use crate::backup::uncompress_backup;
use crate::chunk_coordinate::ChunkCoordinate;
use crate::error::Result;
use anvil_region::position::{RegionChunkPosition, RegionPosition};
use anvil_region::provider::{FolderRegionProvider, RegionProvider};
use std::fs::remove_dir_all;
use std::path::{Path, PathBuf};

/// Struct for manipulating a world from a backup
struct RestoreAccess {
    /// Chunk source
    src_path: PathBuf,
    /// Chunk destination
    dest_path: PathBuf,
}

impl RestoreAccess {
    /// Create new RestoreAccess
    pub fn new(world_name: &str, src_path: &Path, dest_path: &Path) -> Result<Self> {
        let src_path = uncompress_backup(src_path)?.join(world_name).join("region");
        let dest_path = dest_path.join(world_name).join("region");

        Ok(RestoreAccess {
            src_path,
            dest_path,
        })
    }

    /// Copy chunk from source to destination
    pub fn copy_chunk(&self, x: i32, z: i32) {
        let region_position = RegionPosition::from_chunk_position(x, z);
        let region_chunk_position = RegionChunkPosition::from_chunk_position(x, z);

        let src_provider = FolderRegionProvider::new(self.src_path.to_str().unwrap());
        let dest_provider = FolderRegionProvider::new(self.dest_path.to_str().unwrap());

        let mut src_region = src_provider.get_region(region_position).unwrap();
        let src_chunk_compound_tag = src_region
            .read_chunk(region_chunk_position)
            .expect("Unable to load chunk");

        let mut dst_region = dest_provider.get_region(region_position).unwrap();

        dst_region
            .write_chunk(region_chunk_position, src_chunk_compound_tag)
            .expect("Unable to write chunk");
    }

    /// Cleanup process
    pub fn cleanup(self) -> Result<()> {
        Ok(remove_dir_all("tmp")?)
    }
}

/// Restore a range of chunks from a backup
pub fn restore_range_from_backup(
    world_name: &str,
    lower: ChunkCoordinate,
    upper: ChunkCoordinate,
    backup_path: &Path,
    minecraft_dir: &Path,
) -> Result<u64> {
    let chunk_access = RestoreAccess::new(world_name, backup_path, minecraft_dir)?;
    let mut count = 0;

    for x in lower.x..=upper.x {
        for z in lower.z..=upper.z {
            chunk_access.copy_chunk(x, z);
            count += 1;
        }
    }

    chunk_access.cleanup()?;
    Ok(count)
}

/// Restore a single chunk from a backup
pub fn restore_chunk_from_backup(
    world_name: &str,
    chunk: ChunkCoordinate,
    backup_path: &Path,
    minecraft_dir: &Path,
) -> Result<()> {
    let chunk_access = RestoreAccess::new(world_name, backup_path, minecraft_dir)?;
    chunk_access.copy_chunk(chunk.x, chunk.z);

    chunk_access.cleanup()?;
    Ok(())
}