//! Summarizer Adapter - Bridges zclaw_growth::SummaryLlmDriver with Tauri LLM Client
//!
//! Implements the SummaryLlmDriver trait using the local LlmClient,
//! enabling L0/L1 summary generation via the user's configured LLM.

use zclaw_growth::{MemoryEntry, SummaryLlmDriver, summarizer::{overview_prompt, abstract_prompt}};

/// Tauri-side implementation of SummaryLlmDriver using llm::LlmClient
pub struct TauriSummaryDriver {
    endpoint: String,
    api_key: String,
    model: Option<String>,
}

impl TauriSummaryDriver {
    /// Create a new Tauri summary driver
    pub fn new(endpoint: String, api_key: String, model: Option<String>) -> Self {
        Self {
            endpoint,
            api_key,
            model,
        }
    }

    /// Check if the driver is configured (has endpoint and api_key)
    pub fn is_configured(&self) -> bool {
        !self.endpoint.is_empty() && !self.api_key.is_empty()
    }

    /// Call the LLM API with a simple prompt
    async fn call_llm(&self, prompt: String) -> Result<String, String> {
        let client = reqwest::Client::new();

        let model = self.model.clone().ok_or_else(|| {
            "Summary driver model not configured — kernel_init must be called first".to_string()
        })?;

        let request = serde_json::json!({
            "model": model,
            "messages": [
                { "role": "user", "content": prompt }
            ],
            "temperature": 0.3,
            "max_tokens": 200,
        });

        let response = client
            .post(format!("{}/chat/completions", self.endpoint))
            .header("Authorization", format!("Bearer {}", self.api_key))
            .header("Content-Type", "application/json")
            .json(&request)
            .send()
            .await
            .map_err(|e| format!("Summary LLM request failed: {}", e))?;

        if !response.status().is_success() {
            let status = response.status();
            let body = response.text().await.unwrap_or_default();
            return Err(format!("Summary LLM error {}: {}", status, body));
        }

        let json: serde_json::Value = response
            .json()
            .await
            .map_err(|e| format!("Failed to parse summary response: {}", e))?;

        json.get("choices")
            .and_then(|c| c.get(0))
            .and_then(|c| c.get("message"))
            .and_then(|m| m.get("content"))
            .and_then(|c| c.as_str())
            .map(|s| s.to_string())
            .ok_or_else(|| "Invalid summary LLM response format".to_string())
    }
}

#[async_trait::async_trait]
impl SummaryLlmDriver for TauriSummaryDriver {
    async fn generate_overview(&self, entry: &MemoryEntry) -> Result<String, String> {
        let prompt = overview_prompt(entry);
        self.call_llm(prompt).await
    }

    async fn generate_abstract(&self, entry: &MemoryEntry) -> Result<String, String> {
        let prompt = abstract_prompt(entry);
        self.call_llm(prompt).await
    }
}

/// Global summary driver instance (lazy-initialized)
static SUMMARY_DRIVER: tokio::sync::OnceCell<std::sync::Arc<TauriSummaryDriver>> =
    tokio::sync::OnceCell::const_new();

/// Configure the global summary driver
pub fn configure_summary_driver(driver: TauriSummaryDriver) {
    let _ = SUMMARY_DRIVER.set(std::sync::Arc::new(driver));
    tracing::info!("[SummarizerAdapter] Summary driver configured");
}

/// Check if summary driver is available
pub fn is_summary_driver_configured() -> bool {
    SUMMARY_DRIVER
        .get()
        .map(|d| d.is_configured())
        .unwrap_or(false)
}

/// Get the global summary driver
pub fn get_summary_driver() -> Option<std::sync::Arc<TauriSummaryDriver>> {
    SUMMARY_DRIVER.get().cloned()
}

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

    #[test]
    fn test_summary_driver_not_configured_by_default() {
        assert!(!is_summary_driver_configured());
    }

    #[test]
    fn test_summary_driver_configure_and_check() {
        let driver = TauriSummaryDriver::new(
            "https://example.com/v1".to_string(),
            "test-key".to_string(),
            None,
        );
        assert!(driver.is_configured());

        let empty_driver = TauriSummaryDriver::new(String::new(), String::new(), None);
        assert!(!empty_driver.is_configured());
    }
}