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

package singleprocess

import (
	//	"sync"

	//"github.com/hashicorp/go-hclog"
	//	"github.com/hashicorp/go-memdb"
	"google.golang.org/grpc/codes"
	"google.golang.org/grpc/status"

	"github.com/hashicorp/vagrant/internal/server/proto/vagrant_server"
	//	"github.com/hashicorp/vagrant/internal/server/singleprocess/state"
)

// defaultLogLimitBacklog is the default backlog amount to send down.
const defaultLogLimitBacklog = 100

// TODO: test
func (s *service) GetLogStream(
	req *vagrant_server.GetLogStreamRequest,
	srv vagrant_server.Vagrant_GetLogStreamServer,
) error {
	//log := hclog.FromContext(srv.Context())

	// Default the limit
	if req.LimitBacklog == 0 {
		req.LimitBacklog = defaultLogLimitBacklog
	}

	//	var instanceFunc func(ws memdb.WatchSet) ([]*state.Instance, error)
	switch scope := req.Scope.(type) {
	// case *vagrant_server.GetLogStreamRequest_DeploymentId:
	// 	log = log.With("deployment_id", scope.DeploymentId)
	// 	instanceFunc = func(ws memdb.WatchSet) ([]*state.Instance, error) {
	// 		return s.state.InstancesByDeployment(scope.DeploymentId, ws)
	// 	}

	// case *vagrant_server.GetLogStreamRequest_Application_:
	// 	if scope.Application == nil ||
	// 		scope.Application.Application == nil ||
	// 		scope.Application.Workspace == nil {
	// 		return status.Errorf(
	// 			codes.FailedPrecondition,
	// 			"application scope requires the application and workspace fields to be set",
	// 		)
	// 	}

	// 	log = log.With(
	// 		"project", scope.Application.Application.Project,
	// 		"application", scope.Application.Application.Application,
	// 		"workspace", scope.Application.Workspace.Workspace,
	// 	)
	// 	instanceFunc = func(ws memdb.WatchSet) ([]*state.Instance, error) {
	// 		return s.state.InstancesByApp(
	// 			scope.Application.Application,
	// 			scope.Application.Workspace,
	// 			ws,
	// 		)
	// 	}

	default:
		return status.Errorf(
			codes.FailedPrecondition,
			"invalid scope supplied: %T - %T",
			req.Scope, scope,
		)
	}

	// We keep track of what instances we already have readers for here.
	//	var instanceSetLock sync.Mutex
	//instanceSet := make(map[string]struct{})

	// // We loop forever so that we can automatically get any new instances that
	// // join as we have an open log stream.
	// for {
	// 	// Get all our records
	// 	ws := memdb.NewWatchSet()
	// 	records, err := instanceFunc(ws)
	// 	if err != nil {
	// 		return err
	// 	}
	// 	log.Trace("instances loaded", "len", len(records))

	// 	// For each record, start a goroutine that reads the log entries and sends them.
	// 	for _, record := range records {
	// 		instanceId := record.Id
	// 		deploymentId := record.DeploymentId

	// 		// If we already have a reader for this, then do nothing.
	// 		instanceSetLock.Lock()
	// 		_, exit := instanceSet[instanceId]
	// 		instanceSet[instanceId] = struct{}{}
	// 		instanceSetLock.Unlock()
	// 		if exit {
	// 			continue
	// 		}

	// 		// Start our reader up
	// 		r := record.LogBuffer.Reader(req.LimitBacklog)
	// 		instanceLog := log.With("instance_id", instanceId)
	// 		instanceLog.Trace("instance log stream starting")
	// 		go r.CloseContext(srv.Context())
	// 		go func() {
	// 			defer instanceLog.Debug("instance log stream ending")
	// 			defer func() {
	// 				instanceSetLock.Lock()
	// 				defer instanceSetLock.Unlock()
	// 				delete(instanceSet, instanceId)
	// 			}()

	// 			for {
	// 				entries := r.Read(64, true)
	// 				if entries == nil {
	// 					return
	// 				}

	// 				lines := make([]*vagrant_server.LogBatch_Entry, len(entries))
	// 				for i, v := range entries {
	// 					lines[i] = v.(*vagrant_server.LogBatch_Entry)
	// 				}

	// 				instanceLog.Trace("sending instance log data", "entries", len(entries))
	// 				srv.Send(&vagrant_server.LogBatch{
	// 					DeploymentId: deploymentId,
	// 					InstanceId:   instanceId,
	// 					Lines:        lines,
	// 				})
	// 			}
	// 		}()
	// 	}

	// // Wait for changes or to be done
	// if err := ws.WatchCtx(srv.Context()); err != nil {
	// 	// If our context ended, exit with that
	// 	if err := srv.Context().Err(); err != nil {
	// 		return err
	// 	}

	// 	return err
	// }
	//	}
}