use anyhow::Error;
use anyhow::Result;
use diesel::ExpressionMethods;
use diesel::RunQueryDsl;
use diesel::query_dsl::methods::FilterDsl;
use diesel::Connection;
use diesel::BoolExpressionMethods;

use crate::db::DbPool;
use crate::model::Address;
use crate::schema::persons;
use crate::schema;

#[derive(Debug, diesel::Associations, diesel::Queryable, getset::Getters, getset::CopyGetters)]
#[belongs_to(Address)]
#[table_name = "persons"]
pub struct Person {
    #[getset(get_copy = "pub")]
    id: i32,

    #[getset(get = "pub")]
    name: String,

    #[getset(get_copy = "pub")]
    age: i32,
    address_id: i32,
}

#[derive(Insertable)]
#[table_name = "persons"]
struct NewPerson<'a> {
    name: &'a str,
    age: i32,
    address_id: i32,
}


impl Person {
    pub fn create_or_fetch(db: &DbPool, addr: &Address, name: &str, age: i32) -> Result<Self> {
        let conn = db.get()?;

        conn.transaction::<_, Error, _>(|| {
            let new_person = NewPerson {
                name,
                age,
                address_id: addr.id,
            };

            diesel::insert_into(schema::persons::table)
                .values(&new_person)
                .on_conflict_do_nothing()
                .execute(&conn)?;

            schema::persons::table
                .filter({
                    schema::persons::name.eq(name)
                        .and(schema::persons::age.eq(age))
                        .and(schema::persons::address_id.eq(addr.id))
                })
                .first::<Person>(&conn)
                .map_err(Error::from)
        })
    }

    pub fn address(&self, db: &DbPool) -> Result<Address> {
        schema::address::table
            .filter(schema::address::id.eq(self.address_id))
            .first::<Address>(&db.get()?)
            .map_err(Error::from)
    }

    pub fn fetch_by_id(db: &DbPool, id: i32) -> Result<Option<Self>> {
        use diesel::QueryDsl;
        use diesel::OptionalExtension;
        schema::persons::dsl::persons.find(id)
            .first::<Self>(&db.get()?)
            .optional()
            .map_err(Error::from)
    }
}