// VulcanizeDB
// Copyright © 2021 Vulcanize

// This program is free software: you can redistribute it and/or modify
// it under the terms of the GNU Affero General Public License as published by
// the Free Software Foundation, either version 3 of the License, or
// (at your option) any later version.

// This program is distributed in the hope that it will be useful,
// but WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
// GNU Affero General Public License for more details.

// You should have received a copy of the GNU Affero General Public License
// along with this program.  If not, see <http://www.gnu.org/licenses/>.

package metrics

import (
	"strings"
	"time"

	"github.com/ethereum/go-ethereum/metrics"

	"github.com/cerc-io/plugeth-statediff/utils/log"
)

const (
	namespace = "statediff"
)

var (
	IndexerMetrics = RegisterIndexerMetrics(metrics.DefaultRegistry)
	DBMetrics      = RegisterDBMetrics(metrics.DefaultRegistry)
)

// Build a fully qualified metric name
func metricName(subsystem, name string) string {
	if name == "" {
		return ""
	}
	parts := []string{namespace, name}
	if subsystem != "" {
		parts = []string{namespace, subsystem, name}
	}
	// Prometheus uses _ but geth metrics uses / and replaces
	return strings.Join(parts, "/")
}

type IndexerMetricsHandles struct {
	// The total number of processed BlocksCounter
	BlocksCounter metrics.Counter
	// The total number of processed transactions
	TransactionsCounter metrics.Counter
	// The total number of processed receipts
	ReceiptsCounter metrics.Counter
	// The total number of processed logs
	LogsCounter metrics.Counter
	// The total number of access list entries processed
	AccessListEntriesCounter metrics.Counter
	// Time spent waiting for free postgres tx
	FreePostgresTimer metrics.Timer
	// Postgres transaction commit duration
	PostgresCommitTimer metrics.Timer
	// Header processing time
	HeaderProcessingTimer metrics.Timer
	// Uncle processing time
	UncleProcessingTimer metrics.Timer
	// Tx and receipt processing time
	TxAndRecProcessingTimer metrics.Timer
	// State, storage, and code combined processing time
	StateStoreCodeProcessingTimer metrics.Timer

	// Fine-grained code timers
	BuildStateDiffTimer                   metrics.Timer
	CreatedAndUpdatedStateTimer           metrics.Timer
	DeletedOrUpdatedStateTimer            metrics.Timer
	BuildAccountUpdatesTimer              metrics.Timer
	BuildAccountCreationsTimer            metrics.Timer
	ResolveNodeTimer                      metrics.Timer
	SortKeysTimer                         metrics.Timer
	FindIntersectionTimer                 metrics.Timer
	OutputTimer                           metrics.Timer
	IPLDOutputTimer                       metrics.Timer
	DifferenceIteratorNextTimer           metrics.Timer
	DifferenceIteratorCounter             metrics.Counter
	DeletedOrUpdatedStorageTimer          metrics.Timer
	CreatedAndUpdatedStorageTimer         metrics.Timer
	BuildStorageNodesIncrementalTimer     metrics.Timer
	BuildStateDiffObjectTimer             metrics.Timer
	WriteStateDiffObjectTimer             metrics.Timer
	BuildStorageNodesEventualTimer        metrics.Timer
	BuildStorageNodesFromTrieTimer        metrics.Timer
	BuildRemovedAccountStorageNodesTimer  metrics.Timer
	BuildRemovedStorageNodesFromTrieTimer metrics.Timer
	IsWatchedAddressTimer                 metrics.Timer
}

func RegisterIndexerMetrics(reg metrics.Registry) IndexerMetricsHandles {
	ctx := IndexerMetricsHandles{
		BlocksCounter:                         metrics.NewCounter(),
		TransactionsCounter:                   metrics.NewCounter(),
		ReceiptsCounter:                       metrics.NewCounter(),
		LogsCounter:                           metrics.NewCounter(),
		AccessListEntriesCounter:              metrics.NewCounter(),
		FreePostgresTimer:                     metrics.NewTimer(),
		PostgresCommitTimer:                   metrics.NewTimer(),
		HeaderProcessingTimer:                 metrics.NewTimer(),
		UncleProcessingTimer:                  metrics.NewTimer(),
		TxAndRecProcessingTimer:               metrics.NewTimer(),
		StateStoreCodeProcessingTimer:         metrics.NewTimer(),
		BuildStateDiffTimer:                   metrics.NewTimer(),
		CreatedAndUpdatedStateTimer:           metrics.NewTimer(),
		DeletedOrUpdatedStateTimer:            metrics.NewTimer(),
		BuildAccountUpdatesTimer:              metrics.NewTimer(),
		BuildAccountCreationsTimer:            metrics.NewTimer(),
		ResolveNodeTimer:                      metrics.NewTimer(),
		SortKeysTimer:                         metrics.NewTimer(),
		FindIntersectionTimer:                 metrics.NewTimer(),
		OutputTimer:                           metrics.NewTimer(),
		IPLDOutputTimer:                       metrics.NewTimer(),
		DifferenceIteratorNextTimer:           metrics.NewTimer(),
		DifferenceIteratorCounter:             metrics.NewCounter(),
		DeletedOrUpdatedStorageTimer:          metrics.NewTimer(),
		CreatedAndUpdatedStorageTimer:         metrics.NewTimer(),
		BuildStorageNodesIncrementalTimer:     metrics.NewTimer(),
		BuildStateDiffObjectTimer:             metrics.NewTimer(),
		WriteStateDiffObjectTimer:             metrics.NewTimer(),
		BuildStorageNodesEventualTimer:        metrics.NewTimer(),
		BuildStorageNodesFromTrieTimer:        metrics.NewTimer(),
		BuildRemovedAccountStorageNodesTimer:  metrics.NewTimer(),
		BuildRemovedStorageNodesFromTrieTimer: metrics.NewTimer(),
		IsWatchedAddressTimer:                 metrics.NewTimer(),
	}
	subsys := "indexer"
	reg.Register(metricName(subsys, "blocks"), ctx.BlocksCounter)
	reg.Register(metricName(subsys, "transactions"), ctx.TransactionsCounter)
	reg.Register(metricName(subsys, "receipts"), ctx.ReceiptsCounter)
	reg.Register(metricName(subsys, "logs"), ctx.LogsCounter)
	reg.Register(metricName(subsys, "access_list_entries"), ctx.AccessListEntriesCounter)
	reg.Register(metricName(subsys, "t_free_postgres"), ctx.FreePostgresTimer)
	reg.Register(metricName(subsys, "t_postgres_commit"), ctx.PostgresCommitTimer)
	reg.Register(metricName(subsys, "t_header_processing"), ctx.HeaderProcessingTimer)
	reg.Register(metricName(subsys, "t_uncle_processing"), ctx.UncleProcessingTimer)
	reg.Register(metricName(subsys, "t_tx_receipt_processing"), ctx.TxAndRecProcessingTimer)
	reg.Register(metricName(subsys, "t_state_store_code_processing"), ctx.StateStoreCodeProcessingTimer)
	reg.Register(metricName(subsys, "t_build_statediff"), ctx.BuildStateDiffTimer)
	reg.Register(metricName(subsys, "t_created_and_update_state"), ctx.CreatedAndUpdatedStateTimer)
	reg.Register(metricName(subsys, "t_deleted_or_updated_state"), ctx.DeletedOrUpdatedStateTimer)
	reg.Register(metricName(subsys, "t_build_account_updates"), ctx.BuildAccountUpdatesTimer)
	reg.Register(metricName(subsys, "t_build_account_creations"), ctx.BuildAccountCreationsTimer)
	reg.Register(metricName(subsys, "t_resolve_node"), ctx.ResolveNodeTimer)
	reg.Register(metricName(subsys, "t_sort_keys"), ctx.SortKeysTimer)
	reg.Register(metricName(subsys, "t_find_intersection"), ctx.FindIntersectionTimer)
	reg.Register(metricName(subsys, "t_output_fn"), ctx.OutputTimer)
	reg.Register(metricName(subsys, "t_ipld_output_fn"), ctx.IPLDOutputTimer)
	reg.Register(metricName(subsys, "t_difference_iterator_next"), ctx.DifferenceIteratorNextTimer)
	reg.Register(metricName(subsys, "difference_iterator_counter"), ctx.DifferenceIteratorCounter)
	reg.Register(metricName(subsys, "t_created_and_updated_storage"), ctx.CreatedAndUpdatedStorageTimer)
	reg.Register(metricName(subsys, "t_deleted_or_updated_storage"), ctx.DeletedOrUpdatedStorageTimer)
	reg.Register(metricName(subsys, "t_build_storage_nodes_incremental"), ctx.BuildStorageNodesIncrementalTimer)
	reg.Register(metricName(subsys, "t_build_statediff_object"), ctx.BuildStateDiffObjectTimer)
	reg.Register(metricName(subsys, "t_write_statediff_object"), ctx.WriteStateDiffObjectTimer)
	reg.Register(metricName(subsys, "t_created_and_updated_state"), ctx.CreatedAndUpdatedStateTimer)
	reg.Register(metricName(subsys, "t_build_storage_nodes_eventual"), ctx.BuildStorageNodesEventualTimer)
	reg.Register(metricName(subsys, "t_build_storage_nodes_from_trie"), ctx.BuildStorageNodesFromTrieTimer)
	reg.Register(metricName(subsys, "t_build_removed_accounts_storage_nodes"), ctx.BuildRemovedAccountStorageNodesTimer)
	reg.Register(metricName(subsys, "t_build_removed_storage_nodes_from_trie"), ctx.BuildRemovedStorageNodesFromTrieTimer)
	reg.Register(metricName(subsys, "t_is_watched_address"), ctx.IsWatchedAddressTimer)

	log.Debug("Registering statediff indexer metrics.")
	return ctx
}

type dbMetricsHandles struct {
	// Maximum number of open connections to the sql
	maxOpen metrics.Gauge
	// The number of established connections both in use and idle
	open metrics.Gauge
	// The number of connections currently in use
	inUse metrics.Gauge
	// The number of idle connections
	idle metrics.Gauge
	// The total number of connections waited for
	waitedFor metrics.Counter
	// The total time blocked waiting for a new connection
	blockedMilliseconds metrics.Counter
	// The total number of connections closed due to SetMaxIdleConns
	closedMaxIdle metrics.Counter
	// The total number of connections closed due to SetConnMaxLifetime
	closedMaxLifetime metrics.Counter
}

func RegisterDBMetrics(reg metrics.Registry) dbMetricsHandles {
	ctx := dbMetricsHandles{
		maxOpen:             metrics.NewGauge(),
		open:                metrics.NewGauge(),
		inUse:               metrics.NewGauge(),
		idle:                metrics.NewGauge(),
		waitedFor:           metrics.NewCounter(),
		blockedMilliseconds: metrics.NewCounter(),
		closedMaxIdle:       metrics.NewCounter(),
		closedMaxLifetime:   metrics.NewCounter(),
	}
	subsys := "connections"
	reg.Register(metricName(subsys, "max_open"), ctx.maxOpen)
	reg.Register(metricName(subsys, "open"), ctx.open)
	reg.Register(metricName(subsys, "in_use"), ctx.inUse)
	reg.Register(metricName(subsys, "idle"), ctx.idle)
	reg.Register(metricName(subsys, "waited_for"), ctx.waitedFor)
	reg.Register(metricName(subsys, "blocked_milliseconds"), ctx.blockedMilliseconds)
	reg.Register(metricName(subsys, "closed_max_idle"), ctx.closedMaxIdle)
	reg.Register(metricName(subsys, "closed_max_lifetime"), ctx.closedMaxLifetime)

	log.Debug("Registering statediff DB metrics.")
	return ctx
}

// DbStats interface to accommodate different concrete sql stats types
type DbStats interface {
	MaxOpen() int64
	Open() int64
	InUse() int64
	Idle() int64
	WaitCount() int64
	WaitDuration() time.Duration
	MaxIdleClosed() int64
	MaxLifetimeClosed() int64
}

func (met *dbMetricsHandles) Update(stats DbStats) {
	met.maxOpen.Update(stats.MaxOpen())
	met.open.Update(stats.Open())
	met.inUse.Update(stats.InUse())
	met.idle.Update(stats.Idle())
	met.waitedFor.Inc(stats.WaitCount())
	met.blockedMilliseconds.Inc(stats.WaitDuration().Milliseconds())
	met.closedMaxIdle.Inc(stats.MaxIdleClosed())
	met.closedMaxLifetime.Inc(stats.MaxLifetimeClosed())
}

func ReportAndUpdateDuration(msg string, start time.Time, logger log.Logger, timer metrics.Timer) {
	since := UpdateDuration(start, timer)
	// This is very noisy so we log at Trace.
	logger.Trace(msg, "duration", since)
}

func UpdateDuration(start time.Time, timer metrics.Timer) time.Duration {
	since := time.Since(start)
	timer.Update(since)
	return since
}