// Copyright (C) 2021 Storj Labs, Inc.
// See LICENSE for copying information.

package storage

import (
	"sort"
	"time"
)

// Usage holds storage usage stamps and summary for a particular period.
type Usage struct {
	Stamps       []UsageStamp `json:"stamps"`
	Summary      float64      `json:"summary"`
	SummaryBytes float64      `json:"summaryBytes"`
}

// UsageStamp holds data at rest total for an interval beginning at interval start.
type UsageStamp struct {
	AtRestTotal      float64   `json:"atRestTotal"`
	AtRestTotalBytes float64   `json:"atRestTotalBytes"`
	IntervalStart    time.Time `json:"intervalStart"`
}

// UsageStampDailyCache caches storage usage stamps by interval date.
type UsageStampDailyCache map[time.Time]UsageStamp

// Add adds usage stamp to cache aggregating at rest data by date.
func (cache *UsageStampDailyCache) Add(stamp UsageStamp) {
	year, month, day := stamp.IntervalStart.UTC().Date()
	intervalStart := time.Date(year, month, day, 0, 0, 0, 0, time.UTC)

	cached := *cache

	cacheStamp, ok := cached[intervalStart]
	if ok {
		cached[intervalStart] = UsageStamp{
			AtRestTotal:      cacheStamp.AtRestTotal + stamp.AtRestTotal,
			AtRestTotalBytes: cacheStamp.AtRestTotalBytes + stamp.AtRestTotalBytes,
			IntervalStart:    intervalStart,
		}
	} else {
		cached[intervalStart] = UsageStamp{
			AtRestTotal:      stamp.AtRestTotal,
			AtRestTotalBytes: stamp.AtRestTotalBytes,
			IntervalStart:    intervalStart,
		}
	}

	*cache = cached
}

// Sorted returns usage stamp slice sorted by interval start.
func (cache *UsageStampDailyCache) Sorted() []UsageStamp {
	var usage []UsageStamp

	for _, stamp := range *cache {
		usage = append(usage, stamp)
	}
	sort.Slice(usage, func(i, j int) bool {
		return usage[i].IntervalStart.Before(usage[j].IntervalStart)
	})

	return usage
}

// DiskSpace stores all info about storagenode disk space usage.
type DiskSpace struct {
	Allocated int64 `json:"allocated"`
	Used      int64 `json:"usedPieces"`
	Trash     int64 `json:"usedTrash"`
	Free      int64 `json:"free"`
	Available int64 `json:"available"`
	Overused  int64 `json:"overused"`
}

// Add combines disk space with another one.
func (diskSpace *DiskSpace) Add(space DiskSpace) {
	diskSpace.Allocated += space.Allocated
	diskSpace.Used += space.Used
	diskSpace.Trash += space.Trash
	diskSpace.Free += space.Free
	diskSpace.Available += space.Available
	diskSpace.Overused += space.Overused
}