use std::env;

use thiserror::Error;

#[derive(Debug, Clone)]
pub struct Config {
    pub db_user: String,
    pub db_password: String,
    pub db_host: String,
    pub db_port: u16,
    pub db_name: String,
}

#[derive(Debug, Error)]
pub enum ConfigError {
    #[error("missing env var: {0}")]
    MissingVar(&'static str),
    #[error("invalid DB_PORT: {0}")]
    InvalidPort(String),
}

impl Config {
    pub fn from_env() -> Result<Self, ConfigError> {
        dotenvy::dotenv().ok();

        let db_user =
            env::var("DB_USERNAME").map_err(|_| ConfigError::MissingVar("DB_USERNAME"))?;
        let db_password =
            env::var("DB_PASSWORD").map_err(|_| ConfigError::MissingVar("DB_PASSWORD"))?;
        let db_host = env::var("DB_HOST").map_err(|_| ConfigError::MissingVar("DB_HOST"))?;
        let db_name = env::var("DB_NAME").map_err(|_| ConfigError::MissingVar("DB_NAME"))?;
        let db_port_raw = env::var("DB_PORT").map_err(|_| ConfigError::MissingVar("DB_PORT"))?;
        let db_port = db_port_raw
            .parse::<u16>()
            .map_err(|_| ConfigError::InvalidPort(db_port_raw))?;

        Ok(Self {
            db_user,
            db_password,
            db_host,
            db_port,
            db_name,
        })
    }

    pub fn database_url(&self) -> String {
        format!(
            "postgres://{}:{}@{}:{}/{}",
            self.db_user, self.db_password, self.db_host, self.db_port, self.db_name
        )
    }
}