use super::CommonOptions;
use anyhow::{bail, Context, Result};
use clap::Args;
use std::path::PathBuf;
use warg_client::{keyring::Keyring, Config, RegistryUrl};

/// Creates a new warg configuration file.
#[derive(Args)]
pub struct ConfigCommand {
    /// The common command options.
    #[clap(flatten)]
    pub common: CommonOptions,

    /// The path to the registries directory to use.
    #[clap(long, value_name = "REGISTRIES")]
    pub registries_dir: Option<PathBuf>,

    /// The path to the content directory to use.
    #[clap(long, value_name = "CONTENT")]
    pub content_dir: Option<PathBuf>,

    /// Ignore federation hints.
    #[clap(long)]
    pub ignore_federation_hints: Option<bool>,

    /// Auto accept federation hints.
    #[clap(long)]
    pub auto_accept_federation_hints: Option<bool>,

    /// Overwrite the existing configuration file.
    #[clap(long)]
    pub overwrite: bool,

    /// The path to the configuration file to create.
    ///
    /// If not specified, the default of `$CONFIG_DIR/warg/config.json` is used.
    #[clap(value_name = "PATH")]
    pub path: Option<PathBuf>,

    /// The path to the namespace map
    #[clap(long, value_name = "NAMESPACE_PATH")]
    pub namespace_path: Option<PathBuf>,

    /// The backend to use for keyring access
    #[clap(long, value_name = "KEYRING_BACKEND", value_parser = keyring_backend_parser, long_help = keyring_backend_help())]
    pub keyring_backend: Option<String>,
}

impl ConfigCommand {
    /// Executes the command.
    pub async fn exec(self) -> Result<()> {
        let path = self
            .path
            .map(Ok)
            .unwrap_or_else(Config::default_config_path)?;
        let cwd = std::env::current_dir().context("failed to determine current directory")?;

        if self.overwrite && path.is_file() {
            println!(
                "Overwriting configuration file: `{path}`",
                path = path.display()
            );
        }

        let mut changing_home_registry = false;

        let config = if self.overwrite {
            let home_url = self
                .common
                .registry
                .as_ref()
                .map(RegistryUrl::new)
                .transpose()?
                .map(|u| u.to_string())
                .ok_or(anyhow::anyhow!(
                    "Please configure your home registry: warg config --registry <registry-url>"
                ))?;

            changing_home_registry = true;

            Config {
                home_url: Some(home_url),
                registries_dir: self.registries_dir.map(|p| cwd.join(p)),
                content_dir: self.content_dir.map(|p| cwd.join(p)),
                namespace_map_path: self.namespace_path.map(|p| cwd.join(p)),
                keys: self.common.read_config()?.keys,
                keyring_auth: false,
                ignore_federation_hints: self.ignore_federation_hints.unwrap_or_default(),
                auto_accept_federation_hints: self.auto_accept_federation_hints.unwrap_or_default(),
                disable_interactive: false,
                keyring_backend: self.keyring_backend,
            }
        } else {
            let mut config = self.common.read_config()?;
            if self.common.registry.is_some() {
                let home_url = self
                    .common
                    .registry
                    .as_ref()
                    .map(RegistryUrl::new)
                    .transpose()?
                    .map(|u| u.to_string());
                if home_url != config.home_url {
                    changing_home_registry = true;
                    config.home_url = home_url;
                }
            }
            if config.home_url.is_none() {
                bail!("Please configure your home registry: warg config --registry <registry-url>");
            }
            if self.registries_dir.is_some() {
                config.registries_dir = self.registries_dir.map(|p| cwd.join(p));
            }
            if self.content_dir.is_some() {
                config.content_dir = self.content_dir.map(|p| cwd.join(p));
            }
            if self.namespace_path.is_some() {
                config.namespace_map_path = self.namespace_path.map(|p| cwd.join(p));
            }
            if let Some(ignore_federation_hints) = self.ignore_federation_hints {
                config.ignore_federation_hints = ignore_federation_hints;
            }
            if let Some(auto_accept_federation_hints) = self.auto_accept_federation_hints {
                config.auto_accept_federation_hints = auto_accept_federation_hints;
            }
            if self.keyring_backend.is_some() {
                config.keyring_backend = self.keyring_backend;
            }

            config
        };

        // The paths specified on the command line are relative to the current
        // directory.
        //
        // `write_to_file` will handle normalizing the paths to be relative to
        // the configuration file's directory.
        config.write_to_file(&path)?;

        // reset when changing home registry
        if changing_home_registry {
            let client = self.common.create_client(&config).await?;
            client.reset_namespaces().await?;
            client.reset_registry().await?;
        }

        println!("Set configuration file `{path}`", path = path.display(),);

        Ok(())
    }
}

pub(crate) fn keyring_backend_parser(s: &str) -> Result<String, String> {
    if Keyring::SUPPORTED_BACKENDS.contains(&s) {
        Ok(s.to_string())
    } else {
        Err(format!("`{s}` is not a supported keyring backend."))
    }
}

pub(crate) fn keyring_backend_help() -> clap::builder::StyledStr {
    use std::fmt::Write as _;

    let mut help = String::new();

    writeln!(
        &mut help,
        "The backend to use for keyring access. The following options are supported:\n"
    )
    .unwrap();
    for backend in Keyring::SUPPORTED_BACKENDS {
        writeln!(
            &mut help,
            "{:16} {}",
            backend,
            Keyring::describe_backend(backend)
        )
        .unwrap();
    }
    writeln!(
        &mut help,
        "\nThe default is `{}`.",
        Keyring::DEFAULT_BACKEND
    )
    .unwrap();

    help.into()
}