//  Copyright (C) 2020 Éloïs SANCHEZ.
//
// 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 <https://www.gnu.org/licenses/>.

use crate::*;

pub(super) fn apply_block_blocks_chunk<B: Backend>(
    block: &DubpBlockV10,
    gva_db: &mut GvaV1DbTxRw<B::Col>,
) -> KvResult<()> {
    let block_number = block.number().0;
    gva_db.current_blocks_chunk.upsert(
        U32BE(block_number),
        GvaBlockDbV1(DubpBlock::V10(block.clone())),
    );

    if block_number % 1_000 == 999 {
        let current_chunk: Vec<GvaBlockDbV1> = gva_db
            .current_blocks_chunk
            .iter(.., |it| it.values().collect::<Result<Vec<_>, _>>())?;
        let current_chunk_bin = bincode_db()
            .serialize(&current_chunk)
            .map_err(|e| KvError::DeserError(e.into()))?;
        let chunk_hash = Hash::compute_blake3(current_chunk_bin.as_ref());
        let compressed_chunk = lz4_flex::compress_prepend_size(current_chunk_bin.as_ref());
        let chunk_index = U32BE(block_number / 1_000);
        gva_db
            .blocks_chunk_hash
            .upsert(chunk_index, HashDb(chunk_hash));
        gva_db
            .compressed_blocks_chunk
            .upsert(chunk_index, compressed_chunk);
    }

    Ok(())
}

pub(super) fn revert_block_blocks_chunk<B: Backend>(
    block: &DubpBlockV10,
    gva_db: &mut GvaV1DbTxRw<B::Col>,
) -> KvResult<()> {
    let block_number = block.number().0;
    if block_number % 1_000 == 999 {
        // Uncompress las compressed chunk and replace it in current chunk
        let chunk_index = U32BE(block_number / 1_000);
        if let Some(compressed_chunk) = gva_db.compressed_blocks_chunk.get(&chunk_index)? {
            gva_db.blocks_chunk_hash.remove(chunk_index);
            gva_db.compressed_blocks_chunk.remove(chunk_index);
            let current_chunk_bin = lz4_flex::decompress_size_prepended(compressed_chunk.as_ref())
                .map_err(|e| KvError::Custom(format!("{:?}", e).into()))?;
            let current_chunk: Vec<GvaBlockDbV1> = bincode_db()
                .deserialize(current_chunk_bin.as_ref())
                .map_err(|e| KvError::DeserError(e.into()))?;
            let current_chunk_begin = block_number - 999;
            for (i, block) in current_chunk.into_iter().enumerate() {
                gva_db
                    .current_blocks_chunk
                    .upsert(U32BE(current_chunk_begin + i as u32), block);
            }
        } else {
            return Err(KvError::DbCorrupted(
                "Not found last compressed chunk".to_owned(),
            ));
        }
    } else {
        gva_db.current_blocks_chunk.remove(U32BE(block_number));
    }

    Ok(())
}