use clap::Parser;
use s3::creds::Credentials;
use s3::{Bucket, Region};

/// Matrix gateway backend API
#[derive(Parser, Debug, Clone)]
#[clap(author, version, about, long_about = None)]
pub struct AppConfig {
    /// Listen address
    #[clap(short, long, env, default_value = "0.0.0.0:8000")]
    pub listen_address: String,

    /// Website origin
    #[clap(short, long, env, default_value = "http://localhost:8000")]
    pub website_origin: String,

    /// Proxy IP, might end with a star "*"
    #[clap(short, long, env)]
    pub proxy_ip: Option<String>,

    /// Secret key, used to sign some resources. Must be randomly generated
    #[clap(short = 'S', long, env, default_value = "")]
    secret: String,

    /// Matrix API origin
    #[clap(short, long, env, default_value = "http://127.0.0.1:8448")]
    pub matrix_homeserver: String,

    /// Redis connection hostname
    #[clap(long, env, default_value = "localhost")]
    redis_hostname: String,

    /// Redis connection port
    #[clap(long, env, default_value_t = 6379)]
    redis_port: u16,

    /// Redis database number
    #[clap(long, env, default_value_t = 0)]
    redis_db_number: i64,

    /// Redis username
    #[clap(long, env)]
    redis_username: Option<String>,

    /// Redis password
    #[clap(long, env, default_value = "secretredis")]
    redis_password: String,

    /// URL where the OpenID configuration can be found
    #[arg(
        long,
        env,
        default_value = "http://localhost:9001/dex/.well-known/openid-configuration"
    )]
    pub oidc_configuration_url: String,

    /// OpenID client ID
    #[arg(long, env, default_value = "foo")]
    pub oidc_client_id: String,

    /// OpenID client secret
    #[arg(long, env, default_value = "bar")]
    pub oidc_client_secret: String,

    /// OpenID login redirect URL
    #[arg(long, env, default_value = "APP_ORIGIN/oidc_cb")]
    oidc_redirect_url: String,

    /// S3 Bucket name
    #[arg(long, env, default_value = "matrix-gw")]
    s3_bucket_name: String,

    /// S3 region (if not using Minio)
    #[arg(long, env, default_value = "eu-central-1")]
    s3_region: String,

    /// S3 API endpoint
    #[arg(long, env, default_value = "http://localhost:9000")]
    s3_endpoint: String,

    /// S3 access key
    #[arg(long, env, default_value = "minioadmin")]
    s3_access_key: String,

    /// S3 secret key
    #[arg(long, env, default_value = "minioadmin")]
    s3_secret_key: String,

    /// S3 skip auto create bucket if not existing
    #[arg(long, env)]
    pub s3_skip_auto_create_bucket: bool,
}

lazy_static::lazy_static! {
    static ref ARGS: AppConfig = {
        AppConfig::parse()
    };
}

impl AppConfig {
    /// Get parsed command line arguments
    pub fn get() -> &'static AppConfig {
        &ARGS
    }

    /// Get app secret
    pub fn secret(&self) -> &str {
        let mut secret = self.secret.as_str();

        if cfg!(debug_assertions) && secret.is_empty() {
            secret = "DEBUGKEYDEBUGKEYDEBUGKEYDEBUGKEYDEBUGKEYDEBUGKEYDEBUGKEYDEBUGKEY";
        }

        if secret.is_empty() {
            panic!("SECRET is undefined or too short (min 64 chars)!")
        }

        secret
    }

    /// Get Redis connection configuration
    pub fn redis_connection_string(&self) -> String {
        format!(
            "redis://{}:{}@{}:{}/{}",
            self.redis_username.as_deref().unwrap_or(""),
            self.redis_password,
            self.redis_hostname,
            self.redis_port,
            self.redis_db_number
        )
    }

    /// Get OpenID providers configuration
    pub fn openid_provider(&self) -> OIDCProvider<'_> {
        OIDCProvider {
            client_id: self.oidc_client_id.as_str(),
            client_secret: self.oidc_client_secret.as_str(),
            configuration_url: self.oidc_configuration_url.as_str(),
            redirect_url: self
                .oidc_redirect_url
                .replace("APP_ORIGIN", &self.website_origin),
        }
    }

    /// Get s3 bucket credentials
    pub fn s3_credentials(&self) -> anyhow::Result<Credentials> {
        Ok(Credentials::new(
            Some(&self.s3_access_key),
            Some(&self.s3_secret_key),
            None,
            None,
            None,
        )?)
    }

    /// Get S3 bucket
    pub fn s3_bucket(&self) -> anyhow::Result<Box<Bucket>> {
        Ok(Bucket::new(
            &self.s3_bucket_name,
            Region::Custom {
                region: self.s3_region.to_string(),
                endpoint: self.s3_endpoint.to_string(),
            },
            self.s3_credentials()?,
        )?
        .with_path_style())
    }
}

#[derive(Debug, Clone, serde::Serialize)]
pub struct OIDCProvider<'a> {
    pub client_id: &'a str,
    pub client_secret: &'a str,
    pub configuration_url: &'a str,
    pub redirect_url: String,
}

#[cfg(test)]
mod test {
    use crate::app_config::AppConfig;

    #[test]
    fn verify_cli() {
        use clap::CommandFactory;
        AppConfig::command().debug_assert()
    }
}