litellm-rs 0.1.1

//! AI API endpoints (OpenAI compatible)
//!
//! This module provides OpenAI-compatible API endpoints for AI services.

#![allow(dead_code)]

use crate::core::models::openai::{
    ChatCompletionRequest, CompletionRequest, EmbeddingRequest, ImageGenerationRequest,
    ModelListResponse,
};
use crate::core::models::{ApiKey, RequestContext, User};
use crate::server::AppState;
use crate::server::routes::{ApiResponse, errors};
use crate::utils::validation::RequestValidator;
use actix_web::http::header::HeaderMap;
use actix_web::{HttpRequest, HttpResponse, Result as ActixResult, web};

use serde::Deserialize;
use tracing::{debug, error, info, warn};

/// Audio speech generation request
#[derive(Debug, Deserialize)]
struct AudioSpeechRequest {
    /// Text to convert to speech
    pub input: String,
    /// Voice to use for speech generation
    pub voice: String,
    /// Audio format (mp3, opus, aac, flac)
    pub response_format: Option<String>,
    /// Speed of speech (0.25 to 4.0)
    pub speed: Option<f32>,
}

/// Configure AI API routes
pub fn configure_routes(cfg: &mut web::ServiceConfig) {
    cfg.service(
        web::scope("/v1")
            // Chat completions
            .route("/chat/completions", web::post().to(chat_completions))
            // Text completions (legacy)
            .route("/completions", web::post().to(completions))
            // Embeddings
            .route("/embeddings", web::post().to(embeddings))
            // Image generation
            .route("/images/generations", web::post().to(image_generations))
            // Models
            .route("/models", web::get().to(list_models))
            .route("/models/{model_id}", web::get().to(get_model))
            // Audio (future implementation)
            .route(
                "/audio/transcriptions",
                web::post().to(audio_transcriptions),
            )
            .route("/audio/translations", web::post().to(audio_translations))
            .route("/audio/speech", web::post().to(audio_speech)),
    );
}

/// Chat completions endpoint
///
/// OpenAI-compatible chat completions API that supports streaming and non-streaming responses.
pub async fn chat_completions(
    state: web::Data<AppState>,
    req: HttpRequest,
    request: web::Json<ChatCompletionRequest>,
) -> ActixResult<HttpResponse> {
    info!("Chat completion request for model: {}", request.model);

    // Get request context from middleware
    let context = get_request_context(&req)?;

    // Validate request
    if let Err(e) = RequestValidator::validate_chat_completion_request(
        &request.model,
        &request.messages,
        request.max_tokens,
        request.temperature,
    ) {
        warn!("Invalid chat completion request: {}", e);
        return Ok(errors::validation_error(&e.to_string()));
    }

    // Check if streaming is requested
    if request.stream.unwrap_or(false) {
        // Handle streaming request
        handle_streaming_chat_completion(state.get_ref().clone(), request.into_inner(), context)
            .await
    } else {
        // Handle non-streaming request
        match state
            .router
            .route_chat_completion(request.into_inner(), context)
            .await
        {
            Ok(response) => Ok(HttpResponse::Ok().json(response)),
            Err(e) => {
                error!("Chat completion error: {}", e);
                Ok(errors::gateway_error_to_response(e))
            }
        }
    }
}

/// Text completions endpoint (legacy)
///
/// OpenAI-compatible text completions API for backward compatibility.
pub async fn completions(
    state: web::Data<AppState>,
    req: HttpRequest,
    request: web::Json<CompletionRequest>,
) -> ActixResult<HttpResponse> {
    info!("Text completion request for model: {}", request.model);

    // Get request context from middleware
    let context = get_request_context(&req)?;

    // Route request through the core router
    match state
        .router
        .route_completion(request.into_inner(), context)
        .await
    {
        Ok(response) => Ok(HttpResponse::Ok().json(response)),
        Err(e) => {
            error!("Text completion error: {}", e);
            Ok(HttpResponse::InternalServerError().json(serde_json::json!({
                "error": "Internal server error"
            })))
        }
    }
}

/// Embeddings endpoint
///
/// OpenAI-compatible embeddings API for generating text embeddings.
pub async fn embeddings(
    state: web::Data<AppState>,
    req: HttpRequest,
    request: web::Json<EmbeddingRequest>,
) -> ActixResult<HttpResponse> {
    info!("Embedding request for model: {}", request.model);

    // Get request context from middleware
    let context = get_request_context(&req)?;

    // Route request through the core router
    match state
        .router
        .route_embedding(request.into_inner(), context)
        .await
    {
        Ok(response) => Ok(HttpResponse::Ok().json(response)),
        Err(e) => {
            error!("Embedding error: {}", e);
            Ok(HttpResponse::InternalServerError()
                .json(ApiResponse::<()>::error("Error".to_string())))
        }
    }
}

/// Image generation endpoint
///
/// OpenAI-compatible image generation API.
async fn image_generations(
    state: web::Data<AppState>,
    req: HttpRequest,
    request: web::Json<ImageGenerationRequest>,
) -> ActixResult<HttpResponse> {
    info!("Image generation request for model: {:?}", request.model);

    // Get request context from middleware
    let context = get_request_context(&req)?;

    // Route request through the core router
    match state
        .router
        .route_image_generation(request.into_inner(), context)
        .await
    {
        Ok(response) => Ok(HttpResponse::Ok().json(response)),
        Err(e) => {
            error!("Image generation error: {}", e);
            Ok(HttpResponse::InternalServerError()
                .json(ApiResponse::<()>::error("Error".to_string())))
        }
    }
}

/// List available models
///
/// Returns a list of available AI models across all configured providers.
pub async fn list_models(state: web::Data<AppState>) -> ActixResult<HttpResponse> {
    debug!("Listing available models");

    match state.router.list_models().await {
        Ok(models) => {
            let response = ModelListResponse {
                object: "list".to_string(),
                data: models,
            };
            Ok(HttpResponse::Ok().json(response))
        }
        Err(e) => {
            error!("Failed to list models: {}", e);
            Ok(HttpResponse::InternalServerError()
                .json(ApiResponse::<()>::error("Error".to_string())))
        }
    }
}

/// Get specific model information
///
/// Returns detailed information about a specific model.
async fn get_model(
    state: web::Data<AppState>,
    model_id: web::Path<String>,
) -> ActixResult<HttpResponse> {
    debug!("Getting model info for: {}", model_id);

    match state.router.get_model(&model_id).await {
        Ok(Some(model)) => Ok(HttpResponse::Ok().json(model)),
        Ok(None) => {
            Ok(HttpResponse::NotFound().json(ApiResponse::<()>::error("Error".to_string())))
        }
        Err(e) => {
            error!("Failed to get model {}: {}", model_id, e);
            Ok(HttpResponse::InternalServerError()
                .json(ApiResponse::<()>::error("Error".to_string())))
        }
    }
}

/// Audio transcriptions endpoint
async fn audio_transcriptions(
    _state: web::Data<AppState>,
    req: HttpRequest,
    _payload: web::Payload,
) -> ActixResult<HttpResponse> {
    info!("Audio transcriptions request");

    // Get request context (user, API key, etc.)
    let _context = match get_request_context(&req) {
        Ok(ctx) => ctx,
        Err(_) => {
            return Ok(HttpResponse::Unauthorized()
                .json(ApiResponse::<()>::error("Unauthorized".to_string())));
        }
    };

    // For now, return a placeholder response indicating the feature is in development
    let response = serde_json::json!({
        "text": "Audio transcription feature is in development. This endpoint will support OpenAI-compatible audio transcription APIs.",
        "language": "en",
        "duration": 0.0,
        "segments": []
    });

    Ok(HttpResponse::Ok().json(ApiResponse::success(response)))
}

/// Audio translations endpoint
async fn audio_translations(
    _state: web::Data<AppState>,
    req: HttpRequest,
    _payload: web::Payload,
) -> ActixResult<HttpResponse> {
    info!("Audio translations request");

    // Get request context (user, API key, etc.)
    let _context = match get_request_context(&req) {
        Ok(ctx) => ctx,
        Err(_) => {
            return Ok(HttpResponse::Unauthorized()
                .json(ApiResponse::<()>::error("Unauthorized".to_string())));
        }
    };

    // For now, return a placeholder response indicating the feature is in development
    let response = serde_json::json!({
        "text": "Audio translation feature is in development. This endpoint will support OpenAI-compatible audio translation APIs.",
        "language": "en",
        "duration": 0.0,
        "segments": []
    });

    Ok(HttpResponse::Ok().json(ApiResponse::success(response)))
}

/// Audio speech endpoint
async fn audio_speech(
    _state: web::Data<AppState>,
    req: HttpRequest,
    request: web::Json<AudioSpeechRequest>,
) -> ActixResult<HttpResponse> {
    info!(
        "Audio speech request for text: {}",
        &request.input[..50.min(request.input.len())]
    );

    // Get request context (user, API key, etc.)
    let _context = match get_request_context(&req) {
        Ok(ctx) => ctx,
        Err(_) => {
            return Ok(HttpResponse::Unauthorized()
                .json(ApiResponse::<()>::error("Unauthorized".to_string())));
        }
    };

    // For now, return a placeholder audio response
    // In a real implementation, this would generate actual audio using TTS providers
    let audio_data = vec![0u8; 1024]; // Placeholder audio data

    Ok(HttpResponse::Ok()
        .content_type("audio/mpeg")
        .body(audio_data))
}

/// Get request context from headers and middleware extensions
fn get_request_context(req: &HttpRequest) -> ActixResult<RequestContext> {
    // In a real implementation, this would extract the context from request extensions
    // that were set by the authentication middleware
    let mut context = RequestContext::new();

    // Extract request ID
    if let Some(request_id) = req.headers().get("x-request-id") {
        if let Ok(id) = request_id.to_str() {
            context.request_id = id.to_string();
        }
    }

    // Extract user agent
    if let Some(user_agent) = req.headers().get("user-agent") {
        if let Ok(agent) = user_agent.to_str() {
            context.user_agent = Some(agent.to_string());
        }
    }

    Ok(context)
}

/// Extract user from request extensions
fn get_authenticated_user(_headers: &HeaderMap) -> Option<User> {
    // In a real implementation, this would extract the user from request extensions
    // that were set by the authentication middleware
    None
}

/// Extract API key from request extensions
fn get_authenticated_api_key(_headers: &HeaderMap) -> Option<ApiKey> {
    // In a real implementation, this would extract the API key from request extensions
    // that were set by the authentication middleware
    None
}

/// Check if user has permission for the requested operation
fn check_permission(user: Option<&User>, api_key: Option<&ApiKey>, _operation: &str) -> bool {
    // In a real implementation, this would check permissions through the RBAC system
    // For now, assume all authenticated requests are allowed
    user.is_some() || api_key.is_some()
}

/// Log API usage for billing and analytics
async fn log_api_usage(
    _state: &AppState,
    context: &RequestContext,
    model: &str,
    tokens_used: u32,
    cost: f64,
) {
    // In a real implementation, this would log usage to the database
    debug!(
        "API usage: user_id={:?}, model={}, tokens={}, cost={}",
        context.user_id, model, tokens_used, cost
    );
}

/// Handle streaming chat completion
async fn handle_streaming_chat_completion(
    _state: AppState,
    _request: ChatCompletionRequest,
    _context: RequestContext,
) -> ActixResult<HttpResponse> {
    // TODO: Implement streaming support
    // For now, return an error indicating streaming is not yet supported
    error!("Streaming is not yet implemented");
    Ok(errors::validation_error("Streaming is not yet implemented"))
}

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

    #[test]
    fn test_get_request_context() {
        // This test would need a mock HttpRequest in a real implementation
        // For now, we'll test the basic functionality
        let context = RequestContext::new();
        assert!(!context.request_id.is_empty());
        assert!(context.user_agent.is_none());
    }

    #[test]
    fn test_check_permission() {
        // Test with no authentication
        assert!(!check_permission(None, None, "chat"));

        // Test with user (would need actual User instance in real test)
        // assert!(check_permission(Some(&user), None, "chat"));
    }

    #[tokio::test]
    async fn test_log_api_usage() {
        // This would require actual state in a real test
        // For now, just test that the function doesn't panic
        let _context = RequestContext::new();
        // log_api_usage(&state, &context, "gpt-4", 100, 0.002).await;
    }
}