use anyhow::Result;
use tracing::info;
use super::rcon::RconClient;

/// Player information from Minecraft RCON.
pub struct MinecraftPlayer {
    pub name: String,
}

/// Query Minecraft server for active players using RCON `list` command.
pub async fn get_players(rcon_address: &str, rcon_password: &str) -> Result<(Vec<MinecraftPlayer>, u32)> {
    let mut client = RconClient::connect(rcon_address, rcon_password).await?;
    let response = client.command("list").await?;

    // Parse response: "There are X of a max of Y players online: player1, player2"
    let (count, max, players) = parse_list_response(&response);

    info!(
        count = count,
        max = max,
        "Minecraft player list retrieved"
    );

    Ok((players, max))
}

fn parse_list_response(response: &str) -> (u32, u32, Vec<MinecraftPlayer>) {
    // Format: "There are X of a max of Y players online: player1, player2, ..."
    // Or: "There are X of a max Y players online:"
    let parts: Vec<&str> = response.splitn(2, ':').collect();

    let mut count = 0u32;
    let mut max = 0u32;
    let mut found_count = false;

    if let Some(header) = parts.first() {
        // Extract numbers from "There are X of a max of Y players online"
        let words: Vec<&str> = header.split_whitespace().collect();
        for word in words.iter() {
            if let Ok(n) = word.parse::<u32>() {
                if !found_count {
                    count = n;
                    found_count = true;
                } else {
                    max = n;
                }
            }
        }
    }

    let mut players = Vec::new();
    if parts.len() > 1 {
        let player_list = parts[1].trim();
        if !player_list.is_empty() {
            for name in player_list.split(',') {
                let name = name.trim();
                if !name.is_empty() {
                    players.push(MinecraftPlayer {
                        name: name.to_string(),
                    });
                }
            }
        }
    }

    (count, max, players)
}

#[cfg(test)]
mod tests {
    use super::*;

    #[test]
    fn test_parse_list_response() {
        let (count, max, players) = parse_list_response(
            "There are 3 of a max of 20 players online: Steve, Alex, Notch",
        );
        assert_eq!(count, 3);
        assert_eq!(max, 20);
        assert_eq!(players.len(), 3);
        assert_eq!(players[0].name, "Steve");
        assert_eq!(players[1].name, "Alex");
        assert_eq!(players[2].name, "Notch");
    }

    #[test]
    fn test_parse_empty_list() {
        let (count, max, players) = parse_list_response(
            "There are 0 of a max of 20 players online:",
        );
        assert_eq!(count, 0);
        assert_eq!(max, 20);
        assert_eq!(players.len(), 0);
    }
}