#![cfg_attr(test, deny(warnings))]
// While we're getting used to 2018:
#![warn(rust_2018_idioms)]
// Clippy isn't enforced by CI (@alexcrichton isn't a fan).
#![allow(clippy::blacklisted_name)] // frequently used in tests
#![allow(clippy::cognitive_complexity)] // large project
#![allow(clippy::derive_hash_xor_eq)] // there's an intentional incoherence
#![allow(clippy::explicit_into_iter_loop)] // explicit loops are clearer
#![allow(clippy::explicit_iter_loop)] // explicit loops are clearer
#![allow(clippy::identity_op)] // used for vertical alignment
#![allow(clippy::implicit_hasher)] // large project
#![allow(clippy::large_enum_variant)] // large project
#![allow(clippy::new_without_default)] // explicit is maybe clearer
#![allow(clippy::redundant_closure)] // closures can be less verbose
#![allow(clippy::redundant_closure_call)] // closures over try catch blocks
#![allow(clippy::too_many_arguments)] // large project
#![allow(clippy::type_complexity)] // there's an exceptionally complex type
#![allow(clippy::wrong_self_convention)] // perhaps `Rc` should be special-cased in Clippy?
#![allow(clippy::write_with_newline)] // too pedantic
#![allow(clippy::inefficient_to_string)] // this causes suggestions that result in `(*s).to_string()`
#![warn(clippy::needless_borrow)]
#![warn(clippy::redundant_clone)]
// Unit is now interned, and would probably be better as pass-by-copy, but
// doing so causes a lot of & and * shenanigans that makes the code arguably
// less clear and harder to read.
#![allow(clippy::trivially_copy_pass_by_ref)]
// exhaustively destructuring ensures future fields are handled
#![allow(clippy::unneeded_field_pattern)]
// false positives in target-specific code, for details see
// https://github.com/rust-lang/cargo/pull/7251#pullrequestreview-274914270
#![allow(clippy::identity_conversion)]

use std::fmt;
use std::io;

use failure::Error;
use log::debug;
use serde::ser;

use crate::core::shell::Verbosity::Verbose;
use crate::core::Shell;

pub use crate::util::errors::Internal;
pub use crate::util::{CargoResult, CliError, CliResult, Config};

pub const CARGO_ENV: &str = "CARGO";

#[macro_use]
mod macros;

pub mod core;
pub mod ops;
pub mod sources;
pub mod util;

pub struct CommitInfo {
    pub short_commit_hash: String,
    pub commit_hash: String,
    pub commit_date: String,
}

pub struct CfgInfo {
    // Information about the Git repository we may have been built from.
    pub commit_info: Option<CommitInfo>,
    // The release channel we were built for.
    pub release_channel: String,
}

pub struct VersionInfo {
    pub major: u8,
    pub minor: u8,
    pub patch: u8,
    pub pre_release: Option<String>,
    // Information that's only available when we were built with
    // configure/make, rather than Cargo itself.
    pub cfg_info: Option<CfgInfo>,
}

impl fmt::Display for VersionInfo {
    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
        write!(f, "cargo {}.{}.{}", self.major, self.minor, self.patch)?;
        if let Some(channel) = self.cfg_info.as_ref().map(|ci| &ci.release_channel) {
            if channel != "stable" {
                write!(f, "-{}", channel)?;
                let empty = String::new();
                write!(f, "{}", self.pre_release.as_ref().unwrap_or(&empty))?;
            }
        };

        if let Some(ref cfg) = self.cfg_info {
            if let Some(ref ci) = cfg.commit_info {
                write!(f, " ({} {})", ci.short_commit_hash, ci.commit_date)?;
            }
        };
        Ok(())
    }
}

pub fn print_json<T: ser::Serialize>(obj: &T) {
    let encoded = serde_json::to_string(&obj).unwrap();
    println!("{}", encoded);
}

pub fn exit_with_error(err: CliError, shell: &mut Shell) -> ! {
    debug!("exit_with_error; err={:?}", err);
    if let Some(ref err) = err.error {
        if let Some(clap_err) = err.downcast_ref::<clap::Error>() {
            clap_err.exit()
        }
    }

    let CliError {
        error,
        exit_code,
        unknown,
    } = err;
    // `exit_code` of 0 means non-fatal error (e.g., docopt version info).
    let fatal = exit_code != 0;

    let hide = unknown && shell.verbosity() != Verbose;

    if let Some(error) = error {
        if hide {
            drop(shell.error("An unknown error occurred"))
        } else if fatal {
            drop(shell.error(&error))
        } else {
            println!("{}", error);
        }

        if !handle_cause(&error, shell) || hide {
            drop(writeln!(
                shell.err(),
                "\nTo learn more, run the command again \
                 with --verbose."
            ));
        }
    }

    std::process::exit(exit_code)
}

pub fn handle_error(err: &failure::Error, shell: &mut Shell) {
    debug!("handle_error; err={:?}", err);

    let _ignored_result = shell.error(err);
    handle_cause(err, shell);
}

fn handle_cause(cargo_err: &Error, shell: &mut Shell) -> bool {
    fn print(error: &str, shell: &mut Shell) {
        drop(writeln!(shell.err(), "\nCaused by:"));
        drop(writeln!(shell.err(), "  {}", error));
    }

    fn print_stderror_causes(error: &dyn std::error::Error, shell: &mut Shell) {
        let mut cur = std::error::Error::source(error);
        while let Some(err) = cur {
            print(&err.to_string(), shell);
            cur = std::error::Error::source(err);
        }
    }

    let verbose = shell.verbosity();

    // The first error has already been printed to the shell.
    for err in cargo_err.iter_causes() {
        // If we're not in verbose mode then print remaining errors until one
        // marked as `Internal` appears.
        if verbose != Verbose && err.downcast_ref::<Internal>().is_some() {
            return false;
        }

        print(&err.to_string(), shell);

        // Using the `failure` crate currently means that when using
        // `iter_causes` we're only iterating over the `failure` causes, but
        // this doesn't include the causes from the standard library `Error`
        // trait. We don't have a great way of getting an `&dyn Error` from a
        // `&dyn Fail`, so we currently just special case a few errors that are
        // known to maybe have causes and we try to print them here.
        //
        // Note that this isn't an exhaustive match since causes for
        // `std::error::Error` aren't the most common thing in the world.
        if let Some(io) = err.downcast_ref::<io::Error>() {
            print_stderror_causes(io, shell);
        }
    }

    true
}

pub fn version() -> VersionInfo {
    macro_rules! option_env_str {
        ($name:expr) => {
            option_env!($name).map(|s| s.to_string())
        };
    }

    // So this is pretty horrible...
    // There are two versions at play here:
    //   - version of cargo-the-binary, which you see when you type `cargo --version`
    //   - version of cargo-the-library, which you download from crates.io for use
    //     in your packages.
    //
    // We want to make the `binary` version the same as the corresponding Rust/rustc release.
    // At the same time, we want to keep the library version at `0.x`, because Cargo as
    // a library is (and probably will always be) unstable.
    //
    // Historically, Cargo used the same version number for both the binary and the library.
    // Specifically, rustc 1.x.z was paired with cargo 0.x+1.w.
    // We continue to use this scheme for the library, but transform it to 1.x.w for the purposes
    // of `cargo --version`.
    let major = 1;
    let minor = env!("CARGO_PKG_VERSION_MINOR").parse::<u8>().unwrap() - 1;
    let patch = env!("CARGO_PKG_VERSION_PATCH").parse::<u8>().unwrap();

    match option_env!("CFG_RELEASE_CHANNEL") {
        // We have environment variables set up from configure/make.
        Some(_) => {
            let commit_info = option_env!("CFG_COMMIT_HASH").map(|s| CommitInfo {
                commit_hash: s.to_string(),
                short_commit_hash: option_env_str!("CFG_SHORT_COMMIT_HASH").unwrap(),
                commit_date: option_env_str!("CFG_COMMIT_DATE").unwrap(),
            });
            VersionInfo {
                major,
                minor,
                patch,
                pre_release: option_env_str!("CARGO_PKG_VERSION_PRE"),
                cfg_info: Some(CfgInfo {
                    release_channel: option_env_str!("CFG_RELEASE_CHANNEL").unwrap(),
                    commit_info,
                }),
            }
        }
        // We are being compiled by Cargo itself.
        None => VersionInfo {
            major,
            minor,
            patch,
            pre_release: option_env_str!("CARGO_PKG_VERSION_PRE"),
            cfg_info: None,
        },
    }
}