use thirtyfour::prelude::*;

use rand::{distributions::Alphanumeric, seq::IteratorRandom, Rng};
use std::sync::{Arc, Condvar, Mutex};
use std::thread;
use thirtyfour::common::capabilities::firefox::FirefoxPreferences;
use thirtyfour::{FirefoxCapabilities, WebDriver};

use std::io::Read;
use std::time;

use std::future::Future;
use std::process::{Command, Stdio};

const PORT: u16 = 3001;
const BASEURL: &'static str = "http://localhost";

fn url(path: &str) -> String {
    format!("{BASEURL}:{PORT}{path}")
}

#[derive(Debug)]
#[allow(dead_code)]
enum TestError {
    DriverError { message: String },
    CheckError { message: String },
    AppError { message: String },
}

impl From<WebDriverError> for TestError {
    fn from(error: WebDriverError) -> Self {
        Self::DriverError {
            message: error.to_string(),
        }
    }
}

impl From<std::io::Error> for TestError {
    fn from(error: std::io::Error) -> Self {
        Self::AppError {
            message: error.to_string(),
        }
    }
}

fn random_name() -> String {
    let mut rng = rand::thread_rng();
    let length = { 1..=20 }.choose(&mut rng).unwrap();

    let s: String = rng
        .sample_iter(&Alphanumeric)
        .take(length)
        .map(char::from)
        .collect();
    s
}

fn random_number(range: std::ops::Range<usize>) -> usize {
    range.choose(&mut rand::thread_rng()).unwrap()
}

async fn run_test<T, R>(inner: T) -> Result<(), TestError>
where
    T: FnOnce(WebDriver) -> R,
    R: Future<Output = Result<(), TestError>>,
{
    let event_in_parent = Arc::new((Mutex::new(false), Condvar::new()));
    let event_in_subprocess = Arc::clone(&event_in_parent);

    let prepared_event_in_parent = Arc::new((Mutex::new(false), Condvar::new()));
    let prepared_event_in_subprocess = Arc::clone(&prepared_event_in_parent);

    let app = thread::spawn(move || -> Result<(), TestError> {
        {
            let script = concat!(env!("CARGO_MANIFEST_DIR"), "/../prepare-test-instance.sh");

            println!("[sub] starting prepare script {script}");
            let handle_prepare = Command::new(script)
                .stdin(Stdio::null())
                .stdout(Stdio::null())
                .stderr(Stdio::null())
                .output()?;

            assert!(handle_prepare.status.success());
            println!("[sub] preparation ok");
        }

        let mut handle_gecko = {
            println!("[sub] starting geckodriver");
            let handle = Command::new("geckodriver")
                .stdin(Stdio::null())
                .stdout(Stdio::null())
                .stderr(Stdio::null())
                .spawn()?;
            println!("[sub] geckodriver started");
            handle
        };

        {
            println!("[sub] sending prepared event");
            let (lock, cvar) = &*prepared_event_in_subprocess;
            let mut prepared = lock.lock().unwrap();
            *prepared = true;
            cvar.notify_all();
            println!("[sub] sent prepared event");
        }

        let mut handle_app = {
            let script = concat!(env!("CARGO_MANIFEST_DIR"), "/../run-test-instance.sh");

            println!("[sub] starting script {script}");
            let handle = Command::new(script)
                .arg(PORT.to_string())
                .stdin(Stdio::piped())
                .stdout(Stdio::piped())
                .stderr(Stdio::piped())
                .spawn()?;
            println!("[sub] app started");
            handle
        };

        {
            let (lock, cvar) = &*event_in_subprocess;
            println!("[sub] waiting for done event");
            loop {
                let done = lock.try_lock();
                if let Ok(mut done) = done {
                    println!("could get mutex");
                    while !*done {
                        (done, _) = cvar
                            .wait_timeout(done, time::Duration::from_millis(1000))
                            .unwrap();
                        if handle_app.try_wait()?.is_some() {
                            println!("[sub] app died");
                            println!("[sub] killing gecko subprocess");
                            let _ = handle_gecko.kill()?;
                            handle_gecko.wait()?;
                            println!("[sub] killed gecko subprocess");
                            let mut output = String::new();
                            handle_app
                                .stdout
                                .take()
                                .unwrap()
                                .read_to_string(&mut output)
                                .unwrap();
                            handle_app
                                .stderr
                                .take()
                                .unwrap()
                                .read_to_string(&mut output)
                                .unwrap();
                            println!("{}", output);
                            return Err(TestError::AppError {
                                message: format!("app died: {}", output),
                            });
                        }
                        if handle_gecko.try_wait()?.is_some() {
                            println!("[sub] gecko died");
                            println!("[sub] killing app subprocess");
                            let _ = handle_app.kill()?;
                            handle_app.wait()?;
                            println!("[sub] killed app subprocess");
                            return Err(TestError::AppError {
                                message: "gecko died".to_string(),
                            });
                        }
                    }
                    break;
                }
                thread::sleep(time::Duration::from_secs(1));
            }

            println!("[sub] done received");
        }

        println!("[sub] killing app subprocess");
        let _ = handle_app.kill()?;
        handle_app.wait()?;
        println!("[sub] killed app subprocess");

        println!("[sub] killing gecko subprocess");
        let _ = handle_gecko.kill()?;
        handle_gecko.wait()?;
        println!("[sub] killed gecko subprocess");

        println!("[sub] done");

        Ok(())
    });

    thread::spawn(move || {
        let (lock, cvar) = &*prepared_event_in_parent;
        let mut prepared = lock.lock().unwrap();
        while !*prepared {
            println!("waiting for prepared event");
            prepared = cvar.wait(prepared).unwrap();
        }
        println!("prepared received");
    })
    .join()
    .unwrap();

    println!("preparations done, starting tests in 1s");

    thread::sleep(time::Duration::from_secs(1));

    let prefs = FirefoxPreferences::new();
    let mut caps = FirefoxCapabilities::new();
    caps.set_preferences(prefs)?;
    let driver = WebDriver::new("http://localhost:4444", caps).await?;

    // it's shitty, but passing references through async closures is even shittier
    // cloning works for closing, so it's good enough
    let driver_handle = driver.clone();

    // call the actual function
    println!("calling test function");
    let result = inner(driver).await;

    if let Err(ref e) = result {
        println!("test failed, leaving browser open");
        println!("test error: {:?}", e);
        println!("[hit enter to finish]");
        std::io::stdin().read_line(&mut String::new())?;
    }
    // let result: Result<(), TestError> = Ok(());
    println!("test function done");

    println!("deinitializing selenium driver");
    driver_handle.quit().await?;

    // this has to be done in a separate thread, otherwise the condvar handling
    // does not work. it's not sure why.
    thread::spawn(move || {
        // if the child panicked and cannot receive the event, we don't care and just
        // continue to the exit
        println!("sending done event");
        let (lock, cvar) = &*event_in_parent;
        let mut done = lock.lock().unwrap();
        *done = true;
        cvar.notify_all();
        println!("sent done event");
    })
    .join()
    .unwrap();

    println!("waiting for subprocess");
    app.join().map_err(|_| TestError::AppError {
        message: "app panicked".to_string(),
    })??;
    println!("all done");
    Ok(result?)
}

macro_rules! check_eq {
    ($left:expr, $right:expr) => {
        if ($left != $right) {
            return Err(TestError::CheckError {
                message: format!("line {}: {:?} != {:?}", line!(), $left, $right),
            });
        }
    };
}

async fn check_table(
    table: &WebElement,
    head: &Vec<Option<impl AsRef<str>>>,
    body: &Vec<Vec<Option<impl AsRef<str>>>>,
) -> Result<(), TestError> {
    let table_head = table
        .find(By::Tag("thead"))
        .await?
        .find_all(By::Tag("th"))
        .await?;

    check_eq!(table_head.len(), head.len());

    for (i, h) in table_head.iter().enumerate() {
        if let Some(e) = &head[i] {
            check_eq!(h.text().await?, e.as_ref());
        }
    }

    let table_rows = table
        .find(By::Tag("tbody"))
        .await?
        .find_all(By::Tag("tr"))
        .await?;

    check_eq!(table_rows.len(), body.len());

    for (row_i, row) in table_rows.iter().enumerate() {
        let columns = row.find_all(By::Tag("td")).await?;

        check_eq!(columns.len(), body[row_i].len());

        for (column_i, column) in columns.iter().enumerate() {
            if let Some(e) = &body[row_i][column_i] {
                check_eq!(column.text().await?, e.as_ref());
            }
        }
    }
    Ok(())
}

#[tokio::test]
async fn test() -> Result<(), TestError> {
    // let mut handle = {
    //     let script = concat!(env!("CARGO_MANIFEST_DIR"), "/../run-test-instance.sh");

    //     println!("[sub] starting script {script}");
    //     let handle = Command::new(script)
    //         .arg(PORT.to_string())
    //         .stdin(Stdio::null())
    //         .stdout(Stdio::null())
    //         .stderr(Stdio::null())
    //         .spawn()?;
    //     println!("[sub] started");
    //     handle
    // };

    // // at worst, the child already exited, so we don't care about the
    // // return code
    // println!("[sub] killing subprocess");
    // let _ = handle.kill().expect("failed to kill child");
    // handle.wait().unwrap();
    // println!("[sub] killed subprocess");

    // println!("[sub] done");

    // return Ok(());

    run_test(|driver: WebDriver| async move {
        for js_enabled in [true] {
            driver.goto(url("/")).await?;

            check_eq!(driver.title().await?, "Packager");

            let header = driver.find(By::Id("header")).await?;

            let inventory_link = header.find(By::Id("header-link-inventory")).await?;
            check_eq!(inventory_link.text().await?, "Inventory");
            inventory_link.click().await?;

            check_eq!(driver.current_url().await?.as_str(), url("/inventory/"));

            let category_list = driver.find(By::Id("category-list")).await?;

            check_table(
                &category_list,
                &vec![Some("Name"), Some("Weight")],
                &vec![vec![Some("Sum"), Some("0")]],
            )
            .await?;

            let new_category_form = driver.find(By::Id("new-category")).await?;

            let new_category_form_submit = new_category_form
                .find(By::Css("input[type='submit']"))
                .await?;

            check_eq!(new_category_form_submit.is_clickable().await?, !js_enabled);

            // insert a few categories

            let mut rows = vec![vec![Some("Sum".to_string()), Some("0".to_string())]];

            let iterations = random_number(1..5);

            for i in 0..iterations {
                let new_category_form = driver.find(By::Id("new-category")).await?;

                let category_name = random_name();

                let new_category_name_input = new_category_form
                    .find(By::Css("input[name='new-category-name']"))
                    .await?;

                check_eq!(new_category_name_input.value().await?, Some(String::new()));

                new_category_name_input.send_keys(&category_name).await?;

                let new_category_form_submit = new_category_form
                    .find(By::Css("input[type='submit']"))
                    .await?;

                check_eq!(new_category_form_submit.is_clickable().await?, true);
                new_category_form_submit.click().await?;

                let category_list = driver.find(By::Id("category-list")).await?;

                rows.insert(i, vec![Some(category_name), Some("0".to_string())]);

                check_table(&category_list, &vec![Some("Name"), Some("Weight")], &rows).await?;
            }

            // select one of the new categories and check that it's empty
            let category_list = driver.find(By::Id("category-list")).await?;

            let table_rows = category_list
                .find(By::Tag("tbody"))
                .await?
                .find_all(By::Tag("tr"))
                .await?;

            let id = random_number(0..iterations);

            let category_link = &table_rows[id].find_all(By::Tag("td")).await?[0];

            let category_name = category_link.text().await?;

            println!("==================================== name of new category: {category_name}");

            check_eq!(category_link.is_clickable().await?, true);
            category_link.click().await?;

            check_eq!(
                driver
                    .find(By::Id("items"))
                    .await?
                    .text()
                    .await?
                    .to_lowercase()
                    .contains("empty"),
                true
            );

            // now, add an item to the category.

            // check that the preselected category is ours
            let new_item_form = driver.find(By::Id("new-item")).await?;

            let new_item_input_name = new_item_form
                .find(By::Css("input[name='new-item-name']"))
                .await?;

            check_eq!(new_item_input_name.value().await?, Some(String::new()));

            let new_item_input_weight = new_item_form
                .find(By::Css("input[name='new-item-weight']"))
                .await?;

            check_eq!(new_item_input_weight.value().await?, Some(String::new()));

            let new_item_input_category = new_item_form
                .find(By::Css("select[name='new-item-category-id']"))
                .await?;

            check_eq!(
                thirtyfour::components::SelectElement::new(&new_item_input_category)
                    .await?
                    .first_selected_option()
                    .await?
                    .text()
                    .await?,
                category_name.clone()
            );

            let new_item_form_submit = new_item_form.find(By::Css("input[type='submit']")).await?;

            check_eq!(new_item_form_submit.is_clickable().await?, !js_enabled);

            // add a few items
            let iterations = random_number(1..5);

            let mut rows = vec![];

            let mut weights = vec![];

            for _i in 0..iterations {
                let new_item_form = driver.find(By::Id("new-item")).await?;

                let item_name = random_name();
                let item_weight = random_number(0..1500);
                weights.push(item_weight);

                let new_item_name_input = new_item_form
                    .find(By::Css("input[name='new-item-name']"))
                    .await?;

                check_eq!(new_item_name_input.value().await?, Some(String::new()));

                new_item_name_input.send_keys(&item_name).await?;

                let new_item_weight_input = new_item_form
                    .find(By::Css("input[name='new-item-weight']"))
                    .await?;

                check_eq!(new_item_weight_input.value().await?, Some(String::new()));

                new_item_weight_input
                    .send_keys(item_weight.to_string())
                    .await?;

                let new_item_form_submit =
                    new_item_form.find(By::Css("input[type='submit']")).await?;

                check_eq!(new_item_form_submit.is_clickable().await?, true);
                new_item_form_submit.click().await?;

                let item_list = driver.find(By::Id("items")).await?;

                rows.push(vec![
                    Some(item_name),
                    Some(item_weight.to_string()),
                    None,
                    None,
                ]);

                check_table(
                    &item_list,
                    &vec![Some("Name"), Some("Weight"), None, None],
                    &rows,
                )
                .await?;

                // check that the sum of weights is still correct

                let category_list = driver.find(By::Id("category-list")).await?;

                let table_rows = category_list
                    .find(By::Tag("tbody"))
                    .await?
                    .find_all(By::Tag("tr"))
                    .await?;

                let mut found = false;
                for row in &table_rows {
                    let cols = row.find_all(By::Tag("td")).await?;
                    if cols[0].text().await? == category_name {
                        check_eq!(
                            cols[1].text().await?,
                            weights.iter().sum::<usize>().to_string()
                        )
                    }
                    found = true;
                }
                if !found {
                    return Err(TestError::CheckError {
                        message: "did not find a (formerly existing?) category".to_string(),
                    });
                }
            }
        }

        Ok(())
    })
    .await
}