use std::collections::BTreeMap;
use std::path::Path;
use std::sync::atomic::Ordering;
use std::sync::Arc;
use std::time::Duration;

use clap::ArgMatches;
use futures::future::BoxFuture;
use futures::{stream, FutureExt, StreamExt};
use openssl::x509::X509;
use rpc_toolkit::command;
use sqlx::Connection;
use tokio::fs::File;
use torut::onion::OnionAddressV3;
use tracing::instrument;

use super::target::BackupTargetId;
use crate::backup::os::OsBackup;
use crate::backup::BackupMetadata;
use crate::context::rpc::RpcContextConfig;
use crate::context::{RpcContext, SetupContext};
use crate::db::model::{PackageDataEntry, PackageDataEntryRestoring, StaticFiles};
use crate::disk::mount::backup::{BackupMountGuard, PackageBackupMountGuard};
use crate::disk::mount::filesystem::ReadWrite;
use crate::disk::mount::guard::TmpMountGuard;
use crate::hostname::Hostname;
use crate::init::init;
use crate::install::progress::InstallProgress;
use crate::install::{download_install_s9pk, PKG_PUBLIC_DIR};
use crate::notifications::NotificationLevel;
use crate::prelude::*;
use crate::s9pk::manifest::{Manifest, PackageId};
use crate::s9pk::reader::S9pkReader;
use crate::setup::SetupStatus;
use crate::util::display_none;
use crate::util::io::dir_size;
use crate::util::serde::IoFormat;
use crate::volume::{backup_dir, BACKUP_DIR, PKG_VOLUME_DIR};

fn parse_comma_separated(arg: &str, _: &ArgMatches) -> Result<Vec<PackageId>, Error> {
    arg.split(',')
        .map(|s| s.trim().parse().map_err(Error::from))
        .collect()
}

#[command(rename = "restore", display(display_none))]
#[instrument(skip(ctx, password))]
pub async fn restore_packages_rpc(
    #[context] ctx: RpcContext,
    #[arg(parse(parse_comma_separated))] ids: Vec<PackageId>,
    #[arg(rename = "target-id")] target_id: BackupTargetId,
    #[arg] password: String,
) -> Result<(), Error> {
    let fs = target_id
        .load(ctx.secret_store.acquire().await?.as_mut())
        .await?;
    let backup_guard =
        BackupMountGuard::mount(TmpMountGuard::mount(&fs, ReadWrite).await?, &password).await?;

    let (backup_guard, tasks, _) = restore_packages(&ctx, backup_guard, ids).await?;

    tokio::spawn(async move {
        stream::iter(tasks.into_iter().map(|x| (x, ctx.clone())))
            .for_each_concurrent(5, |(res, ctx)| async move {
                match res.await {
                    (Ok(_), _) => (),
                    (Err(err), package_id) => {
                        if let Err(err) = ctx
                            .notification_manager
                            .notify(
                                ctx.db.clone(),
                                Some(package_id.clone()),
                                NotificationLevel::Error,
                                "Restoration Failure".to_string(),
                                format!("Error restoring package {}: {}", package_id, err),
                                (),
                                None,
                            )
                            .await
                        {
                            tracing::error!("Failed to notify: {}", err);
                            tracing::debug!("{:?}", err);
                        };
                        tracing::error!("Error restoring package {}: {}", package_id, err);
                        tracing::debug!("{:?}", err);
                    }
                }
            })
            .await;
        if let Err(e) = backup_guard.unmount().await {
            tracing::error!("Error unmounting backup drive: {}", e);
            tracing::debug!("{:?}", e);
        }
    });

    Ok(())
}

async fn approximate_progress(
    rpc_ctx: &RpcContext,
    progress: &mut ProgressInfo,
) -> Result<(), Error> {
    for (id, size) in &mut progress.target_volume_size {
        let dir = rpc_ctx.datadir.join(PKG_VOLUME_DIR).join(id).join("data");
        if tokio::fs::metadata(&dir).await.is_err() {
            *size = 0;
        } else {
            *size = dir_size(&dir, None).await?;
        }
    }
    Ok(())
}

async fn approximate_progress_loop(
    ctx: &SetupContext,
    rpc_ctx: &RpcContext,
    mut starting_info: ProgressInfo,
) {
    loop {
        if let Err(e) = approximate_progress(rpc_ctx, &mut starting_info).await {
            tracing::error!("Failed to approximate restore progress: {}", e);
            tracing::debug!("{:?}", e);
        } else {
            *ctx.setup_status.write().await = Some(Ok(starting_info.flatten()));
        }
        tokio::time::sleep(Duration::from_secs(1)).await;
    }
}

#[derive(Debug, Default)]
struct ProgressInfo {
    package_installs: BTreeMap<PackageId, Arc<InstallProgress>>,
    src_volume_size: BTreeMap<PackageId, u64>,
    target_volume_size: BTreeMap<PackageId, u64>,
}
impl ProgressInfo {
    fn flatten(&self) -> SetupStatus {
        let mut total_bytes = 0;
        let mut bytes_transferred = 0;

        for progress in self.package_installs.values() {
            total_bytes += ((progress.size.unwrap_or(0) as f64) * 2.2) as u64;
            bytes_transferred += progress.downloaded.load(Ordering::SeqCst);
            bytes_transferred += ((progress.validated.load(Ordering::SeqCst) as f64) * 0.2) as u64;
            bytes_transferred += progress.unpacked.load(Ordering::SeqCst);
        }

        for size in self.src_volume_size.values() {
            total_bytes += *size;
        }

        for size in self.target_volume_size.values() {
            bytes_transferred += *size;
        }

        if bytes_transferred > total_bytes {
            bytes_transferred = total_bytes;
        }

        SetupStatus {
            total_bytes: Some(total_bytes),
            bytes_transferred,
            complete: false,
        }
    }
}

#[instrument(skip(ctx))]
pub async fn recover_full_embassy(
    ctx: SetupContext,
    disk_guid: Arc<String>,
    embassy_password: String,
    recovery_source: TmpMountGuard,
    recovery_password: Option<String>,
) -> Result<(Arc<String>, Hostname, OnionAddressV3, X509), Error> {
    let backup_guard = BackupMountGuard::mount(
        recovery_source,
        recovery_password.as_deref().unwrap_or_default(),
    )
    .await?;

    let os_backup_path = backup_guard.as_ref().join("os-backup.cbor");
    let mut os_backup: OsBackup = IoFormat::Cbor.from_slice(
        &tokio::fs::read(&os_backup_path)
            .await
            .with_ctx(|_| (ErrorKind::Filesystem, os_backup_path.display().to_string()))?,
    )?;

    os_backup.account.password = argon2::hash_encoded(
        embassy_password.as_bytes(),
        &rand::random::<[u8; 16]>()[..],
        &argon2::Config::rfc9106_low_mem(),
    )
    .with_kind(ErrorKind::PasswordHashGeneration)?;

    let secret_store = ctx.secret_store().await?;

    os_backup.account.save(&secret_store).await?;

    secret_store.close().await;

    let cfg = RpcContextConfig::load(ctx.config_path.clone()).await?;

    init(&cfg).await?;

    let rpc_ctx = RpcContext::init(ctx.config_path.clone(), disk_guid.clone()).await?;

    let ids: Vec<_> = backup_guard
        .metadata
        .package_backups
        .keys()
        .cloned()
        .collect();
    let (backup_guard, tasks, progress_info) =
        restore_packages(&rpc_ctx, backup_guard, ids).await?;
    let task_consumer_rpc_ctx = rpc_ctx.clone();
    tokio::select! {
        _ = async move {
            stream::iter(tasks.into_iter().map(|x| (x,  task_consumer_rpc_ctx.clone())))
                .for_each_concurrent(5, |(res, ctx)| async move {
                    match res.await {
                        (Ok(_), _) => (),
                        (Err(err), package_id) => {
                            if let Err(err) = ctx.notification_manager.notify(
                                ctx.db.clone(),
                                Some(package_id.clone()),
                                NotificationLevel::Error,
                                "Restoration Failure".to_string(), format!("Error restoring package {}: {}", package_id,err), (), None).await{
                                tracing::error!("Failed to notify: {}", err);
                                tracing::debug!("{:?}", err);
                                };
                            tracing::error!("Error restoring package {}: {}", package_id, err);
                            tracing::debug!("{:?}", err);
                        },
                    }
                }).await;

        } => {

        },
        _ = approximate_progress_loop(&ctx, &rpc_ctx, progress_info) => unreachable!(concat!(module_path!(), "::approximate_progress_loop should not terminate")),
    }

    backup_guard.unmount().await?;
    rpc_ctx.shutdown().await?;

    Ok((
        disk_guid,
        os_backup.account.hostname,
        os_backup.account.key.tor_address(),
        os_backup.account.root_ca_cert,
    ))
}

#[instrument(skip(ctx, backup_guard))]
async fn restore_packages(
    ctx: &RpcContext,
    backup_guard: BackupMountGuard<TmpMountGuard>,
    ids: Vec<PackageId>,
) -> Result<
    (
        BackupMountGuard<TmpMountGuard>,
        Vec<BoxFuture<'static, (Result<(), Error>, PackageId)>>,
        ProgressInfo,
    ),
    Error,
> {
    let guards = assure_restoring(ctx, ids, &backup_guard).await?;

    let mut progress_info = ProgressInfo::default();

    let mut tasks = Vec::with_capacity(guards.len());
    for (manifest, guard) in guards {
        let id = manifest.id.clone();
        let (progress, task) = restore_package(ctx.clone(), manifest, guard).await?;
        progress_info
            .package_installs
            .insert(id.clone(), progress.clone());
        progress_info
            .src_volume_size
            .insert(id.clone(), dir_size(backup_dir(&id), None).await?);
        progress_info.target_volume_size.insert(id.clone(), 0);
        let package_id = id.clone();
        tasks.push(
            async move {
                if let Err(e) = task.await {
                    tracing::error!("Error restoring package {}: {}", id, e);
                    tracing::debug!("{:?}", e);
                    Err(e)
                } else {
                    Ok(())
                }
            }
            .map(|x| (x, package_id))
            .boxed(),
        );
    }

    Ok((backup_guard, tasks, progress_info))
}

#[instrument(skip(ctx, backup_guard))]
async fn assure_restoring(
    ctx: &RpcContext,
    ids: Vec<PackageId>,
    backup_guard: &BackupMountGuard<TmpMountGuard>,
) -> Result<Vec<(Manifest, PackageBackupMountGuard)>, Error> {
    let mut guards = Vec::with_capacity(ids.len());

    let mut insert_packages = BTreeMap::new();

    for id in ids {
        let peek = ctx.db.peek().await;

        let model = peek.as_package_data().as_idx(&id);

        if !model.is_none() {
            return Err(Error::new(
                eyre!("Can't restore over existing package: {}", id),
                crate::ErrorKind::InvalidRequest,
            ));
        }
        let guard = backup_guard.mount_package_backup(&id).await?;
        let s9pk_path = Path::new(BACKUP_DIR).join(&id).join(format!("{}.s9pk", id));
        let mut rdr = S9pkReader::open(&s9pk_path, false).await?;

        let manifest = rdr.manifest().await?;
        let version = manifest.version.clone();
        let progress = Arc::new(InstallProgress::new(Some(
            tokio::fs::metadata(&s9pk_path).await?.len(),
        )));

        let public_dir_path = ctx
            .datadir
            .join(PKG_PUBLIC_DIR)
            .join(&id)
            .join(version.as_str());
        tokio::fs::create_dir_all(&public_dir_path).await?;

        let license_path = public_dir_path.join("LICENSE.md");
        let mut dst = File::create(&license_path).await?;
        tokio::io::copy(&mut rdr.license().await?, &mut dst).await?;
        dst.sync_all().await?;

        let instructions_path = public_dir_path.join("INSTRUCTIONS.md");
        let mut dst = File::create(&instructions_path).await?;
        tokio::io::copy(&mut rdr.instructions().await?, &mut dst).await?;
        dst.sync_all().await?;

        let icon_path = Path::new("icon").with_extension(&manifest.assets.icon_type());
        let icon_path = public_dir_path.join(&icon_path);
        let mut dst = File::create(&icon_path).await?;
        tokio::io::copy(&mut rdr.icon().await?, &mut dst).await?;
        dst.sync_all().await?;
        insert_packages.insert(
            id.clone(),
            PackageDataEntry::Restoring(PackageDataEntryRestoring {
                install_progress: progress.clone(),
                static_files: StaticFiles::local(&id, &version, manifest.assets.icon_type()),
                manifest: manifest.clone(),
            }),
        );

        guards.push((manifest, guard));
    }
    ctx.db
        .mutate(|db| {
            for (id, package) in insert_packages {
                db.as_package_data_mut().insert(&id, &package)?;
            }
            Ok(())
        })
        .await?;
    Ok(guards)
}

#[instrument(skip(ctx, guard))]
async fn restore_package<'a>(
    ctx: RpcContext,
    manifest: Manifest,
    guard: PackageBackupMountGuard,
) -> Result<(Arc<InstallProgress>, BoxFuture<'static, Result<(), Error>>), Error> {
    let id = manifest.id.clone();
    let s9pk_path = Path::new(BACKUP_DIR)
        .join(&manifest.id)
        .join(format!("{}.s9pk", id));

    let metadata_path = Path::new(BACKUP_DIR).join(&id).join("metadata.cbor");
    let metadata: BackupMetadata = IoFormat::Cbor.from_slice(
        &tokio::fs::read(&metadata_path)
            .await
            .with_ctx(|_| (ErrorKind::Filesystem, metadata_path.display().to_string()))?,
    )?;

    let mut secrets = ctx.secret_store.acquire().await?;
    let mut secrets_tx = secrets.begin().await?;
    for (iface, key) in metadata.network_keys {
        let k = key.0.as_slice();
        sqlx::query!(
            "INSERT INTO network_keys (package, interface, key) VALUES ($1, $2, $3) ON CONFLICT (package, interface) DO NOTHING",
            id.to_string(),
            iface.to_string(),
            k,
        )
        .execute(secrets_tx.as_mut()).await?;
    }
    // DEPRECATED
    for (iface, key) in metadata.tor_keys {
        let k = key.0.as_slice();
        sqlx::query!(
            "INSERT INTO tor (package, interface, key) VALUES ($1, $2, $3) ON CONFLICT (package, interface) DO NOTHING",
            id.to_string(),
            iface.to_string(),
            k,
        )
        .execute(secrets_tx.as_mut()).await?;
    }
    secrets_tx.commit().await?;
    drop(secrets);

    let len = tokio::fs::metadata(&s9pk_path)
        .await
        .with_ctx(|_| (ErrorKind::Filesystem, s9pk_path.display().to_string()))?
        .len();
    let file = File::open(&s9pk_path)
        .await
        .with_ctx(|_| (ErrorKind::Filesystem, s9pk_path.display().to_string()))?;

    let progress = InstallProgress::new(Some(len));
    let marketplace_url = metadata.marketplace_url;

    let progress = Arc::new(progress);

    ctx.db
        .mutate(|db| {
            db.as_package_data_mut().insert(
                &id,
                &PackageDataEntry::Restoring(PackageDataEntryRestoring {
                    install_progress: progress.clone(),
                    static_files: StaticFiles::local(
                        &id,
                        &manifest.version,
                        manifest.assets.icon_type(),
                    ),
                    manifest: manifest.clone(),
                }),
            )
        })
        .await?;
    Ok((
        progress.clone(),
        async move {
            download_install_s9pk(ctx, manifest, marketplace_url, progress, file, None).await?;

            guard.unmount().await?;

            Ok(())
        }
        .boxed(),
    ))
}