gitig/src/app.rs

/*! Application-specific logic lives here */
// Parts Copyright 2017-2019, Stephan Sokolow

// Standard library imports
use std::path::PathBuf;

// 3rd-party crate imports
use reqwest::blocking::Client;
use reqwest::header::{ACCEPT, CONTENT_TYPE, USER_AGENT};
use structopt::StructOpt;

use log::{debug, error, info, trace, warn};

// Local Imports
use crate::errors::*;
use crate::gitignore::Gitignore;
use crate::helpers::{git_dir, BoilerplateOpts, HELP_TEMPLATE};
use crate::template::*;

/// The verbosity level when no `-q` or `-v` arguments are given, with `0` being `-q`
pub const DEFAULT_VERBOSITY: u64 = 1;
pub const DEFAULT_USER_AGENT: &str = "gitig";

/// Command-line argument schema
///
/// ## Relevant Conventions:
///
///  * Make sure that there is a blank space between the `<name>` `<version>` line and the
///    description text or the `--help` output won't comply with the platform conventions that
///    `help2man` depends on to generate your manpage. (Specifically, it will mistake the `<name>
///    <version>` line for part of the description.)
///  * `StructOpt`'s default behaviour of including the author name in the `--help` output is an
///    oddity among Linux commands and, if you don't disable it, you run the risk of people
///    unfamiliar with `StructOpt` assuming that you are an egotistical person who made a conscious
///    choice to add it.
///
///    The proper standardized location for author information is the `AUTHOR` section which you
///    can read about by typing `man help2man`.
///
/// ## Cautions:
///  * Subcommands do not inherit `template` and it must be re-specified for each one. ([clap-rs/clap#1184](https://github.com/clap-rs/clap/issues/1184))
///  * Double-check that your choice of `about` or `long_about` is actually overriding this
///    doc comment. The precedence is affected by things you wouldn't expect, such as the presence
///    or absence of `template` and it's easy to wind up with this doc-comment as your `--help`
///    ([TeXitoi/structopt#173](https://github.com/TeXitoi/structopt/issues/173))
///  * Do not begin the description text for subcommands with `\n`. It will break the formatting in
///    the top-level help output's list of subcommands.
#[derive(StructOpt, Debug)]
#[structopt(template = HELP_TEMPLATE,
            about = "TODO: Replace me with the description text for the command",
            global_setting = structopt::clap::AppSettings::ColoredHelp)]
pub struct CliOpts {
    #[allow(clippy::missing_docs_in_private_items)] // StructOpt won't let us document this
    #[structopt(flatten)]
    pub boilerplate: BoilerplateOpts,

    /// Subcommands
    #[structopt(subcommand)]
    cmd: Command,
}

/// Subcommands
#[derive(StructOpt, Debug)]
pub enum Command {
    /// Add a line to the gitignore
    Add {
        /// The glob string that should be added
        glob: String,
    },
    /// Download a gitignore for a language
    Get {
        /// The language for which the gitignore should be downloaded
        lang: String,
    },
    /// List all available templates that can be downloaded
    ListTemplates,
}

/// Runs the command `add`
fn run_add(glob: &str) -> Result<()> {
    trace!("running command `add` with glob '{}'", &glob);
    let root = match git_dir()? {
        Some(r) => r,
        None => return Err(ErrorKind::NoGitRootFound.into()),
    };
    info!("Working with git root in {:?}", root);

    let mut file_path = PathBuf::from(&root);
    file_path.push(".gitignore");
    let gitig = Gitignore::from_path(&file_path);
    gitig.add_line(glob)?;

    Ok(())
}

/// Runs the command `get`
fn run_get(lang: &str) -> Result<()> {
    unimplemented!();
}

/// Runs the command `list-templates`
fn run_list_templates() -> Result<()> {
    let client = Client::new();
    let res = client
        .get("https://api.github.com/repos/github/gitignore/contents//")
        .header(ACCEPT, "application/jsonapplication/vnd.github.v3+json")
        .header(CONTENT_TYPE, "application/json")
        .header(USER_AGENT, format!("{} {}", DEFAULT_USER_AGENT, env!("CARGO_PKG_VERSION")))
        .send()
        .chain_err(|| "Error while sending request to query all templates")?;
    let body: Vec<Template> = res.json().chain_err(|| "json")?;

    body.iter().filter(|t| t.is_gitignore_template()).for_each(|t| println!("{}", t.pretty_name()));
    Ok(())
}

/// The actual `main()`
pub fn main(opts: CliOpts) -> Result<()> {
    match opts.cmd {
        Command::Add { glob } => run_add(&glob)?,
        Command::Get { lang } => run_get(&lang)?,
        Command::ListTemplates => run_list_templates()?,
    };

    Ok(())
}

// Tests go below the code where they'll be out of the way when not the target of attention
#[cfg(test)]
mod tests {
    use super::CliOpts;

    // TODO: Unit test to verify that the doc comment on `CliOpts` isn't overriding the intended
    // about string.

    #[test]
    /// Test something
    fn test_something() {
        // TODO: Test something
    }
}