-- Preflight (до миграций) для перехода на группы-когорты, курсы и перенос лаб/материалов.
-- Только чтение. Запускать на копии рабочей БД до применения миграций.
-- Пример:
--   psql -h localhost -U lms -d lms -f deploy/preflight/groups-courses.sql

\pset pager off
\echo '=== 1. Группы, не подходящие под шаблон ^(.+)-([0-9])([0-9]+)(БО|МО)$ ==='
SELECT id, name
FROM identity.groups
WHERE name !~ '^(.+)-([0-9])([0-9]+)(БО|МО)$'
ORDER BY name;

\echo '=== 2. Разобранные группы с одинаковым кортежем (stream, degree, number, course, enrollment_year) ==='
WITH params AS (
    SELECT CASE
        WHEN EXTRACT(MONTH FROM now()) >= 9 THEN EXTRACT(YEAR FROM now())
        ELSE EXTRACT(YEAR FROM now()) - 1
    END::int AS academic_year_start
),
parsed AS (
    SELECT
        g.name,
        m[1] AS stream,
        m[2]::int AS course,
        m[3]::int AS number,
        m[4] AS degree,
        (SELECT academic_year_start FROM params) - (m[2]::int - 1) AS enrollment_year
    FROM identity.groups g
    CROSS JOIN LATERAL (
        SELECT regexp_match(g.name, '^(.+)-([0-9])([0-9]+)(БО|МО)$') AS m
    ) parsed_name
    WHERE m IS NOT NULL
)
SELECT stream, degree, number, course, enrollment_year,
       count(*) AS groups,
       array_agg(name ORDER BY name) AS names
FROM parsed
GROUP BY stream, degree, number, course, enrollment_year
HAVING count(*) > 1
ORDER BY stream, degree, course, number;

\echo '=== 3. Группы, которые не разберутся шаблоном (потребуют ручного разбора) ==='
WITH parsed AS (
    SELECT
        g.id,
        g.name,
        m[1] AS stream,
        m[2]::int AS course,
        m[3]::int AS number,
        m[4] AS degree
    FROM identity.groups g
    CROSS JOIN LATERAL (
        SELECT regexp_match(g.name, '^(.+)-([0-9])([0-9]+)(БО|МО)$') AS m
    ) parsed_name
)
SELECT id, name, stream, course, number, degree
FROM parsed
WHERE stream IS NULL
   OR course IS NULL
   OR number IS NULL
   OR degree IS NULL
ORDER BY name;

\echo '=== 4. Одинаковые имена групп (после снятия UNIQUE станут допустимы) ==='
SELECT name, count(*) AS groups
FROM identity.groups
GROUP BY name
HAVING count(*) > 1
ORDER BY name;

\echo '=== 5. Студенты без текущей группы ==='
SELECT s.student_no, a.login, s.last_name, s.first_name
FROM identity.students s
JOIN identity.accounts a ON a.id = s.account_id
LEFT JOIN identity.enrollments e ON e.student_id = s.account_id
WHERE e.id IS NULL
ORDER BY s.student_no;

\echo '=== 6. Аккаунты по ролям (до появления статусов) ==='
SELECT role, count(*) AS accounts
FROM identity.accounts
GROUP BY role
ORDER BY role;

\echo '=== 7. Дубли номеров лабораторных (все лабы переезжают в один курс C) ==='
SELECT number,
       count(*) AS labs,
       array_agg(id ORDER BY created_at) AS ids,
       array_agg(title ORDER BY created_at) AS titles
FROM academic.labs
GROUP BY number
HAVING count(*) > 1
ORDER BY number;

\echo '=== 8. Лабораторные по семестрам ==='
SELECT semester_id, number, count(*) AS labs
FROM academic.labs
GROUP BY semester_id, number
HAVING count(*) > 1
ORDER BY semester_id, number;

\echo '=== 9. Дубли slug глав (до перехода на частичные индексы) ==='
SELECT slug, count(*) AS chapters
FROM academic.chapters
GROUP BY slug
HAVING count(*) > 1
ORDER BY slug;

\echo '=== 10. Объём материалов ==='
SELECT
    (SELECT count(*) FROM academic.chapters) AS chapters,
    (SELECT count(*) FROM academic.sections) AS sections,
    (SELECT count(*) FROM academic.articles) AS articles,
    (SELECT count(*) FROM academic.article_assets) AS article_assets;

\echo '=== 11. Активы без статьи ==='
SELECT count(*) AS assets_without_article
FROM academic.article_assets
WHERE article_id IS NULL;

\echo '=== 12. Семестры ==='
SELECT id, title, year, active
FROM academic.semesters
ORDER BY year, title;