// file: kb_lib/src/pair_candle_aggregation.rs

//! Pair-candle aggregation service.

/// One pair-candle aggregation result.
#[derive(Debug, Clone, serde::Serialize, serde::Deserialize)]
pub struct PairCandleAggregationResult {
    /// Related pair id.
    pub pair_id: i64,
    /// Candle timeframe in seconds.
    pub timeframe_seconds: i64,
    /// Inclusive bucket start in unix seconds.
    pub bucket_start_unix: i64,
    /// Persisted candle id.
    pub pair_candle_id: i64,
}

/// Pair-candle aggregation service.
///
/// This service materializes a small set of standard timeframes in base storage.
/// Arbitrary timeframes are rebuilt on demand through `PairCandleQueryService`.
#[derive(Debug, Clone)]
pub struct PairCandleAggregationService {
    database: std::sync::Arc<crate::Database>,
    persistence: crate::DetectionPersistenceService,
}

impl PairCandleAggregationService {
    /// Creates a new pair-candle aggregation service.
    pub fn new(database: std::sync::Arc<crate::Database>) -> Self {
        let persistence = crate::DetectionPersistenceService::new(database.clone());
        return Self { database, persistence };
    }

    /// Returns the list of materialized timeframes in seconds.
    pub fn materialized_timeframes_seconds(&self) -> std::vec::Vec<i64> {
        return vec![60, 300, 900, 3600];
    }

    /// Rebuilds all impacted materialized candles for one resolved transaction signature.
    pub async fn record_transaction_by_signature(
        &self,
        signature: &str,
    ) -> Result<std::vec::Vec<crate::PairCandleAggregationResult>, crate::Error> {
        let transaction_result =
            crate::query_chain_transactions_get_by_signature(self.database.as_ref(), signature)
                .await;
        let transaction_option = match transaction_result {
            Ok(transaction_option) => transaction_option,
            Err(error) => return Err(error),
        };
        let transaction = match transaction_option {
            Some(transaction) => transaction,
            None => {
                return Err(crate::Error::InvalidState(format!(
                    "cannot aggregate pair candles for unknown transaction '{}'",
                    signature
                )));
            },
        };
        let transaction_id = match transaction.id {
            Some(transaction_id) => transaction_id,
            None => {
                return Err(crate::Error::InvalidState(format!(
                    "transaction '{}' has no internal id",
                    signature
                )));
            },
        };
        let trade_events_result = crate::query_trade_events_list_by_transaction_id(
            self.database.as_ref(),
            transaction_id,
        )
        .await;
        let trade_events = match trade_events_result {
            Ok(trade_events) => trade_events,
            Err(error) => return Err(error),
        };
        let materialized_timeframes = self.materialized_timeframes_seconds();
        let mut seen = std::collections::HashSet::<(i64, i64, i64)>::new();
        let mut results = std::vec::Vec::new();
        for trade_event in &trade_events {
            let event_time_option_result =
                extract_trade_event_unix_time(self.database.as_ref(), trade_event).await;
            let event_time_option = match event_time_option_result {
                Ok(event_time_option) => event_time_option,
                Err(error) => return Err(error),
            };
            let event_time_unix = match event_time_option {
                Some(event_time_unix) => event_time_unix,
                None => continue,
            };
            for timeframe_seconds in &materialized_timeframes {
                let bucket_start_unix_result =
                    bucket_start_unix(event_time_unix, *timeframe_seconds);
                let bucket_start_unix = match bucket_start_unix_result {
                    Ok(bucket_start_unix) => bucket_start_unix,
                    Err(error) => return Err(error),
                };
                let dedupe_key = (trade_event.pair_id, *timeframe_seconds, bucket_start_unix);
                if seen.contains(&dedupe_key) {
                    continue;
                }
                seen.insert(dedupe_key);
                let rebuilt_result = self
                    .rebuild_one_candle(trade_event.pair_id, *timeframe_seconds, bucket_start_unix)
                    .await;
                let rebuilt = match rebuilt_result {
                    Ok(rebuilt) => rebuilt,
                    Err(error) => return Err(error),
                };
                if let Some(rebuilt) = rebuilt {
                    results.push(rebuilt);
                }
            }
        }
        if !results.is_empty() {
            let payload = serde_json::json!({
                "transactionSignature": signature,
                "pairCandleCount": results.len()
            });
            let observation_result = self
                .persistence
                .record_observation(&crate::DetectionObservationInput::new(
                    "pair.candle_aggregation".to_string(),
                    crate::ObservationSourceKind::Dex,
                    transaction.source_endpoint_name.clone(),
                    transaction.signature.clone(),
                    transaction.slot,
                    payload.clone(),
                ))
                .await;
            let observation_id = match observation_result {
                Ok(observation_id) => observation_id,
                Err(error) => return Err(error),
            };
            let signal_result = self
                .persistence
                .record_signal(&crate::DetectionSignalInput::new(
                    "signal.pair.candle_aggregation.recorded".to_string(),
                    crate::AnalysisSignalSeverity::Low,
                    transaction.signature.clone(),
                    Some(observation_id),
                    None,
                    payload,
                ))
                .await;
            if let Err(error) = signal_result {
                return Err(error);
            }
        }
        return Ok(results);
    }

    async fn rebuild_one_candle(
        &self,
        pair_id: i64,
        timeframe_seconds: i64,
        bucket_start_unix: i64,
    ) -> Result<std::option::Option<crate::PairCandleAggregationResult>, crate::Error> {
        let trade_events_result =
            crate::query_trade_events_list_by_pair_id(self.database.as_ref(), pair_id).await;
        let trade_events = match trade_events_result {
            Ok(trade_events) => trade_events,
            Err(error) => return Err(error),
        };
        let candle_option_result = build_candle_from_trade_events(
            self.database.as_ref(),
            pair_id,
            timeframe_seconds,
            bucket_start_unix,
            &trade_events,
        )
        .await;
        let candle_option = match candle_option_result {
            Ok(candle_option) => candle_option,
            Err(error) => return Err(error),
        };
        let candle = match candle_option {
            Some(candle) => candle,
            None => return Ok(None),
        };
        let pair_candle_id_result =
            crate::query_pair_candles_upsert(self.database.as_ref(), &candle).await;
        let pair_candle_id = match pair_candle_id_result {
            Ok(pair_candle_id) => pair_candle_id,
            Err(error) => return Err(error),
        };
        return Ok(Some(crate::PairCandleAggregationResult {
            pair_id,
            timeframe_seconds,
            bucket_start_unix,
            pair_candle_id,
        }));
    }
}

pub(crate) async fn build_candle_from_trade_events(
    database: &crate::Database,
    pair_id: i64,
    timeframe_seconds: i64,
    bucket_start_unix: i64,
    trade_events: &[crate::TradeEventDto],
) -> Result<std::option::Option<crate::PairCandleDto>, crate::Error> {
    let bucket_end_unix = bucket_start_unix.saturating_add(timeframe_seconds);
    let mut rows = std::vec::Vec::<TradeEventForCandle>::new();
    for trade_event in trade_events {
        if trade_event.pair_id != pair_id {
            continue;
        }
        let event_time_option_result = extract_trade_event_unix_time(database, trade_event).await;
        let event_time_option = match event_time_option_result {
            Ok(event_time_option) => event_time_option,
            Err(error) => return Err(error),
        };
        let event_time_unix = match event_time_option {
            Some(event_time_unix) => event_time_unix,
            None => continue,
        };
        if event_time_unix < bucket_start_unix || event_time_unix >= bucket_end_unix {
            continue;
        }
        let price_quote_per_base = match trade_event.price_quote_per_base {
            Some(price_quote_per_base) => price_quote_per_base,
            None => continue,
        };
        rows.push(TradeEventForCandle {
            event_time_unix,
            decoded_event_id: trade_event.decoded_event_id,
            signature: trade_event.signature.clone(),
            trade_side: trade_event.trade_side,
            price_quote_per_base,
            base_amount_raw: trade_event.base_amount_raw.clone(),
            quote_amount_raw: trade_event.quote_amount_raw.clone(),
        });
    }
    if rows.is_empty() {
        return Ok(None);
    }
    rows.sort_by(|left, right| {
        let time_compare = left.event_time_unix.cmp(&right.event_time_unix);
        if time_compare != std::cmp::Ordering::Equal {
            return time_compare;
        }
        return left.decoded_event_id.cmp(&right.decoded_event_id);
    });
    let open_price_quote_per_base = rows[0].price_quote_per_base;
    let close_price_quote_per_base = rows[rows.len() - 1].price_quote_per_base;
    let mut high_price_quote_per_base = open_price_quote_per_base;
    let mut low_price_quote_per_base = open_price_quote_per_base;
    let mut trade_count = 0_i64;
    let mut buy_count = 0_i64;
    let mut sell_count = 0_i64;
    let mut base_volume_raw = std::option::Option::<std::string::String>::None;
    let mut quote_volume_raw = std::option::Option::<std::string::String>::None;
    for row in &rows {
        trade_count += 1;
        if row.trade_side == crate::SwapTradeSide::BuyBase {
            buy_count += 1;
        }
        if row.trade_side == crate::SwapTradeSide::SellBase {
            sell_count += 1;
        }
        if row.price_quote_per_base > high_price_quote_per_base {
            high_price_quote_per_base = row.price_quote_per_base;
        }
        if row.price_quote_per_base < low_price_quote_per_base {
            low_price_quote_per_base = row.price_quote_per_base;
        }
        base_volume_raw = add_raw_amounts(base_volume_raw, row.base_amount_raw.clone());
        quote_volume_raw = add_raw_amounts(quote_volume_raw, row.quote_amount_raw.clone());
    }
    return Ok(Some(crate::PairCandleDto::new(
        pair_id,
        timeframe_seconds,
        bucket_start_unix,
        bucket_end_unix,
        open_price_quote_per_base,
        high_price_quote_per_base,
        low_price_quote_per_base,
        close_price_quote_per_base,
        trade_count,
        buy_count,
        sell_count,
        base_volume_raw,
        quote_volume_raw,
        Some(rows[0].signature.clone()),
        Some(rows[rows.len() - 1].signature.clone()),
    )));
}

pub(crate) async fn extract_trade_event_unix_time(
    database: &crate::Database,
    trade_event: &crate::TradeEventDto,
) -> Result<std::option::Option<i64>, crate::Error> {
    let transaction_result =
        crate::query_chain_transactions_get_by_signature(database, trade_event.signature.as_str())
            .await;
    let transaction_option = match transaction_result {
        Ok(transaction_option) => transaction_option,
        Err(error) => return Err(error),
    };
    let transaction = match transaction_option {
        Some(transaction) => transaction,
        None => return Ok(Some(trade_event.created_at.timestamp())),
    };
    match transaction.block_time_unix {
        Some(block_time_unix) => return Ok(Some(block_time_unix)),
        None => return Ok(Some(trade_event.created_at.timestamp())),
    }
}

pub(crate) fn bucket_start_unix(
    event_time_unix: i64,
    timeframe_seconds: i64,
) -> Result<i64, crate::Error> {
    if timeframe_seconds <= 0 {
        return Err(crate::Error::InvalidState(format!(
            "invalid timeframe_seconds '{}'",
            timeframe_seconds
        )));
    }
    return Ok((event_time_unix / timeframe_seconds) * timeframe_seconds);
}

fn add_raw_amounts(
    left: std::option::Option<std::string::String>,
    right: std::option::Option<std::string::String>,
) -> std::option::Option<std::string::String> {
    match (left, right) {
        (None, None) => return None,
        (Some(left), None) => return Some(left),
        (None, Some(right)) => return Some(right),
        (Some(left), Some(right)) => {
            let left_value_result = left.parse::<i128>();
            let left_value = match left_value_result {
                Ok(left_value) => left_value,
                Err(_) => return Some(left),
            };
            let right_value_result = right.parse::<i128>();
            let right_value = match right_value_result {
                Ok(right_value) => right_value,
                Err(_) => return Some(left),
            };
            return Some((left_value + right_value).to_string());
        },
    }
}

#[derive(Debug, Clone)]
struct TradeEventForCandle {
    event_time_unix: i64,
    decoded_event_id: i64,
    signature: std::string::String,
    trade_side: crate::SwapTradeSide,
    price_quote_per_base: f64,
    base_amount_raw: std::option::Option<std::string::String>,
    quote_amount_raw: std::option::Option<std::string::String>,
}

#[cfg(test)]
mod tests {
    async fn make_database() -> std::sync::Arc<crate::Database> {
        let tempdir_result = tempfile::tempdir();
        let tempdir = match tempdir_result {
            Ok(tempdir) => tempdir,
            Err(error) => panic!("tempdir must succeed: {}", error),
        };
        let database_path = tempdir.path().join("pair_candle_aggregation.sqlite3");
        let config = crate::DatabaseConfig {
            enabled: true,
            backend: crate::DatabaseBackend::Sqlite,
            sqlite: crate::SqliteDatabaseConfig {
                path: database_path.to_string_lossy().to_string(),
                create_if_missing: true,
                busy_timeout_ms: 5000,
                max_connections: 1,
                auto_initialize_schema: true,
                use_wal: true,
            },
        };
        let database_result = crate::Database::connect_and_initialize(&config).await;
        let database = match database_result {
            Ok(database) => database,
            Err(error) => panic!("database init must succeed: {}", error),
        };
        return std::sync::Arc::new(database);
    }

    async fn seed_fluxbeam_swap_transaction(
        database: std::sync::Arc<crate::Database>,
        signature: &str,
        block_time_unix: i64,
        base_amount_raw: &str,
        quote_amount_raw: &str,
    ) {
        let transaction_model = crate::TransactionModelService::new(database.clone());
        let dex_decode = crate::DexDecodeService::new(database.clone());
        let dex_detect = crate::DexDetectService::new(database.clone());
        let trade_aggregation = crate::TradeAggregationService::new(database.clone());
        let resolved_transaction = serde_json::json!({
            "slot": 960001,
            "blockTime": block_time_unix,
            "version": 0,
            "transaction": {
                "message": {
                    "instructions": [
                        {
                            "programId": crate::FLUXBEAM_PROGRAM_ID,
                            "program": "fluxbeam",
                            "stackHeight": 1,
                            "accounts": [
                                "CandlePool111",
                                "CandleLpMint111",
                                "CandleTokenA111",
                                crate::WSOL_MINT_ID
                            ],
                            "parsed": {
                                "info": {
                                    "instruction": "swap",
                                    "pool": "CandlePool111",
                                    "tokenA": "CandleTokenA111",
                                    "tokenB": crate::WSOL_MINT_ID,
                                    "baseAmountRaw": base_amount_raw,
                                    "quoteAmountRaw": quote_amount_raw
                                }
                            },
                            "data": "opaque"
                        }
                    ]
                }
            },
            "meta": {
                "err": null,
                "logMessages": [
                    "Program log: Instruction: Swap",
                    "Program log: buy"
                ]
            }
        });
        let project_result = transaction_model
            .persist_resolved_transaction(
                signature,
                Some("helius_primary_http".to_string()),
                &resolved_transaction,
            )
            .await;
        if let Err(error) = project_result {
            panic!("projection must succeed: {}", error);
        }
        let decode_result = dex_decode.decode_transaction_by_signature(signature).await;
        if let Err(error) = decode_result {
            panic!("dex decode must succeed: {}", error);
        }
        let detect_result = dex_detect.detect_transaction_by_signature(signature).await;
        if let Err(error) = detect_result {
            panic!("dex detect must succeed: {}", error);
        }
        let trade_result = trade_aggregation.record_transaction_by_signature(signature).await;
        if let Err(error) = trade_result {
            panic!("trade aggregation must succeed: {}", error);
        }
    }

    #[tokio::test]
    async fn record_transaction_by_signature_creates_materialized_candles() {
        let database = make_database().await;
        seed_fluxbeam_swap_transaction(
            database.clone(),
            "sig-pair-candle-1",
            1_700_000_000,
            "1000",
            "2000",
        )
        .await;
        seed_fluxbeam_swap_transaction(
            database.clone(),
            "sig-pair-candle-2",
            1_700_000_020,
            "1000",
            "3000",
        )
        .await;
        seed_fluxbeam_swap_transaction(
            database.clone(),
            "sig-pair-candle-3",
            1_700_000_070,
            "1000",
            "1500",
        )
        .await;
        let service = crate::PairCandleAggregationService::new(database.clone());
        let result_1 = service.record_transaction_by_signature("sig-pair-candle-1").await;
        if let Err(error) = result_1 {
            panic!("candle aggregation 1 must succeed: {}", error);
        }
        let result_2 = service.record_transaction_by_signature("sig-pair-candle-2").await;
        if let Err(error) = result_2 {
            panic!("candle aggregation 2 must succeed: {}", error);
        }
        let result_3 = service.record_transaction_by_signature("sig-pair-candle-3").await;
        if let Err(error) = result_3 {
            panic!("candle aggregation 3 must succeed: {}", error);
        }
        let pools_result = crate::query_pools_list(database.as_ref()).await;
        let pools = match pools_result {
            Ok(pools) => pools,
            Err(error) => panic!("pool list must succeed: {}", error),
        };
        let pool_id = pools[0].id.unwrap_or_default();
        let pair_result = crate::query_pairs_get_by_pool_id(database.as_ref(), pool_id).await;
        let pair_option = match pair_result {
            Ok(pair_option) => pair_option,
            Err(error) => panic!("pair fetch must succeed: {}", error),
        };
        let pair = match pair_option {
            Some(pair) => pair,
            None => panic!("pair must exist"),
        };
        let pair_id = pair.id.unwrap_or_default();
        let candles_result =
            crate::query_pair_candles_list_by_pair_and_timeframe(database.as_ref(), pair_id, 60)
                .await;
        let candles = match candles_result {
            Ok(candles) => candles,
            Err(error) => panic!("candle list must succeed: {}", error),
        };
        assert_eq!(candles.len(), 2);
        assert_eq!(candles[0].open_price_quote_per_base, 2.0);
        assert_eq!(candles[0].high_price_quote_per_base, 3.0);
        assert_eq!(candles[0].low_price_quote_per_base, 2.0);
        assert_eq!(candles[0].close_price_quote_per_base, 3.0);
        assert_eq!(candles[0].trade_count, 2);
        assert_eq!(candles[0].base_volume_raw, Some("2000".to_string()));
        assert_eq!(candles[0].quote_volume_raw, Some("5000".to_string()));
        assert_eq!(candles[1].open_price_quote_per_base, 1.5);
        assert_eq!(candles[1].close_price_quote_per_base, 1.5);
        assert_eq!(candles[1].trade_count, 1);
    }

    #[tokio::test]
    async fn materialized_candle_rebuild_is_idempotent() {
        let database = make_database().await;
        seed_fluxbeam_swap_transaction(
            database.clone(),
            "sig-pair-candle-idempotent",
            1_700_001_000,
            "1000",
            "2500",
        )
        .await;
        let service = crate::PairCandleAggregationService::new(database.clone());
        let first_result =
            service.record_transaction_by_signature("sig-pair-candle-idempotent").await;
        let first_results = match first_result {
            Ok(first_results) => first_results,
            Err(error) => panic!("first candle aggregation must succeed: {}", error),
        };
        assert!(!first_results.is_empty());
        let second_result =
            service.record_transaction_by_signature("sig-pair-candle-idempotent").await;
        let second_results = match second_result {
            Ok(second_results) => second_results,
            Err(error) => panic!("second candle aggregation must succeed: {}", error),
        };
        assert!(!second_results.is_empty());
        let pools_result = crate::query_pools_list(database.as_ref()).await;
        let pools = match pools_result {
            Ok(pools) => pools,
            Err(error) => panic!("pool list must succeed: {}", error),
        };
        let pool_id = pools[0].id.unwrap_or_default();
        let pair_result = crate::query_pairs_get_by_pool_id(database.as_ref(), pool_id).await;
        let pair_option = match pair_result {
            Ok(pair_option) => pair_option,
            Err(error) => panic!("pair fetch must succeed: {}", error),
        };
        let pair = match pair_option {
            Some(pair) => pair,
            None => panic!("pair must exist"),
        };
        let pair_id = pair.id.unwrap_or_default();
        let candles_result =
            crate::query_pair_candles_list_by_pair_and_timeframe(database.as_ref(), pair_id, 60)
                .await;
        let candles = match candles_result {
            Ok(candles) => candles,
            Err(error) => panic!("candle list must succeed: {}", error),
        };
        assert_eq!(candles.len(), 1);
        assert_eq!(candles[0].trade_count, 1);
    }
}