use color_eyre::eyre::{eyre, Result};
use console::style;
use indoc::formatdoc;

use crate::cli::args::ToolArg;
use crate::config::Config;
use crate::env;
use crate::shell::get_shell;
use crate::toolset::{InstallOptions, ToolSource, ToolsetBuilder};

/// Sets a tool version for the current session
///
/// Only works in a session where mise is already activated.
///
/// This works by setting environment variables for the current shell session
/// such as `MISE_NODE_VERSION=20` which is "eval"ed as a shell function created
/// by `mise activate`.
#[derive(Debug, clap::Args)]
#[clap(verbatim_doc_comment, visible_alias = "sh", after_long_help = AFTER_LONG_HELP)]
pub struct Shell {
    /// Tool(s) to use
    #[clap(value_name = "TOOL@VERSION")]
    tool: Vec<ToolArg>,

    /// Number of jobs to run in parallel
    /// [default: 4]
    #[clap(long, short, env = "MISE_JOBS", verbatim_doc_comment)]
    jobs: Option<usize>,

    /// Directly pipe stdin/stdout/stderr from plugin to user
    /// Sets --jobs=1
    #[clap(long, overrides_with = "jobs")]
    raw: bool,

    /// Removes a previously set version
    #[clap(long, short)]
    unset: bool,
}

impl Shell {
    pub fn run(self) -> Result<()> {
        let config = Config::try_get()?;
        if !env::is_activated() {
            err_inactive()?;
        }

        let mut ts = ToolsetBuilder::new().with_args(&self.tool).build(&config)?;
        let opts = InstallOptions {
            force: false,
            jobs: self.jobs,
            raw: self.raw,
            latest_versions: false,
        };
        ts.install_arg_versions(&config, &opts)?;
        ts.notify_if_versions_missing();

        let shell = get_shell(None).expect("no shell detected");

        for (p, tv) in ts.list_current_installed_versions() {
            let source = &ts.versions.get(p.fa()).unwrap().source;
            if matches!(source, ToolSource::Argument) {
                let k = format!("MISE_{}_VERSION", p.id().to_uppercase());
                let op = if self.unset {
                    shell.unset_env(&k)
                } else {
                    shell.set_env(&k, &tv.version)
                };
                miseprintln!("{op}");
            }
        }

        Ok(())
    }
}

fn err_inactive() -> Result<()> {
    Err(eyre!(formatdoc!(
        r#"
                mise is not activated in this shell session.
                Please run `{}` first in your shell rc file.
                "#,
        style("mise activate").yellow()
    )))
}

static AFTER_LONG_HELP: &str = color_print::cstr!(
    r#"<bold><underline>Examples:</underline></bold>

    $ <bold>mise shell node@20</bold>
    $ <bold>node -v</bold>
    v20.0.0
"#
);

#[cfg(test)]
mod tests {
    use std::env;

    use insta::assert_snapshot;

    use crate::test::reset;

    #[test]
    fn test_shell() {
        reset();
        let err = assert_cli_err!("shell", "tiny@1.0.1");
        assert_snapshot!(err);
        env::set_var("__MISE_DIFF", "");
        env::set_var("MISE_SHELL", "zsh");
        assert_cli_snapshot!("shell", "tiny@1.0.1");
        env::remove_var("__MISE_DIFF");
        env::remove_var("MISE_SHELL");
    }
}
