fraiseql-server 2.0.0-alpha.1

//! ClickHouse backup provider.

use std::collections::HashMap;

use super::backup_provider::{BackupError, BackupInfo, BackupProvider, BackupResult, StorageUsage};

/// ClickHouse backup provider.
///
/// Creates backups using ClickHouse's native backup mechanism.
#[allow(dead_code)]
pub struct ClickhouseBackupProvider {
    /// ClickHouse HTTP endpoint
    endpoint_url: String,
    /// Backup directory
    backup_dir:   String,
}

impl ClickhouseBackupProvider {
    /// Create new ClickHouse backup provider.
    pub fn new(endpoint_url: String, backup_dir: String) -> Self {
        Self {
            endpoint_url,
            backup_dir,
        }
    }

    fn generate_backup_id() -> String {
        let timestamp = std::time::SystemTime::now()
            .duration_since(std::time::UNIX_EPOCH)
            .map(|d| d.as_secs())
            .unwrap_or(0);
        format!("clickhouse-{}", timestamp)
    }
}

#[async_trait::async_trait]
impl BackupProvider for ClickhouseBackupProvider {
    fn name(&self) -> &'static str {
        "clickhouse"
    }

    async fn health_check(&self) -> BackupResult<()> {
        // In production: GET /ping
        Ok(())
    }

    async fn backup(&self) -> BackupResult<BackupInfo> {
        let backup_id = Self::generate_backup_id();

        // In production:
        // 1. POST /api/backup with backup name
        // 2. ClickHouse creates hard links to data files
        // 3. Download backup files
        // 4. Store compressed to backup location

        Ok(BackupInfo {
            backup_id,
            store_name: "clickhouse".to_string(),
            timestamp: std::time::SystemTime::now()
                .duration_since(std::time::UNIX_EPOCH)
                .map(|d| d.as_secs() as i64)
                .unwrap_or(0),
            size_bytes: 0,
            verified: false,
            compression: None, // ClickHouse snapshot has own compression
            metadata: {
                let mut m = HashMap::new();
                m.insert("method".to_string(), "native_snapshot".to_string());
                m.insert("partitioned".to_string(), "true".to_string());
                m
            },
        })
    }

    async fn restore(&self, backup_id: &str, verify: bool) -> BackupResult<()> {
        // In production:
        // 1. Restore backup files to ClickHouse data directory
        // 2. Run ATTACH TABLE for each table
        // 3. Verify row counts match
        if verify {
            self.verify_backup(backup_id).await?;
        }
        Ok(())
    }

    async fn list_backups(&self) -> BackupResult<Vec<BackupInfo>> {
        Ok(Vec::new())
    }

    async fn get_backup(&self, backup_id: &str) -> BackupResult<BackupInfo> {
        Err(BackupError::NotFound {
            store:     "clickhouse".to_string(),
            backup_id: backup_id.to_string(),
        })
    }

    async fn delete_backup(&self, _backup_id: &str) -> BackupResult<()> {
        Ok(())
    }

    async fn verify_backup(&self, _backup_id: &str) -> BackupResult<()> {
        // In production: Check backup integrity via checksums
        Ok(())
    }

    async fn get_storage_usage(&self) -> BackupResult<StorageUsage> {
        Ok(StorageUsage {
            total_bytes:             0,
            backup_count:            0,
            oldest_backup_timestamp: None,
            newest_backup_timestamp: None,
        })
    }
}

#[cfg(test)]
mod tests {
    use super::*;

    #[tokio::test]
    async fn test_clickhouse_backup() {
        let provider =
            ClickhouseBackupProvider::new("http://localhost:8123".to_string(), "/tmp".to_string());
        let backup = provider.backup().await.unwrap();
        assert_eq!(backup.store_name, "clickhouse");
    }
}