use std::path::PathBuf;

use crate::{
    event::{
        CommandPayload,
        emit::{emit_command, emit_warning},
    },
    util::io,
};

/// Handles external functions (such as through URL deep linkage)
/// Link is extracted value (link) in somewhat URL format, such as
/// subdomain1/subdomain2
/// (Does not include modrinth://)
pub async fn handle_url(sublink: &str) -> crate::Result<CommandPayload> {
    Ok(match sublink.split_once('/') {
        // /mod/{id}   -    Installs a mod of mod id
        Some(("mod", id)) => CommandPayload::InstallMod { id: id.to_string() },
        // /version/{id}   -    Installs a specific version of id
        Some(("version", id)) => {
            CommandPayload::InstallVersion { id: id.to_string() }
        }
        // /modpack/{id}   -    Installs a modpack of modpack id
        Some(("modpack", id)) => {
            CommandPayload::InstallModpack { id: id.to_string() }
        }
        _ => {
            emit_warning(&format!(
                "Invalid command, unrecognized path: {sublink}"
            ))
            .await?;
            return Err(crate::ErrorKind::InputError(format!(
                "Invalid command, unrecognized path: {sublink}"
            ))
            .into());
        }
    })
}

pub async fn parse_command(
    command_string: &str,
) -> crate::Result<CommandPayload> {
    tracing::debug!("Parsing command: {}", &command_string);

    // modrinth://some-command
    // This occurs when following a web redirect link
    if let Some(sublink) = command_string.strip_prefix("modrinth://") {
        Ok(handle_url(sublink).await?)
    } else {
        // We assume anything else is a filepath to an .mrpack file
        let path = PathBuf::from(command_string);
        let path = io::canonicalize(path)?;
        if let Some(ext) = path.extension() {
            if ext == "mrpack" {
                return Ok(CommandPayload::RunMRPack { path });
            }
        }
        emit_warning(&format!(
            "Invalid command, unrecognized filetype: {}",
            path.display()
        ))
        .await?;
        Err(crate::ErrorKind::InputError(format!(
            "Invalid command, unrecognized filetype: {}",
            path.display()
        ))
        .into())
    }
}

pub async fn parse_and_emit_command(command_string: &str) -> crate::Result<()> {
    let command = parse_command(command_string).await?;
    emit_command(command).await?;
    Ok(())
}
