use serde::Deserialize;

use crate::error::{CoreError, CoreResult};

#[derive(Deserialize, Clone, Debug)]
#[serde(rename_all = "lowercase")]
pub enum DatabaseType {
    Postgres,
    Sqlite,
}

#[derive(Deserialize, Clone, Debug)]
pub struct DatabaseConfig {
    pub db_type: DatabaseType,
    pub url: String,
}

#[derive(Deserialize, Clone, Debug)]
#[serde(rename_all = "lowercase")]
pub enum ThumbnailFormat {
    Jpeg,
    Webp,
}

#[derive(Deserialize, Clone, Debug)]
pub struct ThumbnailConfig {
    pub format: ThumbnailFormat,
    pub quality: u8,
    pub width: u32,
    pub height: u32,
    pub library_path: String,
}

#[derive(Deserialize, Clone, Debug)]
pub struct Config {
    pub database_url: String,
    pub database_db_type: DatabaseType,
    pub server_address: String,
    pub jwt_secret: String,
    pub media_library_path: String,
    pub broker_url: String,

    #[serde(default = "default_max_upload_size")]
    pub max_upload_size_mb: u32,

    #[serde(default = "default_storage_quota")]
    pub default_storage_quota_gb: u64,

    #[serde(default = "default_allowed_sort_columns")]
    pub allowed_sort_columns: Vec<String>,

    pub thumbnail_config: Option<ThumbnailConfig>,
}

fn default_max_upload_size() -> u32 {
    100
}
fn default_storage_quota() -> u64 {
    10
}
fn default_allowed_sort_columns() -> Vec<String> {
    vec!["created_at".to_string(), "original_filename".to_string()]
}

#[derive(Clone, Debug)]
pub struct AppConfig {
    pub database: DatabaseConfig,
    pub server_address: String,
    pub jwt_secret: String,
    pub media_library_path: String,
    pub broker_url: String,
    pub max_upload_size_mb: Option<u32>,
    pub default_storage_quota_gb: Option<u64>,
    pub allowed_sort_columns: Option<Vec<String>>,
    pub thumbnail_config: Option<ThumbnailConfig>,
}

pub fn load_config() -> CoreResult<AppConfig> {
    let env_path = dotenvy::dotenv()
        .map_err(|e| CoreError::Config(format!("Failed to load .env file: {}", e)))?;
    println!("Loaded config from {}", env_path.display());

    let config = config::Config::builder()
        .add_source(
            config::Environment::default()
                .with_list_parse_key("allowed_sort_columns")
                .list_separator(",")
                .try_parsing(true)
                .separator("__"),
        )
        .build()
        .map_err(|e| CoreError::Config(format!("Failed to build config: {}", e)))?;

    let config: Config = config
        .try_deserialize()
        .map_err(|e| CoreError::Config(format!("Failed to deserialize config: {}", e)))?;

    Ok(AppConfig {
        database: DatabaseConfig {
            db_type: config.database_db_type,
            url: config.database_url,
        },
        server_address: config.server_address,
        jwt_secret: config.jwt_secret,
        media_library_path: config.media_library_path,
        broker_url: config.broker_url,
        max_upload_size_mb: Some(config.max_upload_size_mb),
        default_storage_quota_gb: Some(config.default_storage_quota_gb),
        allowed_sort_columns: Some(config.allowed_sort_columns),
        thumbnail_config: config.thumbnail_config,
    })
}