// Copyright (c) HashiCorp, Inc.
// SPDX-License-Identifier: BUSL-1.1

package session

import (
	"context"
	"fmt"

	"github.com/hashicorp/boundary/internal/errors"
	"github.com/hashicorp/boundary/internal/event"
)

// StateReport is used to report on the state of a Session.
type StateReport struct {
	SessionId   string
	Status      Status
	Connections []*Connection
	// Unrecognized indicates that the SessionId was not found in the database.
	Unrecognized bool
}

// WorkerStatusReport is a domain service function that, given a Worker's
// session state reports, performs a few tasks:
//  1. Updates the bytes up and down statistics for each reported connection.
//  2. Compares the state of sessions and connections as reported by a Worker,
//     to the known state in the repositories. It returns a StateReport object
//     for each session that is in the canceling or terminated state.
//  3. Checks for any orphaned connections, which is defined as a connection
//     that is in an active state, but was not reported by worker. Any orphaned
//     connections will be marked as closed.
func WorkerStatusReport(ctx context.Context, repo *Repository, connRepo *ConnectionRepository, workerId string, report []*StateReport) ([]*StateReport, error) {
	const op = "session.WorkerStatusReport"

	reportedConnectionIds := make([]string, 0)
	reportedConnections := make([]*Connection, 0)
	reportedSessions := make([]string, 0, len(report))
	for _, r := range report {
		reportedSessions = append(reportedSessions, r.SessionId)
		for _, c := range r.Connections {
			reportedConnectionIds = append(reportedConnectionIds, c.GetPublicId())
			reportedConnections = append(reportedConnections, c)
		}
	}

	err := connRepo.updateBytesUpBytesDown(ctx, reportedConnections...)
	if err != nil {
		return nil, errors.New(ctx, errors.Internal, op, fmt.Sprintf("failed to update bytes up and down for worker reported connections: %v", err))
	}

	notActive, err := repo.CheckIfNotActive(ctx, reportedSessions)
	if err != nil {
		return nil, errors.New(ctx, errors.Internal, op, fmt.Sprintf("Error checking session state for worker %s: %v", workerId, err))
	}

	closed, err := connRepo.closeOrphanedConnections(ctx, workerId, reportedConnectionIds)
	if err != nil {
		return nil, errors.New(ctx, errors.Internal, op, fmt.Sprintf("Error closing orphaned connections for worker %s: %v", workerId, err))
	}
	if len(closed) > 0 {
		event.WriteSysEvent(ctx, op, "marked unclaimed connections as closed", "worker_id", workerId, "count", len(closed))
	}

	return notActive, nil
}