//! Integration with `clap`
//!
//! CLI argument structs are defined in this module. Execution logic for each
//! command goes in a submodule.

use std::path::PathBuf;

use clap::{Parser, Subcommand};

use crate::{config::DatabaseBackend, error};

mod db;
mod serve;

/// Command line arguments
#[derive(Parser)]
#[clap(
    about,
    version = crate::version(),
)]
pub(crate) struct Args {
    #[clap(subcommand)]
    pub(crate) command: Command,
}

#[derive(Subcommand)]
pub(crate) enum Command {
    /// Run the server.
    Serve(ServeArgs),

    /// Database utilities
    #[clap(subcommand)]
    Db(DbCommand),
}

/// Wrapper for the `--config` arg.
///
/// This exists to centralize the `mut_arg` code that sets the help value based
/// on runtime information.
#[derive(clap::Args)]
#[clap(mut_arg("config", |x| {
    let help = "Set the path to the configuration file";
    x.help(help).long_help(format!(
        "{}\n\nIf this option is specified, the provided value is used \
         as-is.\n\nIf this option is not specified, then the XDG Base \
         Directory Specification is followed, searching for the path `{}` \
         in the configuration directories.
        ",
        help,
        crate::config::DEFAULT_PATH.display(),
    ))
}))]
pub(crate) struct ConfigArg {
    /// Path to the configuration file
    #[clap(long, short)]
    pub(crate) config: Option<PathBuf>,
}

#[derive(clap::Args)]
pub(crate) struct ServeArgs {
    #[clap(flatten)]
    pub(crate) config: ConfigArg,
}

#[derive(Subcommand)]
pub(crate) enum DbCommand {
    /// Convert between database backends
    ///
    /// Once this command successfully completes, copy or move the `media`
    /// directory from `IN_PATH` to `OUT_PATH` to complete the migration.
    Convert(DbConvert),
}

#[derive(clap::Args)]
pub(crate) struct DbConvert {
    /// The backend to convert from
    in_backend: DatabaseBackend,

    /// The backend to convert to
    out_backend: DatabaseBackend,

    /// Path to the database to read
    in_path: PathBuf,

    /// Path to write the new database
    out_path: PathBuf,
}

impl Args {
    pub(crate) async fn run(self) -> Result<(), error::Main> {
        match self.command {
            Command::Serve(args) => serve::run(args).await?,
            Command::Db(DbCommand::Convert(args)) => {
                db::convert::run(args).await?
            }
        }
        Ok(())
    }
}