package writecachebitcask

import (
	"context"
	"encoding/binary"

	"git.frostfs.info/TrueCloudLab/frostfs-node/pkg/local_object_storage/blobstor/common"
	"git.frostfs.info/TrueCloudLab/frostfs-node/pkg/local_object_storage/shard/mode"
	"git.frostfs.info/TrueCloudLab/frostfs-node/pkg/local_object_storage/writecache"
	objectSDK "git.frostfs.info/TrueCloudLab/frostfs-sdk-go/object"
	oid "git.frostfs.info/TrueCloudLab/frostfs-sdk-go/object/id"
)

func (c *cache) Get(_ context.Context, addr oid.Address) (*objectSDK.Object, error) {
	region := c.locateRegion(addr)
	return c.regions[region].get(addr)
}

func (c *cache) Head(_ context.Context, addr oid.Address) (*objectSDK.Object, error) {
	region := c.locateRegion(addr)
	return c.regions[region].get(addr)
}

func (c *cache) Put(ctx context.Context, req common.PutPrm) (common.PutRes, error) {
	if uint64(len(req.RawData)) > c.maxObjectSize {
		return common.PutRes{}, writecache.ErrBigObject
	}
	if mode.Mode(c.mode.Load()).ReadOnly() {
		return common.PutRes{}, writecache.ErrReadOnly
	}
	region := c.locateRegion(req.Address)
	return common.PutRes{}, c.regions[region].put(ctx, req.Address, req.RawData)
}

func (c *cache) Delete(ctx context.Context, addr oid.Address) error {
	if mode.Mode(c.mode.Load()).ReadOnly() {
		return writecache.ErrReadOnly
	}
	region := c.locateRegion(addr)
	return c.regions[region].delete(ctx, addr)
}

func (c *cache) locateRegion(addr oid.Address) int {
	id := addr.Object()
	h := binary.LittleEndian.Uint32(id[:4])
	region := h & (uint32(c.regionCount) - 1)
	return int(region)
}