#![cfg(target_os = "android")]
#![allow(non_snake_case)]

use std::ffi::{CStr, CString};
use std::future::Future;

use grammers_client::{Client, Config};
use grammers_client::types::{Dialog, LoginToken};
use grammers_session::{PackedChat, Session};
use jni::JNIEnv;
use jni::objects::{JObject, JString};
use jni::sys::{jboolean, jint, jlong, jstring};
use log;
use log::{error, info, Level};
use once_cell::sync::OnceCell;
use tokio::runtime;
use tokio::runtime::Runtime;

const LOG_MIN_LEVEL: Level = Level::Trace;
const LOG_TAG: &str = ".native.talari";
const API_ID: i32 = 0;
const API_HASH: &str = "";

type Result<T> = std::result::Result<T, Box<dyn std::error::Error>>;

static RUNTIME: OnceCell<Runtime> = OnceCell::new();
static CLIENT: OnceCell<Client> = OnceCell::new();

fn block_on<F: Future>(future: F) -> F::Output {
    if RUNTIME.get().is_none() {
        RUNTIME
            .set(
                runtime::Builder::new_current_thread()
                    .enable_all()
                    .build()
                    .unwrap(),
            )
            .ok();
    }

    RUNTIME.get().unwrap().block_on(future)
}

async fn init_client() -> Result<()> {
    android_logger::init_once(
        android_logger::Config::default()
            .with_min_level(LOG_MIN_LEVEL)
            .with_tag(LOG_TAG),
    );

    if CLIENT.get().is_some() {
        info!("Client is already initialized");
        return Ok(());
    }

    info!("Connecting to Telegram...");

    let client = Client::connect(Config {
        session: Session::new(),
        api_id: API_ID,
        api_hash: API_HASH.to_string(),
        params: Default::default(),
    })
        .await?;

    info!("Connected!");

    CLIENT
        .set(client)
        .map_err(|_| "Client was already initialized")?;

    Ok(())
}

async fn need_login() -> Result<bool> {
    let client = CLIENT.get().ok_or("Client not initialized")?;
    Ok(client.is_authorized().await?)
}

async fn request_login_code(phone: &str) -> Result<LoginToken> {
    let client = CLIENT.get().ok_or("Client not initialized")?;
    let token = client.request_login_code(&phone, API_ID, API_HASH).await?;
    Ok(token)
}

async fn sign_in(token: LoginToken, code: &str) -> Result<()> {
    let client = CLIENT.get().ok_or("Client not initialized")?;
    client.sign_in(&token, &code).await?;
    Ok(())
}

async fn get_dialogs() -> Result<Vec<Dialog>> {
    let client = CLIENT.get().ok_or("Client not initialized")?;

    let mut result = Vec::new();
    let mut dialogs = client.iter_dialogs();
    while let Some(dialog) = dialogs.next().await? {
        result.push(dialog);
    }
    Ok(result)
}

async fn send_message(chat: PackedChat, text: &str) -> Result<()> {
    let client = CLIENT.get().ok_or("Client not initialized")?;
    client.send_message(chat, text).await?;
    Ok(())
}

#[no_mangle]
pub unsafe extern "C" fn Java_dev_lonami_talaria_bindings_Native_initClient(_: JNIEnv, _: JObject) {
    match block_on(init_client()) {
        Ok(_) => info!("Client initialized"),
        Err(e) => error!("Failed to initialize client: {}", e),
    }
}

#[no_mangle]
pub unsafe extern "C" fn Java_dev_lonami_talaria_bindings_Native_needLogin(
    _: JNIEnv,
    _: JObject,
) -> jboolean {
    match block_on(need_login()) {
        Ok(login) => login.into(),
        Err(e) => {
            error!("Failed to check if user is authorized: {}", e);
            false.into()
        }
    }
}

#[no_mangle]
pub unsafe extern "C" fn Java_dev_lonami_talaria_bindings_Native_requestLoginCode(
    env: JNIEnv,
    _: JObject,
    phone: JString,
) -> jlong {
    let phone = CString::from(CStr::from_ptr(env.get_string(phone).unwrap().as_ptr()));

    match block_on(request_login_code(phone.to_str().unwrap())) {
        Ok(token) => Box::into_raw(Box::new(token)) as jlong,
        Err(e) => {
            error!("Failed to request login code: {}", e);
            0 as jlong
        }
    }
}

#[no_mangle]
pub unsafe extern "C" fn Java_dev_lonami_talaria_bindings_Native_signIn(
    env: JNIEnv,
    _: JObject,
    token_ptr: jlong,
    code: JString,
) {
    let token = *Box::from_raw(token_ptr as *mut LoginToken);
    let code = CString::from(CStr::from_ptr(env.get_string(code).unwrap().as_ptr()));

    match block_on(sign_in(token, code.to_str().unwrap())) {
        Ok(_) => info!("Sign in success"),
        Err(e) => error!("Failed to sign in: {}", e),
    }
}

#[no_mangle]
pub unsafe extern "C" fn Java_dev_lonami_talaria_bindings_Native_getDialogs(
    _: JNIEnv,
    _: JObject,
) -> jlong {
    match block_on(get_dialogs()) {
        Ok(dialogs) => Box::into_raw(Box::new(dialogs)) as jlong,
        Err(e) => {
            error!("Failed to get dialogs: {}", e);
            0 as jlong
        }
    }
}

#[no_mangle]
pub unsafe extern "C" fn Java_dev_lonami_talaria_bindings_Native_dialogCount(
    _: JNIEnv,
    _: JObject,
    dialogs_ptr: jlong,
) -> jint {
    let dialogs = Box::leak(Box::from_raw(dialogs_ptr as *mut Vec<Dialog>));
    dialogs.len() as jint
}

#[no_mangle]
pub unsafe extern "C" fn Java_dev_lonami_talaria_bindings_Native_dialogPacked(
    env: JNIEnv,
    _: JObject,
    dialogs_ptr: jlong,
    index: jint,
) -> jstring {
    let dialogs = Box::leak(Box::from_raw(dialogs_ptr as *mut Vec<Dialog>));

    let packed = dialogs[index as usize].chat().pack().to_hex();
    let output = env.new_string(packed).unwrap();
    output.into_inner()
}

#[no_mangle]
pub unsafe extern "C" fn Java_dev_lonami_talaria_bindings_Native_dialogTitle(
    env: JNIEnv,
    _: JObject,
    dialogs_ptr: jlong,
    index: jint,
) -> jstring {
    let dialogs = Box::leak(Box::from_raw(dialogs_ptr as *mut Vec<Dialog>));

    let title = dialogs[index as usize].chat().name();
    let output = env.new_string(title).unwrap();
    output.into_inner()
}

#[no_mangle]
pub unsafe extern "C" fn Java_dev_lonami_talaria_bindings_Native_freeDialogs(
    _: JNIEnv,
    _: JObject,
    dialogs_ptr: jlong,
) {
    let _ = Box::from_raw(dialogs_ptr as *mut Vec<Dialog>);
}

#[no_mangle]
pub unsafe extern "C" fn Java_dev_lonami_talaria_bindings_Native_sendMessage(
    env: JNIEnv,
    _: JObject,
    packed: JString,
    text: JString,
) {
    let packed = CString::from(CStr::from_ptr(env.get_string(packed).unwrap().as_ptr()));
    let text = CString::from(CStr::from_ptr(env.get_string(text).unwrap().as_ptr()));

    let packed = PackedChat::from_hex(packed.to_str().unwrap()).unwrap();
    match block_on(send_message(packed, text.to_str().unwrap())) {
        Ok(_) => info!("Message sent"),
        Err(e) => error!("Failed to send message: {}", e),
    }
}