package operations

import (
	"archive/tar"
	"context"

	"github.com/pojntfx/stfs/internal/converters"
	models "github.com/pojntfx/stfs/internal/db/sqlite/models/metadata"
	"github.com/pojntfx/stfs/internal/encryption"
	"github.com/pojntfx/stfs/internal/persisters"
	"github.com/pojntfx/stfs/internal/records"
	"github.com/pojntfx/stfs/internal/signature"
	"github.com/pojntfx/stfs/internal/tarext"
	"github.com/pojntfx/stfs/pkg/config"
	"github.com/pojntfx/stfs/pkg/recovery"
)

func Delete(
	writer config.DriveWriterConfig,
	reader config.DriveReaderConfig,
	drive config.DriveConfig,
	metadata config.MetadataConfig,
	pipes config.PipeConfig,
	crypto config.CryptoConfig,

	recordSize int,
	name string,

	onHeader func(hdr *models.Header),
) error {
	dirty := false
	tw, cleanup, err := tarext.NewTapeWriter(writer.Drive, writer.DriveIsRegular, recordSize)
	if err != nil {
		return err
	}
	defer cleanup(&dirty)

	metadataPersister := persisters.NewMetadataPersister(metadata.Metadata)
	if err := metadataPersister.Open(); err != nil {
		return err
	}

	lastIndexedRecord, lastIndexedBlock, err := metadataPersister.GetLastIndexedRecordAndBlock(context.Background(), recordSize)
	if err != nil {
		return err
	}

	headersToDelete := []*models.Header{}
	dbhdr, err := metadataPersister.GetHeader(context.Background(), name)
	if err != nil {
		return err
	}
	headersToDelete = append(headersToDelete, dbhdr)

	// If the header refers to a directory, get it's children
	if dbhdr.Typeflag == tar.TypeDir {
		dbhdrs, err := metadataPersister.GetHeaderChildren(context.Background(), name)
		if err != nil {
			return err
		}

		headersToDelete = append(headersToDelete, dbhdrs...)
	}

	// Append deletion hdrs to the tape or tar file
	hdrs := []tar.Header{}
	for _, dbhdr := range headersToDelete {
		hdr, err := converters.DBHeaderToTarHeader(dbhdr)
		if err != nil {
			return err
		}

		hdr.Size = 0 // Don't try to seek after the record
		hdr.PAXRecords[records.STFSRecordVersion] = records.STFSRecordVersion1
		hdr.PAXRecords[records.STFSRecordAction] = records.STFSRecordActionDelete

		hdrs = append(hdrs, *hdr)

		if onHeader != nil {
			dbhdr, err := converters.TarHeaderToDBHeader(-1, -1, -1, -1, hdr)
			if err != nil {
				return err
			}

			onHeader(dbhdr)
		}

		if err := signature.SignHeader(hdr, writer.DriveIsRegular, pipes.Signature, crypto.Identity); err != nil {
			return err
		}

		if err := encryption.EncryptHeader(hdr, pipes.Encryption, crypto.Recipient); err != nil {
			return err
		}

		if err := tw.WriteHeader(hdr); err != nil {
			return err
		}

		dirty = true
	}

	return recovery.Index(
		reader,
		drive,
		metadata,
		pipes,
		crypto,

		recordSize,
		int(lastIndexedRecord),
		int(lastIndexedBlock),
		false,
		1, // Ignore the first header, which is the last header which we already indexed

		func(hdr *tar.Header, i int) error {
			if len(hdrs) <= i {
				return config.ErrTarHeaderMissing
			}

			*hdr = hdrs[i]

			return nil
		},
		func(hdr *tar.Header, isRegular bool) error {
			return nil // We sign above, no need to verify
		},

		onHeader,
	)
}