package store

import (
	"database/sql"
	"errors"

	agentpb "git.ipao.vip/rogee/go-sip/gen/agent"
	"google.golang.org/protobuf/proto"
)

type PendingTaskControl struct {
	TenantID, CommandID, ExecutionID, AgentID, Action, Policy string
	ExpectedRevision                                          int64
	Binding                                                   *agentpb.ExecutionBinding
}

// PendingTaskControls includes unroutable targets rather than silently dropping
// them through an inner join. Missing assignment is an explicit recovery error.
func (s *Store) PendingTaskControls(limit int) ([]PendingTaskControl, error) {
	if limit <= 0 {
		return nil, errors.New("control batch limit must be positive")
	}
	rows, err := s.db.Query(`SELECT c.tenant_id,c.command_id,t.execution_id,c.action,c.active_call_policy,c.expected_revision,a.agent_id,a.binding
 FROM mq_task_controls c JOIN mq_task_control_targets t ON t.tenant_id=c.tenant_id AND t.command_id=c.command_id
 LEFT JOIN execution_agents a ON a.execution_id=t.execution_id
 WHERE c.state='pending' AND t.applied=0 ORDER BY c.rowid,t.execution_id LIMIT ?`, limit)
	if err != nil {
		return nil, err
	}
	defer rows.Close()
	var result []PendingTaskControl
	for rows.Next() {
		var item PendingTaskControl
		var agentID sql.NullString
		var raw []byte
		if err := rows.Scan(&item.TenantID, &item.CommandID, &item.ExecutionID, &item.Action, &item.Policy, &item.ExpectedRevision, &agentID, &raw); err != nil {
			return nil, err
		}
		if agentID.Valid {
			item.AgentID = agentID.String
			item.Binding = &agentpb.ExecutionBinding{}
			if err := proto.Unmarshal(raw, item.Binding); err != nil {
				return nil, err
			}
			if item.Binding.ExecutionId != item.ExecutionID || item.Binding.TenantId != item.TenantID {
				return nil, ErrMessageScope
			}
			item.Binding.TaskRevision = item.ExpectedRevision
		}
		result = append(result, item)
	}
	return result, rows.Err()
}