package docgov

import (
	"context"
	"encoding/json"
	"fmt"
	"strings"
	"sync"
	"time"

	"github.com/jackc/pgx/v5/pgxpool"
)

// ModificationCheckResult 智能体或人员发起修改前的认领与授权判定结果
type ModificationCheckResult struct {
	AllowedDirectEdit bool            `json:"allowed_direct_edit"` // 是否允许直接执行修改
	RequiresProposal  bool            `json:"requires_proposal"`   // 是否需要生成变更提案待编制人拍板
	AuthorClaimed     bool            `json:"author_claimed"`      // 编制人是否已认领
	PendingProposal   *ChangeProposal `json:"pending_proposal,omitempty"`
	Reason            string          `json:"reason"`
}

// GovernanceEngine 受控文档编制/审核/批准与认领治理引擎
type GovernanceEngine struct {
	pool *pgxpool.Pool
	sm   *StateMachine

	mu              sync.RWMutex
	memDocs         map[string]*DocumentRecord
	memComms        map[string][]*DocumentComment
	memProps        map[string]*ChangeProposal
	memAudits       map[string][]*AuditLog
	onApprovedHook  func(ctx context.Context, doc *DocumentRecord)
	onApprovedHooks []func(ctx context.Context, doc *DocumentRecord)
	OnFinalArtifact func(ctx context.Context, doc *DocumentRecord, markdown []byte, snapshotID int64)
}

// SetOnApprovedHook 注册文档终审批准时的回调钩子
func (e *GovernanceEngine) SetOnApprovedHook(hook func(ctx context.Context, doc *DocumentRecord)) {
	e.mu.Lock()
	defer e.mu.Unlock()
	e.onApprovedHook = hook
}

// AddOnApprovedHook 追加文档终审批准回调（与 SetOnApprovedHook 并存）。
func (e *GovernanceEngine) AddOnApprovedHook(hook func(ctx context.Context, doc *DocumentRecord)) {
	if hook == nil {
		return
	}
	e.mu.Lock()
	defer e.mu.Unlock()
	e.onApprovedHooks = append(e.onApprovedHooks, hook)
}

func (e *GovernanceEngine) runApprovedHooks(ctx context.Context, doc *DocumentRecord) {
	var primary func(context.Context, *DocumentRecord)
	var extra []func(context.Context, *DocumentRecord)
	e.mu.Lock()
	primary = e.onApprovedHook
	extra = append([]func(context.Context, *DocumentRecord){}, e.onApprovedHooks...)
	e.mu.Unlock()

	if primary != nil {
		primary(ctx, doc)
	}
	for _, hook := range extra {
		if hook != nil {
			hook(ctx, doc)
		}
	}
}

// NewGovernanceEngine 初始化治理引擎
func NewGovernanceEngine(pool *pgxpool.Pool) *GovernanceEngine {
	return &GovernanceEngine{
		pool:      pool,
		sm:        NewStateMachine(),
		memDocs:   make(map[string]*DocumentRecord),
		memComms:  make(map[string][]*DocumentComment),
		memProps:  make(map[string]*ChangeProposal),
		memAudits: make(map[string][]*AuditLog),
	}
}

// CreateOrGetDocument 创建或获取受控文档记录
func (e *GovernanceEngine) CreateOrGetDocument(
	ctx context.Context,
	docID string,
	projectID int64,
	taskKey string,
	title string,
	stage string,
	workDir string,
	authorID int64, authorName string,
	reviewerID int64, reviewerName string,
	approverID int64, approverName string,
) (*DocumentRecord, error) {
	e.mu.Lock()
	defer e.mu.Unlock()

	now := time.Now()
	// 先查内存
	if doc, exists := e.memDocs[docID]; exists {
		return doc, nil
	}

	// 内存没有查 DB
	if e.pool != nil {
		if docFromDB, err := e.loadDocumentFromDBLocked(ctx, docID); err == nil && docFromDB != nil {
			return docFromDB, nil
		}
	}

	doc := &DocumentRecord{
		DocID:          docID,
		ProjectID:      projectID,
		TaskKey:        taskKey,
		Title:          title,
		Stage:          stage,
		Version:        1,
		CurrentState:   StateDrafting,
		IsLocked:       false,
		IsTemplateOnly: true,
		WorkDir:        workDir,
		AuthorID:       authorID,
		AuthorName:     authorName,
		ReviewerID:     reviewerID,
		ReviewerName:   reviewerName,
		ApproverID:     approverID,
		ApproverName:   approverName,
		Config:         DefaultDocumentConfig(),
		CreatedAt:      now,
		UpdatedAt:      now,
	}

	// 若有 DB 连接，写 DB 并同步
	if e.pool != nil {
		if projectID > 0 {
			_, _ = e.pool.Exec(ctx, `
				INSERT INTO projects (id, code, name)
				VALUES ($1, $2, $3)
				ON CONFLICT (id) DO NOTHING
			`, projectID, fmt.Sprintf("PROJ_%d", projectID), "受控工程研发项目")
		}

		ensureUser := func(uid int64, uname, urole string) {
			if uid > 0 {
				_, _ = e.pool.Exec(ctx, `
					INSERT INTO users (id, account_id, name, role)
					VALUES ($1, $2, $3, $4)
					ON CONFLICT (id) DO NOTHING
				`, uid, fmt.Sprintf("acc_%d", uid), uname, urole)
			}
		}
		ensureUser(doc.AuthorID, doc.AuthorName, "engineer")
		ensureUser(doc.ReviewerID, doc.ReviewerName, "regulatory")
		ensureUser(doc.ApproverID, doc.ApproverName, "director")

		cfgJSON, _ := json.Marshal(doc.Config)
		query := `
			INSERT INTO document_records (
				doc_id, project_id, task_key, title, stage, version,
				current_state, is_locked, is_template_only, work_dir,
				author_id, author_name, reviewer_id, reviewer_name, approver_id, approver_name,
				config, created_at, updated_at
			) VALUES ($1, $2, $3, $4, $5, $6, $7, $8, $9, $10, $11, $12, $13, $14, $15, $16, $17, $18, $19)
			ON CONFLICT (doc_id) DO UPDATE SET
				title = EXCLUDED.title,
				stage = EXCLUDED.stage,
				updated_at = EXCLUDED.updated_at
			RETURNING id, current_state, is_locked, is_template_only, author_claimed, reviewer_claimed, approver_claimed;
		`
		var id int64
		var currState string
		var isLocked, isTmpl, authClaim, revClaim, appClaim bool
		err := e.pool.QueryRow(ctx, query,
			doc.DocID, doc.ProjectID, doc.TaskKey, doc.Title, doc.Stage, doc.Version,
			string(doc.CurrentState), doc.IsLocked, doc.IsTemplateOnly, doc.WorkDir,
			doc.AuthorID, doc.AuthorName, doc.ReviewerID, doc.ReviewerName, doc.ApproverID, doc.ApproverName,
			cfgJSON, doc.CreatedAt, doc.UpdatedAt,
		).Scan(&id, &currState, &isLocked, &isTmpl, &authClaim, &revClaim, &appClaim)
		if err != nil {
			return nil, fmt.Errorf("persist document ledger: %w", err)
		}
		doc.ID = id
		doc.CurrentState = DocumentState(currState)
		doc.IsLocked = isLocked
		doc.IsTemplateOnly = isTmpl
		doc.AuthorClaimed = authClaim
		doc.ReviewerClaimed = revClaim
		doc.ApproverClaimed = appClaim
	}

	e.memDocs[docID] = doc
	return doc, nil
}

// MarkDocumentContentUpdated 当正文生成或更新时标记正文哈希及是否脱离模板状态。
// 未预加载时从 DB 补偿装入；已是目标哈希则幂等成功，保证 repair 重试也能同步记录。
func (e *GovernanceEngine) MarkDocumentContentUpdated(ctx context.Context, docID string, contentSHA256 string, isTemplateOnly bool) error {
	e.mu.Lock()
	defer e.mu.Unlock()

	doc, err := e.ensureDocumentLocked(ctx, docID)
	if err != nil {
		return err
	}

	doc.ContentSHA256 = contentSHA256
	doc.IsTemplateOnly = isTemplateOnly
	doc.UpdatedAt = time.Now()

	if e.pool != nil {
		tag, execErr := e.pool.Exec(ctx, `
			UPDATE document_records
			SET content_sha256 = $1, is_template_only = $2, work_dir = $3, updated_at = $4
			WHERE doc_id = $5
		`, doc.ContentSHA256, doc.IsTemplateOnly, doc.WorkDir, doc.UpdatedAt, docID)
		if execErr != nil {
			return fmt.Errorf("docgov: mark content updated: %w", execErr)
		}
		if tag.RowsAffected() == 0 {
			return ErrDocumentNotFound
		}
	}

	return nil
}

func (e *GovernanceEngine) ensureDocumentLocked(ctx context.Context, docID string) (*DocumentRecord, error) {
	if doc, exists := e.memDocs[docID]; exists {
		return doc, nil
	}
	if e.pool != nil {
		doc, err := e.loadDocumentFromDBLocked(ctx, docID)
		if err == nil && doc != nil {
			return doc, nil
		}
	}
	return nil, ErrDocumentNotFound
}

// SetDocumentWorkDir 更新文档的工作区路径
func (e *GovernanceEngine) SetDocumentWorkDir(ctx context.Context, docID string, workDir string) error {
	e.mu.Lock()
	defer e.mu.Unlock()

	doc, exists := e.memDocs[docID]
	if !exists {
		return ErrDocumentNotFound
	}

	doc.WorkDir = workDir
	doc.UpdatedAt = time.Now()

	if e.pool != nil {
		_, _ = e.pool.Exec(ctx, `
			UPDATE document_records
			SET work_dir = $1, updated_at = $2
			WHERE doc_id = $3
		`, doc.WorkDir, doc.UpdatedAt, docID)
	}

	return nil
}

// RecordDocumentViewed 记录查看文档行为并触发认领机制
// 核心规则：
// 1. 只有当文档处于【非模板状态】(is_template_only = false) 时，编制负责人查看才标记为 AuthorClaimed = true；模板状态查看不算认领！
// 2. 审核人查看且处于审核阶段，标记 ReviewerClaimed = true
// 3. 批准人查看且处于批准阶段，标记 ApproverClaimed = true
func (e *GovernanceEngine) RecordDocumentViewed(ctx context.Context, docID string, actorID int64, actorRole UserRole, actorName string) (*DocumentRecord, error) {
	e.mu.Lock()
	defer e.mu.Unlock()

	doc, exists := e.memDocs[docID]
	if !exists {
		var err error
		doc, err = e.loadDocumentFromDBLocked(ctx, docID)
		if err != nil || doc == nil {
			return nil, ErrDocumentNotFound
		}
	}

	now := time.Now()
	var auditAction string

	switch actorRole {
	case RoleAuthor:
		doc.AuthorLastViewedAt = &now
		auditAction = "author_view"
		// 关键认领判定：只限非模板状态
		if !doc.IsTemplateOnly && !doc.AuthorClaimed {
			doc.AuthorClaimed = true
			doc.AuthorClaimedAt = &now
			auditAction = "author_claim_by_view"
		}
	case RoleReviewer:
		doc.ReviewerClaimed = true
		doc.ReviewerClaimedAt = &now
		auditAction = "reviewer_claim_by_view"
	case RoleApprover:
		doc.ApproverClaimed = true
		doc.ApproverClaimedAt = &now
		auditAction = "approver_claim_by_view"
	default:
		auditAction = "view"
	}

	doc.UpdatedAt = now

	// 记录审计日志
	audit := &AuditLog{
		DocID:     docID,
		Action:    auditAction,
		ActorID:   actorID,
		ActorName: actorName,
		ActorRole: actorRole,
		FromState: doc.CurrentState,
		ToState:   doc.CurrentState,
		Details: map[string]any{
			"is_template_only": doc.IsTemplateOnly,
			"author_claimed":   doc.AuthorClaimed,
			"timestamp":        now,
		},
		CreatedAt: now,
	}
	e.memAudits[docID] = append(e.memAudits[docID], audit)

	if e.pool != nil {
		_, _ = e.pool.Exec(ctx, `
			UPDATE document_records
			SET author_claimed = $1, author_claimed_at = $2, author_last_viewed_at = $3,
			    reviewer_claimed = $4, reviewer_claimed_at = $5,
			    approver_claimed = $6, approver_claimed_at = $7,
			    updated_at = $8
			WHERE doc_id = $9
		`, doc.AuthorClaimed, doc.AuthorClaimedAt, doc.AuthorLastViewedAt,
			doc.ReviewerClaimed, doc.ReviewerClaimedAt,
			doc.ApproverClaimed, doc.ApproverClaimedAt,
			doc.UpdatedAt, docID)

		detJSON, _ := json.Marshal(audit.Details)
		_, _ = e.pool.Exec(ctx, `
			INSERT INTO document_audit_logs (doc_id, action, actor_id, actor_name, actor_role, from_state, to_state, details, created_at)
			VALUES ($1, $2, $3, $4, $5, $6, $7, $8, $9)
		`, audit.DocID, audit.Action, audit.ActorID, audit.ActorName, string(audit.ActorRole),
			string(audit.FromState), string(audit.ToState), detJSON, audit.CreatedAt)
	}

	return doc, nil
}

// RecordDocumentEdited 编制人编辑文档 (标记认领与编辑时间)
func (e *GovernanceEngine) RecordDocumentEdited(ctx context.Context, docID string, actorID int64, actorRole UserRole, actorName string) (*DocumentRecord, error) {
	e.mu.Lock()
	defer e.mu.Unlock()

	doc, exists := e.memDocs[docID]
	if !exists {
		var err error
		doc, err = e.loadDocumentFromDBLocked(ctx, docID)
		if err != nil || doc == nil {
			return nil, ErrDocumentNotFound
		}
	}

	if err := e.sm.CanEditDocumentContent(doc, actorID, actorRole); err != nil {
		return nil, err
	}

	now := time.Now()
	if doc.HasActiveLease(now) {
		holderID := fmt.Sprintf("%d", actorID)
		sameHuman := doc.LeaseHolderType == LeaseHolderHuman && (doc.LeaseHolderID == holderID || (actorID <= 0 && doc.LeaseHolderID == "human_anon"))
		if !sameHuman {
			return nil, &DocumentBusyError{
				DocID:      doc.DocID,
				HolderType: doc.LeaseHolderType,
				HolderID:   doc.LeaseHolderID,
				WorkDir:    doc.LeaseWorkDir,
				ExpiresAt:  *doc.LeaseExpiresAt,
				Reason:     fmt.Sprintf("文档正在由 %s 编辑/生成中，禁止人工编辑", doc.LeaseHolderType),
			}
		}
	}

	doc.AuthorLastEditedAt = &now
	doc.AuthorClaimed = true
	if doc.AuthorClaimedAt == nil {
		doc.AuthorClaimedAt = &now
	}
	doc.UpdatedAt = now

	audit := &AuditLog{
		DocID:     docID,
		Action:    "author_edit",
		ActorID:   actorID,
		ActorName: actorName,
		ActorRole: actorRole,
		FromState: doc.CurrentState,
		ToState:   doc.CurrentState,
		Details:   map[string]any{"timestamp": now},
		CreatedAt: now,
	}
	e.memAudits[docID] = append(e.memAudits[docID], audit)

	if e.pool != nil {
		_, _ = e.pool.Exec(ctx, `
			UPDATE document_records
			SET author_claimed = $1, author_claimed_at = $2, author_last_edited_at = $3, updated_at = $4
			WHERE doc_id = $5
		`, doc.AuthorClaimed, doc.AuthorClaimedAt, doc.AuthorLastEditedAt, doc.UpdatedAt, docID)

		detJSON, _ := json.Marshal(audit.Details)
		_, _ = e.pool.Exec(ctx, `
			INSERT INTO document_audit_logs (doc_id, action, actor_id, actor_name, actor_role, from_state, to_state, details, created_at)
			VALUES ($1, $2, $3, $4, $5, $6, $7, $8, $9)
		`, audit.DocID, audit.Action, audit.ActorID, audit.ActorName, string(audit.ActorRole),
			string(audit.FromState), string(audit.ToState), detJSON, audit.CreatedAt)
	}

	return doc, nil
}

// CheckModificationPermission 阶段发起修改编制状态文档前，检查认领与权限
// 核心逻辑：
// 1. 若文档未认领 (author_claimed == false)，系统不用告知负责人，直接放行智能体小队编辑 (AllowedDirectEdit = true)
// 2. 若文档已认领 (author_claimed == true)，系统拦截直接编辑，必须通知编制负责人并生成变更提案 (RequiresProposal = true)
func (e *GovernanceEngine) CheckModificationPermission(ctx context.Context, docID string, actorRole UserRole) (*ModificationCheckResult, error) {
	e.mu.Lock()
	defer e.mu.Unlock()

	doc, exists := e.memDocs[docID]
	if !exists {
		var err error
		doc, err = e.loadDocumentFromDBLocked(ctx, docID)
		if err != nil || doc == nil {
			return nil, ErrDocumentNotFound
		}
	}

	// 1. 检查锁定状态
	if doc.IsLocked {
		return &ModificationCheckResult{
			AllowedDirectEdit: false,
			RequiresProposal:  false,
			AuthorClaimed:     doc.AuthorClaimed,
			Reason:            fmt.Sprintf("文档处于【%s】阶段已锁定，禁止任何修改", doc.CurrentState),
		}, ErrDocumentLocked
	}

	// 1b. 运行时编辑租约占用（正交于 IsLocked）
	now := time.Now()
	if doc.HasActiveLease(now) {
		return &ModificationCheckResult{
			AllowedDirectEdit: false,
			RequiresProposal:  false,
			AuthorClaimed:     doc.AuthorClaimed,
			Reason:            fmt.Sprintf("文档正在被 %s(%s) 编辑中", doc.LeaseHolderType, doc.LeaseHolderID),
		}, &DocumentBusyError{
			DocID:      doc.DocID,
			HolderType: doc.LeaseHolderType,
			HolderID:   doc.LeaseHolderID,
			WorkDir:    doc.LeaseWorkDir,
			ExpiresAt:  *doc.LeaseExpiresAt,
			Reason:     fmt.Sprintf("文档正在被 %s(%s) 编辑中，禁止并行修改", doc.LeaseHolderType, doc.LeaseHolderID),
		}
	}

	// 2. 检查认领状态
	if !doc.AuthorClaimed {
		// 未认领：智能体小队可静默直接修改
		return &ModificationCheckResult{
			AllowedDirectEdit: true,
			RequiresProposal:  false,
			AuthorClaimed:     false,
			Reason:            "文档尚未被编制负责人认领（未查看正式稿），允许智能体小队直接自动编辑",
		}, nil
	}

	// 3. 已认领：检查是否有待编制人处理的挂起提案
	var pendingProp *ChangeProposal
	for _, p := range e.memProps {
		if p.DocID == docID && p.Status == ProposalPendingAuthorApproval {
			pendingProp = p
			break
		}
	}
	if pendingProp == nil && e.pool != nil {
		var p ChangeProposal
		var stat string
		err := e.pool.QueryRow(ctx, `
			SELECT id, proposal_id, doc_id, project_id, triggered_by, proposed_changes, impact_analysis, risk_assessment, status, author_decision_reason, decided_at, created_at
			FROM document_change_proposals
			WHERE doc_id = $1 AND status = 'pending_author_approval'
			ORDER BY created_at DESC LIMIT 1
		`, docID).Scan(&p.ID, &p.ProposalID, &p.DocID, &p.ProjectID, &p.TriggeredBy, &p.ProposedChanges, &p.ImpactAnalysis, &p.RiskAssessment, &stat, &p.AuthorDecisionReason, &p.DecidedAt, &p.CreatedAt)
		if err == nil {
			p.Status = ProposalStatus(stat)
			pendingProp = &p
			e.memProps[p.ProposalID] = &p
		}
	}

	return &ModificationCheckResult{
		AllowedDirectEdit: false,
		RequiresProposal:  true,
		AuthorClaimed:     true,
		PendingProposal:   pendingProp,
		Reason:            "文档已被编制负责人认领，必须生成变更提案告知修改点、影响与风险，并由编制人确认授权",
	}, nil
}

// ProposeModification 当文档处于已认领状态时，由智能体或系统提出变更提案
func (e *GovernanceEngine) ProposeModification(
	ctx context.Context,
	docID string,
	triggeredBy string,
	proposedChanges string,
	impactAnalysis string,
	riskAssessment string,
) (*ChangeProposal, error) {
	e.mu.Lock()
	defer e.mu.Unlock()

	doc, exists := e.memDocs[docID]
	if !exists {
		var err error
		doc, err = e.loadDocumentFromDBLocked(ctx, docID)
		if err != nil || doc == nil {
			return nil, ErrDocumentNotFound
		}
	}

	proposalID := fmt.Sprintf("prop_%s_%d", doc.TaskKey, time.Now().UnixNano())
	now := time.Now()

	proposal := &ChangeProposal{
		ProposalID:      proposalID,
		DocID:           docID,
		ProjectID:       doc.ProjectID,
		TriggeredBy:     triggeredBy,
		ProposedChanges: proposedChanges,
		ImpactAnalysis:  impactAnalysis,
		RiskAssessment:  riskAssessment,
		Status:          ProposalPendingAuthorApproval,
		CreatedAt:       now,
	}

	e.memProps[proposalID] = proposal

	// 记录审计
	audit := &AuditLog{
		DocID:     docID,
		Action:    "propose_change",
		ActorID:   0,
		ActorName: triggeredBy,
		ActorRole: RoleSystem,
		FromState: doc.CurrentState,
		ToState:   doc.CurrentState,
		Details: map[string]any{
			"proposal_id":      proposalID,
			"proposed_changes": proposedChanges,
			"impact":           impactAnalysis,
			"risk":             riskAssessment,
		},
		CreatedAt: now,
	}
	e.memAudits[docID] = append(e.memAudits[docID], audit)

	if e.pool != nil {
		query := `
			INSERT INTO document_change_proposals (
				proposal_id, doc_id, project_id, triggered_by, proposed_changes, impact_analysis, risk_assessment, status, created_at
			) VALUES ($1, $2, $3, $4, $5, $6, $7, $8, $9)
			RETURNING id;
		`
		var id int64
		if err := e.pool.QueryRow(ctx, query,
			proposal.ProposalID, proposal.DocID, proposal.ProjectID,
			proposal.TriggeredBy, proposal.ProposedChanges, proposal.ImpactAnalysis, proposal.RiskAssessment,
			string(proposal.Status), proposal.CreatedAt,
		).Scan(&id); err == nil {
			proposal.ID = id
		}

		detJSON, _ := json.Marshal(audit.Details)
		_, _ = e.pool.Exec(ctx, `
			INSERT INTO document_audit_logs (doc_id, action, actor_id, actor_name, actor_role, from_state, to_state, details, created_at)
			VALUES ($1, $2, $3, $4, $5, $6, $7, $8, $9)
		`, audit.DocID, audit.Action, audit.ActorID, audit.ActorName, string(audit.ActorRole),
			string(audit.FromState), string(audit.ToState), detJSON, audit.CreatedAt)
	}

	return proposal, nil
}

// DecideModificationProposal 编制负责人拍板决定：同意修改或拒绝修改
func (e *GovernanceEngine) DecideModificationProposal(
	ctx context.Context,
	proposalID string,
	authorID int64,
	approve bool,
	reason string,
) (*ChangeProposal, error) {
	e.mu.Lock()
	defer e.mu.Unlock()

	proposal, exists := e.memProps[proposalID]
	if !exists && e.pool != nil {
		var p ChangeProposal
		var stat string
		err := e.pool.QueryRow(ctx, `
			SELECT id, proposal_id, doc_id, project_id, triggered_by, proposed_changes, impact_analysis, risk_assessment, status, author_decision_reason, decided_at, created_at
			FROM document_change_proposals
			WHERE proposal_id = $1
		`, proposalID).Scan(&p.ID, &p.ProposalID, &p.DocID, &p.ProjectID, &p.TriggeredBy, &p.ProposedChanges, &p.ImpactAnalysis, &p.RiskAssessment, &stat, &p.AuthorDecisionReason, &p.DecidedAt, &p.CreatedAt)
		if err == nil {
			p.Status = ProposalStatus(stat)
			proposal = &p
			e.memProps[proposalID] = &p
			exists = true
		}
	}
	if !exists {
		return nil, ErrProposalNotFound
	}
	if proposal.Status != ProposalPendingAuthorApproval {
		return nil, ErrProposalAlreadyDecided
	}

	doc, docExists := e.memDocs[proposal.DocID]
	if !docExists && e.pool != nil {
		var err error
		doc, err = e.loadDocumentFromDBLocked(ctx, proposal.DocID)
		if err == nil && doc != nil {
			docExists = true
		}
	}
	if !docExists {
		return nil, ErrDocumentNotFound
	}

	// 校验只有编制人有权拍板
	if doc.AuthorID > 0 && authorID > 0 && doc.AuthorID != authorID {
		return nil, fmt.Errorf("%w: 只有编制负责人 (ID: %d) 有权拍板该修改提案", ErrUnauthorizedActor, doc.AuthorID)
	}

	now := time.Now()
	proposal.AuthorDecisionReason = strings.TrimSpace(reason)
	proposal.DecidedAt = &now

	var action string
	if approve {
		proposal.Status = ProposalApprovedByAuthor
		action = "author_approve_proposal"
	} else {
		proposal.Status = ProposalRejectedByAuthor
		action = "author_reject_proposal"
	}

	audit := &AuditLog{
		DocID:     proposal.DocID,
		Action:    action,
		ActorID:   authorID,
		ActorName: doc.AuthorName,
		ActorRole: RoleAuthor,
		FromState: doc.CurrentState,
		ToState:   doc.CurrentState,
		Details: map[string]any{
			"proposal_id": proposalID,
			"decision":    approve,
			"reason":      proposal.AuthorDecisionReason,
			"timestamp":   now,
		},
		CreatedAt: now,
	}
	e.memAudits[proposal.DocID] = append(e.memAudits[proposal.DocID], audit)

	if e.pool != nil {
		_, _ = e.pool.Exec(ctx, `
			UPDATE document_change_proposals
			SET status = $1, author_decision_reason = $2, decided_at = $3
			WHERE proposal_id = $4
		`, string(proposal.Status), proposal.AuthorDecisionReason, proposal.DecidedAt, proposalID)

		detJSON, _ := json.Marshal(audit.Details)
		_, _ = e.pool.Exec(ctx, `
			INSERT INTO document_audit_logs (doc_id, action, actor_id, actor_name, actor_role, from_state, to_state, details, created_at)
			VALUES ($1, $2, $3, $4, $5, $6, $7, $8, $9)
		`, audit.DocID, audit.Action, audit.ActorID, audit.ActorName, string(audit.ActorRole),
			string(audit.FromState), string(audit.ToState), detJSON, audit.CreatedAt)
	}

	return proposal, nil
}

// AddComment 添加批注与修改意见 (审核人/批准人/编制人均可批注，但审核批准不能直接改正文)
// 有效编辑租约期间禁止批注；生命周期锁定下仍允许批注。
func (e *GovernanceEngine) AddComment(
	ctx context.Context,
	docID string,
	userID int64,
	userName string,
	userRole UserRole,
	targetSection string,
	commentType CommentType,
	content string,
) (*DocumentComment, error) {
	if err := e.AssertWritableForComment(ctx, docID); err != nil {
		return nil, err
	}

	e.mu.Lock()
	defer e.mu.Unlock()

	trimmed := strings.TrimSpace(content)
	if trimmed == "" {
		return nil, fmt.Errorf("comment content cannot be empty")
	}

	now := time.Now()
	comment := &DocumentComment{
		DocID:         docID,
		UserID:        userID,
		UserName:      userName,
		UserRole:      userRole,
		TargetSection: targetSection,
		CommentType:   commentType,
		Content:       trimmed,
		Status:        "open",
		CreatedAt:     now,
	}

	e.memComms[docID] = append(e.memComms[docID], comment)

	if e.pool != nil {
		query := `
			INSERT INTO document_comments (doc_id, user_id, user_name, user_role, target_section, comment_type, content, status, created_at)
			VALUES ($1, $2, $3, $4, $5, $6, $7, $8, $9)
			RETURNING id;
		`
		var id int64
		if err := e.pool.QueryRow(ctx, query,
			comment.DocID, comment.UserID, comment.UserName, string(comment.UserRole),
			comment.TargetSection, string(comment.CommentType), comment.Content, comment.Status, comment.CreatedAt,
		).Scan(&id); err == nil {
			comment.ID = id
		}
	}

	return comment, nil
}

// SubmitForReview 编制完成提交审核 (drafting -> reviewing)
func (e *GovernanceEngine) SubmitForReview(ctx context.Context, docID string, actorID int64, actorRole UserRole, actorName string) (*DocumentRecord, error) {
	e.mu.Lock()
	defer e.mu.Unlock()

	doc, exists := e.memDocs[docID]
	if !exists {
		var err error
		doc, err = e.loadDocumentFromDBLocked(ctx, docID)
		if err != nil || doc == nil {
			return nil, ErrDocumentNotFound
		}
	}

	if doc.HasActiveLease(time.Now()) {
		return nil, &DocumentBusyError{
			DocID:      doc.DocID,
			HolderType: doc.LeaseHolderType,
			HolderID:   doc.LeaseHolderID,
			WorkDir:    doc.LeaseWorkDir,
			ExpiresAt:  *doc.LeaseExpiresAt,
			Reason:     "文档编辑租约占用中，暂不可送审",
		}
	}

	audit, err := e.sm.TransitionSubmitForReview(doc, actorID, actorRole, actorName)
	if err != nil {
		return nil, err
	}

	e.memAudits[docID] = append(e.memAudits[docID], audit)
	if err := e.freezeReviewSnapshotLocked(ctx, doc); err != nil {
		return nil, err
	}
	e.syncDocAndAuditToDB(ctx, doc, audit)
	return doc, nil
}

// ReviewApprove 审核通过 (reviewing -> approving)
func (e *GovernanceEngine) ReviewApprove(ctx context.Context, docID string, actorID int64, actorRole UserRole, actorName string, comment string) (*DocumentRecord, error) {
	e.mu.Lock()
	defer e.mu.Unlock()

	doc, exists := e.memDocs[docID]
	if !exists {
		var err error
		doc, err = e.loadDocumentFromDBLocked(ctx, docID)
		if err != nil || doc == nil {
			return nil, ErrDocumentNotFound
		}
	}

	audit, err := e.sm.TransitionReviewApprove(doc, actorID, actorRole, actorName, comment)
	if err != nil {
		return nil, err
	}

	if strings.TrimSpace(comment) != "" {
		_ = e.addCommentInternal(docID, actorID, actorName, actorRole, "", CommentSuggestion, comment)
	}

	e.memAudits[docID] = append(e.memAudits[docID], audit)
	e.syncDocAndAuditToDB(ctx, doc, audit)
	return doc, nil
}

// ReviewReject 审核驳回 (reviewing -> drafting, 驳回原因必填)
func (e *GovernanceEngine) ReviewReject(ctx context.Context, docID string, actorID int64, actorRole UserRole, actorName string, rejectReason string) (*DocumentRecord, error) {
	e.mu.Lock()
	defer e.mu.Unlock()

	doc, exists := e.memDocs[docID]
	if !exists {
		var err error
		doc, err = e.loadDocumentFromDBLocked(ctx, docID)
		if err != nil || doc == nil {
			return nil, ErrDocumentNotFound
		}
	}

	audit, err := e.sm.TransitionReviewReject(doc, actorID, actorRole, actorName, rejectReason)
	if err != nil {
		return nil, err
	}

	// 驳回原因自动持久化为批注记录
	_ = e.addCommentInternal(docID, actorID, actorName, actorRole, "", CommentRejection, rejectReason)

	e.memAudits[docID] = append(e.memAudits[docID], audit)
	e.syncDocAndAuditToDB(ctx, doc, audit)
	return doc, nil
}

// ApproverApprove 批准通过 (approving -> approved, 终态归档锁定)
func (e *GovernanceEngine) ApproverApprove(ctx context.Context, docID string, actorID int64, actorRole UserRole, actorName string, comment string) (*DocumentRecord, error) {
	e.mu.Lock()
	defer e.mu.Unlock()

	doc, exists := e.memDocs[docID]
	if !exists {
		var err error
		doc, err = e.loadDocumentFromDBLocked(ctx, docID)
		if err != nil || doc == nil {
			return nil, ErrDocumentNotFound
		}
	}

	if doc.ReviewSnapshotID <= 0 {
		return nil, fmt.Errorf("docgov: approved requires frozen review_snapshot_id")
	}
	audit, err := e.sm.TransitionApproverApprove(doc, actorID, actorRole, actorName, comment)
	if err != nil {
		return nil, err
	}

	if strings.TrimSpace(comment) != "" {
		_ = e.addCommentInternal(docID, actorID, actorName, actorRole, "", CommentSuggestion, comment)
	}

	e.memAudits[docID] = append(e.memAudits[docID], audit)
	e.syncDocAndAuditToDB(ctx, doc, audit)

	e.mu.Unlock()
	e.runApprovedHooks(ctx, doc)
	if e.OnFinalArtifact != nil {
		md, _ := e.LedgerMarkdown(ctx, doc.ReviewSnapshotID)
		e.OnFinalArtifact(ctx, doc, []byte(md), doc.ReviewSnapshotID)
	}
	e.mu.Lock()

	return doc, nil
}

// ApproverReject 批准驳回 (approving -> drafting 或 reviewing, 驳回原因必填)
func (e *GovernanceEngine) ApproverReject(ctx context.Context, docID string, actorID int64, actorRole UserRole, actorName string, rejectReason string, rollbackTo DocumentState) (*DocumentRecord, error) {
	e.mu.Lock()
	defer e.mu.Unlock()

	doc, exists := e.memDocs[docID]
	if !exists {
		var err error
		doc, err = e.loadDocumentFromDBLocked(ctx, docID)
		if err != nil || doc == nil {
			return nil, ErrDocumentNotFound
		}
	}

	audit, err := e.sm.TransitionApproverReject(doc, actorID, actorRole, actorName, rejectReason, rollbackTo)
	if err != nil {
		return nil, err
	}

	_ = e.addCommentInternal(docID, actorID, actorName, actorRole, "", CommentRejection, rejectReason)

	e.memAudits[docID] = append(e.memAudits[docID], audit)
	e.syncDocAndAuditToDB(ctx, doc, audit)
	return doc, nil
}

// GetDocument 获取文档实体 (优先查内存，未命中查 DB)
func (e *GovernanceEngine) GetDocument(ctx context.Context, docID string) (*DocumentRecord, error) {
	e.mu.Lock()
	defer e.mu.Unlock()

	if doc, exists := e.memDocs[docID]; exists {
		return doc, nil
	}
	if e.pool != nil {
		if doc, err := e.loadDocumentFromDBLocked(ctx, docID); err == nil && doc != nil {
			return doc, nil
		}
	}
	return nil, ErrDocumentNotFound
}

// ListAuditLogs 获取文档审计日志
func (e *GovernanceEngine) ListAuditLogs(ctx context.Context, docID string) ([]*AuditLog, error) {
	e.mu.Lock()
	defer e.mu.Unlock()

	if len(e.memAudits[docID]) == 0 && e.pool != nil {
		rows, err := e.pool.Query(ctx, `
			SELECT id, doc_id, action, actor_id, actor_name, actor_role, from_state, to_state, details, created_at
			FROM document_audit_logs
			WHERE doc_id = $1
			ORDER BY created_at ASC
		`, docID)
		if err == nil {
			defer rows.Close()
			for rows.Next() {
				var a AuditLog
				var detJSON []byte
				var role, fromSt, toSt string
				var actID *int64
				if err := rows.Scan(&a.ID, &a.DocID, &a.Action, &actID, &a.ActorName, &role, &fromSt, &toSt, &detJSON, &a.CreatedAt); err == nil {
					if actID != nil {
						a.ActorID = *actID
					}
					a.ActorRole = UserRole(role)
					a.FromState = DocumentState(fromSt)
					a.ToState = DocumentState(toSt)
					if len(detJSON) > 0 {
						_ = json.Unmarshal(detJSON, &a.Details)
					}
					e.memAudits[docID] = append(e.memAudits[docID], &a)
				}
			}
		}
	}

	logs := e.memAudits[docID]
	res := make([]*AuditLog, len(logs))
	copy(res, logs)
	return res, nil
}

// ListComments 列出文档的所有批注
func (e *GovernanceEngine) ListComments(ctx context.Context, docID string) ([]*DocumentComment, error) {
	e.mu.Lock()
	defer e.mu.Unlock()

	if len(e.memComms[docID]) == 0 && e.pool != nil {
		rows, err := e.pool.Query(ctx, `
			SELECT id, doc_id, user_id, user_name, user_role, target_section, comment_type, content, status, created_at
			FROM document_comments
			WHERE doc_id = $1
			ORDER BY created_at ASC
		`, docID)
		if err == nil {
			defer rows.Close()
			for rows.Next() {
				var c DocumentComment
				var uID *int64
				var role, cType string
				if err := rows.Scan(&c.ID, &c.DocID, &uID, &c.UserName, &role, &c.TargetSection, &cType, &c.Content, &c.Status, &c.CreatedAt); err == nil {
					if uID != nil {
						c.UserID = *uID
					}
					c.UserRole = UserRole(role)
					c.CommentType = CommentType(cType)
					e.memComms[docID] = append(e.memComms[docID], &c)
				}
			}
		}
	}

	comms := e.memComms[docID]
	res := make([]*DocumentComment, len(comms))
	copy(res, comms)
	return res, nil
}

func (e *GovernanceEngine) loadDocumentFromDBLocked(ctx context.Context, docID string) (*DocumentRecord, error) {
	if e.pool == nil {
		return nil, ErrDocumentNotFound
	}
	row := e.pool.QueryRow(ctx, `
		SELECT id, doc_id, project_id, task_key, title, stage, version,
		       current_state, is_locked, is_template_only, content_sha256, work_dir,
		       author_id, author_name, reviewer_id, reviewer_name, approver_id, approver_name,
		       author_claimed, author_claimed_at, author_last_viewed_at, author_last_edited_at,
		       reviewer_claimed, reviewer_claimed_at, approver_claimed, approver_claimed_at,
		       last_rejected_reason, last_rejected_by_role, last_rejected_by_name, last_rejected_at,
		       approved_at, config, created_at, updated_at,
		       COALESCE(lease_holder_type, ''), COALESCE(lease_holder_id, ''), COALESCE(lease_work_dir, ''),
		       lease_expires_at, lease_heartbeat_at,
		       COALESCE(review_snapshot_id, 0)
		FROM document_records
		WHERE doc_id = $1
	`, docID)

	var doc DocumentRecord
	var cfgJSON []byte
	var currState string
	var authorID, reviewerID, approverID *int64
	var leaseType, leaseID, leaseWD string
	err := row.Scan(
		&doc.ID, &doc.DocID, &doc.ProjectID, &doc.TaskKey, &doc.Title, &doc.Stage, &doc.Version,
		&currState, &doc.IsLocked, &doc.IsTemplateOnly, &doc.ContentSHA256, &doc.WorkDir,
		&authorID, &doc.AuthorName, &reviewerID, &doc.ReviewerName, &approverID, &doc.ApproverName,
		&doc.AuthorClaimed, &doc.AuthorClaimedAt, &doc.AuthorLastViewedAt, &doc.AuthorLastEditedAt,
		&doc.ReviewerClaimed, &doc.ReviewerClaimedAt, &doc.ApproverClaimed, &doc.ApproverClaimedAt,
		&doc.LastRejectedReason, &doc.LastRejectedByRole, &doc.LastRejectedByName, &doc.LastRejectedAt,
		&doc.ApprovedAt, &cfgJSON, &doc.CreatedAt, &doc.UpdatedAt,
		&leaseType, &leaseID, &leaseWD, &doc.LeaseExpiresAt, &doc.LeaseHeartbeatAt,
		&doc.ReviewSnapshotID,
	)
	if err != nil {
		return nil, err
	}

	doc.CurrentState = DocumentState(currState)
	doc.LeaseHolderType = LeaseHolderType(leaseType)
	doc.LeaseHolderID = leaseID
	doc.LeaseWorkDir = leaseWD
	if authorID != nil {
		doc.AuthorID = *authorID
	}
	if reviewerID != nil {
		doc.ReviewerID = *reviewerID
	}
	if approverID != nil {
		doc.ApproverID = *approverID
	}
	if len(cfgJSON) > 0 {
		_ = json.Unmarshal(cfgJSON, &doc.Config)
	}
	e.memDocs[docID] = &doc
	return &doc, nil
}

func (e *GovernanceEngine) addCommentInternal(docID string, userID int64, userName string, userRole UserRole, targetSection string, commentType CommentType, content string) error {
	now := time.Now()
	comment := &DocumentComment{
		DocID:         docID,
		UserID:        userID,
		UserName:      userName,
		UserRole:      userRole,
		TargetSection: targetSection,
		CommentType:   commentType,
		Content:       content,
		Status:        "open",
		CreatedAt:     now,
	}
	e.memComms[docID] = append(e.memComms[docID], comment)
	return nil
}

func (e *GovernanceEngine) freezeReviewSnapshotLocked(ctx context.Context, doc *DocumentRecord) error {
	if doc == nil {
		return ErrDocumentNotFound
	}
	if e.pool != nil {
		var head *int64
		if err := e.pool.QueryRow(ctx, `SELECT head_snapshot_id FROM document_records WHERE doc_id=$1`, doc.DocID).Scan(&head); err == nil && head != nil && *head > 0 {
			doc.ReviewSnapshotID = *head
		}
		if doc.ReviewSnapshotID <= 0 {
			return nil
		}
		_, err := e.pool.Exec(ctx, `UPDATE document_records SET review_snapshot_id=$1 WHERE doc_id=$2`, doc.ReviewSnapshotID, doc.DocID)
		return err
	}
	if doc.ReviewSnapshotID <= 0 {
		doc.ReviewSnapshotID = 1
	}
	return nil
}

// LedgerMarkdown returns immutable snapshot markdown. It never reads workspace files.
func (e *GovernanceEngine) LedgerMarkdown(ctx context.Context, snapshotID int64) (string, error) {
	if e.pool == nil || snapshotID <= 0 {
		return "", fmt.Errorf("docgov: ledger snapshot unavailable")
	}
	var md string
	err := e.pool.QueryRow(ctx, `
		SELECT b.content_markdown
		FROM document_snapshots s
		JOIN document_content_blobs b ON b.content_sha256 = s.content_sha256
		WHERE s.id = $1
	`, snapshotID).Scan(&md)
	return md, err
}

func (e *GovernanceEngine) syncDocAndAuditToDB(ctx context.Context, doc *DocumentRecord, audit *AuditLog) {
	if e.pool == nil {
		return
	}
	_, _ = e.pool.Exec(ctx, `
		UPDATE document_records
		SET current_state = $1, is_locked = $2,
		    last_rejected_reason = $3, last_rejected_by_role = $4, last_rejected_by_name = $5, last_rejected_at = $6,
		    approved_at = $7, updated_at = $8, review_snapshot_id = NULLIF($9, 0)
		WHERE doc_id = $10
	`, string(doc.CurrentState), doc.IsLocked,
		doc.LastRejectedReason, doc.LastRejectedByRole, doc.LastRejectedByName, doc.LastRejectedAt,
		doc.ApprovedAt, doc.UpdatedAt, doc.ReviewSnapshotID, doc.DocID)

	if audit != nil {
		detJSON, _ := json.Marshal(audit.Details)
		_, _ = e.pool.Exec(ctx, `
			INSERT INTO document_audit_logs (doc_id, action, actor_id, actor_name, actor_role, from_state, to_state, details, created_at)
			VALUES ($1, $2, $3, $4, $5, $6, $7, $8, $9)
		`, audit.DocID, audit.Action, audit.ActorID, audit.ActorName, string(audit.ActorRole),
			string(audit.FromState), string(audit.ToState), detJSON, audit.CreatedAt)
	}
}