use std::collections::HashSet;
use std::io::{self, Read, Write, Seek, SeekFrom};
use std::path::{Path, PathBuf};
use std::pin::Pin;
use std::sync::{Arc, Mutex};
use std::task::Context;

use anyhow::{bail, format_err, Error};
use futures::stream::{StreamExt, TryStreamExt};
use serde_json::{json, Value};
use tokio::sync::mpsc;
use tokio_stream::wrappers::ReceiverStream;
use xdg::BaseDirectories;

use pathpatterns::{MatchEntry, MatchType, PatternFlag};
use proxmox_io::StdChannelWriter;
use proxmox_sys::fs::{file_get_json, replace_file, CreateOptions, image_size};
use proxmox_router::{ApiMethod, RpcEnvironment, cli::*};
use proxmox_schema::api;
use proxmox_time::{strftime_local, epoch_i64};
use proxmox_async::blocking::TokioWriterAdapter;
use pxar::accessor::{MaybeReady, ReadAt, ReadAtOperation};

use pbs_api_types::{
    BACKUP_ID_SCHEMA, BACKUP_TIME_SCHEMA, BACKUP_TYPE_SCHEMA,
    TRAFFIC_CONTROL_BURST_SCHEMA, TRAFFIC_CONTROL_RATE_SCHEMA,
    Authid, CryptMode, Fingerprint, GroupListItem, HumanByte,
    PruneListItem, PruneOptions, RateLimitConfig, SnapshotListItem,
    StorageStatus,
};
use pbs_client::{
    BACKUP_SOURCE_SCHEMA,
    BackupReader,
    BackupRepository,
    BackupSpecificationType,
    BackupStats,
    BackupWriter,
    ChunkStream,
    FixedChunkStream,
    HttpClient,
    PxarBackupStream,
    RemoteChunkReader,
    UploadOptions,
    delete_ticket_info,
    parse_backup_specification,
    view_task_result,
};
use pbs_client::catalog_shell::Shell;
use pbs_client::tools::{
    complete_archive_name, complete_auth_id, complete_backup_group, complete_backup_snapshot,
    complete_backup_source, complete_chunk_size, complete_group_or_snapshot,
    complete_img_archive_name, complete_pxar_archive_name, complete_repository, connect,
    connect_rate_limited, extract_repository_from_value,
    key_source::{
        crypto_parameters, format_key_source, get_encryption_key_password, KEYFD_SCHEMA,
        KEYFILE_SCHEMA, MASTER_PUBKEY_FD_SCHEMA, MASTER_PUBKEY_FILE_SCHEMA,
    },
    CHUNK_SIZE_SCHEMA, REPO_URL_SCHEMA,
};
use pbs_config::key_config::{KeyConfig, decrypt_key, rsa_encrypt_key_config};
use pbs_datastore::CATALOG_NAME;
use pbs_datastore::backup_info::{BackupDir, BackupGroup};
use pbs_datastore::catalog::{BackupCatalogWriter, CatalogReader, CatalogWriter};
use pbs_datastore::chunk_store::verify_chunk_size;
use pbs_datastore::dynamic_index::{BufferedDynamicReader, DynamicIndexReader};
use pbs_datastore::fixed_index::FixedIndexReader;
use pbs_datastore::index::IndexFile;
use pbs_datastore::manifest::{
    ENCRYPTED_KEY_BLOB_NAME, MANIFEST_BLOB_NAME, ArchiveType, BackupManifest, archive_type,
};
use pbs_datastore::read_chunk::AsyncReadChunk;
use pbs_tools::json;
use pbs_tools::crypt_config::CryptConfig;

mod benchmark;
pub use benchmark::*;
mod mount;
pub use mount::*;
mod task;
pub use task::*;
mod catalog;
pub use catalog::*;
mod snapshot;
pub use snapshot::*;
pub mod key;

fn record_repository(repo: &BackupRepository) {

    let base = match BaseDirectories::with_prefix("proxmox-backup") {
        Ok(v) => v,
        _ => return,
    };

    // usually $HOME/.cache/proxmox-backup/repo-list
    let path = match base.place_cache_file("repo-list") {
        Ok(v) => v,
        _ => return,
    };

    let mut data = file_get_json(&path, None).unwrap_or_else(|_| json!({}));

    let repo = repo.to_string();

    data[&repo] = json!{ data[&repo].as_i64().unwrap_or(0) + 1 };

    let mut map = serde_json::map::Map::new();

    loop {
        let mut max_used = 0;
        let mut max_repo = None;
        for (repo, count) in data.as_object().unwrap() {
            if map.contains_key(repo) { continue; }
            if let Some(count) = count.as_i64() {
                if count > max_used {
                    max_used = count;
                    max_repo = Some(repo);
                }
            }
        }
        if let Some(repo) = max_repo {
            map.insert(repo.to_owned(), json!(max_used));
        } else {
            break;
        }
        if map.len() > 10 { // store max. 10 repos
            break;
        }
    }

    let new_data = json!(map);

    let _ = replace_file(path, new_data.to_string().as_bytes(), CreateOptions::new(), false);
}

async fn api_datastore_list_snapshots(
    client: &HttpClient,
    store: &str,
    group: Option<BackupGroup>,
) -> Result<Value, Error> {

    let path = format!("api2/json/admin/datastore/{}/snapshots", store);

    let mut args = json!({});
    if let Some(group) = group {
        args["backup-type"] = group.backup_type().into();
        args["backup-id"] = group.backup_id().into();
    }

    let mut result = client.get(&path, Some(args)).await?;

    Ok(result["data"].take())
}

pub async fn api_datastore_latest_snapshot(
    client: &HttpClient,
    store: &str,
    group: BackupGroup,
) -> Result<(String, String, i64), Error> {

    let list = api_datastore_list_snapshots(client, store, Some(group.clone())).await?;
    let mut list: Vec<SnapshotListItem> = serde_json::from_value(list)?;

    if list.is_empty() {
        bail!("backup group {:?} does not contain any snapshots.", group.group_path());
    }

    list.sort_unstable_by(|a, b| b.backup_time.cmp(&a.backup_time));

    let backup_time = list[0].backup_time;

    Ok((group.backup_type().to_owned(), group.backup_id().to_owned(), backup_time))
}

async fn backup_directory<P: AsRef<Path>>(
    client: &BackupWriter,
    dir_path: P,
    archive_name: &str,
    chunk_size: Option<usize>,
    catalog: Arc<Mutex<CatalogWriter<TokioWriterAdapter<StdChannelWriter<Error>>>>>,
    pxar_create_options: pbs_client::pxar::PxarCreateOptions,
    upload_options: UploadOptions,
) -> Result<BackupStats, Error> {

    let pxar_stream = PxarBackupStream::open(
        dir_path.as_ref(),
        catalog,
        pxar_create_options,
    )?;
    let mut chunk_stream = ChunkStream::new(pxar_stream, chunk_size);

    let (tx, rx) = mpsc::channel(10); // allow to buffer 10 chunks

    let stream = ReceiverStream::new(rx)
        .map_err(Error::from);

    // spawn chunker inside a separate task so that it can run parallel
    tokio::spawn(async move {
        while let Some(v) = chunk_stream.next().await {
            let _ = tx.send(v).await;
        }
    });

    if upload_options.fixed_size.is_some() {
        bail!("cannot backup directory with fixed chunk size!");
    }

    let stats = client
        .upload_stream(archive_name, stream, upload_options)
        .await?;

    Ok(stats)
}

async fn backup_image<P: AsRef<Path>>(
    client: &BackupWriter,
    image_path: P,
    archive_name: &str,
    chunk_size: Option<usize>,
    upload_options: UploadOptions,
) -> Result<BackupStats, Error> {

    let path = image_path.as_ref().to_owned();

    let file = tokio::fs::File::open(path).await?;

    let stream = tokio_util::codec::FramedRead::new(file, tokio_util::codec::BytesCodec::new())
        .map_err(Error::from);

    let stream = FixedChunkStream::new(stream, chunk_size.unwrap_or(4*1024*1024));

    if upload_options.fixed_size.is_none() {
        bail!("cannot backup image with dynamic chunk size!");
    }

    let stats = client
        .upload_stream(archive_name, stream, upload_options)
        .await?;

    Ok(stats)
}

#[api(
   input: {
        properties: {
            repository: {
                schema: REPO_URL_SCHEMA,
                optional: true,
            },
            "output-format": {
                schema: OUTPUT_FORMAT,
                optional: true,
            },
        }
   }
)]
/// List backup groups.
async fn list_backup_groups(param: Value) -> Result<Value, Error> {

    let output_format = get_output_format(&param);

    let repo = extract_repository_from_value(&param)?;

    let client = connect(&repo)?;

    let path = format!("api2/json/admin/datastore/{}/groups", repo.store());

    let mut result = client.get(&path, None).await?;

    record_repository(&repo);

    let render_group_path = |_v: &Value, record: &Value| -> Result<String, Error> {
        let item: GroupListItem = serde_json::from_value(record.to_owned())?;
        let group = BackupGroup::new(item.backup_type, item.backup_id);
        Ok(group.group_path().to_str().unwrap().to_owned())
    };

    let render_last_backup = |_v: &Value, record: &Value| -> Result<String, Error> {
        let item: GroupListItem = serde_json::from_value(record.to_owned())?;
        let snapshot = BackupDir::new(item.backup_type, item.backup_id, item.last_backup)?;
        Ok(snapshot.relative_path().to_str().unwrap().to_owned())
    };

    let render_files = |_v: &Value, record: &Value| -> Result<String, Error> {
        let item: GroupListItem = serde_json::from_value(record.to_owned())?;
        Ok(pbs_tools::format::render_backup_file_list(&item.files))
    };

    let options = default_table_format_options()
        .sortby("backup-type", false)
        .sortby("backup-id", false)
        .column(ColumnConfig::new("backup-id").renderer(render_group_path).header("group"))
        .column(
            ColumnConfig::new("last-backup")
                .renderer(render_last_backup)
                .header("last snapshot")
                .right_align(false)
        )
        .column(ColumnConfig::new("backup-count"))
        .column(ColumnConfig::new("files").renderer(render_files));

    let mut data: Value = result["data"].take();

    let return_type = &pbs_api_types::ADMIN_DATASTORE_LIST_GROUPS_RETURN_TYPE;

    format_and_print_result_full(&mut data, return_type, &output_format, &options);

    Ok(Value::Null)
}

#[api(
   input: {
        properties: {
            repository: {
                schema: REPO_URL_SCHEMA,
                optional: true,
            },
            group: {
                type: String,
                description: "Backup group.",
            },
            "new-owner": {
                type: Authid,
            },
        }
   }
)]
/// Change owner of a backup group
async fn change_backup_owner(group: String, mut param: Value) -> Result<(), Error> {

    let repo = extract_repository_from_value(&param)?;

    let client = connect(&repo)?;

    param.as_object_mut().unwrap().remove("repository");

    let group: BackupGroup = group.parse()?;

    param["backup-type"] = group.backup_type().into();
    param["backup-id"] = group.backup_id().into();

    let path = format!("api2/json/admin/datastore/{}/change-owner", repo.store());
    client.post(&path, Some(param)).await?;

    record_repository(&repo);

    Ok(())
}

#[api(
   input: {
        properties: {
            repository: {
                schema: REPO_URL_SCHEMA,
                optional: true,
            },
        }
   }
)]
/// Try to login. If successful, store ticket.
async fn api_login(param: Value) -> Result<Value, Error> {

    let repo = extract_repository_from_value(&param)?;

    let client = connect(&repo)?;
    client.login().await?;

    record_repository(&repo);

    Ok(Value::Null)
}

#[api(
   input: {
        properties: {
            repository: {
                schema: REPO_URL_SCHEMA,
                optional: true,
            },
        }
   }
)]
/// Logout (delete stored ticket).
fn api_logout(param: Value) -> Result<Value, Error> {

    let repo = extract_repository_from_value(&param)?;

    delete_ticket_info("proxmox-backup", repo.host(), repo.user())?;

    Ok(Value::Null)
}

#[api(
   input: {
        properties: {
            repository: {
                schema: REPO_URL_SCHEMA,
                optional: true,
            },
            "output-format": {
                schema: OUTPUT_FORMAT,
                optional: true,
            },
        }
   }
)]
/// Show client and optional server version
async fn api_version(param: Value) -> Result<(), Error> {

    let output_format = get_output_format(&param);

    let mut version_info = json!({
        "client": {
            "version": pbs_buildcfg::PROXMOX_PKG_VERSION,
            "release": pbs_buildcfg::PROXMOX_PKG_RELEASE,
            "repoid": pbs_buildcfg::PROXMOX_PKG_REPOID,
        }
    });

    let repo = extract_repository_from_value(&param);
    if let Ok(repo) = repo {
        let client = connect(&repo)?;

        match client.get("api2/json/version", None).await {
            Ok(mut result) => version_info["server"] = result["data"].take(),
            Err(e) => eprintln!("could not connect to server - {}", e),
        }
    }
    if output_format == "text" {
        println!(
            "client version: {}.{}",
            pbs_buildcfg::PROXMOX_PKG_VERSION,
            pbs_buildcfg::PROXMOX_PKG_RELEASE,
        );
        if let Some(server) = version_info["server"].as_object() {
            let server_version = server["version"].as_str().unwrap();
            let server_release = server["release"].as_str().unwrap();
            println!("server version: {}.{}", server_version, server_release);
        }
    } else {
        format_and_print_result(&version_info, &output_format);
    }

    Ok(())
}

#[api(
    input: {
        properties: {
            repository: {
                schema: REPO_URL_SCHEMA,
                optional: true,
            },
            "output-format": {
                schema: OUTPUT_FORMAT,
                optional: true,
            },
        },
    },
)]
/// Start garbage collection for a specific repository.
async fn start_garbage_collection(param: Value) -> Result<Value, Error> {

    let repo = extract_repository_from_value(&param)?;

    let output_format = get_output_format(&param);

    let client = connect(&repo)?;

    let path = format!("api2/json/admin/datastore/{}/gc", repo.store());

    let result = client.post(&path, None).await?;

    record_repository(&repo);

    view_task_result(&client, result, &output_format).await?;

    Ok(Value::Null)
}

struct CatalogUploadResult {
    catalog_writer: Arc<Mutex<CatalogWriter<TokioWriterAdapter<StdChannelWriter<Error>>>>>,
    result: tokio::sync::oneshot::Receiver<Result<BackupStats, Error>>,
}

fn spawn_catalog_upload(
    client: Arc<BackupWriter>,
    encrypt: bool,
) -> Result<CatalogUploadResult, Error> {
    let (catalog_tx, catalog_rx) = std::sync::mpsc::sync_channel(10); // allow to buffer 10 writes
    let catalog_stream = proxmox_async::blocking::StdChannelStream(catalog_rx);
    let catalog_chunk_size = 512*1024;
    let catalog_chunk_stream = ChunkStream::new(catalog_stream, Some(catalog_chunk_size));

    let catalog_writer = Arc::new(Mutex::new(CatalogWriter::new(TokioWriterAdapter::new(StdChannelWriter::new(catalog_tx)))?));

    let (catalog_result_tx, catalog_result_rx) = tokio::sync::oneshot::channel();

    let upload_options = UploadOptions {
        encrypt,
        compress: true,
        ..UploadOptions::default()
    };

    tokio::spawn(async move {
        let catalog_upload_result = client
            .upload_stream(CATALOG_NAME, catalog_chunk_stream, upload_options)
            .await;

        if let Err(ref err) = catalog_upload_result {
            eprintln!("catalog upload error - {}", err);
            client.cancel();
        }

        let _ = catalog_result_tx.send(catalog_upload_result);
    });

    Ok(CatalogUploadResult { catalog_writer, result: catalog_result_rx })
}

#[api(
   input: {
       properties: {
           backupspec: {
               type: Array,
               description: "List of backup source specifications ([<label.ext>:<path>] ...)",
               items: {
                   schema: BACKUP_SOURCE_SCHEMA,
               }
           },
           repository: {
               schema: REPO_URL_SCHEMA,
               optional: true,
           },
           "include-dev": {
               description: "Include mountpoints with same st_dev number (see ``man fstat``) as specified files.",
               optional: true,
               items: {
                   type: String,
                   description: "Path to file.",
               }
           },
           "all-file-systems": {
               type: Boolean,
               description: "Include all mounted subdirectories.",
               optional: true,
           },
           keyfile: {
               schema: KEYFILE_SCHEMA,
               optional: true,
           },
           "keyfd": {
               schema: KEYFD_SCHEMA,
               optional: true,
           },
           "master-pubkey-file": {
               schema: MASTER_PUBKEY_FILE_SCHEMA,
               optional: true,
           },
           "master-pubkey-fd": {
               schema: MASTER_PUBKEY_FD_SCHEMA,
               optional: true,
           },
           "crypt-mode": {
               type: CryptMode,
               optional: true,
           },
           "skip-lost-and-found": {
               type: Boolean,
               description: "Skip lost+found directory.",
               optional: true,
           },
           "backup-type": {
               schema: BACKUP_TYPE_SCHEMA,
               optional: true,
           },
           "backup-id": {
               schema: BACKUP_ID_SCHEMA,
               optional: true,
           },
           "backup-time": {
               schema: BACKUP_TIME_SCHEMA,
               optional: true,
           },
           "chunk-size": {
               schema: CHUNK_SIZE_SCHEMA,
               optional: true,
           },
           rate: {
               schema: TRAFFIC_CONTROL_RATE_SCHEMA,
               optional: true,
           },
           burst: {
               schema: TRAFFIC_CONTROL_BURST_SCHEMA,
               optional: true,
           },
           "exclude": {
               type: Array,
               description: "List of paths or patterns for matching files to exclude.",
               optional: true,
               items: {
                   type: String,
                   description: "Path or match pattern.",
                }
           },
           "entries-max": {
               type: Integer,
               description: "Max number of entries to hold in memory.",
               optional: true,
               default: pbs_client::pxar::ENCODER_MAX_ENTRIES as isize,
           },
           "verbose": {
               type: Boolean,
               description: "Verbose output.",
               optional: true,
           },
       }
   }
)]
/// Create (host) backup.
async fn create_backup(
    param: Value,
    _info: &ApiMethod,
    _rpcenv: &mut dyn RpcEnvironment,
) -> Result<Value, Error> {

    let repo = extract_repository_from_value(&param)?;

    let backupspec_list = json::required_array_param(&param, "backupspec")?;

    let all_file_systems = param["all-file-systems"].as_bool().unwrap_or(false);

    let skip_lost_and_found = param["skip-lost-and-found"].as_bool().unwrap_or(false);

    let verbose = param["verbose"].as_bool().unwrap_or(false);

    let backup_time_opt = param["backup-time"].as_i64();

    let chunk_size_opt = param["chunk-size"].as_u64().map(|v| (v*1024) as usize);

    if let Some(size) = chunk_size_opt {
        verify_chunk_size(size)?;
    }

    let rate = match param["rate"].as_str() {
        Some(s) => Some(s.parse::<HumanByte>()?),
        None => None,
    };
    let burst = match param["burst"].as_str() {
        Some(s) => Some(s.parse::<HumanByte>()?),
        None => None,
    };

    let rate_limit = RateLimitConfig::with_same_inout(rate, burst);

    let crypto = crypto_parameters(&param)?;

    let backup_id = param["backup-id"].as_str().unwrap_or(proxmox_sys::nodename());

    let backup_type = param["backup-type"].as_str().unwrap_or("host");

    let include_dev = param["include-dev"].as_array();

    let entries_max = param["entries-max"].as_u64()
        .unwrap_or(pbs_client::pxar::ENCODER_MAX_ENTRIES as u64);

    let empty = Vec::new();
    let exclude_args = param["exclude"].as_array().unwrap_or(&empty);

    let mut pattern_list = Vec::with_capacity(exclude_args.len());
    for entry in exclude_args {
        let entry = entry.as_str().ok_or_else(|| format_err!("Invalid pattern string slice"))?;
        pattern_list.push(
            MatchEntry::parse_pattern(entry, PatternFlag::PATH_NAME, MatchType::Exclude)
                .map_err(|err| format_err!("invalid exclude pattern entry: {}", err))?
        );
    }

    let mut devices = if all_file_systems { None } else { Some(HashSet::new()) };

    if let Some(include_dev) = include_dev {
        if all_file_systems {
            bail!("option 'all-file-systems' conflicts with option 'include-dev'");
        }

        let mut set = HashSet::new();
        for path in include_dev {
            let path = path.as_str().unwrap();
            let stat = nix::sys::stat::stat(path)
                .map_err(|err| format_err!("fstat {:?} failed - {}", path, err))?;
            set.insert(stat.st_dev);
        }
        devices = Some(set);
    }

    let mut upload_list = vec![];
    let mut target_set = HashSet::new();

    for backupspec in backupspec_list {
        let spec = parse_backup_specification(backupspec.as_str().unwrap())?;
        let filename = &spec.config_string;
        let target = &spec.archive_name;

        if target_set.contains(target) {
            bail!("got target twice: '{}'", target);
        }
        target_set.insert(target.to_string());

        use std::os::unix::fs::FileTypeExt;

        let metadata = std::fs::metadata(filename)
            .map_err(|err| format_err!("unable to access '{}' - {}", filename, err))?;
        let file_type = metadata.file_type();

        match spec.spec_type {
            BackupSpecificationType::PXAR => {
                if !file_type.is_dir() {
                    bail!("got unexpected file type (expected directory)");
                }
                upload_list.push((BackupSpecificationType::PXAR, filename.to_owned(), format!("{}.didx", target), 0));
            }
            BackupSpecificationType::IMAGE => {
                if !(file_type.is_file() || file_type.is_block_device()) {
                    bail!("got unexpected file type (expected file or block device)");
                }

                let size = image_size(&PathBuf::from(filename))?;

                if size == 0 { bail!("got zero-sized file '{}'", filename); }

                upload_list.push((BackupSpecificationType::IMAGE, filename.to_owned(), format!("{}.fidx", target), size));
            }
            BackupSpecificationType::CONFIG => {
                if !file_type.is_file() {
                    bail!("got unexpected file type (expected regular file)");
                }
                upload_list.push((BackupSpecificationType::CONFIG, filename.to_owned(), format!("{}.blob", target), metadata.len()));
            }
            BackupSpecificationType::LOGFILE => {
                if !file_type.is_file() {
                    bail!("got unexpected file type (expected regular file)");
                }
                upload_list.push((BackupSpecificationType::LOGFILE, filename.to_owned(), format!("{}.blob", target), metadata.len()));
            }
        }
    }

    let backup_time = backup_time_opt.unwrap_or_else(epoch_i64);

    let client = connect_rate_limited(&repo, rate_limit)?;
    record_repository(&repo);

    println!("Starting backup: {}/{}/{}", backup_type, backup_id, BackupDir::backup_time_to_string(backup_time)?);

    println!("Client name: {}", proxmox_sys::nodename());

    let start_time = std::time::Instant::now();

    println!("Starting backup protocol: {}", strftime_local("%c", epoch_i64())?);

    let (crypt_config, rsa_encrypted_key) = match crypto.enc_key {
        None => (None, None),
        Some(key_with_source) => {
            println!(
                "{}",
                format_key_source(&key_with_source.source, "encryption")
            );

            let (key, created, fingerprint) =
                decrypt_key(&key_with_source.key, &get_encryption_key_password)?;
            println!("Encryption key fingerprint: {}", fingerprint);

            let crypt_config = CryptConfig::new(key)?;

            match crypto.master_pubkey {
                Some(pem_with_source) => {
                    println!("{}", format_key_source(&pem_with_source.source, "master"));

                    let rsa = openssl::rsa::Rsa::public_key_from_pem(&pem_with_source.key)?;

                    let mut key_config = KeyConfig::without_password(key)?;
                    key_config.created = created; // keep original value

                    let enc_key = rsa_encrypt_key_config(rsa, &key_config)?;

                    (Some(Arc::new(crypt_config)), Some(enc_key))
                },
                _ => (Some(Arc::new(crypt_config)), None),
            }
        }
    };

    let client = BackupWriter::start(
        client,
        crypt_config.clone(),
        repo.store(),
        backup_type,
        backup_id,
        backup_time,
        verbose,
        false
    ).await?;

    let download_previous_manifest = match client.previous_backup_time().await {
        Ok(Some(backup_time)) => {
            println!(
                "Downloading previous manifest ({})",
                strftime_local("%c", backup_time)?
            );
            true
        }
        Ok(None) => {
            println!("No previous manifest available.");
            false
        }
        Err(_) => {
            // Fallback for outdated server, TODO remove/bubble up with 2.0
            true
        }
    };

    let previous_manifest = if download_previous_manifest {
        match client.download_previous_manifest().await {
            Ok(previous_manifest) => {
                match previous_manifest.check_fingerprint(crypt_config.as_ref().map(Arc::as_ref)) {
                    Ok(()) => Some(Arc::new(previous_manifest)),
                    Err(err) => {
                        println!("Couldn't re-use previous manifest - {}", err);
                        None
                    }
                }
            }
            Err(err) => {
                println!("Couldn't download previous manifest - {}", err);
                None
            }
        }
    } else {
        None
    };

    let snapshot = BackupDir::new(backup_type, backup_id, backup_time)?;
    let mut manifest = BackupManifest::new(snapshot);

    let mut catalog = None;
    let mut catalog_result_rx = None;

    for (backup_type, filename, target, size) in upload_list {
        match backup_type {
            BackupSpecificationType::CONFIG => {
                let upload_options = UploadOptions {
                    compress: true,
                    encrypt: crypto.mode == CryptMode::Encrypt,
                    ..UploadOptions::default()
                };

                println!("Upload config file '{}' to '{}' as {}", filename, repo, target);
                let stats = client
                    .upload_blob_from_file(&filename, &target, upload_options)
                    .await?;
                manifest.add_file(target, stats.size, stats.csum, crypto.mode)?;
            }
            BackupSpecificationType::LOGFILE => { // fixme: remove - not needed anymore ?
                let upload_options = UploadOptions {
                    compress: true,
                    encrypt: crypto.mode == CryptMode::Encrypt,
                    ..UploadOptions::default()
                };

                println!("Upload log file '{}' to '{}' as {}", filename, repo, target);
                let stats = client
                    .upload_blob_from_file(&filename, &target, upload_options)
                    .await?;
                manifest.add_file(target, stats.size, stats.csum, crypto.mode)?;
            }
            BackupSpecificationType::PXAR => {
                // start catalog upload on first use
                if catalog.is_none() {
                    let catalog_upload_res = spawn_catalog_upload(client.clone(), crypto.mode == CryptMode::Encrypt)?;
                    catalog = Some(catalog_upload_res.catalog_writer);
                    catalog_result_rx = Some(catalog_upload_res.result);
                }
                let catalog = catalog.as_ref().unwrap();

                println!("Upload directory '{}' to '{}' as {}", filename, repo, target);
                catalog.lock().unwrap().start_directory(std::ffi::CString::new(target.as_str())?.as_c_str())?;

                let pxar_options = pbs_client::pxar::PxarCreateOptions {
                    device_set: devices.clone(),
                    patterns: pattern_list.clone(),
                    entries_max: entries_max as usize,
                    skip_lost_and_found,
                    verbose,
                };

                let upload_options = UploadOptions {
                    previous_manifest: previous_manifest.clone(),
                    compress: true,
                    encrypt: crypto.mode == CryptMode::Encrypt,
                    ..UploadOptions::default()
                };

                let stats = backup_directory(
                    &client,
                    &filename,
                    &target,
                    chunk_size_opt,
                    catalog.clone(),
                    pxar_options,
                    upload_options,
                ).await?;
                manifest.add_file(target, stats.size, stats.csum, crypto.mode)?;
                catalog.lock().unwrap().end_directory()?;
            }
            BackupSpecificationType::IMAGE => {
                println!("Upload image '{}' to '{:?}' as {}", filename, repo, target);

                let upload_options = UploadOptions {
                    previous_manifest: previous_manifest.clone(),
                    fixed_size: Some(size),
                    compress: true,
                    encrypt: crypto.mode == CryptMode::Encrypt,
                };

                let stats = backup_image(
                    &client,
                    &filename,
                    &target,
                    chunk_size_opt,
                    upload_options,
                ).await?;
                manifest.add_file(target, stats.size, stats.csum, crypto.mode)?;
            }
        }
    }

    // finalize and upload catalog
    if let Some(catalog) = catalog {
        let mutex = Arc::try_unwrap(catalog)
            .map_err(|_| format_err!("unable to get catalog (still used)"))?;
        let mut catalog = mutex.into_inner().unwrap();

        catalog.finish()?;

        drop(catalog); // close upload stream

        if let Some(catalog_result_rx) = catalog_result_rx {
            let stats = catalog_result_rx.await??;
            manifest.add_file(CATALOG_NAME.to_owned(), stats.size, stats.csum, crypto.mode)?;
        }
    }

    if let Some(rsa_encrypted_key) = rsa_encrypted_key {
        let target = ENCRYPTED_KEY_BLOB_NAME;
        println!("Upload RSA encoded key to '{:?}' as {}", repo, target);
        let options = UploadOptions { compress: false, encrypt: false, ..UploadOptions::default() };
        let stats = client
            .upload_blob_from_data(rsa_encrypted_key, target, options)
            .await?;
        manifest.add_file(target.to_string(), stats.size, stats.csum, crypto.mode)?;

    }
    // create manifest (index.json)
    // manifests are never encrypted, but include a signature
    let manifest = manifest.to_string(crypt_config.as_ref().map(Arc::as_ref))
        .map_err(|err| format_err!("unable to format manifest - {}", err))?;


    if verbose { println!("Upload index.json to '{}'", repo) };
    let options = UploadOptions { compress: true, encrypt: false, ..UploadOptions::default() };
    client
        .upload_blob_from_data(manifest.into_bytes(), MANIFEST_BLOB_NAME, options)
        .await?;

    client.finish().await?;

    let end_time = std::time::Instant::now();
    let elapsed = end_time.duration_since(start_time);
    println!("Duration: {:.2}s", elapsed.as_secs_f64());

    println!("End Time: {}", strftime_local("%c", epoch_i64())?);

    Ok(Value::Null)
}

async fn dump_image<W: Write>(
    client: Arc<BackupReader>,
    crypt_config: Option<Arc<CryptConfig>>,
    crypt_mode: CryptMode,
    index: FixedIndexReader,
    mut writer: W,
    verbose: bool,
) -> Result<(), Error> {

    let most_used = index.find_most_used_chunks(8);

    let chunk_reader = RemoteChunkReader::new(client.clone(), crypt_config, crypt_mode, most_used);

    // Note: we avoid using BufferedFixedReader, because that add an additional buffer/copy
    // and thus slows down reading. Instead, directly use RemoteChunkReader
    let mut per = 0;
    let mut bytes = 0;
    let start_time = std::time::Instant::now();

    for pos in 0..index.index_count() {
        let digest = index.index_digest(pos).unwrap();
        let raw_data = chunk_reader.read_chunk(digest).await?;
        writer.write_all(&raw_data)?;
        bytes += raw_data.len();
        if verbose {
            let next_per = ((pos+1)*100)/index.index_count();
            if per != next_per {
                eprintln!("progress {}% (read {} bytes, duration {} sec)",
                          next_per, bytes, start_time.elapsed().as_secs());
                per = next_per;
            }
        }
    }

    let end_time = std::time::Instant::now();
    let elapsed = end_time.duration_since(start_time);
    eprintln!("restore image complete (bytes={}, duration={:.2}s, speed={:.2}MB/s)",
              bytes,
              elapsed.as_secs_f64(),
              bytes as f64/(1024.0*1024.0*elapsed.as_secs_f64())
    );


    Ok(())
}

fn parse_archive_type(name: &str) -> (String, ArchiveType) {
    if name.ends_with(".didx") || name.ends_with(".fidx") || name.ends_with(".blob") {
        (name.into(), archive_type(name).unwrap())
    } else if name.ends_with(".pxar") {
        (format!("{}.didx", name), ArchiveType::DynamicIndex)
    } else if name.ends_with(".img") {
        (format!("{}.fidx", name), ArchiveType::FixedIndex)
    } else {
        (format!("{}.blob", name), ArchiveType::Blob)
    }
}

#[api(
   input: {
       properties: {
           repository: {
               schema: REPO_URL_SCHEMA,
               optional: true,
           },
           snapshot: {
               type: String,
               description: "Group/Snapshot path.",
           },
           "archive-name": {
               description: "Backup archive name.",
               type: String,
           },
           target: {
               type: String,
               description: r###"Target directory path. Use '-' to write to standard output.

We do not extract '.pxar' archives when writing to standard output.

"###
           },
           rate: {
               schema: TRAFFIC_CONTROL_RATE_SCHEMA,
               optional: true,
           },
           burst: {
               schema: TRAFFIC_CONTROL_BURST_SCHEMA,
               optional: true,
           },
           "allow-existing-dirs": {
               type: Boolean,
               description: "Do not fail if directories already exists.",
               optional: true,
           },
           keyfile: {
               schema: KEYFILE_SCHEMA,
               optional: true,
           },
           "keyfd": {
               schema: KEYFD_SCHEMA,
               optional: true,
           },
           "crypt-mode": {
               type: CryptMode,
               optional: true,
           },
       }
   }
)]
/// Restore backup repository.
async fn restore(param: Value) -> Result<Value, Error> {
    let repo = extract_repository_from_value(&param)?;

    let verbose = param["verbose"].as_bool().unwrap_or(false);

    let allow_existing_dirs = param["allow-existing-dirs"].as_bool().unwrap_or(false);

    let archive_name = json::required_string_param(&param, "archive-name")?;

    let rate = match param["rate"].as_str() {
        Some(s) => Some(s.parse::<HumanByte>()?),
        None => None,
    };
    let burst = match param["burst"].as_str() {
        Some(s) => Some(s.parse::<HumanByte>()?),
        None => None,
    };

    let rate_limit = RateLimitConfig::with_same_inout(rate, burst);

    let client = connect_rate_limited(&repo, rate_limit)?;
    record_repository(&repo);

    let path = json::required_string_param(&param, "snapshot")?;

    let (backup_type, backup_id, backup_time) = if path.matches('/').count() == 1 {
        let group: BackupGroup = path.parse()?;
        api_datastore_latest_snapshot(&client, repo.store(), group).await?
    } else {
        let snapshot: BackupDir = path.parse()?;
        (snapshot.group().backup_type().to_owned(), snapshot.group().backup_id().to_owned(), snapshot.backup_time())
    };

    let target = json::required_string_param(&param, "target")?;
    let target = if target == "-" { None } else { Some(target) };

    let crypto = crypto_parameters(&param)?;

    let crypt_config = match crypto.enc_key {
        None => None,
        Some(ref key) => {
            let (key, _, _) =
                decrypt_key(&key.key, &get_encryption_key_password).map_err(|err| {
                    eprintln!("{}", format_key_source(&key.source, "encryption"));
                    err
                })?;
            Some(Arc::new(CryptConfig::new(key)?))
        }
    };

    let client = BackupReader::start(
        client,
        crypt_config.clone(),
        repo.store(),
        &backup_type,
        &backup_id,
        backup_time,
        true,
    ).await?;

    let (archive_name, archive_type) = parse_archive_type(archive_name);

    let (manifest, backup_index_data) = client.download_manifest().await?;

    if archive_name == ENCRYPTED_KEY_BLOB_NAME && crypt_config.is_none() {
        eprintln!("Restoring encrypted key blob without original key - skipping manifest fingerprint check!")
    } else {
        if manifest.signature.is_some() {
            if let Some(key) = &crypto.enc_key {
                eprintln!("{}", format_key_source(&key.source, "encryption"));
            }
            if let Some(config) = &crypt_config {
                eprintln!("Fingerprint: {}", Fingerprint::new(config.fingerprint()));
            }
        }
        manifest.check_fingerprint(crypt_config.as_ref().map(Arc::as_ref))?;
    }

    if archive_name == MANIFEST_BLOB_NAME {
        if let Some(target) = target {
            replace_file(target, &backup_index_data, CreateOptions::new(), false)?;
        } else {
            let stdout = std::io::stdout();
            let mut writer = stdout.lock();
            writer.write_all(&backup_index_data)
                .map_err(|err| format_err!("unable to pipe data - {}", err))?;
        }

        return Ok(Value::Null);
    }

    let file_info = manifest.lookup_file_info(&archive_name)?;

    if archive_type == ArchiveType::Blob {

        let mut reader = client.download_blob(&manifest, &archive_name).await?;

        if let Some(target) = target {
           let mut writer = std::fs::OpenOptions::new()
                .write(true)
                .create(true)
                .create_new(true)
                .open(target)
                .map_err(|err| format_err!("unable to create target file {:?} - {}", target, err))?;
            std::io::copy(&mut reader, &mut writer)?;
        } else {
            let stdout = std::io::stdout();
            let mut writer = stdout.lock();
            std::io::copy(&mut reader, &mut writer)
                .map_err(|err| format_err!("unable to pipe data - {}", err))?;
        }

    } else if archive_type == ArchiveType::DynamicIndex {

        let index = client.download_dynamic_index(&manifest, &archive_name).await?;

        let most_used = index.find_most_used_chunks(8);

        let chunk_reader = RemoteChunkReader::new(client.clone(), crypt_config, file_info.chunk_crypt_mode(), most_used);

        let mut reader = BufferedDynamicReader::new(index, chunk_reader);

        let options = pbs_client::pxar::PxarExtractOptions {
            match_list: &[],
            extract_match_default: true,
            allow_existing_dirs,
            on_error: None,
        };

        if let Some(target) = target {
            pbs_client::pxar::extract_archive(
                pxar::decoder::Decoder::from_std(reader)?,
                Path::new(target),
                pbs_client::pxar::Flags::DEFAULT,
                |path| {
                    if verbose {
                        println!("{:?}", path);
                    }
                },
                options,
            )
            .map_err(|err| format_err!("error extracting archive - {}", err))?;
        } else {
            let mut writer = std::fs::OpenOptions::new()
                .write(true)
                .open("/dev/stdout")
                .map_err(|err| format_err!("unable to open /dev/stdout - {}", err))?;

            std::io::copy(&mut reader, &mut writer)
                .map_err(|err| format_err!("unable to pipe data - {}", err))?;
        }
    } else if archive_type == ArchiveType::FixedIndex {

        let index = client.download_fixed_index(&manifest, &archive_name).await?;

        let mut writer = if let Some(target) = target {
            std::fs::OpenOptions::new()
                .write(true)
                .create(true)
                .create_new(true)
                .open(target)
                .map_err(|err| format_err!("unable to create target file {:?} - {}", target, err))?
        } else {
            std::fs::OpenOptions::new()
                .write(true)
                .open("/dev/stdout")
                .map_err(|err| format_err!("unable to open /dev/stdout - {}", err))?
        };

        dump_image(client.clone(), crypt_config.clone(), file_info.chunk_crypt_mode(), index, &mut writer, verbose).await?;
    }

    Ok(Value::Null)
}

#[api(
    input: {
        properties: {
            "dry-run": {
                type: bool,
                optional: true,
                description: "Just show what prune would do, but do not delete anything.",
            },
            group: {
                type: String,
                description: "Backup group",
            },
            "prune-options": {
                type: PruneOptions,
                flatten: true,
            },
            "output-format": {
                schema: OUTPUT_FORMAT,
                optional: true,
            },
            quiet: {
                type: bool,
                optional: true,
                default: false,
                description: "Minimal output - only show removals.",
            },
            repository: {
                schema: REPO_URL_SCHEMA,
                optional: true,
            },
        },
    },
)]
/// Prune a backup repository.
async fn prune(
    dry_run: Option<bool>,
    group: String,
    prune_options: PruneOptions,
    quiet: bool,
    mut param: Value
) -> Result<Value, Error> {
    let repo = extract_repository_from_value(&param)?;

    let client = connect(&repo)?;

    let path = format!("api2/json/admin/datastore/{}/prune", repo.store());

    let group: BackupGroup = group.parse()?;

    let output_format = extract_output_format(&mut param);

    let mut api_param = serde_json::to_value(prune_options)?;
    if let Some(dry_run) = dry_run {
        api_param["dry-run"] = dry_run.into();
    }
    api_param["backup-type"] = group.backup_type().into();
    api_param["backup-id"] = group.backup_id().into();

    let mut result = client.post(&path, Some(api_param)).await?;

    record_repository(&repo);

    let render_snapshot_path = |_v: &Value, record: &Value| -> Result<String, Error> {
        let item: PruneListItem = serde_json::from_value(record.to_owned())?;
        let snapshot = BackupDir::new(item.backup_type, item.backup_id, item.backup_time)?;
        Ok(snapshot.relative_path().to_str().unwrap().to_owned())
    };

    let render_prune_action = |v: &Value, _record: &Value| -> Result<String, Error> {
        Ok(match v.as_bool() {
            Some(true) => "keep",
            Some(false) => "remove",
            None => "unknown",
        }.to_string())
    };

    let options = default_table_format_options()
        .sortby("backup-type", false)
        .sortby("backup-id", false)
        .sortby("backup-time", false)
        .column(ColumnConfig::new("backup-id").renderer(render_snapshot_path).header("snapshot"))
        .column(ColumnConfig::new("backup-time").renderer(pbs_tools::format::render_epoch).header("date"))
        .column(ColumnConfig::new("keep").renderer(render_prune_action).header("action"))
        ;

    let return_type = &pbs_api_types::ADMIN_DATASTORE_PRUNE_RETURN_TYPE;

    let mut data = result["data"].take();

    if quiet {
        let list: Vec<Value> = data.as_array().unwrap().iter().filter(|item| {
            item["keep"].as_bool() == Some(false)
        }).cloned().collect();
        data = list.into();
    }

    format_and_print_result_full(&mut data, return_type, &output_format, &options);

    Ok(Value::Null)
}

#[api(
   input: {
       properties: {
           repository: {
               schema: REPO_URL_SCHEMA,
               optional: true,
           },
           "output-format": {
               schema: OUTPUT_FORMAT,
               optional: true,
           },
       }
   },
    returns: {
        type: StorageStatus,
    },
)]
/// Get repository status.
async fn status(param: Value) -> Result<Value, Error> {

    let repo = extract_repository_from_value(&param)?;

    let output_format = get_output_format(&param);

    let client = connect(&repo)?;

    let path = format!("api2/json/admin/datastore/{}/status", repo.store());

    let mut result = client.get(&path, None).await?;
    let mut data = result["data"].take();

    record_repository(&repo);

    let render_total_percentage = |v: &Value, record: &Value| -> Result<String, Error> {
        let v = v.as_u64().unwrap();
        let total = record["total"].as_u64().unwrap();
        let roundup = total/200;
        let per = ((v+roundup)*100)/total;
        let info = format!(" ({} %)", per);
        Ok(format!("{} {:>8}", v, info))
    };

    let options = default_table_format_options()
        .noheader(true)
        .column(ColumnConfig::new("total").renderer(render_total_percentage))
        .column(ColumnConfig::new("used").renderer(render_total_percentage))
        .column(ColumnConfig::new("avail").renderer(render_total_percentage));

    let return_type = &API_METHOD_STATUS.returns;

    format_and_print_result_full(&mut data, return_type, &output_format, &options);

    Ok(Value::Null)
}

/// This is a workaround until we have cleaned up the chunk/reader/... infrastructure for better
/// async use!
///
/// Ideally BufferedDynamicReader gets replaced so the LruCache maps to `BroadcastFuture<Chunk>`,
/// so that we can properly access it from multiple threads simultaneously while not issuing
/// duplicate simultaneous reads over http.
pub struct BufferedDynamicReadAt {
    inner: Mutex<BufferedDynamicReader<RemoteChunkReader>>,
}

impl BufferedDynamicReadAt {
    fn new(inner: BufferedDynamicReader<RemoteChunkReader>) -> Self {
        Self {
            inner: Mutex::new(inner),
        }
    }
}

impl ReadAt for BufferedDynamicReadAt {
    fn start_read_at<'a>(
        self: Pin<&'a Self>,
        _cx: &mut Context,
        buf: &'a mut [u8],
        offset: u64,
    ) -> MaybeReady<io::Result<usize>, ReadAtOperation<'a>> {
        MaybeReady::Ready(tokio::task::block_in_place(move || {
            let mut reader = self.inner.lock().unwrap();
            reader.seek(SeekFrom::Start(offset))?;
            reader.read(buf)
        }))
    }

    fn poll_complete<'a>(
        self: Pin<&'a Self>,
        _op: ReadAtOperation<'a>,
    ) -> MaybeReady<io::Result<usize>, ReadAtOperation<'a>> {
        panic!("BufferedDynamicReadAt::start_read_at returned Pending");
    }
}

fn main() {
    pbs_tools::setup_libc_malloc_opts();

    let backup_cmd_def = CliCommand::new(&API_METHOD_CREATE_BACKUP)
        .arg_param(&["backupspec"])
        .completion_cb("repository", complete_repository)
        .completion_cb("backupspec", complete_backup_source)
        .completion_cb("keyfile", complete_file_name)
        .completion_cb("master-pubkey-file", complete_file_name)
        .completion_cb("chunk-size", complete_chunk_size);

    let benchmark_cmd_def = CliCommand::new(&API_METHOD_BENCHMARK)
        .completion_cb("repository", complete_repository)
        .completion_cb("keyfile", complete_file_name);

    let list_cmd_def = CliCommand::new(&API_METHOD_LIST_BACKUP_GROUPS)
        .completion_cb("repository", complete_repository);

    let garbage_collect_cmd_def = CliCommand::new(&API_METHOD_START_GARBAGE_COLLECTION)
        .completion_cb("repository", complete_repository);

    let restore_cmd_def = CliCommand::new(&API_METHOD_RESTORE)
        .arg_param(&["snapshot", "archive-name", "target"])
        .completion_cb("repository", complete_repository)
        .completion_cb("snapshot", complete_group_or_snapshot)
        .completion_cb("archive-name", complete_archive_name)
        .completion_cb("target", complete_file_name);

    let prune_cmd_def = CliCommand::new(&API_METHOD_PRUNE)
        .arg_param(&["group"])
        .completion_cb("group", complete_backup_group)
        .completion_cb("repository", complete_repository);

    let status_cmd_def = CliCommand::new(&API_METHOD_STATUS)
        .completion_cb("repository", complete_repository);

    let login_cmd_def = CliCommand::new(&API_METHOD_API_LOGIN)
        .completion_cb("repository", complete_repository);

    let logout_cmd_def = CliCommand::new(&API_METHOD_API_LOGOUT)
        .completion_cb("repository", complete_repository);

    let version_cmd_def = CliCommand::new(&API_METHOD_API_VERSION)
        .completion_cb("repository", complete_repository);

    let change_owner_cmd_def = CliCommand::new(&API_METHOD_CHANGE_BACKUP_OWNER)
        .arg_param(&["group", "new-owner"])
        .completion_cb("group", complete_backup_group)
        .completion_cb("new-owner",  complete_auth_id)
        .completion_cb("repository", complete_repository);

    let cmd_def = CliCommandMap::new()
        .insert("backup", backup_cmd_def)
        .insert("garbage-collect", garbage_collect_cmd_def)
        .insert("list", list_cmd_def)
        .insert("login", login_cmd_def)
        .insert("logout", logout_cmd_def)
        .insert("prune", prune_cmd_def)
        .insert("restore", restore_cmd_def)
        .insert("snapshot", snapshot_mgtm_cli())
        .insert("status", status_cmd_def)
        .insert("key", key::cli())
        .insert("mount", mount_cmd_def())
        .insert("map", map_cmd_def())
        .insert("unmap", unmap_cmd_def())
        .insert("catalog", catalog_mgmt_cli())
        .insert("task", task_mgmt_cli())
        .insert("version", version_cmd_def)
        .insert("benchmark", benchmark_cmd_def)
        .insert("change-owner", change_owner_cmd_def)

        .alias(&["files"], &["snapshot", "files"])
        .alias(&["forget"], &["snapshot", "forget"])
        .alias(&["upload-log"], &["snapshot", "upload-log"])
        .alias(&["snapshots"], &["snapshot", "list"])
        ;

    let rpcenv = CliEnvironment::new();
    run_cli_command(cmd_def, rpcenv, Some(|future| {
        proxmox_async::runtime::main(future)
    }));
}
