use std::path::{Path, PathBuf};
use std::process::{exit, Command, Stdio};
use structopt::StructOpt;
use toml::Value;

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

#[derive(StructOpt, Debug)]
#[structopt(name = "cargo-remote", bin_name = "cargo")]
enum Opts {
    #[structopt(name = "remote")]
    Remote {
        #[structopt(short = "r", long = "remote", help = "Remote ssh build server")]
        remote: Option<String>,

        #[structopt(
            short = "b",
            long = "build-env",
            help = "Set remote environment variables. RUST_BACKTRACE, CC, LIB, etc. ",
            default_value = "RUST_BACKTRACE=1"
        )]
        build_env: String,

        #[structopt(
            short = "d",
            long = "rustup-default",
            help = "Rustup default (stable|beta|nightly)",
            default_value = "stable"
        )]
        rustup_default: String,

        #[structopt(
            short = "e",
            long = "env",
            help = "Environment profile. default_value = /etc/profile",
            default_value = "/etc/profile"
        )]
        env: String,

        #[structopt(
            short = "c",
            long = "copy-back",
            help = "Transfer the target folder or specific file from that folder back to the local machine"
        )]
        copy_back: Option<Option<String>>,

        #[structopt(
            long = "no-copy-lock",
            help = "don't transfer the Cargo.lock file back to the local machine"
        )]
        no_copy_lock: bool,

        #[structopt(
            long = "manifest-path",
            help = "Path to the manifest to execute",
            default_value = "Cargo.toml",
            parse(from_os_str)
        )]
        manifest_path: PathBuf,

        #[structopt(
            short = "h",
            long = "transfer-hidden",
            help = "Transfer hidden files and directories to the build server"
        )]
        hidden: bool,

        #[structopt(help = "cargo command that will be executed remotely")]
        command: String,

        #[structopt(
            help = "cargo options and flags that will be applied remotely",
            name = "remote options"
        )]
        options: Vec<String>,
    },
}

/// Tries to parse the file [`config_path`]. Logs warnings and returns [`None`] if errors occur
/// during reading or parsing, [`Some(Value)`] otherwise.
fn config_from_file(config_path: &Path) -> Option<Value> {
    let config_file = std::fs::read_to_string(config_path)
        .map_err(|e| {
            warn!(
                "Can't parse config file '{}' (error: {})",
                config_path.to_string_lossy(),
                e
            );
        })
        .ok()?;

    let value = config_file
        .parse::<Value>()
        .map_err(|e| {
            warn!(
                "Can't parse config file '{}' (error: {})",
                config_path.to_string_lossy(),
                e
            );
        })
        .ok()?;

    Some(value)
}

fn main() {
    simple_logger::init().unwrap();

    let Opts::Remote {
        remote,
        build_env,
        rustup_default,
        env,
        copy_back,
        no_copy_lock,
        manifest_path,
        hidden,
        command,
        options,
    } = Opts::from_args();

    let mut metadata_cmd = cargo_metadata::MetadataCommand::new();
    metadata_cmd.manifest_path(manifest_path).no_deps();

    let project_metadata = metadata_cmd.exec().unwrap();
    let project_dir = project_metadata.workspace_root;
    info!("Project dir: {:?}", project_dir);
    let mut manifest_path = project_dir.clone();
    manifest_path.push("Cargo.toml");
    let project_name = project_metadata
        .packages
        .iter()
        .find(|p| p.manifest_path == manifest_path)
        .map_or_else(
            || {
                error!("No metadata found. Use --manifest_path for execute");
                exit(-2);
            },
            |p| &p.name,
        );
    info!("Project name: {:?}", project_name);
    let configs = vec![
        config_from_file(&project_dir.join(".cargo-remote.toml")),
        xdg::BaseDirectories::with_prefix("cargo-remote")
            .ok()
            .and_then(|base| base.find_config_file("cargo-remote.toml"))
            .and_then(|p: PathBuf| config_from_file(&p)),
    ];

    // TODO: move Opts::Remote fields into own type and implement complete_from_config(&mut self, config: &Value)
    let build_server = remote
        .or_else(|| {
            configs
                .into_iter()
                .flat_map(|config| config.and_then(|c| c["remote"].as_str().map(String::from)))
                .next()
        })
        .unwrap_or_else(|| {
            error!("No remote build server was defined (use config file or --remote flag)");
            exit(-3);
        });

    let build_path = format!("~/remote-builds/{:?}/", project_name);

    info!("Transferring sources to build server.");
    // transfer project to build server
    let mut rsync_to = Command::new("rsync");
    rsync_to
        .arg("-a".to_owned())
        .arg("--delete")
        .arg("--compress")
        .arg("--info=progress2")
        .arg("--exclude")
        .arg("target");

    if !hidden {
        rsync_to.arg("--exclude").arg(".*");
    }

    rsync_to
        .arg("--rsync-path")
        .arg("mkdir -p remote-builds && rsync")
        .arg(format!("{}/", project_dir.to_string_lossy()))
        .arg(format!("{}:{}", build_server, build_path))
        .stdout(Stdio::inherit())
        .stderr(Stdio::inherit())
        .stdin(Stdio::inherit())
        .output()
        .unwrap_or_else(|e| {
            error!("Failed to transfer project to build server (error: {})", e);
            exit(-4);
        });
    info!("Build ENV: {:?}", build_env);
    info!("Environment profile: {:?}", env);
    info!("Build path: {:?}", build_path);
    let build_command = format!(
        "source {}; rustup default {}; cd {}; {} cargo {} {}",
        env,
        rustup_default,
        build_path,
        build_env,
        command,
        options.join(" ")
    );

    info!("Starting build process.");
    let output = Command::new("ssh")
        .arg(&build_server)
        .arg(build_command)
        .stdout(Stdio::inherit())
        .stderr(Stdio::inherit())
        .stdin(Stdio::inherit())
        .output()
        .unwrap_or_else(|e| {
            error!("Failed to run cargo command remotely (error: {})", e);
            exit(-5);
        });

    if let Some(file_name) = copy_back {
        info!("Transferring artifacts back to client.");
        let file_name = file_name.unwrap_or_else(String::new);
        Command::new("rsync")
            .arg("-a")
            .arg("--delete")
            .arg("--compress")
            .arg("--info=progress2")
            .arg(format!("{}:{}/target/{}", build_server, build_path, file_name))
            .arg(format!("{}/target/{}", project_dir.to_string_lossy(), file_name))
            .stdout(Stdio::inherit())
            .stderr(Stdio::inherit())
            .stdin(Stdio::inherit())
            .output()
            .unwrap_or_else(|e| {
                error!(
                    "Failed to transfer target back to local machine (error: {})",
                    e
                );
                exit(-6);
            });
    }

    if !no_copy_lock {
        info!("Transferring Cargo.lock file back to client.");
        Command::new("rsync")
            .arg("-a")
            .arg("--delete")
            .arg("--compress")
            .arg("--info=progress2")
            .arg(format!("{}:{}/Cargo.lock", build_server, build_path))
            .arg(format!("{}/Cargo.lock", project_dir.to_string_lossy()))
            .stdout(Stdio::inherit())
            .stderr(Stdio::inherit())
            .stdin(Stdio::inherit())
            .output()
            .unwrap_or_else(|e| {
                error!(
                    "Failed to transfer Cargo.lock back to local machine (error: {})",
                    e
                );
                exit(-7);
            });
    }

    if !output.status.success() {
        exit(output.status.code().unwrap_or(1))
    }
}