use anyhow::Result;
use serde::{Deserialize, Serialize};
use serde_json::json;

// Ollama OpenAI-compatible endpoint — granite-code:3b running on RTX 3080
// Ollama is already installed and running: ollama serve
// Model already pulled: ollama pull granite-code:3b

const OLLAMA_URL: &str = "http://localhost:11434/v1/chat/completions";

#[derive(Deserialize)]
struct ChatChoice {
    message: ChatMessage,
}

#[derive(Deserialize)]
struct ChatMessage {
    content: String,
}

#[derive(Deserialize)]
struct ChatResponse {
    choices: Vec<ChatChoice>,
}

pub async fn complete_code(
    client: &reqwest::Client,
    prompt: &str,
    model:  &str,
) -> Result<String> {
    let body = json!({
        "model": model,
        "messages": [
            {
                "role": "system",
                "content": "You are LEGS — a sovereign code executor running on local Granite GPU. Receive architecture specs and produce complete, working, runnable code. No explanations. No prose. Pure code only."
            },
            {
                "role": "user",
                "content": prompt
            }
        ],
        "max_tokens": 2048,
        "temperature": 0.1
    });

    let resp = client
        .post(OLLAMA_URL)
        .json(&body)
        .timeout(std::time::Duration::from_secs(120))
        .send()
        .await;

    match resp {
        Ok(r) if r.status().is_success() => {
            let parsed = r.json::<ChatResponse>().await?;
            Ok(parsed.choices
                .first()
                .map(|c| c.message.content.clone())
                .unwrap_or_else(|| "GRANITE: empty response".to_string()))
        }
        Ok(r) => {
            let status = r.status();
            let text = r.text().await.unwrap_or_default();
            Ok(format!("GRANITE_ERR {}: {}", status, &text[..text.len().min(200)]))
        }
        Err(e) => {
            Ok(format!(
                "GRANITE OFFLINE — is Ollama running?\n  ollama serve\n  ollama list\nError: {}",
                e
            ))
        }
    }
}