// yabridge: a Wine plugin bridge
// Copyright (C) 2020-2022 Robbert van der Helm
//
// This program is free software: you can redistribute it and/or modify
// it under the terms of the GNU General Public License as published by
// the Free Software Foundation, either version 3 of the License, or
// (at your option) any later version.
//
// This program is distributed in the hope that it will be useful,
// but WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
// GNU General Public License for more details.
//
// You should have received a copy of the GNU General Public License
// along with this program.  If not, see <https://www.gnu.org/licenses/>.

use anyhow::Result;
use clap::{app_from_crate, App, AppSettings, Arg};
use colored::Colorize;
use std::collections::HashSet;
use std::env;
use std::path::{Path, PathBuf};

use crate::config::Config;

mod actions;
mod config;
mod files;
mod utils;

fn main() -> Result<()> {
    // We'll modify our `PATH` environment variable so it matches up with
    // `get_augmented_search_path()` from `src/plugin/utils.h` for easier setup
    let yabridge_home = config::yabridge_directories()?.get_data_home();
    env::set_var(
        "PATH",
        match env::var("PATH") {
            Ok(path) => format!("{}:{}", path, yabridge_home.display()),
            _ => format!("{}", yabridge_home.display()),
        },
    );

    let mut config = Config::read()?;

    // Used for validation in `yabridgectl rm <path>`
    let plugin_directories: HashSet<&Path> = config
        .plugin_dirs
        .iter()
        .map(|path| path.as_path())
        .collect();
    // Used for validation in `yabridgectl blacklist rm <path>`
    let blacklist_entries: HashSet<&Path> =
        config.blacklist.iter().map(|path| path.as_path()).collect();

    let matches = app_from_crate!()
        .setting(AppSettings::SubcommandRequiredElseHelp)
        .subcommand(
            App::new("add")
                .about("Add a plugin install location")
                .display_order(1)
                .arg(
                    Arg::new("path")
                        .help("Path to a directory containing Windows VST2 or VST3 plugins")
                        .validator(validate_directory)
                        .takes_value(true)
                        .required(true),
                ),
        )
        .subcommand(
            App::new("rm")
                .about("Remove a plugin install location")
                .display_order(2)
                .arg(
                    Arg::new("path")
                        .help("Path to a previously added directory")
                        .validator(|path| match_in_path_list(Path::new(path), &plugin_directories))
                        .takes_value(true)
                        .required(true),
                ),
        )
        .subcommand(
            App::new("list")
                .about("List the plugin install locations")
                .display_order(3),
        )
        .subcommand(
            App::new("status")
                .about("Show the installation status for all plugins")
                .display_order(4),
        )
        .subcommand(
            App::new("sync")
                .about("Set up or update yabridge for all plugins")
                .display_order(100)
                .arg(
                    Arg::new("force")
                        .short('f')
                        .long("force")
                        .help("Always update files, even not necessary"),
                )
                .arg(
                    Arg::new("no-verify")
                        .short('n')
                        .long("no-verify")
                        .help("Skip post-installation setup checks"),
                )
                .arg(
                    Arg::new("prune")
                        .short('p')
                        .long("prune")
                        .help("Remove unrelated or leftover .so files"),
                )
                .arg(
                    Arg::new("verbose")
                        .short('v')
                        .long("verbose")
                        .help("Print information about plugins being set up or skipped"),
                ),
        )
        .subcommand(
            App::new("set")
                .about("Change the yabridge path (advanced)")
                .display_order(200)
                .setting(AppSettings::ArgRequiredElseHelp)
                .arg(
                    Arg::new("method")
                        .long("method")
                        .help("The installation method to use (deprecated)")
                        .long_help(format!(
                            "This feature has been deprecated in yabridgectl 3.8.0 and should \
                             not be used anymore. \
                             \n\n\
                             The installation method to use. \
                             '{}' works in every situation but it requires you to modify your PATH \
                             environment variable so yabridge is able to find 'yabridge-host.exe'. \
                             'yabridgectl sync' whenever you update yabridge. You'll also have to \
                             rerun 'yabridgectl sync' whenever you update yabridge. \
                             '{}' only works for hosts that support individually sandboxed plugins \
                             such as Bitwig Studio, but it does not require setting environment \
                             variables or to manual updates.",
                            "copy".bright_white(),
                            "symlink".bright_white()
                        ).as_ref())
                        .setting(clap::ArgSettings::NextLineHelp)
                        .possible_values(["copy", "symlink"])
                        .takes_value(true),
                )
                .arg(
                    Arg::new("path")
                        .long("path")
                        .help("Path to the directory containing 'libyabridge-chainloader-{vst2,vst3}.so'")
                        .long_help(
                            "Path to the directory containing 'libyabridge-chainloader-{vst2,vst3}.so'. \
                             If this is not set, then yabridgectl will look in both '/usr/lib' and \
                             '~/.local/share/yabridge' by default.",
                        )
                        .validator(validate_path)
                        .takes_value(true).conflicts_with("path_auto"),
                )
                .arg(
                    Arg::new("path_auto")
                        .long("path-auto")
                        .help("Automatically locate yabridge's files")
                        .long_help(
                            "Automatically locate yabridge's files. This can be used after manually \
                             setting a path with the '--path' option to revert back to the default \
                             auto detection behaviour.",
                        ),
                ).arg(
                    Arg::new("no_verify")
                        .long("no-verify")
                        .help("Always skip post-installation setup checks")
                        .long_help(
                            "Always skip post-installation setup checks. This can be set temporarily \
                             by passing the '--no-verify' option to 'yabridgectl sync'.",
                        )
                        .possible_values(["true", "false"])
                        .takes_value(true),
                ),
        )
        .subcommand(
            App::new("blacklist")
                .about("Manage the indexing blacklist (advanced)")
                .display_order(201)
                .setting(AppSettings::SubcommandRequiredElseHelp)
                .long_about(
                    "Manage the indexing blacklist (advanced)\n\
                     \n\
                     This lets you skip over individual files and entire directories in the \
                     indexing process. You most likely won't have to use this feature.",
                )
                .subcommand(
                    App::new("add")
                        .about("Add a path to the blacklist")
                        .display_order(1)
                        .arg(
                            Arg::new("path")
                                .help("Path to a file or a directory")
                                .validator(validate_path)
                                .takes_value(true)
                                .required(true),
                        ),
                )
                .subcommand(
                    App::new("rm")
                        .about("Remove a path from the blacklist")
                        .display_order(2)
                        .arg(
                            Arg::new("path")
                                .help("Path to a previously added file or directory")
                                .validator(|path| match_in_path_list(Path::new(path), &blacklist_entries))
                                .validator(validate_path)
                                .takes_value(true)
                                .required(true),
                        ),
                )
                .subcommand(
                    App::new("list")
                        .about("List the blacklisted paths")
                        .display_order(3),
                )
                .subcommand(
                    App::new("clear")
                        .about("Clear the entire blacklist")
                        .display_order(4),
                ),
        )
        .get_matches();

    // We're calling canonicalize when adding and setting paths since relative paths would cause
    // some weird behaviour. There's no built-in way to make relative paths absoltue without
    // resolving symlinks, but I don't think this will cause any issues.
    //
    // https://github.com/rust-lang/rust/issues/59117
    match matches.subcommand() {
        Some(("add", options)) => actions::add_directory(
            &mut config,
            options
                .value_of_t_or_exit::<PathBuf>("path")
                .canonicalize()?,
        ),
        Some(("rm", options)) => {
            // Clap sadly doesn't have custom parsers/transforms, so we need to rerun the validator
            // to get the result
            let path = match_in_path_list(
                &options.value_of_t_or_exit::<PathBuf>("path"),
                &plugin_directories,
            )
            .unwrap()
            .to_owned();

            actions::remove_directory(&mut config, &path)
        }
        Some(("list", _)) => actions::list_directories(&config),
        Some(("status", _)) => actions::show_status(&config),
        Some(("sync", options)) => actions::do_sync(
            &mut config,
            &actions::SyncOptions {
                force: options.is_present("force"),
                no_verify: options.is_present("no-verify"),
                prune: options.is_present("prune"),
                verbose: options.is_present("verbose"),
            },
        ),
        Some(("set", options)) => actions::set_settings(
            &mut config,
            &actions::SetOptions {
                method: options.value_of("method"),
                // We've already verified that the path is valid, so we should only be getting
                // errors for missing arguments
                path: options
                    .value_of_t::<PathBuf>("path")
                    .ok()
                    .and_then(|path| path.canonicalize().ok()),
                path_auto: options.is_present("path_auto"),
                no_verify: options.value_of("no_verify").map(|value| value == "true"),
            },
        ),
        Some(("blacklist", blacklist)) => match blacklist.subcommand() {
            Some(("add", options)) => actions::blacklist::add_path(
                &mut config,
                options
                    .value_of_t_or_exit::<PathBuf>("path")
                    .canonicalize()?,
            ),
            Some(("rm", options)) => {
                let path = match_in_path_list(
                    &options.value_of_t_or_exit::<PathBuf>("path"),
                    &blacklist_entries,
                )
                .unwrap()
                .to_owned();

                actions::blacklist::remove_path(&mut config, &path)
            }
            Some(("list", _)) => actions::blacklist::list_paths(&config),
            Some(("clear", _)) => actions::blacklist::clear(&mut config),
            _ => unreachable!(),
        },
        _ => unreachable!(),
    }
}

/// Verify that a path exists and that is is either a directory or a symlink to a directory.
fn validate_directory(path: &str) -> Result<(), String> {
    validate_path(path)?;

    let path = Path::new(path);
    if path.is_dir() {
        Ok(())
    } else {
        Err(format!("'{}' is not a directory", path.display()))
    }
}

/// Verify that a path exists, used for validating arguments.
fn validate_path(path: &str) -> Result<(), String> {
    let path = Path::new(path);

    if path.exists() {
        Ok(())
    } else {
        Err(format!(
            "File or directory '{}' could not be found",
            path.display()
        ))
    }
}

/// Find `path` in `candidates` and return it as an absolute path. If the path is relative, we will
/// try to resolve as much of it as possible (in case the referred to file doesn't exist anymore).
/// We don't iteratively try to resolve symlinks until a candidate matches a path in `candidates`,
/// but this can match a relative path to a symlink that's in the paths list.
fn match_in_path_list<'a>(path: &Path, candidates: &'a HashSet<&Path>) -> Result<&'a Path, String> {
    let absolute_path = if path.is_absolute() {
        path.to_owned()
    } else {
        // This absolute absolute_path is also needed for the `utils::normalize_path()` below
        std::env::current_dir()
            .expect("Couldn't get current directory")
            .join(path)
    };
    if let Some(path) = candidates.get(absolute_path.as_path()) {
        return Ok(path);
    }

    // This will include a trailing slash if `path` was `.`. All paths entered through yabridgectl
    // will be cannonicalized and won't contain a trailing slash, but we'll try both variants
    // anyways just in case someone edited the config file.
    let normalized_path = utils::normalize_path(absolute_path.as_path());

    // Is there a nicer way to strip trailing slashes with the standard library?
    let normalized_path_str = normalized_path
        .to_str()
        .expect("Input path contains invalid characters");
    let normalized_path_without_slash = if normalized_path_str.ends_with('/') {
        Path::new(normalized_path_str.trim_end_matches('/'))
    } else {
        normalized_path.as_path()
    };
    // This ia bit of a hack, but it works
    let normalized_path_with_slash = normalized_path.join("");

    if let Some(path) = candidates
        .get(normalized_path_without_slash)
        .or_else(|| candidates.get(normalized_path_with_slash.as_path()))
    {
        return Ok(path);
    }

    Err(format!(
        "'{}' is not a known path.\n\n\tPossible options are: {}",
        path.display(),
        format!("{:?}", candidates).green()
    ))
}