mod config_files;
mod logger;
mod test_bins;
#[cfg(test)]
mod tests;

#[cfg(feature = "plugin")]
use crate::config_files::NUSHELL_FOLDER;
use crate::logger::{configure, logger};
use log::info;
use miette::Result;
#[cfg(feature = "plugin")]
use nu_cli::read_plugin_file;
use nu_cli::{
    evaluate_commands, evaluate_file, evaluate_repl, gather_parent_env_vars, get_init_cwd,
    report_error,
};
use nu_command::{create_default_context, BufferedReader};
use nu_engine::{get_full_help, CallExt};
use nu_parser::{escape_quote_string, parse};
use nu_protocol::{
    ast::{Call, Expr, Expression},
    engine::{Command, EngineState, Stack, StateWorkingSet},
    Category, Example, IntoPipelineData, PipelineData, RawStream, ShellError, Signature, Span,
    Spanned, SyntaxShape, Value,
};
use std::cell::RefCell;
use std::{
    io::{BufReader, Write},
    path::Path,
    sync::{
        atomic::{AtomicBool, Ordering},
        Arc,
    },
};

thread_local! { static IS_PERF: RefCell<bool> = RefCell::new(false) }

fn main() -> Result<()> {
    // miette::set_panic_hook();
    let miette_hook = std::panic::take_hook();
    std::panic::set_hook(Box::new(move |x| {
        crossterm::terminal::disable_raw_mode().expect("unable to disable raw mode");
        miette_hook(x);
    }));

    // Get initial current working directory.
    let init_cwd = get_init_cwd();
    let mut engine_state = create_default_context(&init_cwd);

    // Custom additions
    let delta = {
        let mut working_set = nu_protocol::engine::StateWorkingSet::new(&engine_state);
        working_set.add_decl(Box::new(nu_cli::NuHighlight));
        working_set.add_decl(Box::new(nu_cli::Print));

        working_set.render()
    };
    let _ = engine_state.merge_delta(delta, None, &init_cwd);

    // TODO: make this conditional in the future
    // Ctrl-c protection section
    let ctrlc = Arc::new(AtomicBool::new(false));
    let handler_ctrlc = ctrlc.clone();
    let engine_state_ctrlc = ctrlc.clone();

    ctrlc::set_handler(move || {
        handler_ctrlc.store(true, Ordering::SeqCst);
    })
    .expect("Error setting Ctrl-C handler");

    engine_state.ctrlc = Some(engine_state_ctrlc);
    // End ctrl-c protection section

    let mut args_to_nushell = vec![];
    let mut script_name = String::new();
    let mut args_to_script = vec![];

    // Would be nice if we had a way to parse this. The first flags we see will be going to nushell
    // then it'll be the script name
    // then the args to the script
    let mut args = std::env::args().skip(1);
    while let Some(arg) = args.next() {
        if !script_name.is_empty() {
            args_to_script.push(escape_quote_string(&arg));
        } else if arg.starts_with('-') {
            // Cool, it's a flag
            let flag_value = match arg.as_ref() {
                "--commands" | "-c" => args.next().map(|a| escape_quote_string(&a)),
                "--config" | "--env-config" => args.next().map(|a| escape_quote_string(&a)),
                "--log-level" | "--testbin" | "--threads" | "-t" => args.next(),
                _ => None,
            };

            args_to_nushell.push(arg);

            if let Some(flag_value) = flag_value {
                args_to_nushell.push(flag_value);
            }
        } else {
            // Our script file
            script_name = arg;
        }
    }

    args_to_nushell.insert(0, "nu".into());

    let nushell_commandline_args = args_to_nushell.join(" ");

    let parsed_nu_cli_args =
        parse_commandline_args(&nushell_commandline_args, &init_cwd, &mut engine_state);

    match parsed_nu_cli_args {
        Ok(binary_args) => {
            if let Some(t) = binary_args.threads {
                // 0 means to let rayon decide how many threads to use
                let threads = t.as_i64().unwrap_or(0);
                rayon::ThreadPoolBuilder::new()
                    .num_threads(threads as usize)
                    .build_global()
                    .expect("error setting number of threads");
            }

            set_is_perf_value(binary_args.perf);

            if binary_args.perf || binary_args.log_level.is_some() {
                // since we're in this section, either perf is true or log_level has been set
                // if log_level is set, just use it
                // otherwise if perf is true, set the log_level to `info` which is what
                // the perf calls are set to.
                let level = binary_args
                    .log_level
                    .map(|level| level.item)
                    .unwrap_or_else(|| "info".to_string());

                logger(|builder| {
                    configure(level.as_str(), builder)?;
                    Ok(())
                })?;
                info!("start logging {}:{}:{}", file!(), line!(), column!());
            }

            if let Some(testbin) = &binary_args.testbin {
                // Call out to the correct testbin
                match testbin.item.as_str() {
                    "echo_env" => test_bins::echo_env(),
                    "cococo" => test_bins::cococo(),
                    "meow" => test_bins::meow(),
                    "meowb" => test_bins::meowb(),
                    "relay" => test_bins::relay(),
                    "iecho" => test_bins::iecho(),
                    "fail" => test_bins::fail(),
                    "nonu" => test_bins::nonu(),
                    "chop" => test_bins::chop(),
                    "repeater" => test_bins::repeater(),
                    _ => std::process::exit(1),
                }
                std::process::exit(0)
            }
            let input = if let Some(redirect_stdin) = &binary_args.redirect_stdin {
                let stdin = std::io::stdin();
                let buf_reader = BufReader::new(stdin);

                PipelineData::ExternalStream {
                    stdout: Some(RawStream::new(
                        Box::new(BufferedReader::new(buf_reader)),
                        Some(ctrlc),
                        redirect_stdin.span,
                    )),
                    stderr: None,
                    exit_code: None,
                    span: redirect_stdin.span,
                    metadata: None,
                }
            } else {
                PipelineData::new(Span::new(0, 0))
            };

            if is_perf_true() {
                info!("redirect_stdin {}:{}:{}", file!(), line!(), column!());
            }

            // First, set up env vars as strings only
            gather_parent_env_vars(&mut engine_state);
            let mut stack = nu_protocol::engine::Stack::new();

            if let Some(commands) = &binary_args.commands {
                #[cfg(feature = "plugin")]
                read_plugin_file(
                    &mut engine_state,
                    &mut stack,
                    NUSHELL_FOLDER,
                    is_perf_true(),
                );

                let ret_val = evaluate_commands(
                    commands,
                    &init_cwd,
                    &mut engine_state,
                    &mut stack,
                    input,
                    is_perf_true(),
                );
                if is_perf_true() {
                    info!("-c command execution {}:{}:{}", file!(), line!(), column!());
                }

                ret_val
            } else if !script_name.is_empty() && binary_args.interactive_shell.is_none() {
                #[cfg(feature = "plugin")]
                read_plugin_file(
                    &mut engine_state,
                    &mut stack,
                    NUSHELL_FOLDER,
                    is_perf_true(),
                );

                let ret_val = evaluate_file(
                    script_name,
                    &args_to_script,
                    &mut engine_state,
                    &mut stack,
                    input,
                    is_perf_true(),
                );
                if is_perf_true() {
                    info!("eval_file execution {}:{}:{}", file!(), line!(), column!());
                }

                ret_val
            } else {
                setup_config(
                    &mut engine_state,
                    &mut stack,
                    binary_args.config_file,
                    binary_args.env_file,
                );
                let history_path = config_files::create_history_path();

                let ret_val =
                    evaluate_repl(&mut engine_state, &mut stack, history_path, is_perf_true());
                if is_perf_true() {
                    info!("repl eval {}:{}:{}", file!(), line!(), column!());
                }

                ret_val
            }
        }
        Err(_) => std::process::exit(1),
    }
}

fn setup_config(
    engine_state: &mut EngineState,
    stack: &mut Stack,
    config_file: Option<Spanned<String>>,
    env_file: Option<Spanned<String>>,
) {
    #[cfg(feature = "plugin")]
    read_plugin_file(engine_state, stack, NUSHELL_FOLDER, is_perf_true());

    if is_perf_true() {
        info!("read_config_file {}:{}:{}", file!(), line!(), column!());
    }

    config_files::read_config_file(engine_state, stack, env_file, is_perf_true(), true);
    config_files::read_config_file(engine_state, stack, config_file, is_perf_true(), false);

    // Give a warning if we see `$config` for a few releases
    {
        let working_set = StateWorkingSet::new(engine_state);
        if working_set.find_variable(b"$config").is_some() {
            println!("warning: use `let-env config = ...` instead of `let config = ...`");
        }
    }
}

fn parse_commandline_args(
    commandline_args: &str,
    init_cwd: &Path,
    engine_state: &mut EngineState,
) -> Result<NushellCliArgs, ShellError> {
    let (block, delta) = {
        let mut working_set = StateWorkingSet::new(engine_state);
        working_set.add_decl(Box::new(Nu));

        let (output, err) = parse(
            &mut working_set,
            None,
            commandline_args.as_bytes(),
            false,
            &[],
        );
        if let Some(err) = err {
            report_error(&working_set, &err);

            std::process::exit(1);
        }

        working_set.hide_decl(b"nu");
        (output, working_set.render())
    };

    let _ = engine_state.merge_delta(delta, None, init_cwd);

    let mut stack = Stack::new();

    // We should have a successful parse now
    if let Some(pipeline) = block.pipelines.get(0) {
        if let Some(Expression {
            expr: Expr::Call(call),
            ..
        }) = pipeline.expressions.get(0)
        {
            let redirect_stdin = call.get_named_arg("stdin");
            let login_shell = call.get_named_arg("login");
            let interactive_shell = call.get_named_arg("interactive");
            let commands: Option<Expression> = call.get_flag_expr("commands");
            let testbin: Option<Expression> = call.get_flag_expr("testbin");
            let perf = call.has_flag("perf");
            let config_file: Option<Expression> = call.get_flag_expr("config");
            let env_file: Option<Expression> = call.get_flag_expr("env-config");
            let log_level: Option<Expression> = call.get_flag_expr("log-level");
            let threads: Option<Value> = call.get_flag(engine_state, &mut stack, "threads")?;

            fn extract_contents(
                expression: Option<Expression>,
            ) -> Result<Option<Spanned<String>>, ShellError> {
                if let Some(expr) = expression {
                    let str = expr.as_string();
                    if let Some(str) = str {
                        Ok(Some(Spanned {
                            item: str,
                            span: expr.span,
                        }))
                    } else {
                        Err(ShellError::TypeMismatch("string".into(), expr.span))
                    }
                } else {
                    Ok(None)
                }
            }

            let commands = extract_contents(commands)?;
            let testbin = extract_contents(testbin)?;
            let config_file = extract_contents(config_file)?;
            let env_file = extract_contents(env_file)?;
            let log_level = extract_contents(log_level)?;

            let help = call.has_flag("help");

            if help {
                let full_help =
                    get_full_help(&Nu.signature(), &Nu.examples(), engine_state, &mut stack);

                let _ = std::panic::catch_unwind(move || {
                    let stdout = std::io::stdout();
                    let mut stdout = stdout.lock();
                    let _ = stdout.write_all(full_help.as_bytes());
                });

                std::process::exit(1);
            }

            if call.has_flag("version") {
                let version = env!("CARGO_PKG_VERSION").to_string();
                let _ = std::panic::catch_unwind(move || {
                    let stdout = std::io::stdout();
                    let mut stdout = stdout.lock();
                    let _ = stdout.write_all(format!("{}\n", version).as_bytes());
                });

                std::process::exit(0);
            }

            return Ok(NushellCliArgs {
                redirect_stdin,
                login_shell,
                interactive_shell,
                commands,
                testbin,
                config_file,
                env_file,
                log_level,
                perf,
                threads,
            });
        }
    }

    // Just give the help and exit if the above fails
    let full_help = get_full_help(&Nu.signature(), &Nu.examples(), engine_state, &mut stack);
    print!("{}", full_help);
    std::process::exit(1);
}

struct NushellCliArgs {
    redirect_stdin: Option<Spanned<String>>,
    #[allow(dead_code)]
    login_shell: Option<Spanned<String>>,
    interactive_shell: Option<Spanned<String>>,
    commands: Option<Spanned<String>>,
    testbin: Option<Spanned<String>>,
    config_file: Option<Spanned<String>>,
    env_file: Option<Spanned<String>>,
    log_level: Option<Spanned<String>>,
    perf: bool,
    threads: Option<Value>,
}

#[derive(Clone)]
struct Nu;

impl Command for Nu {
    fn name(&self) -> &str {
        "nu"
    }

    fn signature(&self) -> Signature {
        Signature::build("nu")
            .usage("The nushell language and shell.")
            .switch("stdin", "redirect the stdin", None)
            .switch("login", "start as a login shell", Some('l'))
            .switch("interactive", "start as an interactive shell", Some('i'))
            .switch("version", "print the version", Some('v'))
            .switch(
                "perf",
                "start and print performance metrics during startup",
                Some('p'),
            )
            .named(
                "testbin",
                SyntaxShape::String,
                "run internal test binary",
                None,
            )
            .named(
                "commands",
                SyntaxShape::String,
                "run the given commands and then exit",
                Some('c'),
            )
            .named(
                "config",
                SyntaxShape::String,
                "start with an alternate config file",
                None,
            )
            .named(
                "env-config",
                SyntaxShape::String,
                "start with an alternate environment config file",
                None,
            )
            .named(
                "log-level",
                SyntaxShape::String,
                "log level for performance logs",
                None,
            )
            .named(
                "threads",
                SyntaxShape::Int,
                "threads to use for parallel commands",
                Some('t'),
            )
            .optional(
                "script file",
                SyntaxShape::Filepath,
                "name of the optional script file to run",
            )
            .rest(
                "script args",
                SyntaxShape::String,
                "parameters to the script file",
            )
            .category(Category::System)
    }

    fn usage(&self) -> &str {
        "The nushell language and shell."
    }

    fn run(
        &self,
        engine_state: &EngineState,
        stack: &mut Stack,
        call: &Call,
        _input: PipelineData,
    ) -> Result<nu_protocol::PipelineData, nu_protocol::ShellError> {
        Ok(Value::String {
            val: get_full_help(&Nu.signature(), &Nu.examples(), engine_state, stack),
            span: call.head,
        }
        .into_pipeline_data())
    }

    fn examples(&self) -> Vec<nu_protocol::Example> {
        vec![
            Example {
                description: "Run a script",
                example: "nu myfile.nu",
                result: None,
            },
            Example {
                description: "Run nushell interactively (as a shell or REPL)",
                example: "nu",
                result: None,
            },
        ]
    }
}

pub fn is_perf_true() -> bool {
    IS_PERF.with(|value| *value.borrow())
}

// #[allow(dead_code)]
// fn is_perf_value() -> bool {
//     IS_PERF.with(|value| *value.borrow())
// }

fn set_is_perf_value(value: bool) {
    IS_PERF.with(|new_value| {
        *new_value.borrow_mut() = value;
    });
}