mod abort_signal;
mod clipboard;
mod prompt_input;
mod render_prompt;
mod tiktoken;

pub use self::abort_signal::{create_abort_signal, AbortSignal};
pub use self::clipboard::set_text;
pub use self::prompt_input::*;
pub use self::render_prompt::render_prompt;
pub use self::tiktoken::cl100k_base_singleton;

use sha2::{Digest, Sha256};
use std::env;
use std::process::Command;

pub fn now() -> String {
    let now = chrono::Local::now();
    now.to_rfc3339_opts(chrono::SecondsFormat::Secs, false)
}

pub fn get_env_name(key: &str) -> String {
    format!(
        "{}_{}",
        env!("CARGO_CRATE_NAME").to_ascii_uppercase(),
        key.to_ascii_uppercase(),
    )
}

/// Split text to tokens
pub fn tokenize(text: &str) -> Vec<String> {
    let tokens = cl100k_base_singleton()
        .lock()
        .encode_with_special_tokens(text);
    let token_bytes: Vec<Vec<u8>> = tokens
        .into_iter()
        .map(|v| cl100k_base_singleton().lock().decode_bytes(vec![v]))
        .collect();
    let mut output = vec![];
    let mut current_bytes = vec![];
    for bytes in token_bytes {
        current_bytes.extend(bytes);
        if let Ok(v) = std::str::from_utf8(&current_bytes) {
            output.push(v.to_string());
            current_bytes.clear();
        }
    }
    output
}

/// Count how many tokens a piece of text needs to consume
pub fn count_tokens(text: &str) -> usize {
    cl100k_base_singleton()
        .lock()
        .encode_with_special_tokens(text)
        .len()
}

pub fn light_theme_from_colorfgbg(colorfgbg: &str) -> Option<bool> {
    let parts: Vec<_> = colorfgbg.split(';').collect();
    let bg = match parts.len() {
        2 => &parts[1],
        3 => &parts[2],
        _ => {
            return None;
        }
    };
    let bg = bg.parse::<u8>().ok()?;
    let (r, g, b) = ansi_colours::rgb_from_ansi256(bg);

    let v = 0.2126 * r as f32 + 0.7152 * g as f32 + 0.0722 * b as f32;

    let light = v > 128.0;
    Some(light)
}

pub fn init_tokio_runtime() -> anyhow::Result<tokio::runtime::Runtime> {
    use anyhow::Context;
    tokio::runtime::Builder::new_current_thread()
        .enable_all()
        .build()
        .with_context(|| "Failed to init tokio")
}

pub fn sha256sum(input: &str) -> String {
    let mut hasher = Sha256::new();
    hasher.update(input);
    let result = hasher.finalize();
    format!("{:x}", result)
}

pub fn detect_os() -> String {
    let os = env::consts::OS;
    if os == "linux" {
        if let Ok(contents) = std::fs::read_to_string("/etc/os-release") {
            for line in contents.lines() {
                if let Some(id) = line.strip_prefix("ID=") {
                    return format!("{os}/{id}");
                }
            }
        }
    }
    os.to_string()
}

pub fn detect_shell() -> (String, String, &'static str) {
    let os = env::consts::OS;
    if os == "windows" {
        if env::var("NU_VERSION").is_ok() {
            ("nushell".into(), "nu.exe".into(), "-c")
        } else if let Some(ret) = env::var("PSModulePath").ok().and_then(|v| {
            let v = v.to_lowercase();
            if v.split(';').count() >= 3 {
                if v.contains("powershell\\7\\") {
                    Some(("pwsh".into(), "pwsh.exe".into(), "-c"))
                } else {
                    Some(("powershell".into(), "powershell.exe".into(), "-Command"))
                }
            } else {
                None
            }
        }) {
            ret
        } else {
            ("cmd".into(), "cmd.exe".into(), "/C")
        }
    } else if env::var("NU_VERSION").is_ok() {
        ("nushell".into(), "nu".into(), "-c")
    } else {
        let shell_cmd = env::var("SHELL").unwrap_or_else(|_| "/bin/sh".to_string());
        let shell_name = match shell_cmd.rsplit_once('/') {
            Some((_, name)) => name.to_string(),
            None => shell_cmd.clone(),
        };
        let shell_name = if shell_name == "nu" {
            "nushell".into()
        } else {
            shell_name
        };
        (shell_name, shell_cmd, "-c")
    }
}

pub fn run_command(eval_str: &str) -> anyhow::Result<i32> {
    let (_shell_name, shell_cmd, shell_arg) = detect_shell();
    let status = Command::new(shell_cmd)
        .arg(shell_arg)
        .arg(eval_str)
        .status()?;
    Ok(status.code().unwrap_or_default())
}

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

    #[test]
    fn test_tokenize() {
        assert_eq!(tokenize("😊 hello world"), ["😊", " hello", " world"]);
        assert_eq!(tokenize("世界"), ["世", "界"]);
    }

    #[test]
    fn test_count_tokens() {
        assert_eq!(count_tokens("😊 hello world"), 4);
    }
}