use tokio::io::{self, AsyncWriteExt, BufReader};
use anyhow::Result;
use crate::generator::MessageGenerator;

pub async fn run_interactive_mode(mut generator: MessageGenerator) -> Result<MessageGenerator> {
    let types = vec!["feat", "fix", "docs", "style", "refactor", "perf", "test", "build", "ci", "chore", "revert"];

    generator.set_type(prompt_type(&types).await?);
    generator.set_scope_opt(prompt_scope().await?);
    generator.set_description(prompt_description().await?);
    generator.set_body_opt(prompt_body().await?);
    let is_breaking = prompt_breaking().await?;
    generator.set_breaking(is_breaking);
    if is_breaking {
        generator.set_breaking_description(prompt_breaking_description().await?);
    }

    println!("\nGenerated commit message:");
    println!("{}", generator.format_message());

    Ok(generator)
}

async fn prompt_type(types: &[&str]) -> Result<String> {
    let mut stdout = io::stdout();

    println!("Select commit type:");
    for (i, t) in types.iter().enumerate() {
        println!("  {} - {}", i, t);
    }
    print!("Enter number (0-{}): ", types.len() - 1);
    stdout.flush().await?;

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

    let idx: Result<usize, _> = input.trim().parse();
    match idx {
        Ok(i) if i < types.len() => Ok(types[i].to_string()),
        Ok(_) => {
            eprintln!("Invalid selection, using default 'chore'");
            Ok("chore".to_string())
        }
        Err(_) => {
            eprintln!("Invalid input, using default 'chore'");
            Ok("chore".to_string())
        }
    }
}

async fn prompt_scope() -> Result<Option<String>> {
    let mut stdout = io::stdout();
    let mut stdin = BufReader::new(io::stdin());

    print!("Scope (optional): ");
    stdout.flush().await?;

    let mut input = String::new();
    stdin.read_line(&mut input).await?;
    let trimmed = input.trim().to_string();
    if trimmed.is_empty() {
        Ok(None)
    } else {
        Ok(Some(trimmed))
    }
}

async fn prompt_description() -> Result<String> {
    let mut stdout = io::stdout();
    let mut stdin = BufReader::new(io::stdin());

    print!("Commit description: ");
    stdout.flush().await?;

    let mut input = String::new();
    stdin.read_line(&mut input).await?;
    Ok(input.trim().to_string())
}

async fn prompt_body() -> Result<Option<String>> {
    let mut stdout = io::stdout();
    let mut stdin = BufReader::new(io::stdin());

    print!("Extended description (optional, leave empty to skip): ");
    stdout.flush().await?;

    let mut input = String::new();
    stdin.read_line(&mut input).await?;
    let trimmed = input.trim().to_string();
    if trimmed.is_empty() {
        Ok(None)
    } else {
        Ok(Some(trimmed))
    }
}

async fn prompt_breaking() -> Result<bool> {
    let mut stdout = io::stdout();
    let mut stdin = BufReader::new(io::stdin());

    print!("Is this a breaking change? [y/N]: ");
    stdout.flush().await?;

    let mut input = String::new();
    stdin.read_line(&mut input).await?;
    Ok(input.trim().eq_ignore_ascii_case("y"))
}

async fn prompt_breaking_description() -> Result<String> {
    let mut stdout = io::stdout();
    let mut stdin = BufReader::new(io::stdin());

    print!("Describe the breaking change: ");
    stdout.flush().await?;

    let mut input = String::new();
    stdin.read_line(&mut input).await?;
    Ok(input.trim().to_string())
}