//! P2P Debugging tool
use crate::{
    args::{
        get_secret_key,
        utils::{chain_spec_value_parser, hash_or_num_value_parser},
        DatabaseArgs, DiscoveryArgs,
    },
    dirs::{DataDirPath, MaybePlatformPath},
    utils::get_single_header,
};
use backon::{ConstantBuilder, Retryable};
use clap::{Parser, Subcommand};
use reth_config::Config;
use reth_db::open_db;
use reth_discv4::NatResolver;
use reth_interfaces::p2p::bodies::client::BodiesClient;
use reth_primitives::{BlockHashOrNumber, ChainSpec, NodeRecord};
use reth_provider::ProviderFactory;
use std::{path::PathBuf, sync::Arc};

/// `reth p2p` command
#[derive(Debug, Parser)]
pub struct Command {
    /// The path to the configuration file to use.
    #[arg(long, value_name = "FILE", verbatim_doc_comment)]
    config: Option<PathBuf>,

    /// The chain this node is running.
    ///
    /// Possible values are either a built-in chain or the path to a chain specification file.
    ///
    /// Built-in chains:
    /// - mainnet
    /// - goerli
    /// - sepolia
    #[arg(
        long,
        value_name = "CHAIN_OR_PATH",
        verbatim_doc_comment,
        default_value = "mainnet",
        value_parser = chain_spec_value_parser
    )]
    chain: Arc<ChainSpec>,

    /// The path to the data dir for all reth files and subdirectories.
    ///
    /// Defaults to the OS-specific data directory:
    ///
    /// - Linux: `$XDG_DATA_HOME/reth/` or `$HOME/.local/share/reth/`
    /// - Windows: `{FOLDERID_RoamingAppData}/reth/`
    /// - macOS: `$HOME/Library/Application Support/reth/`
    #[arg(long, value_name = "DATA_DIR", verbatim_doc_comment, default_value_t)]
    datadir: MaybePlatformPath<DataDirPath>,

    /// Secret key to use for this node.
    ///
    /// This also will deterministically set the peer ID.
    #[arg(long, value_name = "PATH")]
    p2p_secret_key: Option<PathBuf>,

    /// Disable the discovery service.
    #[command(flatten)]
    pub discovery: DiscoveryArgs,

    /// Target trusted peer
    #[arg(long)]
    trusted_peer: Option<NodeRecord>,

    /// Connect only to trusted peers
    #[arg(long)]
    trusted_only: bool,

    /// The number of retries per request
    #[arg(long, default_value = "5")]
    retries: usize,

    #[arg(long, default_value = "any")]
    nat: NatResolver,

    #[clap(flatten)]
    db: DatabaseArgs,

    #[clap(subcommand)]
    command: Subcommands,
}

/// `reth p2p` subcommands
#[derive(Subcommand, Debug)]
pub enum Subcommands {
    /// Download block header
    Header {
        /// The header number or hash
        #[arg(value_parser = hash_or_num_value_parser)]
        id: BlockHashOrNumber,
    },
    /// Download block body
    Body {
        /// The block number or hash
        #[arg(value_parser = hash_or_num_value_parser)]
        id: BlockHashOrNumber,
    },
}
impl Command {
    /// Execute `p2p` command
    pub async fn execute(&self) -> eyre::Result<()> {
        let tempdir = tempfile::TempDir::new()?;
        let noop_db = Arc::new(open_db(&tempdir.into_path(), self.db.log_level)?);

        // add network name to data dir
        let data_dir = self.datadir.unwrap_or_chain_default(self.chain.chain);
        let config_path = self.config.clone().unwrap_or(data_dir.config_path());

        let mut config: Config = confy::load_path(&config_path).unwrap_or_default();

        if let Some(peer) = self.trusted_peer {
            config.peers.trusted_nodes.insert(peer);
        }

        if config.peers.trusted_nodes.is_empty() && self.trusted_only {
            eyre::bail!("No trusted nodes. Set trusted peer with `--trusted-peer <enode record>` or set `--trusted-only` to `false`")
        }

        config.peers.connect_trusted_nodes_only = self.trusted_only;

        let default_secret_key_path = data_dir.p2p_secret_path();
        let secret_key_path = self.p2p_secret_key.clone().unwrap_or(default_secret_key_path);
        let p2p_secret_key = get_secret_key(&secret_key_path)?;

        let mut network_config_builder =
            config.network_config(self.nat, None, p2p_secret_key).chain_spec(self.chain.clone());

        network_config_builder = self.discovery.apply_to_builder(network_config_builder);

        let network = network_config_builder
            .build(Arc::new(ProviderFactory::new(noop_db, self.chain.clone())))
            .start_network()
            .await?;

        let fetch_client = network.fetch_client().await?;
        let retries = self.retries.max(1);
        let backoff = ConstantBuilder::default().with_max_times(retries);

        match self.command {
            Subcommands::Header { id } => {
                let header = (move || get_single_header(fetch_client.clone(), id))
                    .retry(&backoff)
                    .notify(|err, _| println!("Error requesting header: {err}. Retrying..."))
                    .await?;
                println!("Successfully downloaded header: {header:?}");
            }
            Subcommands::Body { id } => {
                let hash = match id {
                    BlockHashOrNumber::Hash(hash) => hash,
                    BlockHashOrNumber::Number(number) => {
                        println!("Block number provided. Downloading header first...");
                        let client = fetch_client.clone();
                        let header = (move || {
                            get_single_header(client.clone(), BlockHashOrNumber::Number(number))
                        })
                        .retry(&backoff)
                        .notify(|err, _| println!("Error requesting header: {err}. Retrying..."))
                        .await?;
                        header.hash()
                    }
                };
                let (_, result) = (move || {
                    let client = fetch_client.clone();
                    client.get_block_bodies(vec![hash])
                })
                .retry(&backoff)
                .notify(|err, _| println!("Error requesting block: {err}. Retrying..."))
                .await?
                .split();
                if result.len() != 1 {
                    eyre::bail!(
                        "Invalid number of headers received. Expected: 1. Received: {}",
                        result.len()
                    )
                }
                let body = result.into_iter().next().unwrap();
                println!("Successfully downloaded body: {body:?}")
            }
        }

        Ok(())
    }
}