pub use self::sled::SledDatabase;
pub use alice::Alice;
pub use bob::Bob;
pub use sqlite::SqliteDatabase;

use crate::fs::ensure_directory_exists;
use crate::protocol::{Database, State};
use anyhow::{bail, Result};
use serde::{Deserialize, Serialize};
use std::fmt::Display;
use std::path::Path;
use std::sync::Arc;

mod alice;
mod bob;
mod sled;
mod sqlite;

#[derive(Clone, Debug, Deserialize, Serialize, PartialEq)]
pub enum Swap {
    Alice(Alice),
    Bob(Bob),
}

impl From<State> for Swap {
    fn from(state: State) -> Self {
        match state {
            State::Alice(state) => Swap::Alice(state.into()),
            State::Bob(state) => Swap::Bob(state.into()),
        }
    }
}

impl From<Swap> for State {
    fn from(value: Swap) -> Self {
        match value {
            Swap::Alice(alice) => State::Alice(alice.into()),
            Swap::Bob(bob) => State::Bob(bob.into()),
        }
    }
}

impl From<Alice> for Swap {
    fn from(from: Alice) -> Self {
        Swap::Alice(from)
    }
}

impl From<Bob> for Swap {
    fn from(from: Bob) -> Self {
        Swap::Bob(from)
    }
}

impl Display for Swap {
    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
        match self {
            Swap::Alice(alice) => Display::fmt(alice, f),
            Swap::Bob(bob) => Display::fmt(bob, f),
        }
    }
}

#[derive(thiserror::Error, Debug, Clone, Copy, PartialEq)]
#[error("Not in the role of Alice")]
struct NotAlice;

#[derive(thiserror::Error, Debug, Clone, Copy, PartialEq)]
#[error("Not in the role of Bob")]
struct NotBob;

impl Swap {
    pub fn try_into_alice(self) -> Result<Alice> {
        match self {
            Swap::Alice(alice) => Ok(alice),
            Swap::Bob(_) => bail!(NotAlice),
        }
    }

    pub fn try_into_bob(self) -> Result<Bob> {
        match self {
            Swap::Bob(bob) => Ok(bob),
            Swap::Alice(_) => bail!(NotBob),
        }
    }
}

pub async fn open_db(
    sled_path: impl AsRef<Path>,
    sqlite_path: impl AsRef<Path>,
    force_sled: bool,
) -> Result<Arc<dyn Database + Send + Sync>> {
    // if sled exists and sqlite doesnt exist try and migrate
    // if sled and sqlite exists and the sled flag is set, use sled
    // if sled and sqlite exists, use sqlite
    match (
        sled_path.as_ref().exists(),
        sqlite_path.as_ref().exists(),
        force_sled,
    ) {
        (true, false, false) => {
            tracing::info!("Attempting to migrate old data to the new sqlite database...");
            let sled_db = SledDatabase::open(sled_path.as_ref()).await?;

            ensure_directory_exists(sqlite_path.as_ref())?;
            tokio::fs::File::create(&sqlite_path).await?;
            let sqlite = SqliteDatabase::open(sqlite_path).await?;

            let swap_states = sled_db.all().await?;
            for (swap_id, state) in swap_states.iter() {
                sqlite.insert_latest_state(*swap_id, state.clone()).await?;
            }

            let monero_addresses = sled_db.get_all_monero_addresses();
            for (swap_id, monero_address) in monero_addresses.flatten() {
                sqlite
                    .insert_monero_address(swap_id, monero_address)
                    .await?;
            }

            let peer_addresses = sled_db.get_all_addresses();
            for (peer_id, addresses) in peer_addresses.flatten() {
                for address in addresses {
                    sqlite.insert_address(peer_id, address).await?;
                }
            }

            let peers = sled_db.get_all_peers();
            for (swap_id, peer_id) in peers.flatten() {
                sqlite.insert_peer_id(swap_id, peer_id).await?;
            }

            tracing::info!("Sucessfully migrated data to sqlite! Using sqlite.");

            Ok(Arc::new(sqlite))
        }
        (_, false, false) => {
            tracing::debug!("Creating and using new sqlite database.");
            ensure_directory_exists(sqlite_path.as_ref())?;
            tokio::fs::File::create(&sqlite_path).await?;
            let sqlite = SqliteDatabase::open(sqlite_path).await?;
            Ok(Arc::new(sqlite))
        }
        (_, true, false) => {
            tracing::debug!("Using existing sqlite database.");
            let sqlite = SqliteDatabase::open(sqlite_path).await?;
            Ok(Arc::new(sqlite))
        }
        (false, _, true) => {
            bail!("Sled database does not exist at specified location")
        }
        (true, _, true) => {
            tracing::debug!("Sled flag set. Using sled database.");
            let sled = SledDatabase::open(sled_path.as_ref()).await?;
            Ok(Arc::new(sled))
        }
    }
}