package docgov

import (
	"context"
	"encoding/json"
	"fmt"

	"chat-agent-system/internal/app/uow"
)

// nullIfZero maps unset duty holders (0) to SQL NULL so nullable FK columns
// (author_id/reviewer_id/approver_id → users.id) accept optional duties.
func nullIfZero(id int64) any {
	if id <= 0 {
		return nil
	}
	return id
}

func (e *GovernanceEngine) syncDocAndAuditToDB(ctx context.Context, doc *DocumentRecord, audit *AuditLog) error {
	if e.pool == nil {
		return nil
	}
	exec := func(sql string, args ...any) error {
		if scope, ok := uow.ScopeFrom(ctx); ok {
			tx, err := uow.AsPG(scope)
			if err != nil {
				return err
			}
			_, err = tx.Exec(ctx, sql, args...)
			return err
		}
		_, err := e.pool.Exec(ctx, sql, args...)
		return err
	}
	if err := exec(`
		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); err != nil {
		return fmt.Errorf("docgov: sync document: %w", err)
	}
	if audit != nil {
		detJSON, _ := json.Marshal(audit.Details)
		if err := exec(`
			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); err != nil {
			return fmt.Errorf("docgov: sync audit: %w", err)
		}
	}
	return nil
}