use std::sync::Arc;

use actix::Actor;
use actix_session::{storage::RedisActorSessionStore, SessionMiddleware};
use actix_web::cookie::Key;
use actix_web::middleware::Logger;
use actix_web::web::Data;
use actix_web::{web, App, HttpResponse, HttpServer};
use gumdrop::Options;
use password_hash::SaltString;
use validator::{validate_email, validate_length};

use crate::actors::database;
use crate::logic::hash_pass;
use crate::model::{Email, Login, PassHash, Role};

pub mod actors;
pub mod logic;
pub mod model;
pub mod routes;

#[derive(Debug, thiserror::Error)]
pub enum Error {
    #[error("Failed to boot. {0:?}")]
    Boot(std::io::Error),
    #[error("Unable to read password file. {0:?}")]
    PassFile(std::io::Error),
    #[error("Unable to read password from STDIN. {0:?}")]
    ReadPass(std::io::Error),
    #[error("{0}")]
    Database(#[from] database::Error),
}

pub type Result<T> = std::result::Result<T, Error>;

#[derive(Options, Debug)]
struct Opts {
    help: bool,
    #[options(command)]
    cmd: Option<Command>,
}

#[derive(Options, Debug)]
enum Command {
    #[options(help = "Run server")]
    Server(ServerOpts),
    #[options(help = "Migrate database")]
    Migrate(MigrateOpts),
    #[options(help = "Generate new salt for passwords")]
    GenerateHash(GenerateHashOpts),
    #[options(help = "Create new account")]
    CreateAccount(CreateAccountOpts),
}

impl Default for Command {
    fn default() -> Self {
        Command::Server(ServerOpts::default())
    }
}

#[derive(Options, Debug)]
struct GenerateHashOpts {
    help: bool,
}

#[derive(Options, Debug)]
struct ServerOpts {
    help: bool,
    bind: String,
    port: u16,
    db_url: Option<String>,
}

impl Default for ServerOpts {
    fn default() -> Self {
        Self { help: false, bind: "0.0.0.0".to_string(), port: 8080, db_url: None }
    }
}

impl ServerOpts {
    fn db_url(&self) -> String {
        self.db_url
            .as_deref()
            .map(String::from)
            .or_else(|| std::env::var("DATABASE_URL").ok())
            .unwrap_or_else(|| String::from("postgres://postgres@localhost/bazzar"))
    }
}

#[derive(Options, Debug)]
struct MigrateOpts {
    help: bool,
    db_url: Option<String>,
}

impl MigrateOpts {
    fn db_url(&self) -> String {
        self.db_url
            .as_deref()
            .map(String::from)
            .or_else(|| std::env::var("DATABASE_URL").ok())
            .unwrap_or_else(|| String::from("postgres://postgres@localhost/bazzar"))
    }
}

#[derive(Debug, Options)]
struct CreateAccountOpts {
    help: bool,
    #[options(command)]
    cmd: Option<CreateAccountCmd>,
}

#[derive(Debug, Options)]
enum CreateAccountCmd {
    Admin(CreateAccountDefinition),
    User(CreateAccountDefinition),
}

#[derive(Debug, Options)]
struct CreateAccountDefinition {
    help: bool,
    #[options(free)]
    login: String,
    #[options(free)]
    email: String,
    #[options(free)]
    pass_file: Option<String>,
    #[options(help = "Database url, it will also look for DATABASE_URL env")]
    db_url: Option<String>,
}

impl CreateAccountDefinition {
    fn db_url(&self) -> String {
        self.db_url
            .as_deref()
            .map(String::from)
            .or_else(|| std::env::var("DATABASE_URL").ok())
            .unwrap_or_else(|| String::from("postgres://postgres@localhost/bazzar"))
    }
}

pub struct Config {
    pass_salt: SaltString,
}

impl Config {
    fn load() -> Self {
        let pass_salt =
            SaltString::new(&std::env::var("PASS_SALT").expect("PASS_SALT is required"))
                .expect("Invalid password salt");
        Self { pass_salt }
    }
}

async fn server(opts: ServerOpts) -> Result<()> {
    let secret_key = Key::generate();
    let redis_connection_string = "127.0.0.1:6379";

    let config = Arc::new(Config::load());
    let db = database::Database::build(&opts.db_url()).await?.start();

    HttpServer::new(move || {
        App::new()
            .wrap(Logger::default())
            .wrap(actix_web::middleware::Compress::default())
            .wrap(SessionMiddleware::new(
                RedisActorSessionStore::new(redis_connection_string),
                secret_key.clone(),
            ))
            .app_data(Data::new(config.clone()))
            .app_data(Data::new(db.clone()))
            .configure(routes::configure)
            .default_service(web::to(HttpResponse::Ok))
    })
    .bind((opts.bind, opts.port))
    .map_err(Error::Boot)?
    .run()
    .await
    .map_err(Error::Boot)
}

async fn migrate(opts: MigrateOpts) -> Result<()> {
    let db = database::Database::build(&opts.db_url()).await?;
    sqlx::migrate!("../db/migrate").run(db.pool()).await.expect("Failed to migrate");
    Ok(())
}

async fn generate_hash(_opts: GenerateHashOpts) -> Result<()> {
    use argon2::password_hash::rand_core::OsRng;
    let salt = SaltString::generate(&mut OsRng);
    println!("{salt}");
    Ok(())
}

async fn create_account(opts: CreateAccountOpts) -> Result<()> {
    let (role, opts) = match opts.cmd.expect("Account type is mandatory") {
        CreateAccountCmd::Admin(opts) => (Role::Admin, opts),
        CreateAccountCmd::User(opts) => (Role::User, opts),
    };
    if !validate_email(&opts.email) {
        panic!("Invalid email address");
    }
    if !validate_length(&opts.login, Some(4), Some(100), None) {
        panic!("Login must have at least 4 characters and no more than 100");
    }
    let db = database::Database::build(&opts.db_url()).await?.start();
    let pass = match opts.pass_file {
        Some(path) => std::fs::read_to_string(path).map_err(Error::PassFile)?,
        None => {
            let mut s = String::with_capacity(100);
            std::io::stdin().read_line(&mut s).map_err(Error::ReadPass)?;
            s
        }
    };
    let config = Config::load();
    let hash = hash_pass(&pass, &config.pass_salt).unwrap();

    db.send(database::CreateAccount {
        email: Email(opts.email),
        login: Login(opts.login),
        pass_hash: PassHash(hash),
        role,
    })
    .await
    .unwrap()
    .unwrap();
    Ok(())
}

#[actix_web::main]
async fn main() -> Result<()> {
    dotenv::dotenv().ok();
    pretty_env_logger::init();

    let opts: Opts = gumdrop::Options::parse_args_default_or_exit();
    match opts.cmd.unwrap_or_default() {
        Command::Migrate(opts) => migrate(opts).await,
        Command::Server(opts) => server(opts).await,
        Command::GenerateHash(opts) => generate_hash(opts).await,
        Command::CreateAccount(opts) => create_account(opts).await,
    }
}