//! Topic management commands
//!
//! This module provides comprehensive topic management functionality including
//! create, list, delete, and describe operations for the message broker.

use clap::ArgMatches;
use serde_json::{Value, json};
use std::error::Error;

/// Handle topic create command
pub async fn handle_topic_create_command(matches: &ArgMatches) -> Result<(), Box<dyn Error>> {
    let name = matches.get_one::<String>("name").unwrap();
    let partitions: u32 = matches.get_one::<String>("partitions").unwrap().parse()?;
    let replication: u32 = matches.get_one::<String>("replication").unwrap().parse()?;
    let retention: u64 = matches.get_one::<String>("retention").unwrap().parse()?;

    println!("🚀 Creating topic '{}'...", name);
    println!("   Partitions: {}", partitions);
    println!("   Replication Factor: {}", replication);
    println!("   Retention: {} hours", retention);

    // Simulate topic creation
    let topic_config = json!({
        "name": name,
        "partitions": partitions,
        "replication_factor": replication,
        "retention_hours": retention,
        "created_at": chrono::Utc::now().to_rfc3339()
    });

    // In a real implementation, this would interact with the broker
    simulate_api_call(&format!("/api/topics"), "POST", &topic_config).await?;

    println!("✅ Topic '{}' created successfully!", name);
    Ok(())
}

/// Handle topic list command
pub async fn handle_topic_list_command(matches: &ArgMatches) -> Result<(), Box<dyn Error>> {
    let detailed = matches.get_flag("detailed");

    println!("📋 Listing topics...");

    // Simulate fetching topic list
    let topics = simulate_get_topics().await?;

    if detailed {
        display_detailed_topics(&topics)?;
    } else {
        display_simple_topics(&topics)?;
    }

    Ok(())
}

/// Handle topic delete command
pub async fn handle_topic_delete_command(matches: &ArgMatches) -> Result<(), Box<dyn Error>> {
    let name = matches.get_one::<String>("name").unwrap();
    let force = matches.get_flag("force");

    if !force {
        print!(
            "⚠️  Are you sure you want to delete topic '{}'? (y/N): ",
            name
        );
        use std::io::{self, Write};
        io::stdout().flush()?;

        let mut input = String::new();
        io::stdin().read_line(&mut input)?;

        if !input.trim().to_lowercase().starts_with('y') {
            println!("❌ Topic deletion cancelled.");
            return Ok(());
        }
    }

    println!("🗑️  Deleting topic '{}'...", name);

    // Simulate topic deletion
    simulate_api_call(&format!("/api/topics/{}", name), "DELETE", &json!({})).await?;

    println!("✅ Topic '{}' deleted successfully!", name);
    Ok(())
}

/// Handle topic describe command
pub async fn handle_topic_describe_command(matches: &ArgMatches) -> Result<(), Box<dyn Error>> {
    let name = matches.get_one::<String>("name").unwrap();

    println!("🔍 Describing topic '{}'...", name);

    // Simulate fetching topic details
    let topic_details = simulate_get_topic_details(name).await?;

    display_topic_details(&topic_details)?;

    Ok(())
}

// Helper functions for simulation
async fn simulate_api_call(
    endpoint: &str,
    method: &str,
    payload: &Value,
) -> Result<(), Box<dyn Error>> {
    // Simulate API call delay
    tokio::time::sleep(tokio::time::Duration::from_millis(200)).await;

    println!("📡 API Call: {} {}", method, endpoint);
    if method != "GET" && method != "DELETE" {
        println!("📤 Payload: {}", serde_json::to_string_pretty(payload)?);
    }

    Ok(())
}

async fn simulate_get_topics() -> Result<Vec<Value>, Box<dyn Error>> {
    // Simulate API delay
    tokio::time::sleep(tokio::time::Duration::from_millis(300)).await;

    Ok(vec![
        json!({
            "name": "user-events",
            "partitions": 3,
            "replication_factor": 2,
            "retention_hours": 168,
            "size_bytes": 1048576,
            "message_count": 15420,
            "created_at": "2024-01-15T10:30:00Z"
        }),
        json!({
            "name": "order-processing",
            "partitions": 5,
            "replication_factor": 3,
            "retention_hours": 72,
            "size_bytes": 2097152,
            "message_count": 8950,
            "created_at": "2024-01-20T14:45:00Z"
        }),
        json!({
            "name": "notification-queue",
            "partitions": 2,
            "replication_factor": 2,
            "retention_hours": 24,
            "size_bytes": 524288,
            "message_count": 3200,
            "created_at": "2024-02-01T09:15:00Z"
        }),
    ])
}

async fn simulate_get_topic_details(name: &str) -> Result<Value, Box<dyn Error>> {
    // Simulate API delay
    tokio::time::sleep(tokio::time::Duration::from_millis(250)).await;

    Ok(json!({
        "name": name,
        "partitions": 3,
        "replication_factor": 2,
        "retention_hours": 168,
        "size_bytes": 1048576,
        "message_count": 15420,
        "created_at": "2024-01-15T10:30:00Z",
        "partition_details": [
            {
                "partition_id": 0,
                "leader": "broker-1",
                "replicas": ["broker-1", "broker-2"],
                "in_sync_replicas": ["broker-1", "broker-2"],
                "size_bytes": 349525,
                "message_count": 5140,
                "log_start_offset": 0,
                "log_end_offset": 5140
            },
            {
                "partition_id": 1,
                "leader": "broker-2",
                "replicas": ["broker-2", "broker-3"],
                "in_sync_replicas": ["broker-2", "broker-3"],
                "size_bytes": 349525,
                "message_count": 5140,
                "log_start_offset": 0,
                "log_end_offset": 5140
            },
            {
                "partition_id": 2,
                "leader": "broker-3",
                "replicas": ["broker-3", "broker-1"],
                "in_sync_replicas": ["broker-3", "broker-1"],
                "size_bytes": 349526,
                "message_count": 5140,
                "log_start_offset": 0,
                "log_end_offset": 5140
            }
        ],
        "consumer_groups": [
            {
                "group_id": "analytics-service",
                "members": 2,
                "lag": 120
            },
            {
                "group_id": "backup-service",
                "members": 1,
                "lag": 0
            }
        ]
    }))
}

fn display_simple_topics(topics: &[Value]) -> Result<(), Box<dyn Error>> {
    println!();
    println!("┌─────────────────────┬───────────┬─────────────┬──────────────┬───────────────┐");
    println!("│ Topic Name          │ Partitions│ Replication │ Message Count│ Size (KB)     │");
    println!("├─────────────────────┼───────────┼─────────────┼──────────────┼───────────────┤");

    for topic in topics {
        let name = topic["name"].as_str().unwrap_or("Unknown");
        let partitions = topic["partitions"].as_u64().unwrap_or(0);
        let replication = topic["replication_factor"].as_u64().unwrap_or(0);
        let message_count = topic["message_count"].as_u64().unwrap_or(0);
        let size_kb = topic["size_bytes"].as_u64().unwrap_or(0) / 1024;

        println!(
            "│ {:<19} │ {:<9} │ {:<11} │ {:<12} │ {:<13} │",
            name, partitions, replication, message_count, size_kb
        );
    }

    println!("└─────────────────────┴───────────┴─────────────┴──────────────┴───────────────┘");
    println!();

    Ok(())
}

fn display_detailed_topics(topics: &[Value]) -> Result<(), Box<dyn Error>> {
    for (i, topic) in topics.iter().enumerate() {
        if i > 0 {
            println!();
        }

        println!("📊 Topic: {}", topic["name"].as_str().unwrap_or("Unknown"));
        println!(
            "   Partitions: {}",
            topic["partitions"].as_u64().unwrap_or(0)
        );
        println!(
            "   Replication Factor: {}",
            topic["replication_factor"].as_u64().unwrap_or(0)
        );
        println!(
            "   Retention: {} hours",
            topic["retention_hours"].as_u64().unwrap_or(0)
        );
        println!(
            "   Message Count: {}",
            topic["message_count"].as_u64().unwrap_or(0)
        );
        println!(
            "   Size: {} KB",
            topic["size_bytes"].as_u64().unwrap_or(0) / 1024
        );
        println!(
            "   Created: {}",
            topic["created_at"].as_str().unwrap_or("Unknown")
        );
    }

    Ok(())
}

fn display_topic_details(topic: &Value) -> Result<(), Box<dyn Error>> {
    println!();
    println!(
        "📊 Topic Details: {}",
        topic["name"].as_str().unwrap_or("Unknown")
    );
    println!("━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━");

    // Basic information
    println!("📋 Basic Information:");
    println!("   Name: {}", topic["name"].as_str().unwrap_or("Unknown"));
    println!(
        "   Partitions: {}",
        topic["partitions"].as_u64().unwrap_or(0)
    );
    println!(
        "   Replication Factor: {}",
        topic["replication_factor"].as_u64().unwrap_or(0)
    );
    println!(
        "   Retention: {} hours",
        topic["retention_hours"].as_u64().unwrap_or(0)
    );
    println!(
        "   Total Messages: {}",
        topic["message_count"].as_u64().unwrap_or(0)
    );
    println!(
        "   Total Size: {} KB",
        topic["size_bytes"].as_u64().unwrap_or(0) / 1024
    );
    println!(
        "   Created: {}",
        topic["created_at"].as_str().unwrap_or("Unknown")
    );

    // Partition details
    println!();
    println!("🗂️  Partition Details:");
    println!("┌─────┬─────────┬─────────────────────────┬─────────────┬──────────────┐");
    println!("│ ID  │ Leader  │ Replicas                │ Messages    │ Size (KB)    │");
    println!("├─────┼─────────┼─────────────────────────┼─────────────┼──────────────┤");

    if let Some(partitions) = topic["partition_details"].as_array() {
        for partition in partitions {
            let id = partition["partition_id"].as_u64().unwrap_or(0);
            let leader = partition["leader"].as_str().unwrap_or("Unknown");
            let replicas = partition["replicas"]
                .as_array()
                .map(|r| {
                    r.iter()
                        .map(|v| v.as_str().unwrap_or(""))
                        .collect::<Vec<_>>()
                        .join(", ")
                })
                .unwrap_or_else(|| "Unknown".to_string());
            let messages = partition["message_count"].as_u64().unwrap_or(0);
            let size_kb = partition["size_bytes"].as_u64().unwrap_or(0) / 1024;

            println!(
                "│ {:<3} │ {:<7} │ {:<23} │ {:<11} │ {:<12} │",
                id,
                leader,
                &replicas[..replicas.len().min(23)],
                messages,
                size_kb
            );
        }
    }

    println!("└─────┴─────────┴─────────────────────────┴─────────────┴──────────────┘");

    // Consumer groups
    println!();
    println!("👥 Active Consumer Groups:");
    if let Some(groups) = topic["consumer_groups"].as_array() {
        if groups.is_empty() {
            println!("   No active consumer groups");
        } else {
            println!("┌─────────────────────┬─────────┬─────────┐");
            println!("│ Group ID            │ Members │ Lag     │");
            println!("├─────────────────────┼─────────┼─────────┤");

            for group in groups {
                let group_id = group["group_id"].as_str().unwrap_or("Unknown");
                let members = group["members"].as_u64().unwrap_or(0);
                let lag = group["lag"].as_u64().unwrap_or(0);

                println!("│ {:<19} │ {:<7} │ {:<7} │", group_id, members, lag);
            }

            println!("└─────────────────────┴─────────┴─────────┘");
        }
    }

    println!();
    Ok(())
}
