//! OFI Features Demo
//!
//! Demonstrates how to use the OFI (Order Flow Imbalance) calculator
//! with MBP-10 order book snapshots.

use data::providers::databento::mbp10::{BidAskPair, Mbp10Snapshot};
use ml::features::ofi_calculator::{OFICalculator, OFIFeatures};

fn main() -> Result<(), Box<dyn std::error::Error>> {
    println!("=== OFI Features Demo ===\n");

    // Create OFI calculator
    let mut calculator = OFICalculator::new();

    // Create sample MBP-10 snapshots (simulating real market data)
    let snapshots = create_sample_snapshots();

    println!("Processing {} snapshots...\n", snapshots.len());

    for (i, snapshot) in snapshots.iter().enumerate() {
        // Calculate OFI features
        let features = calculator.calculate(snapshot)?;

        // Display results
        println!("Snapshot #{}", i + 1);
        println!("  Mid Price: ${:.2}", snapshot.mid_price());
        println!("  Spread: ${:.4}", snapshot.spread());
        println!("\n  OFI Features:");
        println!("    OFI Level 1 (normalized):  {:>8.3}", features.ofi_level1);
        println!("    OFI Level 5 (weighted):    {:>8.3}", features.ofi_level5);
        println!("    Depth Imbalance:           {:>8.3}", features.depth_imbalance);
        println!("    VPIN:                      {:>8.3}", features.vpin);
        println!("    Kyle's Lambda:             {:>8.6}", features.kyle_lambda);
        println!("    Bid Slope:                 {:>8.1}", features.bid_slope);
        println!("    Ask Slope:                 {:>8.1}", features.ask_slope);
        println!("    Trade Imbalance:           {:>8.3}", features.trade_imbalance);
        
        // Validate features
        if !features.is_valid() {
            println!("  ⚠️  WARNING: Invalid features detected!");
        } else {
            println!("  ✓ All features valid (finite)");
        }
        
        println!();
    }

    // Convert to array format (for ML model input)
    let final_snapshot = snapshots.last().unwrap();
    let final_features = calculator.calculate(final_snapshot)?;
    let feature_array = final_features.to_array();
    
    println!("Feature Array (for ML models):");
    println!("{:?}", feature_array);
    println!("\nArray length: {} (indices 226-233)", feature_array.len());

    Ok(())
}

/// Create sample MBP-10 snapshots for demonstration
fn create_sample_snapshots() -> Vec<Mbp10Snapshot> {
    vec![
        // Snapshot 1: Balanced book
        create_snapshot(
            1640995200000000000,
            5000_000_000_000_000, // $5000.00 bid
            5000_100_000_000_000, // $5000.01 ask
            100,
            100,
        ),
        // Snapshot 2: Bid rises (bullish signal)
        create_snapshot(
            1640995201000000000,
            5000_050_000_000_000, // $5000.05 bid (rises)
            5000_100_000_000_000, // $5000.01 ask
            120,
            90,
        ),
        // Snapshot 3: Ask falls (bullish signal)
        create_snapshot(
            1640995202000000000,
            5000_050_000_000_000,
            5000_075_000_000_000, // $5000.075 ask (falls)
            130,
            80,
        ),
        // Snapshot 4: Bid-heavy book
        create_snapshot(
            1640995203000000000,
            5000_075_000_000_000, // Bid continues rising
            5000_100_000_000_000,
            200, // Large bid size
            100,
        ),
        // Snapshot 5: Reversal - Ask rises (bearish signal)
        create_snapshot(
            1640995204000000000,
            5000_050_000_000_000, // Bid falls back
            5000_150_000_000_000, // Ask jumps up
            100,
            150,
        ),
    ]
}

fn create_snapshot(
    timestamp: u64,
    bid_px: i64,
    ask_px: i64,
    bid_sz: u32,
    ask_sz: u32,
) -> Mbp10Snapshot {
    let levels = vec![
        BidAskPair {
            bid_px,
            bid_sz,
            bid_ct: 5,
            ask_px,
            ask_sz,
            ask_ct: 6,
        },
        BidAskPair {
            bid_px: bid_px - 10_000_000_000,
            bid_sz: bid_sz * 2,
            bid_ct: 8,
            ask_px: ask_px + 10_000_000_000,
            ask_sz: ask_sz * 2,
            ask_ct: 7,
        },
        BidAskPair {
            bid_px: bid_px - 20_000_000_000,
            bid_sz: bid_sz * 3,
            bid_ct: 10,
            ask_px: ask_px + 20_000_000_000,
            ask_sz: ask_sz * 3,
            ask_ct: 9,
        },
        BidAskPair {
            bid_px: bid_px - 30_000_000_000,
            bid_sz: bid_sz * 4,
            bid_ct: 12,
            ask_px: ask_px + 30_000_000_000,
            ask_sz: ask_sz * 4,
            ask_ct: 11,
        },
        BidAskPair {
            bid_px: bid_px - 40_000_000_000,
            bid_sz: bid_sz * 5,
            bid_ct: 15,
            ask_px: ask_px + 40_000_000_000,
            ask_sz: ask_sz * 5,
            ask_ct: 13,
        },
    ];

    Mbp10Snapshot::new("ES.FUT".to_string(), timestamp, levels, 0, 100)
}