use std::{
    fs::{create_dir_all, File},
    io::Write,
    path::Path,
};

use serde::{Deserialize, Serialize};

use crate::{
    data::{
        gameversion::{check_game_versions, VersionLevel},
        modloader::Modloader,
    },
    db::setup,
    errors::{Error, MLE},
};

#[derive(Debug, Clone, Serialize, Deserialize)]
pub struct Cfg {
    pub data: String,
    pub cache: String,
    pub versions: String,
    pub defaults: Defaults,
    pub apis: Apis,
}

impl Default for Cfg {
    fn default() -> Self {
        let cache_dir = dirs::cache_dir()
            .unwrap()
            .join("modlist")
            .to_string_lossy()
            .to_string();
        Self {
            data: cache_dir.clone(),
            cache: format!("{cache_dir}/cache"),
            versions: cache_dir,
            defaults: Defaults {
                modloader: Modloader::Fabric,
                version: VersionLevel::Release,
            },
            apis: Apis {
                modrinth: String::from("https://api.modrinth.com/v2/"),
            },
        }
    }
}

#[derive(Debug, Clone, Serialize, Deserialize)]
pub struct Apis {
    pub modrinth: String,
}

#[derive(Debug, Clone, Serialize, Deserialize)]
pub struct Defaults {
    pub modloader: Modloader,
    pub version: VersionLevel,
}

impl Cfg {
    /// # Errors
    pub async fn init(path: Option<String>) -> MLE<Self> {
        let configfile = if let Some(cf) = path.clone() {
            cf
        } else {
            let Some(config_dir) = dirs::config_dir() else {
                return Err(Error::SysDirNotFound("config".to_string()));
            };
            config_dir
                .join("modlist")
                .join("config.toml")
                .to_string_lossy()
                .to_string()
        };

        if let Some(err) = File::open(&configfile).err() {
            if err.kind() == std::io::ErrorKind::NotFound && path.is_none() {
                create_config(&configfile)?;
            } else {
                return Err(err.into());
            };
        };

        let config: Cfg = config::Config::builder()
            .add_source(config::File::with_name(&configfile).required(false))
            .add_source(
                config::Environment::with_prefix("MODLIST").separator("_"),
            )
            .build()?
            .try_deserialize()?;

        //Check cache
        if !Path::new(&config.cache).exists() {
            create_cache(&config.cache)?;
        };
        //Check database
        let datafile = format!("{}/data.db", config.data);
        match File::open(&datafile) {
            Ok(..) => (),
            Err(..) => create_database(&datafile)?,
        };
        //Check versions
        let versionfile = format!("{}/versions.json", config.versions);
        if File::open(&versionfile).is_err() {
            create_versions_dummy(&versionfile)?;
            check_game_versions(&versionfile, true).await?;
        }

        Ok(config)
    }
}

fn create_config(path: &str) -> MLE<()> {
    create_dir_all(path.split("config.toml").collect::<Vec<&str>>()[0])?;
    let mut file = File::create(path)?;
    file.write_all(toml::to_string(&Cfg::default())?.as_bytes())?;
    println!("Created default config ({path})");
    Ok(())
}

fn create_database(path: &str) -> MLE<()> {
    File::create(path)?;
    setup(path)?;
    println!("Created database ({path})");
    Ok(())
}

fn create_cache(path: &str) -> MLE<()> {
    create_dir_all(path)?;
    println!("Created cache ({path})");
    Ok(())
}

fn create_versions_dummy(path: &str) -> MLE<()> {
    File::create(path)?;
    println!("Created version file ({path})");
    Ok(())
}