use std::path::{Path, PathBuf};

use brush_core::builtins;
use clap::Parser;

/// Evaluate the provided script in the current shell environment.
#[derive(Parser)]
pub(crate) struct DotCommand {
    /// Path to the script to evaluate.
    script_path: String,

    /// Any arguments to be passed as positional parameters to the script.
    #[arg(trailing_var_arg = true, allow_hyphen_values = true)]
    script_args: Vec<String>,
}

impl builtins::Command for DotCommand {
    type Error = brush_core::Error;

    async fn execute<SE: brush_core::ShellExtensions>(
        &self,
        context: brush_core::ExecutionContext<'_, SE>,
    ) -> Result<brush_core::ExecutionResult, Self::Error> {
        // TODO(dot): Handle trap inheritance.
        // hydrashell: POSIX requires `.` to search PATH when its operand has no slash.
        // Git's `git-subtree` relies on this with `. git-sh-setup`; treating the
        // operand as cwd-relative leaves `require_work_tree` undefined.
        let script_path = Path::new(&self.script_path);
        let resolved_path = if context.shell.options().source_builtin_searches_path
            && !self.script_path.chars().any(std::path::is_separator)
        {
            context
                .shell
                .env_str("PATH")
                .and_then(|path| {
                    std::env::split_paths(path.as_ref())
                        .map(|dir| dir.join(script_path))
                        .find(|candidate| candidate.is_file())
                })
                .unwrap_or_else(|| PathBuf::from(script_path))
        } else {
            PathBuf::from(script_path)
        };

        context
            .shell
            .source_script(&resolved_path, self.script_args.iter(), &context.params)
            .await
    }
}