// Batches resource — client.batches().create() / list() / retrieve() / cancel()

use crate::client::OpenAI;
use crate::error::OpenAIError;
use crate::pagination::{Page, Paginator};
use crate::types::batch::{Batch, BatchCreateRequest, BatchList, BatchListParams};

/// Access batch endpoints.
///
/// OpenAI guide: <https://platform.openai.com/docs/guides/batch>
/// API reference: <https://platform.openai.com/docs/api-reference/batch>
pub struct Batches<'a> {
    client: &'a OpenAI,
}

impl<'a> Batches<'a> {
    pub(crate) fn new(client: &'a OpenAI) -> Self {
        Self { client }
    }

    /// Create a batch.
    ///
    /// `POST /batches`
    pub async fn create(&self, request: BatchCreateRequest) -> Result<Batch, OpenAIError> {
        self.client.post("/batches", &request).await
    }

    /// List batches.
    ///
    /// `GET /batches`
    pub async fn list(&self) -> Result<BatchList, OpenAIError> {
        self.client.get("/batches").await
    }

    /// List batches with pagination parameters.
    ///
    /// `GET /batches`
    pub async fn list_page(&self, params: BatchListParams) -> Result<BatchList, OpenAIError> {
        self.client
            .get_with_query("/batches", &params.to_query())
            .await
    }

    /// Auto-paginate through all batches.
    ///
    /// Returns a [`Paginator`] stream that yields individual [`Batch`] items,
    /// automatically fetching subsequent pages.
    pub fn list_auto(&self, params: BatchListParams) -> Paginator<Batch> {
        let client = self.client.clone();
        let base_params = params;
        Paginator::new(move |cursor| {
            let client = client.clone();
            let mut params = base_params.clone();
            if cursor.is_some() {
                params.after = cursor;
            }
            async move {
                let list: BatchList = client
                    .get_with_query("/batches", &params.to_query())
                    .await?;
                let after_cursor = list
                    .last_id
                    .clone()
                    .or_else(|| list.data.last().map(|b| b.id.clone()));
                Ok(Page {
                    has_more: list.has_more.unwrap_or(false),
                    after_cursor,
                    data: list.data,
                })
            }
        })
    }

    /// Retrieve a batch.
    ///
    /// `GET /batches/{batch_id}`
    pub async fn retrieve(&self, batch_id: &str) -> Result<Batch, OpenAIError> {
        self.client.get(&format!("/batches/{batch_id}")).await
    }

    /// Cancel a batch.
    ///
    /// `POST /batches/{batch_id}/cancel`
    pub async fn cancel(&self, batch_id: &str) -> Result<Batch, OpenAIError> {
        self.client
            .post(
                &format!("/batches/{batch_id}/cancel"),
                &serde_json::Value::Null,
            )
            .await
    }
}

#[cfg(test)]
mod tests {
    use crate::OpenAI;
    use crate::config::ClientConfig;
    use crate::types::batch::{BatchCreateRequest, BatchListParams};

    const BATCH_JSON: &str = r#"{
        "id": "batch_abc123",
        "object": "batch",
        "endpoint": "/v1/chat/completions",
        "input_file_id": "file-abc123",
        "completion_window": "24h",
        "status": "validating",
        "created_at": 1699012949
    }"#;

    #[tokio::test]
    async fn test_batches_create() {
        let mut server = mockito::Server::new_async().await;
        let mock = server
            .mock("POST", "/batches")
            .match_header("authorization", "Bearer sk-test")
            .with_status(200)
            .with_header("content-type", "application/json")
            .with_body(BATCH_JSON)
            .create_async()
            .await;

        let client = OpenAI::with_config(ClientConfig::new("sk-test").base_url(server.url()));
        let request = BatchCreateRequest::new("file-abc123", "/v1/chat/completions", "24h");

        let batch = client.batches().create(request).await.unwrap();
        assert_eq!(batch.id, "batch_abc123");
        assert_eq!(batch.status, crate::types::batch::BatchStatus::Validating);
        mock.assert_async().await;
    }

    #[tokio::test]
    async fn test_batches_retrieve() {
        let mut server = mockito::Server::new_async().await;
        let mock = server
            .mock("GET", "/batches/batch_abc123")
            .with_status(200)
            .with_header("content-type", "application/json")
            .with_body(BATCH_JSON)
            .create_async()
            .await;

        let client = OpenAI::with_config(ClientConfig::new("sk-test").base_url(server.url()));
        let batch = client.batches().retrieve("batch_abc123").await.unwrap();
        assert_eq!(batch.id, "batch_abc123");
        mock.assert_async().await;
    }

    #[tokio::test]
    async fn test_batches_cancel() {
        let mut server = mockito::Server::new_async().await;
        let mock = server
            .mock("POST", "/batches/batch_abc123/cancel")
            .with_status(200)
            .with_header("content-type", "application/json")
            .with_body(
                r#"{
                    "id": "batch_abc123",
                    "object": "batch",
                    "endpoint": "/v1/chat/completions",
                    "input_file_id": "file-abc123",
                    "completion_window": "24h",
                    "status": "cancelling",
                    "created_at": 1699012949
                }"#,
            )
            .create_async()
            .await;

        let client = OpenAI::with_config(ClientConfig::new("sk-test").base_url(server.url()));
        let batch = client.batches().cancel("batch_abc123").await.unwrap();
        assert_eq!(batch.status, crate::types::batch::BatchStatus::Cancelling);
        mock.assert_async().await;
    }

    #[tokio::test]
    async fn test_batches_list_auto_multi_page() {
        use futures_util::StreamExt;

        let mut server = mockito::Server::new_async().await;

        let _mock_p1 = server
            .mock("GET", "/batches")
            .match_query(mockito::Matcher::Missing)
            .with_status(200)
            .with_header("content-type", "application/json")
            .with_body(
                r#"{
                    "object": "list",
                    "data": [
                        {"id": "batch_1", "object": "batch", "endpoint": "/v1/chat/completions", "input_file_id": "file-1", "completion_window": "24h", "status": "completed", "created_at": 1},
                        {"id": "batch_2", "object": "batch", "endpoint": "/v1/chat/completions", "input_file_id": "file-2", "completion_window": "24h", "status": "completed", "created_at": 2}
                    ],
                    "has_more": true,
                    "last_id": "batch_2"
                }"#,
            )
            .create_async()
            .await;

        let _mock_p2 = server
            .mock("GET", "/batches")
            .match_query(mockito::Matcher::AllOf(vec![
                mockito::Matcher::UrlEncoded("after".into(), "batch_2".into()),
            ]))
            .with_status(200)
            .with_header("content-type", "application/json")
            .with_body(
                r#"{
                    "object": "list",
                    "data": [
                        {"id": "batch_3", "object": "batch", "endpoint": "/v1/chat/completions", "input_file_id": "file-3", "completion_window": "24h", "status": "completed", "created_at": 3}
                    ],
                    "has_more": false,
                    "last_id": "batch_3"
                }"#,
            )
            .create_async()
            .await;

        let client = OpenAI::with_config(ClientConfig::new("sk-test").base_url(server.url()));
        let stream = client.batches().list_auto(BatchListParams::new());
        let batches: Vec<_> = stream
            .collect::<Vec<_>>()
            .await
            .into_iter()
            .map(|r| r.unwrap())
            .collect();

        assert_eq!(batches.len(), 3);
        assert_eq!(batches[0].id, "batch_1");
        assert_eq!(batches[2].id, "batch_3");
    }
}
