drop schema if exists public cascade;
create schema public;

create type holder_type as enum ('BANK', 'PERSON', 'COMPANY');

create table holder (
  "id" bigint primary key generated always as identity,
  "type" holder_type not null,
  "created_at" timestamp not null default current_timestamp
);

/************************************************************************
 * Bank
 * Liée par références à titulaire (holder) pas d'incrément automatique
 * puisque c'est celui de titulaire
 ************************************************************************/
create table bank (
  "id" bigint primary key references holder(id),
  "name" text not null
);

insert into holder (type) values ('BANK') returning holder;
insert into bank (id, name) values (1, 'Banque de l''Est');

/************************************************************************
 * Person
 * Liée par références à titulaire (holder) pas d'incrément automatique
 * on delete cascade : Lors de la suppression du titualaire, person est
 * supprimé aussi. Sans cela la suppression est interdite.
 ************************************************************************/
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 check (birthdate <= current_date - interval '15 years')
);

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

/************************************************************************
 * Company
 *
 ************************************************************************/
create table currency (
  "code" text primary key,
  "name" text
);

insert into currency
  values ('EUR', 'Euro'), ('JPY', 'Yen'), ('USD', 'US Dollar'),
  ('GBP', 'Livre Sterling'), ('KRW', 'Won');

/************************************************************************
 * Exchange Rate
 * La clé primaire est sur les deux colonnes currency_code et date
 * Il n'y a qu'un seul taux de change par monnaie ET par jour
 ************************************************************************/
create table exchange_rate (
  "currency_code" text references currency(code) on delete cascade,
  "date" date ,
  "rate" decimal not null,
  primary key (currency_code, date)
);

create temporary table eurofxref (
  "date" date,
  USD decimal, JPY decimal, BGN text, CYP text, CZK decimal,
  DKK decimal, EEK text, GBP decimal, HUF decimal, LTL text,
  LVL text, MTL text, PLN decimal, ROL text, RON text,
  SEK decimal, SIT text, SKK text, CHF decimal, ISK text,
  NOK decimal, HRK text, RUB text, TRL text, TRY text,
  AUD decimal, BRL text, CAD decimal, CNY text, HKD decimal,
  IDR text, ILS text, INR text, KRW decimal, MXN text,
  MYR text, NZD decimal, PHP text, SGD decimal, THB text,
  ZAR decimal,
  dumb text
);

copy eurofxref FROM '/docker-entrypoint-initdb.d/banque/eurofxref-hist.csv' (FORMAT CSV, header, delimiter ',', ENCODING 'UTF8');

insert into exchange_rate
select 'USD', date, USD  from eurofxref;

insert into exchange_rate
select 'JPY', date, JPY from eurofxref;

insert into exchange_rate
select 'GBP', date, GBP from eurofxref;

insert into exchange_rate
select 'KRW', date, KRW from eurofxref;

create or replace function latest_exchange_rate (
  p_code text,
  p_date date
)
returns decimal
language sql
as $$
select rate
  from exchange_rate
  where currency_code = p_code
    and date < p_date
    order by date desc
    limit 1;
$$;

/*
 * Account
 * La contrainte check (balance >= 0) empêche les soldes négatifs
 */

CREATE OR REPLACE FUNCTION rand_account(n integer)
RETURNS text
LANGUAGE plpgsql
AS $$
DECLARE
  chars text := '0123456789ABCDEFGHIJKLMNOPQRSTUVWXYZ';
  out text := '';
  b bytea := gen_random_bytes(n); -- n octets aléatoires
  i int;
  idx int;
begin
  IF n <= 0 THEN
    RAISE EXCEPTION 'La longueur doit être > 0';
  END IF;

  FOR i IN 0..(n - 1) LOOP
    idx := (get_byte(b, i) % length(chars)) + 1;
    out := out || substr(chars, idx, 1);
  END LOOP;

  RETURN out;
END;
$$;

create table account (
  "id" bigint primary key generated always as identity,
  "opened_at" date not null default current_date,
  "balance" numeric(18,6) not null default 0,
  "currency_code" text not null references currency (code)
);

/*
 * 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" decimal(4,3) not null default 1 check (share > 0 and share <= 1),
  primary key (account_id, holder_id)
);

create table transaction (
  "id" bigint primary key generated always as identity,
  "transaction_date" timestamp not null default current_timestamp,
  amount decimal not null check (amount > 0)
);

create table operation (
  "id" bigint primary key generated always as identity,
  "transaction_id" bigint not null references transaction(id),
  "account_id" bigint not null references account(id),
  amount decimal not null check (amount > 0),
  direction text not null check (direction in ('DEBIT', 'CREDIT'))
);

/************************************************************************
 * Procédures
 * Permet dans un bloc de code d'exécuter plusieurs opérations d'un seul coup
 * Si une erreur survient RIEN n'est enregistré
 ************************************************************************/
create or replace procedure add_bank (
  name text
)
language plpgsql
as $$
declare
  v_holder_id bigint;
begin

  insert into holder(type) values ('BANK')
  returning id into v_holder_id;

  insert into bank(id, name)
  values (v_holder_id, name);

  raise notice 'Titulaire créé : % = %',
    v_holder_id, name;
end;
$$;

create or replace procedure add_person (
  p_firstname text,
  p_lastname text,
  p_birthdate date
)
language plpgsql
as $$
declare
  v_holder_id bigint;
begin

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

  insert into person(id, firstname, lastname, birthdate)
  values (v_holder_id, p_firstname, p_lastname, p_birthdate);

  raise notice 'Titulaire créé : % = % %',
    v_holder_id, p_firstname, p_lastname;
end;
$$;

call add_person('Françoise', 'Zanetti', '1995-04-12');
call add_person('Justin', 'Hébrard', '1993-03-11');

create or replace procedure add_company (
 p_name text,
 p_registration_number text,
 p_creation_date date
)
language plpgsql
as $$
declare
  v_holder_id bigint;
begin

  insert into holder(type) values ('COMPANY')
  returning id into v_holder_id;

  insert into company(id, name, registration_number, creation_date)
  values (v_holder_id, p_name, p_registration_number, p_creation_date);

  raise notice 'Titulaire créé : % = % %',
    v_holder_id, p_name, p_registration_number;
end;
$$;

call add_company('Boulangerie de Valorgue', 'FR19803269968', '2014-08-19');

create or replace procedure add_account(
    p_currency text,
    p_holders int[],
    p_shares numeric[]
)
language plpgsql
as $$
declare
    v_account_id int;
    v_sum numeric(6,4) := 0;
    v_count int;
begin
    -- Vérification des tailles
    if array_length(p_holders, 1) is null or array_length(p_shares, 1) is null then
        raise exception 'Les tableaux de titulaires et de parts ne peuvent pas être vides.';
    end if;

    if array_length(p_holders, 1) <> array_length(p_shares, 1) then
        raise exception 'Les tableaux de titulaires et de parts doivent avoir la même taille.';
    end if;

    -- Calcul de la somme des parts
    -- select sum(unnest(p_shares)) into v_sum;
    for i in 1..array_length(p_shares, 1) loop
        v_sum := v_sum + p_shares[i];
    end loop;

    if abs(v_sum - 1.0) > 0.0001 then
        raise exception 'La somme des parts (%.4f) doit être égale à 1.0000', v_sum;
    end if;

    -- Vérification des titulaires
    select count(*) into v_count from holder where id = any(p_holders);
    if v_count <> array_length(p_holders, 1) then
        raise exception 'Un ou plusieurs titulaires n''existent pas.';
    end if;

    -- Création du compte
    insert into account(currency_code, balance)
    values (p_currency, 0)
    returning id into v_account_id;

    -- Association des titulaires
    for i in 1..array_length(p_holders, 1) loop
        insert into account_holder(account_id, holder_id, share)
        values (v_account_id, p_holders[i], p_shares[i]);
    end loop;

    raise notice 'Compte créé avec succès (ID=%) avec % titulaires.',
        v_account_id, array_length(p_holders, 1);
end;
$$;

call add_account('EUR', array[1], array[1]);
call add_account('USD', array[1], array[1]);
call add_account('JPY', array[1], array[1]);

update account set balance = 100000 where id = 1;
update account set balance = 50000 where id = 2;
update account set balance = 2000000 where id = 3;

call add_account('EUR', array[2, 3], array[0.6, 0.4]);

call add_person('Kaneda', 'Shōtarō', '1982-12-20');
call add_account('JPY', array[5], array[1]);

call add_company('Boucherie Sanzot', 'FR68487684235', '2014-08-14');
call add_account('EUR', array[6], array[1]);

call add_company('America Logistics', '95-4524149', '1996-09-24');
call add_account('EUR', array[7], array[1]);
call add_account('USD', array[7], array[1]);

/************************************************************************
 * Dépôts et retraits
 ************************************************************************/
create or replace procedure add_depot (
  p_account_id bigint,
  p_amount decimal
)
language plpgsql
as $$
declare
  v_id bigint;
begin
  insert into transaction (amount)
  values (p_amount)
  returning id into v_id;

  insert into operation (transaction_id, account_id, amount, direction)
  values (v_id, p_account_id, p_amount, 'CREDIT');

  raise notice 'Dépôt de % sur le compte %', p_amount, p_account_id;
end;
$$;

create or replace procedure add_retrait (
  p_account_id bigint,
  p_amount decimal
)
language plpgsql
as $$
declare
  v_id bigint;
begin
  insert into transaction (amount)
  values (p_amount)
  returning id into v_id;

  insert into operation (transaction_id, account_id, amount, direction)
  values (v_id, p_account_id, p_amount, 'DEBIT');

  raise notice 'Retrait de % sur le compte %', p_amount, p_account_id;
end;
$$;

call add_depot(4, 100);
call add_retrait(4, 20);

call add_depot(5, 150);
call add_depot(6, 200);
call add_depot(7, 180);
call add_depot(8, 300);

call add_retrait(5, 30);
call add_depot(5, 10);
call add_depot(5, 60);

create or replace view holder_detail as
select h.id, h.type,
  case
  when type = 'PERSON' then firstname || ' ' || lastname
  else name
  end as nom,
  case
  when type = 'PERSON' then age(birthdate)
  when type = 'COMPANY' then age(c.creation_date)
  end as age
from holder h
  left join person p on p.id = h.id
  left join company c on c.id = h.id;

create or replace view account_detail as
select a.balance,
  a.balance * ah.share as balance_currency,
  a.balance * ah.share / latest_exchange_rate(a.currency_code, current_date),
  a.currency_code,
  hd.nom
from account a
join account_holder ah on ah.account_id = a.id
join holder_detail hd on ah.holder_id = hd.id;


/************************************************************************
 * Transactions
 ************************************************************************/

insert into transaction (amount) values (100);

insert into operation (transaction_id, account_id, amount, direction)
  values (1, 4, 100, 'CREDIT');

insert into operation (transaction_id, account_id, amount, direction)
  values (1, 1, 100, 'DEBIT');

insert into transaction (amount) values (10000);

insert into operation (transaction_id, account_id, amount, direction)
  values (2, 5, 10000, 'CREDIT');

insert into operation (transaction_id, account_id, amount, direction)
  values (2, 3, 10000, 'DEBIT');

/************************************************************************
 * Vues
 ************************************************************************/

create or replace view holder_details as
select h.id, h.type,
  case
  when type = 'PERSON' then firstname || ' ' || lastname
  else name
  end as nom,
  case
  when type = 'PERSON' then age(birthdate)
  when type = 'COMPANY' then age(c.creation_date)
  end as age
from holder h
  left join person p on p.id = h.id
  left join company c on c.id = h.id;

create or replace view account_details as
select
  a.balance,
  a.currency_code,
  hd.nom, hd.age
from account a
join account_holder ah on ah.account_id = a.id
join holder_details hd on ah.holder_id = hd.id;