755); err != nil {
		return backupResultDTO{}, internal(err)
	}
	now := time.Now()
	stamp := now.Format("20060102-150405")
	path := filepath.Join(dir, fmt.Sprintf("system-%s.db", stamp))
	if _, err := s.sys.ExecContext(ctx, `VACUUM INTO ?`, path); err != nil {
		return backupResultDTO{}, internal(err)
	}
	eventPath := filepath.Join(dir, fmt.Sprintf("event-%s.db", stamp))
	if _, err := s.ev.ExecContext(ctx, `VACUUM INTO ?`, eventPath); err != nil {
		return backupResultDTO{}, internal(err)
	}
	s.audit(ctx, "system.backup", "backup", 0, nil, map[string]any{"path": path})
	return backupResultDTO{Path: path, CreatedAt: now.UTC().Format(time.RFC3339)}, nil
}