use config::{Config, ConfigError, Environment, File};
use serde::Deserialize;

#[derive(Debug, Deserialize, Clone)]
pub struct S3Config {
    pub endpoint: String,
    pub region: String,
    pub bucket: String,
    pub access_key: String,
    pub secret_key: String,
    /// Public base URL used to build emote image URLs returned in API responses.
    /// Example: "https://s3.eu-central-1.wasabisys.com/open3dlab-emoji"
    pub public_url: String,
}

#[derive(Debug, Deserialize, Clone)]
pub struct DatabaseConfig {
    /// Database URL.
    /// SQLite example:  "sqlite://mikebase.db"
    /// PostgreSQL example: "postgresql://user:pass@localhost/mikebase"
    pub url: String,
}

#[derive(Debug, Deserialize, Clone)]
pub struct ServerConfig {
    #[serde(default = "default_host")]
    pub host: String,
    #[serde(default = "default_port")]
    pub port: u16,
}

fn default_host() -> String {
    "0.0.0.0".to_string()
}

fn default_port() -> u16 {
    3000
}

#[derive(Debug, Deserialize, Clone)]
pub struct AuthConfig {
    pub username: String,
    pub password: String,
}

#[derive(Debug, Deserialize, Clone)]
pub struct ImportConfig {
    #[serde(default = "default_allowed_hosts")]
    pub allowed_hosts: Vec<String>,
}

fn default_allowed_hosts() -> Vec<String> {
    vec!["smutba.se".to_string()]
}

#[derive(Debug, Deserialize, Clone)]
pub struct AppConfig {
    pub s3: S3Config,
    pub database: DatabaseConfig,
    #[serde(default)]
    pub server: ServerConfig,
    pub auth: Option<AuthConfig>,
    #[serde(default)]
    pub import: ImportConfig,
}

impl Default for ServerConfig {
    fn default() -> Self {
        Self {
            host: default_host(),
            port: default_port(),
        }
    }
}

impl Default for ImportConfig {
    fn default() -> Self {
        Self {
            allowed_hosts: default_allowed_hosts(),
        }
    }
}

impl AppConfig {
    pub fn load() -> Result<Self, ConfigError> {
        let cfg = Config::builder()
            // Optional config file (config.toml)
            .add_source(File::with_name("config").required(false))
            // Environment variables with prefix APP (e.g. APP__S3__BUCKET)
            .add_source(
                Environment::with_prefix("APP")
                    .separator("__")
                    .try_parsing(true),
            )
            .build()?;

        cfg.try_deserialize()
    }
}