use crate::config::WorldConfig;
use crate::region::Region;
use flate2::write::GzEncoder;
use flate2::Compression;
use std::convert::TryFrom;
use std::fs::{copy, create_dir, File};
use std::path::PathBuf;

/// Backup a file
///
/// # Param
/// * `file_name` - file name
/// * `world_path` - path to the world folder
/// * `backup_path` - path to the backup folder
pub fn backup_file(
    file_name: &str,
    mut world_path: PathBuf,
    mut backup_path: PathBuf,
) -> Result<u64, std::io::Error> {
    world_path.push(file_name);
    backup_path.push(file_name);

    copy(world_path, backup_path)
}

/// Backup a directory
///
/// # Param
/// * `dir_name` - directory name
/// * `world_path` - path to the world folder
/// * `backup_path` - path to the backup folder
pub fn backup_dir(
    dir_name: &str,
    world_path: &PathBuf,
    backup_path: &PathBuf,
) -> Result<u64, std::io::Error> {
    let mut src_dir = world_path.clone();
    src_dir.push(dir_name);
    let mut backup_dir = backup_path.clone();
    backup_dir.push(dir_name);
    create_dir(&backup_dir)?;

    let mut file_count = 0;
    for entry in src_dir.read_dir()? {
        let entry = entry?;
        let mut target = backup_dir.clone();
        target.push(entry.file_name());

        copy(entry.path(), target)?;
        file_count += 1;
    }

    Ok(file_count)
}

/// Backup the regions
///
/// # Param
/// * `dir_name` - name of the backup folder
/// * `save_radius` - block radius to save
/// * `world_path` - path to the world folder
/// * `backup_path` - path to the backup folder
pub fn backup_region(
    dir_name: &str,
    save_radius: u64,
    world_path: &PathBuf,
    backup_path: &PathBuf,
) -> Result<u64, std::io::Error> {
    let mut count: u64 = 0;
    let mut src_dir = world_path.clone();
    src_dir.push(dir_name);
    let mut backup_dir = backup_path.clone();
    backup_dir.push(dir_name);
    create_dir(&backup_dir)?;

    let save_radius = (save_radius as f64 / 512.0).ceil() as i64;

    for entry in src_dir.read_dir()? {
        let entry = entry?;
        let file_name = entry.file_name().to_str().unwrap().to_string();

        if let Ok(region) = Region::try_from(file_name) {
            if region.x.abs() <= save_radius && region.y.abs() <= save_radius {
                let mut target = backup_dir.clone();
                target.push(entry.file_name());

                copy(entry.path(), target)?;
                count += 1;
            }
        }
    }

    Ok(count)
}

/// Backup a world
///
/// # Param
/// * `world_path` - path to the world folder
/// * `backup_path` - path to the backup folder
/// * `world_config` - world config options
pub fn backup_world(
    world_path: PathBuf,
    mut backup_path: PathBuf,
    world_config: &WorldConfig,
) -> Result<u64, std::io::Error> {
    let region_count;
    backup_path.push(&world_config.world_name);
    create_dir(backup_path.as_path())?;

    backup_region("poi", world_config.save_radius, &world_path, &backup_path)?;
    region_count = backup_region(
        "region",
        world_config.save_radius,
        &world_path,
        &backup_path,
    )?;
    Ok(region_count)
}

/// Backup the overworld
///
/// # Param
/// * `world_path` - path to the world folder
/// * `backup_path` - path to the backup folder
/// * `world_config` - world config options
pub fn backup_overworld(
    world_path: PathBuf,
    backup_path: PathBuf,
    world_config: &WorldConfig,
) -> Result<(u64, u64), std::io::Error> {
    backup_dir("data", &world_path, &backup_path)?;
    backup_dir("stats", &world_path, &backup_path)?;

    backup_file("level.dat", world_path.clone(), backup_path.clone())?;
    backup_file("level.dat_old", world_path.clone(), backup_path.clone())?;
    backup_file("session.lock", world_path.clone(), backup_path.clone())?;
    backup_file("uid.dat", world_path.clone(), backup_path.clone())?;

    let player_count = backup_dir("playerdata", &world_path, &backup_path)?;
    let region_count = backup_world(world_path, backup_path, world_config)?;

    Ok((region_count, player_count))
}

/// Backup the nether
///
/// # Param
/// * `world_path` - path to the world folder
/// * `backup_path` - path to the backup folder
/// * `world_config` - world config options
pub fn backup_nether(
    world_path: PathBuf,
    backup_path: PathBuf,
    world_config: &WorldConfig,
) -> Result<u64, std::io::Error> {
    let mut nether_path = world_path;
    nether_path.push("DIM-1");

    backup_world(nether_path, backup_path, world_config)
}

/// Backup the end
///
/// # Param
/// * `world_path` - path to the world folder
/// * `backup_path` - path to the backup folder
/// * `world_config` - world config options
pub fn backup_end(
    world_path: PathBuf,
    backup_path: PathBuf,
    world_config: &WorldConfig,
) -> Result<u64, std::io::Error> {
    let mut end_path = world_path;
    end_path.push("DIM1");

    backup_world(end_path, backup_path, world_config)
}

/// Compress the backup after the files have been copied
///
/// # Param
/// * `tmp_dir`: tmp directory with the backed up files
/// * `output_file`: output archive
pub fn compress_backup(tmp_dir: &PathBuf, output_file: &PathBuf) -> Result<(), std::io::Error> {
    let archive = File::create(output_file)?;
    let enc = GzEncoder::new(archive, Compression::default());
    let mut tar_builder = tar::Builder::new(enc);
    tar_builder.append_dir_all(".", tmp_dir)?;
    Ok(())
}