use std::sync::Arc;

use futures_util::future;
use ipld_core::ipld::Ipld;
use jacquard::{
    api::com_atproto::sync::subscribe_repos::{Commit, SubscribeReposMessage, Sync},
    types::string::Handle,
};
use jacquard_repo::{BlockStore, MemoryBlockStore};
use sqlx::{Pool, Postgres, query};
use thiserror::Error;
use tokio::{sync::broadcast, task::JoinHandle};

use crate::{backfill::backfill, utils::ipld_json::ipld_to_json_value};

trait Ingest {
    type Error;
    async fn ingest(&self, conn: Arc<Pool<Postgres>>) -> Result<(), Self::Error>;
}

#[derive(Debug, Error)]
enum CommitError {
    #[error("Error parsing #commit event: {}", .0)]
    ParseCarBytes(#[from] jacquard_repo::RepoError),
}

impl Ingest for Commit<'_> {
    type Error = CommitError;
    async fn ingest(&self, conn: Arc<Pool<Postgres>>) -> Result<(), Self::Error> {
        let car = jacquard_repo::car::parse_car_bytes(&self.blocks).await?;
        let storage = Arc::new(MemoryBlockStore::new_from_blocks(car.blocks));

        let ops = future::join_all(self.ops.clone().into_iter().map(|op| async {
            // get block data by cid, or None if errors/not found
            if let Some(cid) = &op.cid {
                if let Ok(cid) = cid.0.to_ipld()
                    && let Ok(contents) = storage.get(&cid).await
                    && let Some(contents) = contents
                    && let Ok(val) = serde_ipld_dagcbor::from_slice::<Ipld>(&contents)
                {
                    (op, ipld_to_json_value(&val).ok())
                } else {
                    (op, None)
                }
            } else {
                (op, None)
            }
        }))
        .await;

        future::join_all(ops.into_iter().map(|(op, val)| async {
            let mut path = op.path.split("/");
            let Some(collection) = path.next() else {
                eprintln!("Invalid path ({})", op.path.as_str());
                return;
            };
            let Some(rkey) = path.next() else {
                eprintln!("Invalid path ({})", op.path.as_str());
                return;
            };
            // assert the path is only collection/rkey
            if path.next().is_some() {
                eprintln!("Invalid path ({})", op.path.as_str());
                return;
            };
            match op.action.clone().as_str() {
                "create" | "update" => {
                    let Some(cid) = op.cid.map(|x| x.0.to_string()) else {
                        eprintln!(
                            "Missing cid for {} {}/{}",
                            op.action.clone().as_str(),
                            collection,
                            rkey
                        );
                        return;
                    };
                    let Some(val) = val else {
                        eprintln!(
                            "Missing value for {} {}/{}/{}",
                            op.action.clone().as_str(),
                            collection,
                            rkey,
                            cid
                        );
                        return;
                    };
                    if let Err(err) = query!(
                        "INSERT INTO records (collection, rkey, cid, record) 
						VALUES ($1, $2, $3, $4)
						ON CONFLICT (collection, rkey)
						DO UPDATE SET
							cid = EXCLUDED.cid,
							record = EXCLUDED.record;",
                        collection,
                        rkey,
                        cid,
                        val
                    )
                    .execute(&*conn)
                    .await
                    {
                        eprintln!(
                            "Error applying {} to {}/{}/{}\n{}",
                            op.action.clone().as_str(),
                            collection,
                            rkey,
                            cid,
                            err
                        );
                    } else {
                        println!(
                            "{} {}/{}/{}",
                            op.action.clone().as_str(),
                            collection,
                            rkey,
                            cid
                        );
                    };
                }
                "delete" => {
                    if let Err(err) = query!(
                        "DELETE FROM records WHERE 
							collection = $1 
							and rkey = $2",
                        collection,
                        rkey,
                    )
                    .execute(&*conn)
                    .await
                    {
                        eprintln!("Error deleting {}/{}\n{}", collection, rkey, err);
                    } else {
                        println!("delete {}/{}", collection, rkey);
                    };
                }
                _ => {
                    println!(
                        "unknown action {} for {:#?} {:#?}",
                        op.action.as_str(),
                        op,
                        val
                    )
                }
            }
        }))
        .await;

        Ok(())
    }
}

impl Ingest for Sync<'_> {
    type Error = crate::backfill::Error;
    async fn ingest(&self, conn: Arc<Pool<Postgres>>) -> Result<(), Self::Error> {
        backfill(conn, None).await
    }
}

pub fn ingest(
    mut reciever: broadcast::Receiver<SubscribeReposMessage<'static>>,
    conn: Arc<Pool<Postgres>>,
) -> JoinHandle<()> {
    tokio::spawn(async move {
        loop {
            let next = match reciever.recv().await {
                Ok(val) => val,
                Err(err) => match err {
                    broadcast::error::RecvError::Closed => {
                        eprintln!("Ingestion failed. Quitting");
                        break;
                    }
                    broadcast::error::RecvError::Lagged(skipped) => {
                        eprintln!("Warning: lagging behind. Skipping {skipped} messages");
                        continue;
                    }
                },
            };

            match next {
                SubscribeReposMessage::Commit(commit) => {
                    commit.ingest(conn.clone()).await.unwrap_or_else(|err| {
                        eprintln!("error handling #commit({}): {:?}", commit.clone().rev, err)
                    })
                }
                SubscribeReposMessage::Sync(sync) => {
                    sync.ingest(conn.clone()).await.unwrap_or_else(|err| {
                        eprintln!("error handling #sync({}): {:?}", sync.clone().rev, err)
                    })
                }
                SubscribeReposMessage::Identity(identity) => println!(
                    "ignoring #identity({}) event. has user migrated?",
                    identity.handle.unwrap_or(Handle::raw("handle.invalid"))
                ),
                SubscribeReposMessage::Account(account) => println!(
                    "ignoring #account({} {}) event. has user deactivated?",
                    account.active,
                    account.status.unwrap_or("unknown".into())
                ),
                SubscribeReposMessage::Info(info) => {
                    println!("ignoring #info({}) event", info.name)
                }
                SubscribeReposMessage::Unknown(_) => {
                    println!("ignoring unknown event. is meview outdated?")
                }
            };
        }
    })
}