Scoreboard/server/internal/rules/apply.go

package rules

import (
	"database/sql"
	"fmt"
	"sort"
	"strings"
)

// ApplyResult 汇总一次导入实际落库的行数。
type ApplyResult struct {
	ProfilesWritten int      `json:"profilesWritten"`
	ProfilesDeleted int      `json:"profilesDeleted"`
	ChannelsWritten int      `json:"channelsWritten"`
	EventsUpdated   int      `json:"eventsUpdated"`
	SettingsWritten int      `json:"settingsWritten"`
	EventsSkipped   []string `json:"eventsSkipped,omitempty"`
}

// Apply 把差异预览落地。规则包语义是「全量覆盖」，因此按 Next 的目标状态同步，
// 而不是逐条套用 diff 列表——这样重复导入同一份规则包是幂等的。
// 只填了 Next 的变更集（例如确认导入时重新 Parse 上传内容）同样可以调用，等价于强制全量导入。
//
// 落地顺序：模板 → 通道 → 删除无主模板 → 项目开关 → 赛事设置。
// 通道先改完再删模板，避免「模板被换掉」时误判引用。
// Apply 不负责重算积分：分值一变，调用方必须全量重算（devdocs 02 §7.3）。
func Apply(db *sql.DB, cs *ChangeSet) (*ApplyResult, error) {
	if cs == nil || cs.Next == nil {
		return nil, ErrNilChangeSet
	}
	next := cs.Next.Canonical()
	if err := next.Validate(); err != nil {
		return nil, err
	}

	cur, err := Load(db)
	if err != nil {
		return nil, err
	}
	targets, unknown, err := resolveTargets(cur, &next)
	if err != nil {
		return nil, err
	}

	tx, err := db.Begin()
	if err != nil {
		return nil, fmt.Errorf("开启事务: %w", err)
	}
	defer func() { _ = tx.Rollback() }()

	res := &ApplyResult{EventsSkipped: unknown}

	// 1. 模板全量 upsert，并建立「编码 → id」映射供通道引用。
	profileIDs := map[string]int64{}
	for _, prof := range next.Profiles {
		id, err := upsertProfile(tx, prof)
		if err != nil {
			return nil, err
		}
		profileIDs[prof.Code] = id
		res.ProfilesWritten++
	}

	// 2. 通道：只覆盖规则包明确提到的项目。
	eventIDs := map[string]int64{}
	for _, ev := range cur.Events {
		eventIDs[ev.Code] = ev.ID
	}
	codes := make([]string, 0, len(targets))
	for code := range targets {
		codes = append(codes, code)
	}
	sort.Strings(codes)

	for _, code := range codes {
		eventID, ok := eventIDs[code]
		if !ok {
			continue
		}
		if _, err := tx.Exec(`DELETE FROM event_score_channels WHERE event_id = ?`, eventID); err != nil {
			return nil, fmt.Errorf("清理项目 %s 的计分通道: %w", code, err)
		}
		for i, ch := range targets[code] {
			profileID, ok := profileIDs[ch.Profile]
			if !ok {
				return nil, fmt.Errorf("项目 %s 的通道引用了不存在的模板 %q", code, ch.Profile)
			}
			if _, err := tx.Exec(`INSERT INTO event_score_channels (event_id, scope, basis, profile_id, sort_order, count_to_team)
				VALUES (?, ?, ?, ?, ?, ?)`, eventID, string(ch.Scope), string(ch.Basis), profileID, i,
				boolToInt(ch.CountsToTeam())); err != nil {
				return nil, fmt.Errorf("写入项目 %s 的计分通道: %w", code, err)
			}
		}
		res.ChannelsWritten++
	}

	// 3. 删除目标规则包里已没有的模板；仍被引用就报错，绝不静默拆掉别人的配置。
	for _, prof := range cur.Pack.Profiles {
		if _, keep := profileIDs[prof.Code]; keep {
			continue
		}
		if err := deleteProfile(tx, prof.Code); err != nil {
			return nil, err
		}
		res.ProfilesDeleted++
	}

	// 4. 项目开关：只改 override 里显式给出的字段。
	for _, ov := range next.EventOverrides {
		eventID, ok := eventIDs[ov.EventCode]
		if !ok || (ov.Scored == nil && ov.Multiplier == nil) {
			continue
		}
		scored, err := currentScored(tx, eventID)
		if err != nil {
			return nil, err
		}
		if ov.Scored != nil {
			scored = *ov.Scored
		}
		multiplier, err := currentMultiplier(tx, eventID)
		if err != nil {
			return nil, err
		}
		if ov.Multiplier != nil {
			multiplier = *ov.Multiplier
		}
		if _, err := tx.Exec(`UPDATE events SET scored = ?, multiplier = ? WHERE id = ?`,
			boolToInt(scored), multiplier, eventID); err != nil {
			return nil, fmt.Errorf("更新项目 %s: %w", ov.EventCode, err)
		}
		res.EventsUpdated++
	}

	// 5. 赛事设置。
	settings := settingsFromPack(&next)
	for _, key := range settingsKeys() {
		if _, err := tx.Exec(`INSERT INTO settings (key, value, updated_at) VALUES (?, ?, datetime('now'))
			ON CONFLICT(key) DO UPDATE SET value = excluded.value, updated_at = datetime('now')`,
			key, settings[key]); err != nil {
			return nil, fmt.Errorf("写入赛事设置 %s: %w", key, err)
		}
		res.SettingsWritten++
	}

	if err := tx.Commit(); err != nil {
		return nil, fmt.Errorf("提交导入事务: %w", err)
	}
	return res, nil
}

func upsertProfile(tx *sql.Tx, prof Profile) (int64, error) {
	if _, err := tx.Exec(`INSERT INTO scoring_profiles
			(code, name, tie_mode, record_bonus_mode, award_ranks, last_place_zero)
			VALUES (?, ?, ?, ?, ?, ?)
		ON CONFLICT(code) DO UPDATE SET
			name = excluded.name,
			tie_mode = excluded.tie_mode,
			record_bonus_mode = excluded.record_bonus_mode,
			award_ranks = excluded.award_ranks,
			last_place_zero = excluded.last_place_zero,
			updated_at = datetime('now')`,
		prof.Code, prof.Name, string(prof.TieMode), string(prof.RecordBonusMode), prof.AwardRanks, boolToInt(prof.LastPlaceZero)); err != nil {
		return 0, fmt.Errorf("写入积分模板 %s: %w", prof.Code, err)
	}

	var id int64
	if err := tx.QueryRow(`SELECT id FROM scoring_profiles WHERE code = ?`, prof.Code).Scan(&id); err != nil {
		return 0, fmt.Errorf("读取积分模板 %s 的 id: %w", prof.Code, err)
	}
	if _, err := tx.Exec(`DELETE FROM scoring_profile_rules WHERE profile_id = ?`, id); err != nil {
		return 0, fmt.Errorf("清理积分模板 %s 的明细: %w", prof.Code, err)
	}
	for _, r := range prof.Rules {
		if _, err := tx.Exec(`INSERT INTO scoring_profile_rules (profile_id, rank, points) VALUES (?, ?, ?)`,
			id, r.Rank, r.Points); err != nil {
			return 0, fmt.Errorf("写入积分模板 %s 的名次 %d: %w", prof.Code, r.Rank, err)
		}
	}
	return id, nil
}

func deleteProfile(tx *sql.Tx, code string) error {
	var id int64
	if err := tx.QueryRow(`SELECT id FROM scoring_profiles WHERE code = ?`, code).Scan(&id); err != nil {
		if err == sql.ErrNoRows {
			return nil
		}
		return fmt.Errorf("读取积分模板 %s: %w", code, err)
	}

	refs, err := profileRefs(tx, id)
	if err != nil {
		return err
	}
	if len(refs) > 0 {
		return fmt.Errorf("%w: 模板 %s 仍被 %s 引用", ErrProfileInUse, code, strings.Join(refs, "、"))
	}

	if _, err := tx.Exec(`DELETE FROM scoring_profile_rules WHERE profile_id = ?`, id); err != nil {
		return fmt.Errorf("删除积分模板 %s 的明细: %w", code, err)
	}
	if _, err := tx.Exec(`DELETE FROM scoring_profiles WHERE id = ?`, id); err != nil {
		return fmt.Errorf("删除积分模板 %s: %w", code, err)
	}
	return nil
}

func profileRefs(tx *sql.Tx, profileID int64) ([]string, error) {
	var refs []string
	var channels int
	if err := tx.QueryRow(`SELECT COUNT(*) FROM event_score_channels WHERE profile_id = ?`, profileID).Scan(&channels); err != nil {
		return nil, fmt.Errorf("统计模板引用: %w", err)
	}
	if channels > 0 {
		refs = append(refs, fmt.Sprintf("%d 个计分通道", channels))
	}
	var sports int
	if err := tx.QueryRow(`SELECT COUNT(*) FROM sports WHERE default_profile_id = ?`, profileID).Scan(&sports); err != nil {
		return nil, fmt.Errorf("统计模板引用: %w", err)
	}
	if sports > 0 {
		refs = append(refs, fmt.Sprintf("%d 个大项的默认模板", sports))
	}
	return refs, nil
}

func currentScored(tx *sql.Tx, eventID int64) (bool, error) {
	var v int
	if err := tx.QueryRow(`SELECT scored FROM events WHERE id = ?`, eventID).Scan(&v); err != nil {
		return false, fmt.Errorf("读取项目计分开关: %w", err)
	}
	return v != 0, nil
}

func currentMultiplier(tx *sql.Tx, eventID int64) (float64, error) {
	var v float64
	if err := tx.QueryRow(`SELECT multiplier FROM events WHERE id = ?`, eventID).Scan(&v); err != nil {
		return 0, fmt.Errorf("读取项目权重: %w", err)
	}
	return v, nil
}

func boolToInt(v bool) int {
	if v {
		return 1
	}
	return 0
}