drop schema bank cascade;
create schema bank;

/*
 * Holder : table commune à tous les titulaires
 */
create table holder (
  "id" bigint primary key generated always as identity,          -- identifiant unique
  "type" text not null check ("type" in ('PERSON', 'COMPANY')),
  "created_at" timestamp not null default now()                  -- date de création
);

/*
 * Person
 */
create table person (
  "id" bigint primary key references holder(id) on delete cascade,
  "firstname" text not null,
  "lastname" text not null,
  "birthdate" date not null
);

/*
 * Company
 */
create table company (
  "id" bigint primary key references holder(id) on delete cascade,
  "name" text not null,
  "registration_number" text unique not null,
  "created_at" date not null
);

/*
 * Insertion des données
 */

-- Création d’un titulaire de type personne physique
insert into holder(type) values ('PERSON') returning id;

-- Utilisons l'id qui est retourné (1)
insert into person(id, firstname, lastname, birthdate)
  values (1, 'Françoise', 'Zanetti', '1995-04-12');

-- Création d’un titulaire de type entreprise
insert into holder(type) values ('COMPANY') returning id;

-- Utilisons l'id qui est retourné (2)
insert into company(id, name, registration_number, created_at)
  values (2, 'Boulangerie de Valorgue', 'FR19803269968', '2014-08-19');

/*
 * Visualisation des données
 */

-- Liste de tous les titulaires
create view list_holders as
select h.id, h.type, h.created_at,
       p.firstname || ' ' || p.lastname as person,
       c.name as company
from holder h
left join person p on p.id = h.id
left join company c on c.id = h.id
order by h.id;

/*
 * Suppression des données
 */

insert into holder(type) values ('PERSON') returning id;

insert into person(id, firstname, lastname, birthdate)
  values (3, 'Lucas', 'Zanetti', '2002-05-09');

select * from person;

delete from holder where id = 3; 

-- La suppresion du titulaire entraine la suppression de l'individu
select * from person;

-- Contrainte sur l'âge du titulaire
alter table person
add constraint chk_person_minimum_age
check (birthdate <= current_date - interval '15 years');

insert into holder(type) values ('PERSON') returning id;

insert into person(id, firstname, lastname, birthdate)
  values (3, 'Mattéo', 'Zanetti', '2012-12-12');

/*
 * Account
 * Chaque compte a un numéro unique.
 * La contrainte check (balance >= 0) empêche les soldes négatifs
 */
create table account (
  id bigint primary key generated always as identity,
  number text unique not null,
  opened_at date not null default current_date,
  closed_at date,
  balance numeric(18,6) not null default 0 check (balance >= 0)
);

/*
 * Account -> Holder
 * Cette table établit la relation n–n entre account et holder.
 * Un compte joint correspond donc à plusieurs lignes dans cette table.
 * La contrainte share assure que les parts sont comprises entre 0 et 1.
 */
create table account_holder (
  account_id int not null references account(id) on delete cascade,
  holder_id int not null references holder(id) on delete cascade,
  share numeric(4,3) default 1 check (share > 0 and share <= 1),
  primary key (account_id, holder_id)
);

/*
 * Compte individuel pour Françoise Zanetti.
 */

insert into account (number) 
  values ('AA') returning id;

insert into account_holder
  values (1, 1);

/*
 * Ajout d'un nouveau titulaire : Justin Hébrard né le 11/03/1993.
 */

insert into holder(type) values ('PERSON') returning id;

insert into person(id, firstname, lastname, birthdate)
  values (5, 'Justin', 'Hébrard', '1993-03-11');

/*
 * Compte joint pour Françoise et Justin.
 */

insert into account (number) 
  values ('AB') returning id;

insert into account_holder
  values (2, 1, 0.5);

insert into account_holder
  values (2, 5, 0.5);