use serde::{Deserialize, Serialize};

use super::client::LlmClient;
use crate::error::AgentError;

// ── Embedding types ────────────────────────────────────────────

#[derive(Serialize)]
struct EmbeddingRequest {
    model: String,
    input: Vec<String>,
}

#[derive(Deserialize)]
struct EmbeddingResponse {
    data: Vec<EmbeddingData>,
}

#[derive(Deserialize)]
struct EmbeddingData {
    embedding: Vec<f64>,
    index: usize,
}

// ── Embedding implementation ───────────────────────────────────

impl LlmClient {
    pub fn embed_model(&self) -> &str {
        &self.embed_model
    }

    /// Generate embeddings for a batch of texts
    pub async fn embed(&self, texts: Vec<String>) -> Result<Vec<Vec<f64>>, AgentError> {
        let url = format!("{}/v1/embeddings", self.base_url.trim_end_matches('/'));

        let request_body = EmbeddingRequest {
            model: self.embed_model.clone(),
            input: texts,
        };

        let mut req = self
            .http
            .post(&url)
            .header("content-type", "application/json")
            .json(&request_body);

        if let Some(auth) = self.auth_header() {
            req = req.header("Authorization", auth);
        }

        let resp = req
            .send()
            .await
            .map_err(|e| AgentError::Other(format!("Embedding request failed: {e}")))?;

        if !resp.status().is_success() {
            let status = resp.status();
            let body = resp.text().await.unwrap_or_default();
            return Err(AgentError::Other(format!(
                "Embedding API returned {status}: {body}"
            )));
        }

        let body: EmbeddingResponse = resp
            .json()
            .await
            .map_err(|e| AgentError::Other(format!("Failed to parse embedding response: {e}")))?;

        let mut data = body.data;
        data.sort_by_key(|d| d.index);

        Ok(data.into_iter().map(|d| d.embedding).collect())
    }
}
