// Package approval 提供自定义审批流的运行时引擎。
//
// 设计说明：
//   - 配置侧（flow/node）与运行时（instance/task）分离：配置由租户/平台编辑，
//     运行时实例创建后不可编辑，节点信息以任务表快照为准，避免改配置影响在途单据；
//   - 租户侧与平台侧共用本引擎，通过 scope 区分数据来源：
//     租户侧审批人取租户用户/租户角色/组织主管/职位，
//     平台侧审批人取平台用户/平台角色（平台账号不归属租户）；
//   - 当期只实现顺序链流转（按 sort 升序），prev_keys / next_keys / condition_expr
//     为条件分支预留，后续扩展无需改表。
package approval

import (
	"encoding/json"
	"fmt"
	"sort"
	"strconv"
	"strings"
	"time"

	"server/models"

	"github.com/beego/beego/v2/client/orm"
)

// Approver 展开后的单个审批人
type Approver struct {
	ID   uint64
	Name string
}

// SubmitInput 提交审批入参
type SubmitInput struct {
	Scope      int8   // 1租户侧 2平台侧
	Tid        uint64 // 租户ID（租户侧=本租户）
	BizTid     uint64 // 业务来源租户（平台侧必填）
	BizType    string
	FlowCode   string // 按审批流编号发起（优先于 BizType 默认流）
	BizID      uint64
	BizTitle   string
	SubmitUID  uint64 // 发起人ID（租户侧为 uid，平台侧为 AdminUser.id）
	SubmitName string
	DeptID     uint64                 // 发起人部门
	FlowID     uint64                 // 指定流程；0 表示按 FlowCode/BizType 取流程
	FormData   map[string]interface{} // 发起表单数据，供条件分支求值
}

// Node 流程节点（两侧统一结构，承载图连线）
type Node struct {
	ID            uint64
	NodeKey       string
	NodeName      string
	NodeType      int8
	ApproverType  int8
	ApproverIDs   string
	MultiMode     int8
	AllowReturn   int8
	TimeoutHours  int
	Sort          int
	PrevKeys      string // 前置节点 node_key 列表(逗号分隔)
	NextKeys      string // 后继节点 node_key 列表(逗号分隔)
	ConditionExpr string // 作为条件网关某出边目标时的进入条件
}

// Flow 流程定义（两侧统一结构，含图索引）
type Flow struct {
	ID        uint64
	BizType   string
	FlowName  string
	IsDefault int8
	Status    int8
	Nodes     []Node
	ByKey     map[string]*Node
	StartKey  string
}

// ErrNoFlow 表示未找到可用流程
type ErrNoFlow struct {
	BizType string
}

func (e *ErrNoFlow) Error() string {
	return "未找到适用于该单据的审批流程"
}

// ErrNoApprover 表示节点未能解析出任何审批人
type ErrNoApprover struct {
	NodeName string
	NodeKey  string
}

func (e *ErrNoApprover) Error() string {
	return fmt.Sprintf("节点「%s」未解析到有效审批人，请检查审批人配置", e.NodeName)
}

// ============================ 配置读取 ============================

// tenantFlows 查询租户侧流程列表（可按 biz_type 过滤）
func tenantFlows(tid uint64, bizType string) ([]models.TenantApprovalFlow, error) {
	qs := models.Orm.QueryTable(new(models.TenantApprovalFlow)).
		Filter("tid", tid).
		Filter("is_deleted", 0)
	if bizType != "" {
		qs = qs.Filter("biz_type", bizType)
	}
	var rows []models.TenantApprovalFlow
	_, err := qs.OrderBy("-id").All(&rows)
	return rows, err
}

// tenantFlowNodes 查询租户侧流程的全部节点（含开始/审批/条件/结束，携带图连线）
func tenantFlowNodes(flowID uint64) ([]Node, error) {
	var rows []models.TenantApprovalNode
	if _, err := models.Orm.QueryTable(new(models.TenantApprovalNode)).
		Filter("flow_id", flowID).
		Filter("is_deleted", 0).
		OrderBy("sort", "id").
		All(&rows); err != nil && err != orm.ErrNoRows {
		return nil, err
	}
	out := make([]Node, 0, len(rows))
	for _, r := range rows {
		out = append(out, Node{
			ID:            r.ID,
			NodeKey:       r.NodeKey,
			NodeName:      r.NodeName,
			NodeType:      r.NodeType,
			ApproverType:  r.ApproverType,
			ApproverIDs:   r.ApproverIDs,
			MultiMode:     r.MultiMode,
			AllowReturn:   r.AllowReturn,
			TimeoutHours:  r.TimeoutHours,
			Sort:          r.Sort,
			PrevKeys:      r.PrevKeys,
			NextKeys:      r.NextKeys,
			ConditionExpr: r.ConditionExpr,
		})
	}
	return out, nil
}

// platformFlows 查询平台侧流程列表
func platformFlows(bizType string) ([]models.PlatformApprovalFlow, error) {
	qs := models.Orm.QueryTable(new(models.PlatformApprovalFlow)).Filter("is_deleted", 0)
	if bizType != "" {
		qs = qs.Filter("biz_type", bizType)
	}
	var rows []models.PlatformApprovalFlow
	_, err := qs.OrderBy("-id").All(&rows)
	return rows, err
}

// platformFlowNodes 查询平台侧流程的全部节点（含图连线）
func platformFlowNodes(flowID uint64) ([]Node, error) {
	var rows []models.PlatformApprovalNode
	if _, err := models.Orm.QueryTable(new(models.PlatformApprovalNode)).
		Filter("flow_id", flowID).
		Filter("is_deleted", 0).
		OrderBy("sort", "id").
		All(&rows); err != nil && err != orm.ErrNoRows {
		return nil, err
	}
	out := make([]Node, 0, len(rows))
	for _, r := range rows {
		out = append(out, Node{
			ID:            r.ID,
			NodeKey:       r.NodeKey,
			NodeName:      r.NodeName,
			NodeType:      r.NodeType,
			ApproverType:  r.ApproverType,
			ApproverIDs:   r.ApproverIDs,
			MultiMode:     r.MultiMode,
			AllowReturn:   r.AllowReturn,
			TimeoutHours:  r.TimeoutHours,
			Sort:          r.Sort,
			PrevKeys:      r.PrevKeys,
			NextKeys:      r.NextKeys,
			ConditionExpr: r.ConditionExpr,
		})
	}
	return out, nil
}

// LoadFlow 按 scope 加载流程（flowID=0 时取该单据类型的默认启用流程）
func LoadFlow(scope int8, tid uint64, bizType string, flowID uint64) (*Flow, error) {
	if scope == models.ApprovalScopePlatform {
		var candidates []models.PlatformApprovalFlow
		var err error
		if flowID > 0 {
			var one models.PlatformApprovalFlow
			if e := models.Orm.QueryTable(new(models.PlatformApprovalFlow)).
				Filter("id", flowID).Filter("is_deleted", 0).One(&one); e != nil {
				return nil, &ErrNoFlow{BizType: bizType}
			}
			candidates = []models.PlatformApprovalFlow{one}
		} else {
			candidates, err = platformFlows(bizType)
		}
		if err != nil || len(candidates) == 0 {
			return nil, &ErrNoFlow{BizType: bizType}
		}
		return buildPlatformFlow(pickPlatformFlow(candidates))
	}

	var candidates []models.TenantApprovalFlow
	var err error
	if flowID > 0 {
		var one models.TenantApprovalFlow
		if e := models.Orm.QueryTable(new(models.TenantApprovalFlow)).
			Filter("id", flowID).Filter("tid", tid).Filter("is_deleted", 0).One(&one); e != nil {
			return nil, &ErrNoFlow{BizType: bizType}
		}
		candidates = []models.TenantApprovalFlow{one}
	} else {
		candidates, err = tenantFlows(tid, bizType)
	}
	if err != nil || len(candidates) == 0 {
		return nil, &ErrNoFlow{BizType: bizType}
	}
	return buildTenantFlow(pickTenantFlow(candidates))
}

// LoadFlowByCode 按审批流编号加载流程（供各程序按编号发起）
func LoadFlowByCode(scope int8, tid uint64, code string) (*Flow, error) {
	code = strings.TrimSpace(code)
	if code == "" {
		return nil, &ErrNoFlow{BizType: code}
	}
	if scope == models.ApprovalScopePlatform {
		var one models.PlatformApprovalFlow
		if err := models.Orm.QueryTable(new(models.PlatformApprovalFlow)).
			Filter("flow_code", code).Filter("is_deleted", 0).One(&one); err != nil {
			return nil, &ErrNoFlow{BizType: code}
		}
		return buildPlatformFlow(one)
	}
	var one models.TenantApprovalFlow
	if err := models.Orm.QueryTable(new(models.TenantApprovalFlow)).
		Filter("flow_code", code).Filter("tid", tid).Filter("is_deleted", 0).One(&one); err != nil {
		return nil, &ErrNoFlow{BizType: code}
	}
	return buildTenantFlow(one)
}

// buildTenantFlow / buildPlatformFlow 装配租户/平台流程（含图索引）
func buildTenantFlow(f models.TenantApprovalFlow) (*Flow, error) {
	nodes, err := tenantFlowNodes(f.ID)
	if err != nil {
		return nil, err
	}
	if len(nodes) == 0 {
		return nil, &ErrNoFlow{BizType: f.BizType}
	}
	return assembleFlow(f.ID, f.BizType, f.FlowName, nodes), nil
}

func buildPlatformFlow(f models.PlatformApprovalFlow) (*Flow, error) {
	nodes, err := platformFlowNodes(f.ID)
	if err != nil {
		return nil, err
	}
	if len(nodes) == 0 {
		return nil, &ErrNoFlow{BizType: f.BizType}
	}
	return assembleFlow(f.ID, f.BizType, f.FlowName, nodes), nil
}

// assembleFlow 构建图索引 ByKey 与入口 StartKey（优先开始类型节点，否则取无前置节点）
func assembleFlow(id uint64, bizType, name string, nodes []Node) *Flow {
	f := &Flow{ID: id, BizType: bizType, FlowName: name, Nodes: nodes, ByKey: make(map[string]*Node, len(nodes))}
	for i := range f.Nodes {
		f.ByKey[f.Nodes[i].NodeKey] = &f.Nodes[i]
	}
	for i := range f.Nodes {
		if f.Nodes[i].NodeType == models.ApprovalNodeStart {
			f.StartKey = f.Nodes[i].NodeKey
			break
		}
	}
	if f.StartKey == "" {
		for i := range f.Nodes {
			if strings.TrimSpace(f.Nodes[i].PrevKeys) == "" {
				f.StartKey = f.Nodes[i].NodeKey
				break
			}
		}
	}
	if f.StartKey == "" && len(f.Nodes) > 0 {
		f.StartKey = f.Nodes[0].NodeKey
	}
	return f
}

// pickTenantFlow 在候选流程中择优：优先「默认 + 启用」，其次任一启用，最后首条。
func pickTenantFlow(rows []models.TenantApprovalFlow) models.TenantApprovalFlow {
	for _, r := range rows {
		if r.IsDefault == 1 && r.Status == 1 {
			return r
		}
	}
	for _, r := range rows {
		if r.Status == 1 {
			return r
		}
	}
	return rows[0]
}

// pickPlatformFlow 同 pickTenantFlow，平台侧口径。
func pickPlatformFlow(rows []models.PlatformApprovalFlow) models.PlatformApprovalFlow {
	for _, r := range rows {
		if r.IsDefault == 1 && r.Status == 1 {
			return r
		}
	}
	for _, r := range rows {
		if r.Status == 1 {
			return r
		}
	}
	return rows[0]
}

// ============================ 审批人解析 ============================

// parseIDs 解析逗号分隔的 ID 列表
func parseIDs(raw string) []uint64 {
	out := make([]uint64, 0, 4)
	for _, part := range strings.Split(raw, ",") {
		part = strings.TrimSpace(part)
		if part == "" {
			continue
		}
		if v, err := strconv.ParseUint(part, 10, 64); err == nil && v > 0 {
			out = append(out, v)
		}
	}
	return out
}

// resolveApprovers 按 scope 解析节点审批人。
// 发起人相关类型需要 SubmitInput 上下文。
func resolveApprovers(scope int8, node Node, in SubmitInput) ([]Approver, error) {
	ids := parseIDs(node.ApproverIDs)

	switch node.ApproverType {
	case models.ApprovalApproverUser:
		if scope == models.ApprovalScopePlatform {
			return platformUsers(ids), nil
		}
		return tenantUsers(uint64(in.Tid), ids), nil

	case models.ApprovalApproverRole:
		if scope == models.ApprovalScopePlatform {
			return platformRoleUsers(ids), nil
		}
		return tenantRoleUsers(uint64(in.Tid), ids), nil

	case models.ApprovalApproverInitiator:
		if in.SubmitUID == 0 {
			return nil, nil
		}
		return []Approver{{ID: in.SubmitUID, Name: in.SubmitName}}, nil

	case models.ApprovalApproverOrgLeader:
		// 指定部门的负责人；approver_ids 存组织ID
		if len(ids) == 0 {
			return nil, nil
		}
		return orgLeaders(in.Tid, ids), nil

	case models.ApprovalApproverInitLeader:
		// 发起人所在部门负责人
		if in.DeptID == 0 {
			return nil, nil
		}
		return orgLeaders(in.Tid, []uint64{in.DeptID}), nil

	case models.ApprovalApproverPosition:
		// 指定职位（approver_ids 存 BackendPosition.id），按员工职位名匹配
		if len(ids) == 0 {
			return nil, nil
		}
		return positionUsers(uint64(in.Tid), ids), nil
	}
	return nil, nil
}

// resolveNotifyTargets 解析通知节点的通知对象（支持多类型）。
// approver_ids 兼容两种存储格式：
//  1. 旧格式：纯数字 CSV —— 单类型，配合 node.ApproverType（历史数据）；
//  2. 多选格式："类型:ID" CSV（如 "1:52,5:0"）—— 类型取值同 approver_type，
//     自动定位类型（5发起人本人 / 6发起人主管）无需指定对象，ID 占位 0。
// 各类型的解析结果按 ID 去重合并。
func resolveNotifyTargets(scope int8, node Node, in SubmitInput) ([]Approver, error) {
	if !strings.Contains(node.ApproverIDs, ":") {
		return resolveApprovers(scope, node, in)
	}
	typeOrder := make([]int8, 0, 4)
	idsByType := make(map[int8][]uint64)
	for _, part := range strings.Split(node.ApproverIDs, ",") {
		part = strings.TrimSpace(part)
		if part == "" {
			continue
		}
		kv := strings.SplitN(part, ":", 2)
		t, err := strconv.Atoi(strings.TrimSpace(kv[0]))
		if err != nil || t < int(models.ApprovalApproverUser) || t > int(models.ApprovalApproverInitLeader) {
			continue
		}
		at := int8(t)
		if _, ok := idsByType[at]; !ok {
			typeOrder = append(typeOrder, at)
		}
		if len(kv) == 2 {
			if id, err := strconv.ParseUint(strings.TrimSpace(kv[1]), 10, 64); err == nil && id > 0 {
				idsByType[at] = append(idsByType[at], id)
			}
		}
	}
	merged := make([]Approver, 0, 8)
	for _, t := range typeOrder {
		sub := Node{ApproverType: t, ApproverIDs: joinApproverIDs(idsByType[t])}
		approvers, err := resolveApprovers(scope, sub, in)
		if err != nil {
			return nil, err
		}
		merged = append(merged, approvers...)
	}
	return dedupeApprovers(merged), nil
}

// joinApproverIDs 把 ID 列表拼成 CSV（与 parseIDs 互逆）
func joinApproverIDs(ids []uint64) string {
	parts := make([]string, 0, len(ids))
	for _, id := range ids {
		if id > 0 {
			parts = append(parts, strconv.FormatUint(id, 10))
		}
	}
	return strings.Join(parts, ",")
}

// tenantUsers 按 uid 取租户用户
func tenantUsers(tid uint64, uids []uint64) []Approver {
	if len(uids) == 0 {
		return nil
	}
	var rows []models.SystemTenantUser
	if _, err := models.Orm.QueryTable(new(models.SystemTenantUser)).
		Filter("tid", tid).
		Filter("uid__in", uids).
		Filter("delete_time__isnull", true).
		All(&rows); err != nil {
		return nil
	}
	out := make([]Approver, 0, len(rows))
	for _, r := range rows {
		out = append(out, Approver{ID: r.Uid, Name: firstNonEmptyPtr(r.Name, r.Account)})
	}
	return out
}

// tenantRoleUsers 按租户角色取全部成员
func tenantRoleUsers(tid uint64, roleIDs []uint64) []Approver {
	if len(roleIDs) == 0 {
		return nil
	}
	var rows []models.SystemTenantUser
	if _, err := models.Orm.QueryTable(new(models.SystemTenantUser)).
		Filter("tid", tid).
		Filter("group_id__in", roleIDs).
		Filter("delete_time__isnull", true).
		All(&rows); err != nil {
		return nil
	}
	out := make([]Approver, 0, len(rows))
	for _, r := range rows {
		out = append(out, Approver{ID: r.Uid, Name: firstNonEmptyPtr(r.Name, r.Account)})
	}
	return out
}

// platformUsers 按 id 取平台用户
func platformUsers(ids []uint64) []Approver {
	if len(ids) == 0 {
		return nil
	}
	var rows []models.AdminUser
	if _, err := models.Orm.QueryTable(new(models.AdminUser)).
		Filter("id__in", ids).
		Filter("delete_time__isnull", true).
		All(&rows); err != nil {
		return nil
	}
	out := make([]Approver, 0, len(rows))
	for _, r := range rows {
		out = append(out, Approver{ID: r.ID, Name: approverName(r.Name, r.Account)})
	}
	return out
}

// platformRoleUsers 按平台角色取全部成员（AdminRole cid=1 为平台角色）
func platformRoleUsers(roleIDs []uint64) []Approver {
	if len(roleIDs) == 0 {
		return nil
	}
	var users []models.AdminUser
	if _, err := models.Orm.QueryTable(new(models.AdminUser)).
		Filter("role_id__in", roleIDs).
		Filter("delete_time__isnull", true).
		All(&users); err != nil {
		return nil
	}
	out := make([]Approver, 0, len(users))
	for _, r := range users {
		out = append(out, Approver{ID: r.ID, Name: approverName(r.Name, r.Account)})
	}
	return out
}

// orgLeaders 取组织负责人
func orgLeaders(tid uint64, orgIDs []uint64) []Approver {
	var orgs []models.BackendOrganization
	if _, err := models.Orm.QueryTable(new(models.BackendOrganization)).
		Filter("id__in", orgIDs).
		Filter("delete_time__isnull", true).
		All(&orgs); err != nil {
		return nil
	}
	// 负责人可能指向员工ID，也可能指向租户用户uid，这里统一再查一次租户用户
	leaderIDs := make([]uint64, 0, len(orgs))
	for _, o := range orgs {
		if o.LeaderID != nil && *o.LeaderID > 0 {
			leaderIDs = append(leaderIDs, *o.LeaderID)
		}
	}
	if len(leaderIDs) == 0 {
		return nil
	}
	return tenantUsers(tid, leaderIDs)
}

// positionUsers 按职位取员工：职位ID → 职位名 → 员工(职位字段) → 登录账号 → 租户用户
func positionUsers(tid uint64, positionIDs []uint64) []Approver {
	var positions []models.BackendPosition
	if _, err := models.Orm.QueryTable(new(models.BackendPosition)).
		Filter("id__in", positionIDs).
		Filter("delete_time__isnull", true).
		All(&positions); err != nil {
		return nil
	}
	names := make([]string, 0, len(positions))
	for _, p := range positions {
		if strings.TrimSpace(p.PositionName) != "" {
			names = append(names, p.PositionName)
		}
	}
	if len(names) == 0 {
		return nil
	}
	var employees []models.BackendEmployee
	if _, err := models.Orm.QueryTable(new(models.BackendEmployee)).
		Filter("tid", tid).
		Filter("position__in", names).
		Filter("delete_time__isnull", true).
		All(&employees); err != nil {
		return nil
	}
	accounts := make([]string, 0, len(employees))
	for _, e := range employees {
		if strings.TrimSpace(e.Account) != "" {
			accounts = append(accounts, e.Account)
		}
	}
	if len(accounts) == 0 {
		return nil
	}
	var users []models.SystemTenantUser
	if _, err := models.Orm.QueryTable(new(models.SystemTenantUser)).
		Filter("tid", tid).
		Filter("account__in", accounts).
		Filter("delete_time__isnull", true).
		All(&users); err != nil {
		return nil
	}
	out := make([]Approver, 0, len(users))
	for _, u := range users {
		out = append(out, Approver{ID: u.Uid, Name: firstNonEmptyPtr(u.Name, u.Account)})
	}
	return out
}

// approverName 优先取姓名字段，回退到账号（平台侧 Account 为普通字符串）
func approverName(name *string, account string) string {
	if s := firstNonEmptyPtr(name); s != "" {
		return s
	}
	return strings.TrimSpace(account)
}

// firstNonEmptyPtr 取第一个非空字符串指针的值
func firstNonEmptyPtr(vals ...*string) string {
	for _, v := range vals {
		if v != nil && strings.TrimSpace(*v) != "" {
			return strings.TrimSpace(*v)
		}
	}
	return ""
}

// dedupeApprovers 去重并保持顺序
func dedupeApprovers(in []Approver) []Approver {
	seen := make(map[uint64]bool, len(in))
	out := make([]Approver, 0, len(in))
	for _, a := range in {
		if a.ID == 0 || seen[a.ID] {
			continue
		}
		seen[a.ID] = true
		out = append(out, a)
	}
	return out
}

// ============================ 运行时：发起前的可用流查询 ============================

// AvailableFlow 业务侧选择用的轻量结构
type AvailableFlow struct {
	FlowID   uint64 `json:"flow_id"`
	FlowCode string `json:"flow_code"`
	FlowName string `json:"flow_name"`
	BizType  string `json:"biz_type"`
}

// ListAvailableFlows 按 bizType + 用户部门 过滤“当前可用”审批流。
// 直接查询 flow 表中 biz_type 匹配且 status=1 未删除的流程。
// 租户侧额外按 apply_dept_ids 部门过滤。
// 平台侧（scope=2）忽略部门过滤（因平台 flow 无 apply_dept_ids）。
func ListAvailableFlows(scope int8, tid uint64, bizType string, userOrgID uint64) ([]AvailableFlow, error) {
	// 租户侧预计算一次当前用户组织的“祖先链”（含自身），选中上级部门或公司均命中
	var path []uint64
	if scope == models.ApprovalScopeTenant && userOrgID > 0 {
		path = buildOrgPath(tid, userOrgID)
	}
	out := make([]AvailableFlow, 0)
	if scope == models.ApprovalScopePlatform {
		var rows []models.PlatformApprovalFlow
		_, _ = models.Orm.QueryTable(new(models.PlatformApprovalFlow)).
			Filter("biz_type", bizType).Filter("is_deleted", 0).Filter("status", 1).
			OrderBy("id").All(&rows)
		for _, f := range rows {
			out = append(out, AvailableFlow{FlowID: f.ID, FlowCode: f.FlowCode, FlowName: f.FlowName, BizType: f.BizType})
		}
		return out, nil
	}
	var rows []models.TenantApprovalFlow
	_, _ = models.Orm.QueryTable(new(models.TenantApprovalFlow)).
		Filter("tid", tid).Filter("biz_type", bizType).Filter("is_deleted", 0).Filter("status", 1).
		OrderBy("id").All(&rows)
	for _, f := range rows {
		if !deptMatch(f.ApplyDeptIDs, path) {
			continue
		}
		out = append(out, AvailableFlow{FlowID: f.ID, FlowCode: f.FlowCode, FlowName: f.FlowName, BizType: f.BizType})
	}
	return out, nil
}

// deptMatch csv 空视为全公司通用；否则与 path (包含自身与祖先部门ID) 任一命中即命中。
func deptMatch(csv string, path []uint64) bool {
	csv = strings.TrimSpace(csv)
	if csv == "" {
		return true
	}
	if len(path) == 0 {
		return false
	}
	inPath := make(map[uint64]bool, len(path))
	for _, id := range path {
		inPath[id] = true
	}
	for _, part := range strings.Split(csv, ",") {
		if v, err := strconv.ParseUint(strings.TrimSpace(part), 10, 64); err == nil && inPath[v] {
			return true
		}
	}
	return false
}

// buildOrgPath 从当前部门沿 parent_id 向上追到根，返回含自身的 ID 链（环保护）
func buildOrgPath(tid, orgID uint64) []uint64 {
	if orgID == 0 {
		return nil
	}
	var all []models.BackendOrganization
	_, _ = models.Orm.QueryTable(new(models.BackendOrganization)).
		Filter("tid", tid).Filter("delete_time__isnull", true).
		All(&all, "id", "parent_id")
	parent := make(map[uint64]uint64, len(all))
	for _, o := range all {
		parent[o.ID] = o.ParentID
	}
	out := []uint64{orgID}
	seen := map[uint64]bool{orgID: true}
	cur := orgID
	for {
		p, ok := parent[cur]
		if !ok || p == 0 || seen[p] {
			break
		}
		out = append(out, p)
		seen[p] = true
		cur = p
	}
	return out
}

// ============================ 运行时：提交 ============================

// Submit 提交单据进入审批，创建实例并按图展开首个可执行节点的任务。
// 优先按 FlowCode 命中流程；无审批节点时直接置为已通过。
func Submit(in SubmitInput) (uint64, error) {
	var (
		flow *Flow
		err  error
	)
	if strings.TrimSpace(in.FlowCode) != "" {
		flow, err = LoadFlowByCode(in.Scope, in.Tid, in.FlowCode)
	} else {
		flow, err = LoadFlow(in.Scope, in.Tid, in.BizType, in.FlowID)
	}
	if err != nil {
		return 0, err
	}

	now := time.Now()
	inst := models.ApprovalInstance{
		Scope:          in.Scope,
		Tid:            in.Tid,
		BizTid:         in.BizTid,
		FlowID:         flow.ID,
		BizType:        in.BizType,
		BizID:          in.BizID,
		BizTitle:       in.BizTitle,
		SubmitUserID:   in.SubmitUID,
		SubmitUserName: in.SubmitName,
		SubmitDeptID:   in.DeptID,
		SubmitTime:     &now,
		Status:         models.ApprovalInstanceRunning,
	}
	if len(in.FormData) > 0 {
		if b, e := json.Marshal(in.FormData); e == nil {
			s := string(b)
			inst.FormData = &s
		}
	}
	instID, err := models.Orm.Insert(&inst)
	if err != nil {
		return 0, err
	}

	start := flow.ByKey[flow.StartKey]
	hasApproval, firstApprovalName, firstApprovalKey := anyApprovalNode(flow)
	notifyFn := func(n *Node) { fireNotifyTasks(uint64(instID), in, n) }
	node, approvers := nextExecutable(flow, in.FormData, start, in, notifyFn)
	if node == nil {
		// 无可执行审批节点
		if hasApproval {
			// 配了审批节点但均无有效审批人：视为配置错误，回滚实例
			_, _ = models.Orm.QueryTable(new(models.ApprovalInstance)).
				Filter("id", instID).Update(orm.Params{"is_deleted": 1, "status": models.ApprovalInstanceCanceled})
			return 0, &ErrNoApprover{NodeName: firstApprovalName, NodeKey: firstApprovalKey}
		}
		finishInstance(uint64(instID), models.ApprovalInstanceApproved)
		return uint64(instID), nil
	}

	if err := createTasks(uint64(instID), in, *node, approvers); err != nil {
		return uint64(instID), err
	}
	if _, err := models.Orm.QueryTable(new(models.ApprovalInstance)).
		Filter("id", instID).Update(orm.Params{"current_node": node.NodeKey}); err != nil {
		return uint64(instID), err
	}
	return uint64(instID), nil
}

// anyApprovalNode 判断流程是否含审批节点，并返回首个审批节点信息
func anyApprovalNode(flow *Flow) (bool, string, string) {
	for i := range flow.Nodes {
		if flow.Nodes[i].NodeType == models.ApprovalNodeApproval {
			return true, flow.Nodes[i].NodeName, flow.Nodes[i].NodeKey
		}
	}
	return false, "", ""
}

// advanceFrom 从 cur 沿出边前进，遇条件网关求值选路，返回首个审批节点（nil 表示到终点）。
// onNotify 可选回调：当路径经过通知节点时触发，由调用方负责创建通知任务。
func advanceFrom(flow *Flow, formData map[string]interface{}, cur *Node, onNotify ...func(*Node)) *Node {
	visited := make(map[string]bool)
	node := pickNext(flow, formData, cur)
	for node != nil {
		if visited[node.NodeKey] {
			return nil // 环保护
		}
		visited[node.NodeKey] = true
		switch node.NodeType {
		case models.ApprovalNodeApproval:
			return node
		case models.ApprovalNodeEnd:
			return nil
		case models.ApprovalNodeNotify:
			if len(onNotify) > 0 && onNotify[0] != nil {
				onNotify[0](node)
			}
			node = pickNext(flow, formData, node)
		default: // start / condition：继续向后
			node = pickNext(flow, formData, node)
		}
	}
	return nil
}

// pickNext 取节点的下一个目标：普通节点取唯一出边；条件网关按各目标 condition_expr 互斥选路，空条件为默认分支
func pickNext(flow *Flow, formData map[string]interface{}, node *Node) *Node {
	if node == nil {
		return nil
	}
	outs := splitKeys(node.NextKeys)
	if len(outs) == 0 {
		return nil
	}
	if node.NodeType != models.ApprovalNodeCondition {
		return flow.ByKey[outs[0]]
	}
	var def *Node
	for _, k := range outs {
		t := flow.ByKey[k]
		if t == nil {
			continue
		}
		if strings.TrimSpace(t.ConditionExpr) == "" {
			if def == nil {
				def = t
			}
			continue
		}
		if evalCondition(t.ConditionExpr, formData) {
			return t
		}
	}
	return def
}

// nextExecutable 沿图找到下一个「有有效审批人」的审批节点；无人审批节点自动跳过
// nextExecutable 获取下一个可执行审批节点及其审批人（跳过通知节点并通过 onNotify 回调触发）
func nextExecutable(flow *Flow, formData map[string]interface{}, cur *Node, in SubmitInput, onNotify ...func(*Node)) (*Node, []Approver) {
	node := advanceFrom(flow, formData, cur, onNotify...)
	visited := make(map[string]bool)
	for node != nil {
		if visited[node.NodeKey] {
			break
		}
		visited[node.NodeKey] = true
		approvers, err := resolveApprovers(in.Scope, *node, in)
		if err == nil {
			approvers = dedupeApprovers(approvers)
			if len(approvers) > 0 {
				return node, approvers
			}
		}
		node = advanceFrom(flow, formData, node, onNotify...)
	}
	return nil, nil
}

// splitKeys 拆分逗号分隔的 node_key 列表
func splitKeys(raw string) []string {
	out := make([]string, 0, 4)
	for _, p := range strings.Split(raw, ",") {
		if s := strings.TrimSpace(p); s != "" {
			out = append(out, s)
		}
	}
	return out
}

// instanceFormData 解析实例的表单快照
func instanceFormData(inst *models.ApprovalInstance) map[string]interface{} {
	if inst == nil || inst.FormData == nil || strings.TrimSpace(*inst.FormData) == "" {
		return nil
	}
	m := make(map[string]interface{})
	if err := json.Unmarshal([]byte(*inst.FormData), &m); err != nil {
		return nil
	}
	return m
}

// submitFromInstance 由实例重建提交上下文（供推进时解析审批人）
func submitFromInstance(inst *models.ApprovalInstance, formData map[string]interface{}) SubmitInput {
	return SubmitInput{
		Scope:      inst.Scope,
		Tid:        inst.Tid,
		BizTid:     inst.BizTid,
		BizType:    inst.BizType,
		BizID:      inst.BizID,
		SubmitUID:  inst.SubmitUserID,
		SubmitName: inst.SubmitUserName,
		DeptID:     inst.SubmitDeptID,
		FormData:   formData,
	}
}

// createTasks 为一个节点展开审批任务
func createTasks(instID uint64, in SubmitInput, node Node, approvers []Approver) error {
	timeout := node.TimeoutHours
	if timeout <= 0 {
		timeout = 48
	}
	deadline := time.Now().Add(time.Duration(timeout) * time.Hour)
	multiMode := node.MultiMode
	if multiMode != models.ApprovalMultiAll {
		multiMode = models.ApprovalMultiAny
	}

	tasks := make([]models.ApprovalTask, 0, len(approvers))
	for _, a := range approvers {
		tasks = append(tasks, models.ApprovalTask{
			InstanceID:   instID,
			Scope:        in.Scope,
			Tid:          in.Tid,
			BizType:      in.BizType,
			BizID:        in.BizID,
			NodeKey:      node.NodeKey,
			NodeName:     node.NodeName,
			Sort:         node.Sort,
			ApproverID:   a.ID,
			ApproverName: a.Name,
			MultiMode:    multiMode,
			Status:       models.ApprovalTaskPending,
			Deadline:     &deadline,
		})
	}
	_, err := models.Orm.InsertMulti(len(tasks), tasks)
	return err
}

// fireNotifyTasks 为通知节点创建已读通知任务（不阻塞流程）
func fireNotifyTasks(instID uint64, in SubmitInput, notifyNode *Node) {
	recipients, _ := resolveNotifyTargets(in.Scope, *notifyNode, in)
	recipients = dedupeApprovers(recipients)
	if len(recipients) == 0 {
		return
	}
	now := time.Now()
	tasks := make([]models.ApprovalTask, 0, len(recipients))
	for _, r := range recipients {
		tasks = append(tasks, models.ApprovalTask{
			InstanceID:   instID,
			Scope:        in.Scope,
			Tid:          in.Tid,
			BizType:      in.BizType,
			BizID:        in.BizID,
			NodeKey:      notifyNode.NodeKey,
			NodeName:     notifyNode.NodeName,
			Sort:         notifyNode.Sort,
			ApproverID:   r.ID,
			ApproverName: r.Name,
			Status:       models.ApprovalTaskNotified,
			FinishTime:   &now,
		})
	}
	_, _ = models.Orm.InsertMulti(len(tasks), tasks)
}

// finishInstance 结束实例
func finishInstance(instID uint64, status int8) {
	now := time.Now()
	_, _ = models.Orm.QueryTable(new(models.ApprovalInstance)).
		Filter("id", instID).Update(orm.Params{
		"status":      status,
		"finish_time": now,
		"update_time": now,
	})
}

// ============================ 运行时：审批 ============================

// ApproveInput 审批入参
type ApproveInput struct {
	ApproverID uint64 // 审批人ID
	Pass       bool
	Comment    string
	// BizTid 平台侧操作时按业务租户校验/展示用（可留空）
	BizTid uint64
}

// ApproveResult 审批结果
type ApproveResult struct {
	InstanceID   uint64
	InstanceStat int8   // 实例新状态
	CurrentNode  string // 新当前节点（完成时为空）
	Finished     bool
	Message      string
}

// Approve 处理一条审批任务：按或签/会签推进到下一节点或结束实例。
func Approve(taskID uint64, in ApproveInput) (*ApproveResult, error) {
	var task models.ApprovalTask
	if err := models.Orm.QueryTable(new(models.ApprovalTask)).
		Filter("id", taskID).
		Filter("is_deleted", 0).
		One(&task); err != nil {
		return nil, err
	}
	if task.Status != models.ApprovalTaskPending {
		return nil, fmt.Errorf("该审批任务已处理")
	}
	if task.ApproverID != in.ApproverID {
		return nil, fmt.Errorf("您无权审批该任务")
	}

	var inst models.ApprovalInstance
	if err := models.Orm.QueryTable(new(models.ApprovalInstance)).
		Filter("id", task.InstanceID).
		Filter("is_deleted", 0).
		One(&inst); err != nil {
		return nil, err
	}
	if inst.Status != models.ApprovalInstanceRunning {
		return nil, fmt.Errorf("该单据当前状态不可审批")
	}

	now := time.Now()

	// 驳回：整个实例结束（与退回上一节点区分）
	if !in.Pass {
		_, err := models.Orm.QueryTable(new(models.ApprovalTask)).
			Filter("id", taskID).
			Update(orm.Params{
				"status":      models.ApprovalTaskRejected,
				"action":      models.ApprovalActionReject,
				"comment":     in.Comment,
				"finish_time": now,
				"update_time": now,
			})
		if err != nil {
			return nil, err
		}
		// 同节点其余待办一并置为跳过，避免留下永远待办的僵尸任务
		_, _ = models.Orm.QueryTable(new(models.ApprovalTask)).
			Filter("instance_id", task.InstanceID).
			Filter("node_key", task.NodeKey).
			Filter("status", models.ApprovalTaskPending).
			Filter("id__neq", taskID).
			Update(orm.Params{"status": models.ApprovalTaskSkipped, "update_time": now})

		finishInstance(task.InstanceID, models.ApprovalInstanceRejected)
		return &ApproveResult{
			InstanceID:   task.InstanceID,
			InstanceStat: models.ApprovalInstanceRejected,
			Finished:     true,
			Message:      "已驳回",
		}, nil
	}

	// 通过：更新当前任务
	_, err := models.Orm.QueryTable(new(models.ApprovalTask)).
		Filter("id", taskID).
		Update(orm.Params{
			"status":      models.ApprovalTaskApproved,
			"action":      models.ApprovalActionApprove,
			"comment":     in.Comment,
			"finish_time": now,
			"update_time": now,
		})
	if err != nil {
		return nil, err
	}

	// 或签：任一通过即推进，会签：需全部通过
	if task.MultiMode == models.ApprovalMultiAny {
		_, _ = models.Orm.QueryTable(new(models.ApprovalTask)).
			Filter("instance_id", task.InstanceID).
			Filter("node_key", task.NodeKey).
			Filter("status", models.ApprovalTaskPending).
			Update(orm.Params{"status": models.ApprovalTaskSkipped, "update_time": now})
	} else {
		remaining, _ := models.Orm.QueryTable(new(models.ApprovalTask)).
			Filter("instance_id", task.InstanceID).
			Filter("node_key", task.NodeKey).
			Filter("status", models.ApprovalTaskPending).
			Count()
		if remaining > 0 {
			return &ApproveResult{
				InstanceID:   task.InstanceID,
				InstanceStat: models.ApprovalInstanceRunning,
				CurrentNode:  task.NodeKey,
				Message:      fmt.Sprintf("已通过，等待其余 %d 位审批人", remaining),
			}, nil
		}
	}

	// 当前节点完成 → 推进下一节点
	return advance(task.InstanceID, task.NodeKey, in)
}

// advance 沿图推进到下一个可执行审批节点；无后继则结束实例
func advance(instID uint64, currentKey string, in ApproveInput) (*ApproveResult, error) {
	var inst models.ApprovalInstance
	if err := models.Orm.QueryTable(new(models.ApprovalInstance)).
		Filter("id", instID).Filter("is_deleted", 0).One(&inst); err != nil {
		return nil, err
	}

	flow, err := LoadFlow(inst.Scope, inst.Tid, inst.BizType, inst.FlowID)
	if err != nil {
		// 配置被删除时保守处理：按已完成结束
		finishInstance(instID, models.ApprovalInstanceApproved)
		return &ApproveResult{
			InstanceID:   instID,
			InstanceStat: models.ApprovalInstanceApproved,
			Finished:     true,
			Message:      "审批已通过",
		}, nil
	}

	formData := instanceFormData(&inst)
	si := submitFromInstance(&inst, formData)
	cur := flow.ByKey[currentKey]
	notifyFn := func(n *Node) { fireNotifyTasks(instID, si, n) }
	node, approvers := nextExecutable(flow, formData, cur, si, notifyFn)
	if node == nil {
		finishInstance(instID, models.ApprovalInstanceApproved)
		return &ApproveResult{
			InstanceID:   instID,
			InstanceStat: models.ApprovalInstanceApproved,
			Finished:     true,
			Message:      "审批已全部通过",
		}, nil
	}

	if err := createTasks(instID, si, *node, approvers); err != nil {
		return nil, err
	}
	now := time.Now()
	if _, err := models.Orm.QueryTable(new(models.ApprovalInstance)).
		Filter("id", instID).Update(orm.Params{"current_node": node.NodeKey, "update_time": now}); err != nil {
		return nil, err
	}
	return &ApproveResult{
		InstanceID:   instID,
		InstanceStat: models.ApprovalInstanceRunning,
		CurrentNode:  node.NodeKey,
		Message:      "已流转至「" + node.NodeName + "」",
	}, nil
}

// ============================ 条件表达式求值 ============================

// evalCondition 求值条件表达式：支持 == != > >= < <= 与 && ||（不含括号）。空表达式恒真。
func evalCondition(expr string, data map[string]interface{}) bool {
	expr = strings.TrimSpace(expr)
	if expr == "" {
		return true
	}
	for _, orPart := range strings.Split(expr, "||") {
		if evalAnd(orPart, data) {
			return true
		}
	}
	return false
}

func evalAnd(part string, data map[string]interface{}) bool {
	for _, atom := range strings.Split(part, "&&") {
		if !evalAtom(atom, data) {
			return false
		}
	}
	return true
}

var condOps = []string{">=", "<=", "!=", "==", ">", "<"}

func evalAtom(s string, data map[string]interface{}) bool {
	s = strings.TrimSpace(s)
	if s == "" {
		return true
	}
	for _, op := range condOps {
		idx := strings.Index(s, op)
		if idx <= 0 {
			continue
		}
		lv := resolveCondVal(strings.TrimSpace(s[:idx]), data)
		rv := parseCondLiteral(strings.TrimSpace(s[idx+len(op):]))
		return compareCond(lv, op, rv)
	}
	return false
}

// resolveCondVal 取字段值：支持点路径 a.b.c
func resolveCondVal(key string, data map[string]interface{}) interface{} {
	if data == nil {
		return nil
	}
	if v, ok := data[key]; ok {
		return v
	}
	var cur interface{} = data
	for _, seg := range strings.Split(key, ".") {
		m, ok := cur.(map[string]interface{})
		if !ok {
			return nil
		}
		v, ok := m[seg]
		if !ok {
			return nil
		}
		cur = v
	}
	return cur
}

func parseCondLiteral(raw string) interface{} {
	raw = strings.TrimSpace(raw)
	if len(raw) >= 2 {
		if (raw[0] == '"' || raw[0] == '\'') && raw[len(raw)-1] == raw[0] {
			return raw[1 : len(raw)-1]
		}
	}
	if n, err := strconv.ParseFloat(raw, 64); err == nil {
		return n
	}
	return raw
}

func toFloat(v interface{}) (float64, bool) {
	switch x := v.(type) {
	case float64:
		return x, true
	case float32:
		return float64(x), true
	case int:
		return float64(x), true
	case int64:
		return float64(x), true
	case uint64:
		return float64(x), true
	case json.Number:
		if f, e := x.Float64(); e == nil {
			return f, true
		}
	case string:
		if f, e := strconv.ParseFloat(strings.TrimSpace(x), 64); e == nil {
			return f, true
		}
	}
	return 0, false
}

func compareCond(l interface{}, op string, r interface{}) bool {
	lf, lok := toFloat(l)
	rf, rok := toFloat(r)
	if lok && rok {
		switch op {
		case ">":
			return lf > rf
		case "<":
			return lf < rf
		case ">=":
			return lf >= rf
		case "<=":
			return lf <= rf
		case "==":
			return lf == rf
		case "!=":
			return lf != rf
		}
	}
	ls := condString(l)
	rs := condString(r)
	switch op {
	case "==":
		return ls == rs
	case "!=":
		return ls != rs
	}
	return false
}

func condString(v interface{}) string {
	if v == nil {
		return ""
	}
	switch x := v.(type) {
	case string:
		return x
	case bool:
		if x {
			return "true"
		}
		return "false"
	case float64:
		return strconv.FormatFloat(x, 'f', -1, 64)
	default:
		return fmt.Sprintf("%v", v)
	}
}

// SortNodes 按 sort 升序排序（导出供配置端校验使用）
func SortNodes(nodes []Node) {
	sort.SliceStable(nodes, func(i, j int) bool { return nodes[i].Sort < nodes[j].Sort })
}