use clap::{Parser, Subcommand};
use std::process;
use wfassoc::{Program, RegisterKind, WfError};

type Result<T> = std::result::Result<T, WfError>;

// region: Command Line Parser

/// Simple program to manage Windows file associations
#[derive(Parser)]
#[command(name = "Windows File Association Operator", version, about)]
struct Cli {
    /// The toml file introducing the complete program
    #[arg(
        short = 'c',
        long = "config",
        value_name = "PROG_CONFIG",
        required = true
    )]
    config_file: String,

    /// The scope where wfassoc operate
    #[arg(short = 'f', long = "for", value_name = "TARGET", value_enum, default_value_t = ForTarget::User)]
    for_which: ForTarget,

    #[command(subcommand)]
    command: Commands,
}

#[derive(clap::ValueEnum, Clone)]
enum ForTarget {
    #[value(name = "user")]
    User,
    #[value(name = "system")]
    System,
}

impl From<ForTarget> for RegisterKind {
    fn from(target: ForTarget) -> Self {
        match target {
            ForTarget::User => RegisterKind::User,
            ForTarget::System => RegisterKind::System,
        }
    }
}

#[derive(Subcommand)]
enum Commands {
    /// Register the program
    #[command(name = "register")]
    Register,
    /// Unregister the program
    #[command(name = "unregister")]
    Unregister,
    /// Query file associations
    #[command(name = "query")]
    Query,
}

// endregion

// region: Correponding Runner

fn run_register(cli: Cli) -> Result<()> {
    let program = Program::new();
    let kind: RegisterKind = cli.for_which.into();
    program.register(kind)
}

fn run_unregister(cli: Cli) -> Result<()> {
    let program = Program::new();
    program.unregister()
}

fn run_query(cli: Cli) -> Result<()> {
    let program = Program::new();
    program.query()
}

// endregion

fn main() {
    let cli = Cli::parse();

    let rv = match &cli.command {
        Commands::Register => run_register(cli),
        Commands::Unregister => run_unregister(cli),
        Commands::Query => run_query(cli),
    };
    rv.unwrap_or_else(|e| {
        eprintln!("Runtime error: {}.", e);
        process::exit(1)
    });
}