// Copyright 2025 Neuraville Inc.
// SPDX-License-Identifier: Apache-2.0

/*!
Snapshot service implementation.

Provides snapshot creation, restoration, and management.

Copyright 2025 Neuraville Inc.
Licensed under the Apache License, Version 2.0
*/

use async_trait::async_trait;
use std::path::PathBuf;
use tracing::{info, warn};

use crate::traits::{SnapshotCreateOptions, SnapshotMetadata, SnapshotService};
use crate::types::{ServiceError, ServiceResult};

/// Default implementation of SnapshotService
pub struct SnapshotServiceImpl {
    #[allow(dead_code)] // Used for future file I/O implementation
    snapshot_dir: PathBuf,
}

impl SnapshotServiceImpl {
    /// Create a new SnapshotServiceImpl
    ///
    /// # Arguments
    /// * `snapshot_dir` - Directory where snapshots are stored
    pub fn new(snapshot_dir: PathBuf) -> Self {
        Self { snapshot_dir }
    }
}

#[async_trait]
impl SnapshotService for SnapshotServiceImpl {
    async fn create_snapshot(
        &self,
        options: SnapshotCreateOptions,
    ) -> ServiceResult<SnapshotMetadata> {
        // Generate unique snapshot ID
        let snapshot_id = uuid::Uuid::new_v4().to_string();
        let timestamp = chrono::Utc::now().to_rfc3339();

        // TODO: Serialize genome from ConnectomeService
        // TODO: If stateful, serialize NPU state from RuntimeService
        // TODO: Write to disk in snapshot_dir

        info!(target: "feagi-services", "Created snapshot: {} (stateful: {})",
            snapshot_id, options.stateful);

        Ok(SnapshotMetadata {
            snapshot_id: snapshot_id.clone(),
            created_at: timestamp,
            name: options.name.unwrap_or_else(|| snapshot_id.clone()),
            description: options.description,
            stateful: options.stateful,
            size_bytes: 0, // TODO: Calculate actual size
        })
    }

    async fn restore_snapshot(&self, snapshot_id: &str) -> ServiceResult<()> {
        // TODO: Load snapshot from disk
        // TODO: Deserialize and apply to ConnectomeService/RuntimeService

        info!(target: "feagi-services", "Restored snapshot: {}", snapshot_id);

        Ok(())
    }

    async fn list_snapshots(&self) -> ServiceResult<Vec<SnapshotMetadata>> {
        // TODO: Scan snapshot_dir and load metadata

        Ok(Vec::new())
    }

    async fn delete_snapshot(&self, snapshot_id: &str) -> ServiceResult<()> {
        // TODO: Delete snapshot files from disk

        info!(target: "feagi-services", "Deleted snapshot: {}", snapshot_id);

        Ok(())
    }

    async fn get_snapshot_artifact(
        &self,
        snapshot_id: &str,
        format: &str,
    ) -> ServiceResult<Vec<u8>> {
        // TODO: Load and return snapshot artifact

        warn!(target: "feagi-services", "get_snapshot_artifact not yet implemented: {} ({})",
            snapshot_id, format);

        Err(ServiceError::NotImplemented(
            "Snapshot artifact retrieval not yet implemented".to_string(),
        ))
    }
}
