package writecachebitcask

import (
	"errors"
	"fmt"

	"git.frostfs.info/TrueCloudLab/frostfs-node/pkg/local_object_storage/shard/mode"
	"git.frostfs.info/TrueCloudLab/frostfs-node/pkg/local_object_storage/writecache"
	"git.frostfs.info/TrueCloudLab/frostfs-node/pkg/util/logger"
)

// SetLogger sets logger. It is used after the shard ID was generated to use it in logs.
func (c *cache) SetLogger(l *logger.Logger) {
	c.log = l
}

func (c *cache) DumpInfo() writecache.Info {
	return writecache.Info{
		Path: c.path,
	}
}

func (c *cache) Open(readOnly bool) error {
	// Validate
	if c.bucketCount&(c.bucketCount-1) != 0 {
		return fmt.Errorf("numBuckets must be a power of 2: got %d", c.bucketCount)
	}
	if c.regionCount&(c.regionCount-1) != 0 {
		return fmt.Errorf("numRegions must be a power of 2: got %d", c.regionCount)
	}
	if c.regionCount >= c.bucketCount {
		return errors.New("numBuckets must be greater than numRegions")
	}

	// Create regions
	c.regions = make([]*region, c.regionCount)
	for i := 0; i < c.regionCount; i++ {
		c.regions[i] = &region{
			opts:    &c.options,
			index:   i,
			keyDir:  make([][]*entry, c.bucketCount/c.regionCount),
			flushCh: make(chan uint32, c.maxPendingLogFileFlush),
		}
	}

	if readOnly {
		_ = c.SetMode(mode.ReadOnly)
	} else {
		_ = c.SetMode(mode.ReadWrite)
	}

	return nil
}

func (c *cache) Init() error {
	for _, r := range c.regions {
		go r.flushWorker()
		if err := r.init(); err != nil {
			r.close()
			return err
		}
	}
	return nil
}

func (c *cache) Close() error {
	var lastErr error
	if !c.closed.Swap(true) {
		for _, r := range c.regions {
			if err := r.close(); err != nil {
				lastErr = err
			}
		}
	}
	return lastErr
}

func (c *cache) SetMode(m mode.Mode) error {
	c.mode.Store(uint32(m))
	return nil
}