extern crate proxmox_backup;

use failure::*;
use std::os::unix::io::AsRawFd;

use proxmox_backup::tools;
use proxmox_backup::cli::command::*;
use proxmox_backup::api::schema::*;
use proxmox_backup::api::router::*;
//use proxmox_backup::backup::chunk_store::*;
//use proxmox_backup::backup::image_index::*;
//use proxmox_backup::config::datastore;
use proxmox_backup::catar::encoder::*;
use proxmox_backup::backup::chunker::*;
use proxmox_backup::backup::datastore::*;
use serde_json::{Value};

fn required_string_param<'a>(param: &'a Value, name: &str) -> &'a str {
    param[name].as_str().expect(&format!("missing parameter '{}'", name))
}

fn backup_dir(
    datastore: &DataStore,
    path: &str,
    dir: &mut nix::dir::Dir,
    target: &str,
    chunk_size: usize,
) -> Result<(), Error> {

    let mut target = std::path::PathBuf::from(target);

    if let Some(ext) = target.extension() {
        if ext != "aidx" {
            bail!("got wrong file extension - expected '.aidx'");
        }
    } else {
        target.set_extension("aidx");
    }

    // fixme: implement chunked writer
    // let writer = std::fs::OpenOptions::new()
    //    .create(true)
    //    .write(true)
    //    .truncate(true)
    //    .open("mytest.catar")?;

    let mut index = datastore.create_archive_writer(&target, chunk_size)?;

    let path = std::path::PathBuf::from(path);

    CaTarEncoder::encode(path, dir, index)?;

    Ok(())
}

fn backup_image(datastore: &DataStore, file: &std::fs::File, size: usize, target: &str, chunk_size: usize) -> Result<(), Error> {

    let mut target = std::path::PathBuf::from(target);

    if let Some(ext) = target.extension() {
        if ext != "iidx" {
            bail!("got wrong file extension - expected '.iidx'");
        }
    } else {
        target.set_extension("iidx");
    }

    let mut index = datastore.create_image_writer(&target, size, chunk_size)?;

    tools::file_chunker(file, chunk_size, |pos, chunk| {
        index.add_chunk(pos, chunk)?;
        Ok(true)
    })?;

    index.close()?; // commit changes

    Ok(())
}

fn create_backup(param: Value, _info: &ApiMethod) -> Result<Value, Error> {

    let filename = required_string_param(&param, "filename");
    let store = required_string_param(&param, "store");
    let target = required_string_param(&param, "target");

    let mut chunk_size = 4*1024*1024;

    if let Some(size) = param["chunk-size"].as_u64() {
        static SIZES: [u64; 7] = [64, 128, 256, 512, 1024, 2048, 4096];

        if SIZES.contains(&size) {
            chunk_size = (size as usize) * 1024;
        } else {
            bail!("Got unsupported chunk size '{}'", size);
        }
    }

    let datastore = DataStore::open(store)?;

    let file = std::fs::File::open(filename)?;
    let rawfd = file.as_raw_fd();
    let stat = nix::sys::stat::fstat(rawfd)?;

    if (stat.st_mode & libc::S_IFDIR) != 0 {
        println!("Backup directory '{}' to '{}'", filename, store);

        let mut dir = nix::dir::Dir::from_fd(rawfd)?;

        backup_dir(&datastore, &filename, &mut dir, &target, chunk_size)?;

    } else if (stat.st_mode & (libc::S_IFREG|libc::S_IFBLK)) != 0 {
        println!("Backup file '{}' to '{}'", filename, store);

        if stat.st_size <= 0 { bail!("got strange file size '{}'", stat.st_size); }
        let size = stat.st_size as usize;

        backup_image(&datastore, &file, size, &target, chunk_size)?;

        let idx = datastore.open_image_reader(target)?;
        idx.print_info();

    } else {
        bail!("unsupported file type (expected a directory, file or block device)");
    }

    //datastore.garbage_collection()?;

    Ok(Value::Null)
}


fn main() {

    let cmd_def = CliCommand::new(
        ApiMethod::new(
            create_backup,
            ObjectSchema::new("Create backup.")
                .required("filename", StringSchema::new("Source name (file or directory name)"))
                .required("store", StringSchema::new("Datastore name."))
                .required("target", StringSchema::new("Target name."))
                .optional(
                    "chunk-size",
                    IntegerSchema::new("Chunk size in KB. Must be a power of 2.")
                        .minimum(64)
                        .maximum(4096)
                        .default(4096)
                )
        ))
        .arg_param(vec!["filename", "target"])
        .completion_cb("store", proxmox_backup::config::datastore::complete_datastore_name);


    if let Err(err) = run_cli_command(&cmd_def.into()) {
        eprintln!("Error: {}", err);
        print_cli_usage();
        std::process::exit(-1);
    }

}