leptos-helios 0.8.1

//! Database-specific adapters and implementations
//!
//! This module provides database-specific implementations including PostgreSQL,
//! ClickHouse, and other database adapters.

use super::errors::DataSourceError;
use super::traits::*;
use super::types::*;
use async_trait::async_trait;
use polars::prelude::*;
use std::sync::{Arc, Mutex};
use tokio::sync::RwLock;

#[cfg(feature = "database")]
use clickhouse::Client as ClickHouseClient;
#[cfg(feature = "database")]
use sqlx::{PgPool, Postgres, Row};

/// PostgreSQL adapter
pub struct PostgresAdapter {
    config: ConnectionConfig,
    #[cfg(feature = "database")]
    pool: Option<Arc<PgPool>>,
    #[cfg(not(feature = "database"))]
    pool: Option<Arc<RwLock<MockConnectionPool>>>,
}

impl PostgresAdapter {
    pub fn new(config: ConnectionConfig) -> Self {
        Self { config, pool: None }
    }

    pub async fn initialize(&mut self) -> Result<(), DataSourceError> {
        #[cfg(feature = "database")]
        {
            let pool = PgPool::connect(&self.config.connection_string)
                .await
                .map_err(|e| DataSourceError::ConnectionFailed(e.to_string()))?;
            self.pool = Some(Arc::new(pool));
        }
        #[cfg(not(feature = "database"))]
        {
            let pool = MockConnectionPool::new(&self.config).await?;
            self.pool = Some(Arc::new(RwLock::new(pool)));
        }
        Ok(())
    }
}

#[async_trait]
impl DataSource for PostgresAdapter {
    fn name(&self) -> &str {
        "PostgreSQL"
    }

    fn source_type(&self) -> &str {
        "postgresql"
    }

    async fn connect(
        &self,
        _config: &ConnectionConfig,
    ) -> Result<Box<dyn Connection>, DataSourceError> {
        let pool = self
            .pool
            .as_ref()
            .ok_or_else(|| DataSourceError::ConnectionFailed("Pool not initialized".to_string()))?;

        let conn = PostgresConnection::new(pool.clone()).await?;
        Ok(Box::new(conn))
    }

    async fn test_connection(&self, _config: &ConnectionConfig) -> Result<bool, DataSourceError> {
        // Test connection by executing a simple query
        match self.connect(_config).await {
            Ok(_) => Ok(true),
            Err(_) => Ok(false),
        }
    }

    fn supported_features(&self) -> Vec<String> {
        vec![
            "transactions".to_string(),
            "prepared_statements".to_string(),
            "schema_introspection".to_string(),
            "json_support".to_string(),
            "array_support".to_string(),
        ]
    }

    fn connection_limits(&self) -> ConnectionLimits {
        ConnectionLimits::new()
            .with_max_connections(100)
            .with_max_query_time(std::time::Duration::from_secs(300))
            .with_max_result_size(100_000_000)
            .with_max_parameters(1000)
    }

    async fn get_stats(&self) -> Result<DataSourceStats, DataSourceError> {
        // Return mock stats for now
        Ok(DataSourceStats::new())
    }
}

/// PostgreSQL connection implementation
pub struct PostgresConnection {
    #[cfg(feature = "database")]
    pool: Arc<PgPool>,
    #[cfg(not(feature = "database"))]
    pool: Arc<RwLock<MockConnectionPool>>,
    stats: Arc<Mutex<ConnectionStats>>,
}

impl PostgresConnection {
    pub async fn new(
        #[cfg(feature = "database")] pool: Arc<PgPool>,
        #[cfg(not(feature = "database"))] pool: Arc<RwLock<MockConnectionPool>>,
    ) -> Result<Self, DataSourceError> {
        Ok(Self {
            pool,
            stats: Arc::new(Mutex::new(ConnectionStats::new(
                uuid::Uuid::new_v4().to_string(),
            ))),
        })
    }
}

#[async_trait]
impl Connection for PostgresConnection {
    async fn execute_query(&self, _query: &str) -> Result<DataFrame, DataSourceError> {
        let start_time = std::time::Instant::now();

        #[cfg(feature = "database")]
        {
            let rows = sqlx::query(_query)
                .fetch_all(&*self.pool)
                .await
                .map_err(|e| DataSourceError::QueryFailed(e.to_string()))?;

            // Convert rows to DataFrame
            let mut data: Vec<Vec<String>> = Vec::new();
            let mut columns: Vec<String> = Vec::new();

            if let Some(first_row) = rows.first() {
                for (i, column) in first_row.columns().iter().enumerate() {
                    columns.push(column.name().to_string());
                }

                for row in &rows {
                    let mut row_data = Vec::new();
                    for i in 0..columns.len() {
                        let value = row
                            .try_get::<String, _>(i)
                            .unwrap_or_else(|_| "NULL".to_string());
                        row_data.push(value);
                    }
                    data.push(row_data);
                }
            }

            let execution_time = start_time.elapsed();
            self.stats
                .lock()
                .unwrap()
                .record_successful_query(execution_time);

            // Create DataFrame from data
            let mut df_builder = DataFrame::new(Vec::new()).unwrap();
            for (i, column) in columns.iter().enumerate() {
                let series: Series = data
                    .iter()
                    .map(|row| row[i].clone())
                    .collect::<Vec<String>>()
                    .into_iter()
                    .collect();
                df_builder = df_builder.with_column(series.with_name(column)).unwrap();
            }

            Ok(df_builder)
        }

        #[cfg(not(feature = "database"))]
        {
            // Mock implementation
            let execution_time = start_time.elapsed();
            self.stats
                .lock()
                .unwrap()
                .record_successful_query(execution_time);

            // Return empty DataFrame
            Ok(DataFrame::new(Vec::new()).unwrap())
        }
    }

    async fn execute_query_with_params(
        &self,
        query: &str,
        _params: &[&dyn ToSql],
    ) -> Result<DataFrame, DataSourceError> {
        // For now, just execute the query without parameters
        self.execute_query(query).await
    }

    async fn execute_statement(&self, _statement: &str) -> Result<u64, DataSourceError> {
        let start_time = std::time::Instant::now();

        #[cfg(feature = "database")]
        {
            let result = sqlx::query(_statement)
                .execute(&*self.pool)
                .await
                .map_err(|e| DataSourceError::QueryFailed(e.to_string()))?;

            let execution_time = start_time.elapsed();
            self.stats
                .lock()
                .unwrap()
                .record_successful_query(execution_time);

            Ok(result.rows_affected())
        }

        #[cfg(not(feature = "database"))]
        {
            let execution_time = start_time.elapsed();
            self.stats
                .lock()
                .unwrap()
                .record_successful_query(execution_time);
            Ok(1) // Mock affected rows
        }
    }

    async fn execute_statement_with_params(
        &self,
        statement: &str,
        _params: &[&dyn ToSql],
    ) -> Result<u64, DataSourceError> {
        // For now, just execute the statement without parameters
        self.execute_statement(statement).await
    }

    async fn begin_transaction(&self) -> Result<Box<dyn Transaction>, DataSourceError> {
        // Mock transaction implementation
        Ok(Box::new(MockTransaction::new()))
    }

    async fn get_schema(&self) -> Result<super::types::Schema, DataSourceError> {
        // Mock schema implementation
        let mut schema = super::types::Schema::new();

        // Add a sample table
        let mut table = TableInfo::new("users".to_string());
        table.add_column(ColumnInfo::new("id".to_string(), "INTEGER".to_string()));
        table.add_column(ColumnInfo::new("name".to_string(), "VARCHAR".to_string()));
        table.add_primary_key("id".to_string());
        schema.add_table(table);

        Ok(schema)
    }

    async fn get_table_info(&self, table_name: &str) -> Result<TableInfo, DataSourceError> {
        // Mock table info implementation
        let mut table = TableInfo::new(table_name.to_string());
        table.add_column(ColumnInfo::new("id".to_string(), "INTEGER".to_string()));
        table.add_column(ColumnInfo::new("name".to_string(), "VARCHAR".to_string()));
        Ok(table)
    }

    async fn list_tables(&self) -> Result<Vec<String>, DataSourceError> {
        // Mock table list
        Ok(vec![
            "users".to_string(),
            "orders".to_string(),
            "products".to_string(),
        ])
    }

    async fn list_views(&self) -> Result<Vec<String>, DataSourceError> {
        // Mock view list
        Ok(vec!["user_summary".to_string()])
    }

    async fn table_exists(&self, table_name: &str) -> Result<bool, DataSourceError> {
        let tables = self.list_tables().await?;
        Ok(tables.contains(&table_name.to_string()))
    }

    async fn get_stats(&self) -> Result<ConnectionStats, DataSourceError> {
        Ok(self.stats.lock().unwrap().clone())
    }

    async fn close(&self) -> Result<(), DataSourceError> {
        // Connection will be closed when dropped
        Ok(())
    }
}

/// ClickHouse adapter
pub struct ClickHouseAdapter {
    config: ConnectionConfig,
    #[cfg(feature = "database")]
    client: Option<ClickHouseClient>,
    #[cfg(not(feature = "database"))]
    client: Option<Arc<RwLock<MockClickHouseClient>>>,
}

impl ClickHouseAdapter {
    pub fn new(config: ConnectionConfig) -> Self {
        Self {
            config,
            client: None,
        }
    }

    pub async fn initialize(&mut self) -> Result<(), DataSourceError> {
        #[cfg(feature = "database")]
        {
            let client = ClickHouseClient::default()
                .with_url(&self.config.connection_string)
                .map_err(|e| DataSourceError::ConnectionFailed(e.to_string()))?;
            self.client = Some(client);
        }
        #[cfg(not(feature = "database"))]
        {
            let client = MockClickHouseClient::new(&self.config).await?;
            self.client = Some(Arc::new(RwLock::new(client)));
        }
        Ok(())
    }
}

#[async_trait]
impl DataSource for ClickHouseAdapter {
    fn name(&self) -> &str {
        "ClickHouse"
    }

    fn source_type(&self) -> &str {
        "clickhouse"
    }

    async fn connect(
        &self,
        _config: &ConnectionConfig,
    ) -> Result<Box<dyn Connection>, DataSourceError> {
        let client = self.client.as_ref().ok_or_else(|| {
            DataSourceError::ConnectionFailed("Client not initialized".to_string())
        })?;

        let conn = ClickHouseConnection::new(client.clone()).await?;
        Ok(Box::new(conn))
    }

    async fn test_connection(&self, _config: &ConnectionConfig) -> Result<bool, DataSourceError> {
        match self.connect(_config).await {
            Ok(_) => Ok(true),
            Err(_) => Ok(false),
        }
    }

    fn supported_features(&self) -> Vec<String> {
        vec![
            "columnar_storage".to_string(),
            "compression".to_string(),
            "distributed_queries".to_string(),
            "materialized_views".to_string(),
            "replication".to_string(),
        ]
    }

    fn connection_limits(&self) -> ConnectionLimits {
        ConnectionLimits::new()
            .with_max_connections(50)
            .with_max_query_time(std::time::Duration::from_secs(600))
            .with_max_result_size(1_000_000_000) // 1GB
            .with_max_parameters(10000)
    }

    async fn get_stats(&self) -> Result<DataSourceStats, DataSourceError> {
        Ok(DataSourceStats::new())
    }
}

/// ClickHouse connection implementation
pub struct ClickHouseConnection {
    #[cfg(feature = "database")]
    client: ClickHouseClient,
    #[cfg(not(feature = "database"))]
    client: Arc<RwLock<MockClickHouseClient>>,
    stats: Arc<Mutex<ConnectionStats>>,
}

impl ClickHouseConnection {
    pub async fn new(
        #[cfg(feature = "database")] client: ClickHouseClient,
        #[cfg(not(feature = "database"))] client: Arc<RwLock<MockClickHouseClient>>,
    ) -> Result<Self, DataSourceError> {
        Ok(Self {
            client,
            stats: Arc::new(Mutex::new(ConnectionStats::new(
                uuid::Uuid::new_v4().to_string(),
            ))),
        })
    }
}

#[async_trait]
impl Connection for ClickHouseConnection {
    async fn execute_query(&self, _query: &str) -> Result<DataFrame, DataSourceError> {
        let start_time = std::time::Instant::now();

        // Mock implementation for now
        let execution_time = start_time.elapsed();
        self.stats
            .lock()
            .unwrap()
            .record_successful_query(execution_time);

        // Return empty DataFrame
        Ok(DataFrame::new(Vec::new()).unwrap())
    }

    async fn execute_query_with_params(
        &self,
        query: &str,
        _params: &[&dyn ToSql],
    ) -> Result<DataFrame, DataSourceError> {
        self.execute_query(query).await
    }

    async fn execute_statement(&self, _statement: &str) -> Result<u64, DataSourceError> {
        let start_time = std::time::Instant::now();
        let execution_time = start_time.elapsed();
        self.stats
            .lock()
            .unwrap()
            .record_successful_query(execution_time);
        Ok(1) // Mock affected rows
    }

    async fn execute_statement_with_params(
        &self,
        statement: &str,
        _params: &[&dyn ToSql],
    ) -> Result<u64, DataSourceError> {
        self.execute_statement(statement).await
    }

    async fn begin_transaction(&self) -> Result<Box<dyn Transaction>, DataSourceError> {
        Ok(Box::new(MockTransaction::new()))
    }

    async fn get_schema(&self) -> Result<super::types::Schema, DataSourceError> {
        let mut schema = super::types::Schema::new();

        // Add a sample table
        let mut table = TableInfo::new("events".to_string());
        table.add_column(ColumnInfo::new(
            "timestamp".to_string(),
            "DateTime".to_string(),
        ));
        table.add_column(ColumnInfo::new("user_id".to_string(), "UInt64".to_string()));
        table.add_column(ColumnInfo::new(
            "event_type".to_string(),
            "String".to_string(),
        ));
        schema.add_table(table);

        Ok(schema)
    }

    async fn get_table_info(&self, table_name: &str) -> Result<TableInfo, DataSourceError> {
        let mut table = TableInfo::new(table_name.to_string());
        table.add_column(ColumnInfo::new("id".to_string(), "UInt64".to_string()));
        table.add_column(ColumnInfo::new("data".to_string(), "String".to_string()));
        Ok(table)
    }

    async fn list_tables(&self) -> Result<Vec<String>, DataSourceError> {
        Ok(vec![
            "events".to_string(),
            "users".to_string(),
            "sessions".to_string(),
        ])
    }

    async fn list_views(&self) -> Result<Vec<String>, DataSourceError> {
        Ok(vec!["daily_events".to_string()])
    }

    async fn table_exists(&self, table_name: &str) -> Result<bool, DataSourceError> {
        let tables = self.list_tables().await?;
        Ok(tables.contains(&table_name.to_string()))
    }

    async fn get_stats(&self) -> Result<ConnectionStats, DataSourceError> {
        Ok(self.stats.lock().unwrap().clone())
    }

    async fn close(&self) -> Result<(), DataSourceError> {
        Ok(())
    }
}

// Mock implementations for when database features are not enabled
#[cfg(not(feature = "database"))]
pub struct MockConnectionPool {
    config: ConnectionConfig,
}

#[cfg(not(feature = "database"))]
impl MockConnectionPool {
    pub async fn new(config: &ConnectionConfig) -> Result<Self, DataSourceError> {
        Ok(Self {
            config: config.clone(),
        })
    }
}

#[cfg(not(feature = "database"))]
pub struct MockClickHouseClient {
    config: ConnectionConfig,
}

#[cfg(not(feature = "database"))]
impl MockClickHouseClient {
    pub async fn new(config: &ConnectionConfig) -> Result<Self, DataSourceError> {
        Ok(Self {
            config: config.clone(),
        })
    }
}

pub struct MockTransaction {
    active: bool,
}

impl MockTransaction {
    pub fn new() -> Self {
        Self { active: true }
    }
}

#[async_trait]
impl Transaction for MockTransaction {
    async fn execute_query(&self, _query: &str) -> Result<DataFrame, DataSourceError> {
        Ok(DataFrame::new(Vec::new()).unwrap())
    }

    async fn execute_query_with_params(
        &self,
        query: &str,
        _params: &[&dyn ToSql],
    ) -> Result<DataFrame, DataSourceError> {
        self.execute_query(query).await
    }

    async fn execute_statement(&self, _statement: &str) -> Result<u64, DataSourceError> {
        Ok(1)
    }

    async fn execute_statement_with_params(
        &self,
        statement: &str,
        _params: &[&dyn ToSql],
    ) -> Result<u64, DataSourceError> {
        self.execute_statement(statement).await
    }

    async fn commit(&self) -> Result<(), DataSourceError> {
        Ok(())
    }

    async fn rollback(&self) -> Result<(), DataSourceError> {
        Ok(())
    }

    fn is_active(&self) -> bool {
        self.active
    }
}