//! Download NQ.FUT (Nasdaq-100 E-mini futures) historical data from Databento
//!
//! This downloads 1 day of OHLCV-1m data for NQ.FUT on 2024-01-02 (same date as ES.FUT)

use std::env;

#[tokio::main]
async fn main() -> Result<(), Box<dyn std::error::Error>> {
    println!("━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━");
    println!("  Databento NQ.FUT Historical Download");
    println!("━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━");
    println!();

    // Check for API key
    let api_key = env::var("DATABENTO_API_KEY")
        .map_err(|_| "DATABENTO_API_KEY environment variable not set")?;

    println!("✅ API Key found: {}...{}", &api_key[0..10], &api_key[api_key.len()-10..]);
    println!();

    // Test parameters
    let symbol = "NQ.FUT";
    let dataset = "GLBX.MDP3";
    let schema = "ohlcv-1m";
    let start_date = "2024-01-02";
    let end_date = "2024-01-02";

    println!("📋 Download Parameters:");
    println!("  Symbol:      {} (Nasdaq-100 E-mini Futures)", symbol);
    println!("  Dataset:     {} (CME Group MDP 3.0)", dataset);
    println!("  Schema:      {} (1-minute OHLCV bars)", schema);
    println!("  Date:        {} (single trading day)", start_date);
    println!();

    // Create HTTP client for Databento Historical API
    let client = reqwest::Client::builder()
        .timeout(std::time::Duration::from_secs(30))
        .build()?;

    // Build request URL
    let url = format!(
        "https://hist.databento.com/v0/timeseries.get_range?dataset={}&symbols={}&schema={}&start={}T00:00:00Z&end={}T23:59:59Z&encoding=dbn&stype_in=parent",
        dataset, symbol, schema, start_date, end_date
    );

    println!("🔗 Request URL:");
    println!("  {}", url);
    println!();

    println!("📥 Sending request...");

    // Make request with Basic Authentication
    let response = client
        .get(&url)
        .basic_auth(&api_key, Some(""))
        .send()
        .await?;

    // Check status
    let status = response.status();
    println!("📊 Response Status: {}", status);
    println!();

    if !status.is_success() {
        let error_text = response.text().await?;
        eprintln!("❌ Request failed!");
        eprintln!("Status: {}", status);
        eprintln!("Response: {}", error_text);
        return Err(format!("API returned error: {}", status).into());
    }

    // Get response body
    let body = response.bytes().await?;
    let size = body.len();

    println!("✅ Download successful!");
    println!("━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━");
    println!("  Size:         {} bytes ({:.2} KB)", size, size as f64 / 1024.0);

    // Estimate cost (based on ES.FUT: 96KB cost ~$0.0002)
    let size_gb = size as f64 / 1_073_741_824.0;
    let cost_low = size_gb * 0.50;
    let cost_high = size_gb * 2.00;

    println!("  Size (GB):    {:.10}", size_gb);
    println!("  Estimated:    ${:.6} - ${:.6}", cost_low, cost_high);

    // Read current balance from COST_TRACKING.md
    let cost_tracking_path = "COST_TRACKING.md";
    let current_balance = if let Ok(content) = std::fs::read_to_string(cost_tracking_path) {
        // Extract current credits from "**Current Credits**: ~$124.9998"
        if let Some(line) = content.lines().find(|l| l.contains("**Current Credits**")) {
            // Parse the number after "$"
            if let Some(dollar_pos) = line.rfind('$') {
                let balance_str = &line[dollar_pos+1..].trim();
                balance_str.parse::<f64>().unwrap_or(125.0)
            } else {
                125.0
            }
        } else {
            125.0
        }
    } else {
        125.0
    };

    println!("  Credits Left: ~${:.4}", current_balance - cost_high);
    println!();

    // Save to file
    let output_path = format!("test_data/real/databento/{}_{}_{}.dbn", symbol.replace("/", "_"), schema, start_date);
    std::fs::create_dir_all("test_data/real/databento")?;
    std::fs::write(&output_path, &body)?;

    println!("💾 Saved to: {}", output_path);
    println!();

    // Verify file
    if std::path::Path::new(&output_path).exists() {
        let file_size = std::fs::metadata(&output_path)?.len();
        println!("✅ File verified: {} bytes", file_size);
    } else {
        println!("⚠️  Warning: File not found after write");
    }

    println!();
    println!("━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━");
    println!("  Download Complete!");
    println!("━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━");
    println!();
    println!("💡 Next Steps:");
    println!("  1. Validate data: cargo run -p backtesting_service --example validate_dbn_data -- test_data/real/databento/{}_{}_{}.dbn", symbol.replace("/", "_"), schema, start_date);
    println!("  2. Update COST_TRACKING.md with usage details");

    Ok(())
}