use clap::{App, Arg, SubCommand, crate_version};
use console::{style, Emoji};
use indicatif::ProgressBar;
use syntect::easy::HighlightFile;
use syntect::parsing::SyntaxSet;
use syntect::highlighting::{ThemeSet, Style};
use syntect::util::{as_24_bit_terminal_escaped};
use std::fs::remove_file;
use std::io::BufRead;
use std::process::Command;
use std::sync::mpsc::channel;
use std::time::Duration;
use notify::DebouncedEvent;
use notify::{RecommendedWatcher, Watcher, RecursiveMode};

fn main() {
    let matches = App::new("rustlings")
        .version(crate_version!())
        .author("Olivia Hugger")
        .about("Test")
        .subcommand(SubCommand::with_name("verify").alias("v"))
        .subcommand(SubCommand::with_name("watch").alias("w"))
        .subcommand(
            SubCommand::with_name("run")
                .alias("r")
                .arg(Arg::with_name("file").required(true).index(1)),
        ).get_matches();

    let ss = SyntaxSet::load_defaults_newlines();
    let ts = ThemeSet::load_defaults();
    
    println!(r#"                 _   _ _                  "#);
    println!(r#"  _ __ _   _ ___| |_| (_)_ __   __ _ ___  "#);
    println!(r#" | '__| | | / __| __| | | '_ \ / _` / __| "#);
    println!(r#" | |  | |_| \__ \ |_| | | | | | (_| \__ \ "#);
    println!(r#" |_|   \__,_|___/\__|_|_|_| |_|\__, |___/ "#);
    println!(r#"                               |___/      "#);
    println!("");

    if let Some(matches) = matches.subcommand_matches("run") {
        if let Some(filename) = matches.value_of("file") {
            let bar = ProgressBar::new_spinner();
            bar.set_message(format!("Compiling {}...", filename).as_str());
            bar.enable_steady_tick(100);
            let compilecmd = Command::new("rustc")
                .args(&[filename, "-o", "temp"])
                .output()
                .expect("fail");
            bar.set_message(format!("Running {}...", filename).as_str());
            if compilecmd.status.success() {
                let runcmd = Command::new("./temp").output().expect("fail");
                bar.finish_and_clear();

                if runcmd.status.success() {
                    println!("{}", String::from_utf8_lossy(&runcmd.stdout));
                    let formatstr =
                        format!("{} Successfully ran {}", Emoji("✅", "✓"), filename);
                    println!("{}", style(formatstr).green());
                    clean();
                } else {
                    println!("{}", String::from_utf8_lossy(&runcmd.stdout));
                    println!("{}", String::from_utf8_lossy(&runcmd.stderr));

                    let formatstr =
                        format!("{} Ran {} with errors", Emoji("⚠️ ", "!"), filename);
                    println!("{}", style(formatstr).red());
                    clean();
                }
            } else {
                bar.finish_and_clear();
                let formatstr = format!(
                    "{} Compilation of {} failed! Compiler error message:\n",
                    Emoji("⚠️ ", "!"),
                    filename
                );
                println!("{}", style(formatstr).red());
                println!("{}", String::from_utf8_lossy(&compilecmd.stderr));
                clean();
            }
        } else {
            panic!("Please supply a filename!");
        }
    }

    if let Some(_) = matches.subcommand_matches("verify") {
        match verify() {
            Ok(_) => {}
            Err(_) => std::process::exit(1),
        }
    }

    if let Some(_) = matches.subcommand_matches("watch") {
        watch().unwrap();
    }

    if let None = matches.subcommand_name() {
        let mut highlighter = HighlightFile::new("default_out.md", &ss, &ts.themes["base16-eighties.dark"]).unwrap();
        for maybe_line in highlighter.reader.lines() {
            let line = maybe_line.unwrap();
            let regions: Vec<(Style, &str)> = highlighter.highlight_lines.highlight(&line, &ss);
            println!("{}", as_24_bit_terminal_escaped(&regions[..], true));
        }
    }

    println!("\x1b[0m");
}

fn watch() -> notify::Result<()> {
    let (tx, rx) = channel();

    let mut watcher: RecommendedWatcher = Watcher::new(tx, Duration::from_secs(2))?;
    watcher.watch("./exercises", RecursiveMode::Recursive)?;

    let _ignored = verify();

    loop {
        match rx.recv() {
            Ok(event) => {
                match event {
                    DebouncedEvent::Chmod(_)
                    | DebouncedEvent::Write(_) => {
                        let _ignored = verify();
                    }
                    _ => {}
                }
            },
            Err(e) => println!("watch error: {:?}", e),
        }
    }
}

fn verify() -> Result<(), ()> {
    compile_only("exercises/ex1.rs")?;
    compile_only("exercises/ex2.rs")?;
    compile_only("exercises/ex3.rs")?;
    compile_only("exercises/ex4.rs")?;
    compile_only("exercises/ex5.rs")?;
    compile_only("exercises/variables/variables1.rs")?;
    compile_only("exercises/variables/variables2.rs")?;
    compile_only("exercises/variables/variables3.rs")?;
    compile_only("exercises/variables/variables4.rs")?;
    compile_only("exercises/functions/functions1.rs")?;
    compile_only("exercises/functions/functions2.rs")?;
    compile_only("exercises/functions/functions3.rs")?;
    compile_only("exercises/functions/functions4.rs")?;
    compile_only("exercises/functions/functions5.rs")?;
    compile_only("exercises/primitive_types/primitive_types1.rs")?;
    compile_only("exercises/primitive_types/primitive_types2.rs")?;
    compile_only("exercises/primitive_types/primitive_types3.rs")?;
    compile_only("exercises/primitive_types/primitive_types4.rs")?;
    compile_only("exercises/primitive_types/primitive_types5.rs")?;
    compile_only("exercises/primitive_types/primitive_types6.rs")?;
    test("exercises/tests/tests1.rs")?;
    test("exercises/tests/tests2.rs")?;
    test("exercises/tests/tests3.rs")?;
    test("exercises/tests/tests4.rs")?;
    test("exercises/if/if1.rs")?;
    compile_only("exercises/strings/strings1.rs")?;
    compile_only("exercises/strings/strings2.rs")?;
    compile_only("exercises/strings/strings3.rs")?;
    compile_only("exercises/move_semantics/move_semantics1.rs")?;
    compile_only("exercises/move_semantics/move_semantics2.rs")?;
    compile_only("exercises/move_semantics/move_semantics3.rs")?;
    compile_only("exercises/move_semantics/move_semantics4.rs")?;
    compile_only("exercises/modules/modules1.rs")?;
    compile_only("exercises/modules/modules2.rs")?;
    compile_only("exercises/macros/macros1.rs")?;
    compile_only("exercises/macros/macros2.rs")?;
    compile_only("exercises/macros/macros3.rs")?;
    compile_only("exercises/macros/macros4.rs")?;
    test("exercises/error_handling/errors1.rs")?;
    test("exercises/error_handling/errors2.rs")?;
    test("exercises/error_handling/errors3.rs")?;
    test("exercises/error_handling/errorsn.rs")?;
    compile_only("exercises/error_handling/option1.rs")?;
    test("exercises/error_handling/result1.rs")?;
    Ok(())
}

fn compile_only(filename: &str) -> Result<(), ()> {
    let bar = ProgressBar::new_spinner();
    bar.set_message(format!("Compiling {}...", filename).as_str());
    bar.enable_steady_tick(100);
    let compilecmd = Command::new("rustc")
        .args(&[filename, "-o", "temp", "--color", "always"])
        .output()
        .expect("fail");
    bar.finish_and_clear();
    if compilecmd.status.success() {
        let formatstr = format!(
            "{} Successfully compiled {}!",
            Emoji("✅", "✓"),
            filename
        );
        println!("{}", style(formatstr).green());
        clean();
        Ok(())
    } else {
        let formatstr = format!(
            "{} Compilation of {} failed! Compiler error message:\n",
            Emoji("⚠️ ", "!"),
            filename
        );
        println!("{}", style(formatstr).red());
        println!("{}", String::from_utf8_lossy(&compilecmd.stderr));
        clean();
        Err(())
    }
}

fn test(filename: &str) -> Result<(), ()> {
    let bar = ProgressBar::new_spinner();
    bar.set_message(format!("Testing {}...", filename).as_str());
    bar.enable_steady_tick(100);
    let testcmd = Command::new("rustc")
        .args(&["--test", filename, "-o", "temp"])
        .output()
        .expect("fail");
    bar.finish_and_clear();
    if testcmd.status.success() {
        let formatstr = format!("{} Successfully tested {}!", Emoji("✅", "✓"), filename);
        println!("{}", style(formatstr).green());
        clean();
        Ok(())
    } else {
        let formatstr = format!(
            "{} Testing of {} failed! Please try again.",
            Emoji("⚠️ ", "!"),
            filename
        );
        println!("{}", style(formatstr).red());
        clean();
        Err(())
    }
}

fn clean() {
    let _ignored = remove_file("temp");
}