//! # Learning Curves Example
//!
//! Demonstrates how agent learning curves are computed and displayed.
//!
//! ## What This Example Shows
//! - Recording execution data over time
//! - Computing learning curves from historical data
//! - Understanding performance trends
//! - Visualizing improvement over time
//!
//! ## Run
//! ```bash
//! cargo run --example 02-learning-curves -p vapora-knowledge-graph
//! ```

use chrono::{Duration, Utc};

fn main() {
    println!("=== Learning Curves Example ===\n");

    // Step 1: Simulate 30 days of execution history
    let now = Utc::now();

    #[derive(Clone)]
    struct DailyStats {
        date: String,
        executions: u32,
        successful: u32,
        avg_duration_ms: u32,
    }

    let mut daily_data = vec![];

    for day in 0..30 {
        let date_obj = now - Duration::days(day);
        let date_str = date_obj.format("%Y-%m-%d").to_string();

        // Simulate improvement: success rate increases over time
        let base_success_rate = 0.70 + (day as f64 / 30.0) * 0.22; // From 70% to 92%
        let executions = 10;
        let successful = (executions as f64 * base_success_rate) as u32;
        let avg_duration = 300 - (day as u32 * 3); // Tasks get faster

        daily_data.push(DailyStats {
            date: date_str,
            executions,
            successful,
            avg_duration_ms: avg_duration,
        });
    }

    // Reverse to show chronologically
    daily_data.reverse();

    // Step 2: Display learning curve data
    println!("=== Agent: developer-bob (30-day history) ===\n");
    println!("Date      | Success Rate | Duration | Trend");
    println!("-----------|------|");

    let mut prev_success = 0.0;
    for data in &daily_data {
        let success_rate = (data.successful as f64 / data.executions as f64) * 100.0;
        let trend = if success_rate > prev_success {
            "↑"
        } else if success_rate < prev_success {
            "↓"
        } else {
            "→"
        };

        let bar_length = (success_rate / 5.0) as usize;
        let bar = "█".repeat(bar_length) + &"░".repeat(20 - bar_length);

        println!(
            "{} | {} | {:.0}% | {}ms | {}",
            data.date, bar, success_rate, data.avg_duration_ms, trend
        );
        prev_success = success_rate;
    }

    // Step 3: Compute overall learning curve
    println!("\n=== Learning Curve Analysis ===\n");

    let total_executions: u32 = daily_data.iter().map(|d| d.executions).sum();
    let total_successful: u32 = daily_data.iter().map(|d| d.successful).sum();
    let overall_success = (total_successful as f64 / total_executions as f64) * 100.0;

    println!("Total executions: {}", total_executions);
    println!("Total successful: {}", total_successful);
    println!("Overall success rate: {:.1}%\n", overall_success);

    // Compute 7-day and 14-day windows
    let recent_7 = &daily_data[daily_data.len() - 7..];
    let recent_14 = &daily_data[daily_data.len() - 14..];

    let recent_7_success: f64 = recent_7.iter().map(|d| d.successful as f64).sum::<f64>()
        / recent_7.iter().map(|d| d.executions as f64).sum::<f64>();
    let recent_14_success: f64 = recent_14.iter().map(|d| d.successful as f64).sum::<f64>()
        / recent_14.iter().map(|d| d.executions as f64).sum::<f64>();

    println!("Last 7 days success rate: {:.1}%", recent_7_success * 100.0);
    println!(
        "Last 14 days success rate: {:.1}%",
        recent_14_success * 100.0
    );

    // Step 4: Demonstrate recency bias
    println!("\n=== Recency Bias ===");
    println!("Recent days weighted 3× higher than older days");
    println!("Last 7 days: 3.0x weight");
    println!("Days 8-30: 1.0x weight\n");

    let weighted_recent = recent_7_success * 3.0;
    let weighted_older: f64 = daily_data[0..23]
        .iter()
        .map(|d| (d.successful as f64 / d.executions as f64))
        .sum::<f64>()
        / 23.0;
    let weighted_older = weighted_older * 1.0;

    let final_score = (weighted_recent + weighted_older) / (3.0 + 1.0);
    println!("Weighted score: {:.1}%", final_score * 100.0);

    // Step 5: Recommendations
    println!("\n=== Agent Performance Trend ===");
    let improvement =
        recent_7_success - (daily_data[0].successful as f64 / daily_data[0].executions as f64);
    if improvement > 0.0 {
        println!("✓ IMPROVING (+{:.1}%)", improvement * 100.0);
        println!("  → Agent is learning from experience");
        println!("  → Ready for more complex tasks");
    } else if improvement < 0.0 {
        println!("✗ DECLINING ({:.1}%)", improvement * 100.0);
        println!("  → Check for blocking issues");
        println!("  → Consider additional training");
    } else {
        println!("→ STABLE");
        println!("  → Consistent performance");
    }
}