// Copyright (C) 2016 The Android Open Source Project
//
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
//      http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.

package stash

import (
	"fmt"
	"reflect"
	"sync"
	"time"

	"android.googlesource.com/platform/tools/gpu/framework/event"
	"android.googlesource.com/platform/tools/gpu/framework/log"
	"android.googlesource.com/platform/tools/gpu/gapid/search"
	"android.googlesource.com/platform/tools/gpu/gapid/search/eval"
	"github.com/golang/protobuf/ptypes"
)

var entityClass = reflect.TypeOf(&Entity{})

// EntityHandler is a fuction that can be invoked for each entry in a
// stream of entities.
type EntityHandler func(log.Context, *Entity) error

type entityIndex struct {
	mu       sync.Mutex
	entities []*Entity
	byID     map[string]*Entity
	onAdd    event.Broadcast
}

func (i *entityIndex) init() {
	i.entities = []*Entity{}
	i.byID = map[string]*Entity{}
}

func (i *entityIndex) lockedAddEntry(ctx log.Context, entity *Entity) {
	i.entities = append(i.entities, entity)
	i.byID[entity.Upload.Id] = entity
	if err := i.onAdd.Send(ctx, entity); err != nil {
		ctx.Fail(err, "Stash notification failed")
	}
}

func (e *entityIndex) Lookup(ctx log.Context, id string) (*Entity, error) {
	e.mu.Lock()
	defer e.mu.Unlock()
	return e.byID[id], nil
}

func (e *entityIndex) Search(ctx log.Context, query *search.Query, handler EntityHandler) error {
	filter := eval.Filter(ctx, query, entityClass, event.AsHandler(ctx, handler))
	initial := event.AsProducer(ctx, e.entities)
	if query.Monitor {
		return event.Monitor(ctx, &e.mu, e.onAdd.Listen, initial, filter)
	}
	return event.Feed(ctx, filter, initial)
}

func (e *Entity) Format(f fmt.State, c rune) {
	name := "?"
	if len(e.Upload.Name) > 0 {
		name = e.Upload.Name[0]
	}
	t, _ := ptypes.Timestamp(e.Timestamp)
	fmt.Fprintf(f, "%s %s : %s", name, t.Format(time.Stamp), e.Upload.Id)
}