use std::env;

use diesel::dsl::sql;
use diesel::prelude::*;
use diesel_migrations::embed_migrations;
use dotenv::dotenv;

use errors::DatabaseError;
use models::*;
use schema::schedules::dsl::*;
use crate::types::EmgauwaUid;

pub mod errors;
pub mod models;
pub mod schema;

embed_migrations!("migrations");

fn get_connection() -> SqliteConnection {
    dotenv().ok();

    let database_url = env::var("DATABASE_URL").expect("DATABASE_URL must be set");
    SqliteConnection::establish(&database_url)
        .unwrap_or_else(|_| panic!("Error connecting to {}", database_url))
}

pub fn run_migrations() {
    let connection = get_connection();
    embedded_migrations::run(&connection).expect("Failed to run migrations.");
}

pub fn get_schedules() -> Vec<Schedule> {
    let connection = get_connection();
    schedules
        .load::<Schedule>(&connection)
        .expect("Error loading schedules")
}

pub fn get_schedule_by_uid(filter_uid: EmgauwaUid) -> Result<Schedule, DatabaseError> {
    let connection = get_connection();
    let result = schedules
        .filter(uid.eq(filter_uid))
        .first::<Schedule>(&connection)
        .or(Err(DatabaseError::NotFound))?;

    Ok(result)
}

pub fn create_schedule(new_name: &str, new_periods: &Periods) -> Result<Schedule, DatabaseError> {
    let connection = get_connection();

    let new_schedule = NewSchedule {
        uid: &EmgauwaUid::default(),
        name: new_name,
        periods: new_periods
    };

    diesel::insert_into(schedules)
        .values(&new_schedule)
        .execute(&connection)
        .or(Err(DatabaseError::InsertError))?;

    let result = schedules
        .find(sql("last_insert_rowid()"))
        .get_result::<Schedule>(&connection)
        .or(Err(DatabaseError::InsertGetError))?;

    Ok(result)
}