mod non_stream;
mod shared;
mod stream;

use actix_web::{http::StatusCode, web, HttpResponse};

use crate::agent::llm::api::models::StreamOptions;
use crate::agent::llm::providers::anthropic::api_types::AnthropicMessagesRequest;
use crate::server::{app_state::AppState, error::AppError};

use super::conversion::convert_messages_request;
use super::errors::{anthropic_error_response, AnthropicError};
use super::resolution::resolve_model;

pub async fn messages(
    app_state: web::Data<AppState>,
    req: web::Json<AnthropicMessagesRequest>,
) -> Result<HttpResponse, AppError> {
    let stream = req.stream.unwrap_or(false);
    let request = req.into_inner();
    let response_model = request.model.clone();
    let forward_id = uuid::Uuid::new_v4().to_string();

    let resolution = {
        let config = app_state.config.read().await;
        resolve_model(&config.anthropic_model_mapping, &response_model)
    };

    let mut openai_request = match convert_messages_request(request) {
        Ok(request) => request,
        Err(err) => return Ok(anthropic_error_response(err)),
    };
    openai_request.model = resolution.mapped_model.clone();
    if openai_request.model.trim().is_empty() {
        return Ok(anthropic_error_response(AnthropicError::new(
            StatusCode::BAD_REQUEST,
            "invalid_request",
            "model is required (no default model fallback)".to_string(),
        )));
    }

    // Enable usage tracking for streaming requests.
    if stream {
        openai_request.stream_options = Some(StreamOptions {
            include_usage: true,
        });
    }

    if stream {
        stream::handle_streaming_messages(
            app_state,
            openai_request,
            resolution.response_model,
            forward_id,
        )
        .await
    } else {
        non_stream::handle_non_streaming_messages(
            app_state,
            openai_request,
            resolution.response_model,
            forward_id,
        )
        .await
    }
}
