use clap::{Parser, Subcommand, ValueEnum};

// region: Clap Declaration

#[derive(Debug, Clone, Copy, PartialEq, Eq, PartialOrd, Ord, Hash, ValueEnum)]
pub enum RegScope {
    #[value(name = "user")]
    User,
    #[value(name = "system")]
    System,
}

impl From<RegScope> for wfassoc::Scope {
    fn from(value: RegScope) -> Self {
        match value {
            RegScope::User => wfassoc::Scope::User,
            RegScope::System => wfassoc::Scope::System,
        }
    }
}

#[derive(Debug, Clone, Copy, PartialEq, Eq, PartialOrd, Ord, Hash, ValueEnum)]
pub enum RegView {
    #[value(name = "user")]
    User,
    #[value(name = "system")]
    System,
    #[value(name = "hybrid")]
    Hybrid,
}

impl From<RegView> for wfassoc::View {
    fn from(value: RegView) -> Self {
        match value {
            RegView::User => wfassoc::View::User,
            RegView::System => wfassoc::View::System,
            RegView::Hybrid => wfassoc::View::Hybrid,
        }
    }
}

#[derive(Debug, Clone, Copy, PartialEq, Eq, PartialOrd, Ord, Hash, ValueEnum)]
pub enum ExtListStyle {
    #[value(name = "human")]
    Human,
    #[value(name = "machine")]
    Machine,
}

/// Simple program to manage Windows file associations
#[derive(Parser)]
#[command(name = "Windows File Association Operator", version, about)]
pub struct Cli {
    /// The TOML manifest file representing the complete program
    #[arg(
        short = 'm',
        long = "manifest",
        value_name = "MANIFEST_TOML",
        required = true
    )]
    pub manifest_file: String,
    #[command(subcommand)]
    pub command: CliCommands,
}

#[derive(Subcommand)]
pub enum CliCommands {
    #[command(name = "register")]
    #[command(about = "Register application with given manifest and scope.")]
    Register {
        /// The scope where wfassoc operate.
        #[arg(short = 't', long = "target", value_name = "TARGET", required = true, value_enum, default_value_t = RegScope::User)]
        target: RegScope,
    },
    #[command(name = "unregister")]
    #[command(about = "Unregister application with given manifest and scope.")]
    Unregister {
        /// The scope where wfassoc operate.
        #[arg(short = 't', long = "target", value_name = "TARGET", required = true, value_enum, default_value_t = RegScope::User)]
        target: RegScope,
    },
    #[command(name = "status")]
    #[command(about = "Fetch the status of registration with given manifest and scope.")]
    Status {
        /// The scope where fetch info.
        #[arg(short = 't', long = "target", value_name = "TARGET", required = true, value_enum, default_value_t = RegScope::User)]
        target: RegScope,
    },
    #[command(name = "ext")]
    #[command(about = "File extension related operations according to given program manifest.")]
    Ext {
        #[command(subcommand)]
        command: CliExtCommands,
    },
}

#[derive(Subcommand)]
pub enum CliExtCommands {
    #[command(name = "link")]
    #[command(about = "Link user given file extension to the program declared in manifest file.")]
    Link {
        /// The scope where link file extension.
        #[arg(short = 't', long = "target", value_name = "TARGET", required = true, value_enum, default_value_t = RegScope::User)]
        target: RegScope,
        // The file extensions used for this operation. Specify * for all file extension.
        #[arg(required = true, value_name = "EXTS", num_args = 1..)]
        exts: Vec<String>,
    },
    #[command(name = "unlink")]
    #[command(
        about = "Unlink user given file extension from the program declared in manifest file."
    )]
    Unlink {
        /// The scope where unlink file extension.
        #[arg(short = 't', long = "target", value_name = "TARGET", required = true, value_enum, default_value_t = RegScope::User)]
        target: RegScope,
        // The file extensions used for this operation. Specify * for all file extension.
        #[arg(required = true, value_name = "EXTS", num_args = 1..)]
        exts: Vec<String>,
    },
    #[command(name = "list")]
    #[command(
        about = "List the association status for all extensions declared in given program manifest."
    )]
    List {
        /// The view where list file extension.
        #[arg(short = 't', long = "target", value_name = "TARGET", required = true, value_enum, default_value_t = RegView::User)]
        target: RegView,
        /// The style when listing file extensions.
        #[arg(short = 's', long = "style", value_name = "STYLE", required = true, value_enum, default_value_t = ExtListStyle::Human)]
        style: ExtListStyle,
    },
}

// endregion

/// Parse current commandline argument.
///
/// Please note that if there is "help" or "version" command matched,
/// or any command line parse error occurs,
/// this function will order program exit immediately.
/// This is the mechanism of `clap` crate.
pub fn parse() -> Cli {
    Cli::parse()
}