// Copyright 2024 PingCAP, Inc. Licensed under Apache-2.0.

package storage

import (
	"github.com/pingcap/log"
	"go.uber.org/zap"

	"github.com/pingcap-inc/clinic/pkg/ngm/keyviz/keyvisual/decorator"
	"github.com/pingcap-inc/clinic/pkg/ngm/keyviz/keyvisual/matrix"
	"github.com/pingcap-inc/clinic/pkg/ngm/keyviz/keyvisual/region"
)

// Source data pre processing parameters.
const (
	// preThreshold   = 128
	// preRatioTarget = 512.
	preTarget = 3072

	dirtyWrittenBytes uint64 = 1 << 32
)

// CreateStorageAxis converts the RegionsInfo to a StorageAxis.
func CreateStorageAxis(regions region.RegionsInfo, labeler decorator.Labeler) matrix.Axis {
	regionsLen := regions.Len()
	if regionsLen <= 0 {
		panic("At least one RegionInfo")
	}

	keys := regions.GetKeys()
	valuesList := make([][]uint64, len(region.ResponseTags))
	for i, tag := range region.ResponseTags {
		valuesList[i] = regions.GetValues(tag)
	}

	preAxis := matrix.CreateAxis(keys, valuesList)
	wash(&preAxis)

	axis := IntoStorageAxis(preAxis, labeler)
	log.Debug("New StorageAxis", zap.Int("region length", regionsLen), zap.Int("focus keys length", len(axis.Keys)))
	return axis
}

// IntoStorageAxis converts ResponseAxis to StorageAxis.
func IntoStorageAxis(responseAxis matrix.Axis, labeler decorator.Labeler) matrix.Axis {
	// axis := preAxis.Focus(strategy, preThreshold, len(keys)/preRatioTarget, preTarget)
	axis := responseAxis.Divide(labeler, preTarget)
	var storageValuesList [][]uint64
	storageValuesList = append(storageValuesList, axis.ValuesList[1:]...)
	return matrix.CreateAxis(axis.Keys, storageValuesList)
}

// IntoResponseAxis converts StorageAxis to ResponseAxis.
func IntoResponseAxis(storageAxis matrix.Axis, baseTag region.StatTag) matrix.Axis {
	// add integration values
	valuesList := make([][]uint64, 1, len(region.ResponseTags))
	writtenBytes := storageAxis.ValuesList[0]
	readBytes := storageAxis.ValuesList[1]
	integration := make([]uint64, len(writtenBytes))
	for i := range integration {
		integration[i] = writtenBytes[i] + readBytes[i]
	}
	valuesList[0] = integration
	valuesList = append(valuesList, storageAxis.ValuesList...)
	// swap baseTag
	for i, tag := range region.ResponseTags {
		if tag == baseTag {
			valuesList[0], valuesList[i] = valuesList[i], valuesList[0]
			return matrix.CreateAxis(storageAxis.Keys, valuesList)
		}
	}
	panic("unreachable")
}

// TODO: Temporary solution, need to trace the source of dirty data.
func wash(axis *matrix.Axis) {
	for i, value := range axis.ValuesList[1] {
		if value >= dirtyWrittenBytes {
			for j := range region.ResponseTags {
				axis.ValuesList[j][i] = 0
			}
		}
	}
}