first commit

server/migrations/001_initial_schema.sql

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+create extension if not exists pgcrypto;
+
+create type user_role as enum ('student', 'instructor', 'admin');
+create type course_status as enum ('draft', 'published', 'archived');
+create type lesson_access_level as enum ('public', 'enrolled');
+create type media_status as enum ('processing', 'ready', 'failed');
+create type asset_kind as enum ('document', 'spreadsheet', 'archive', 'image', 'link');
+
+create table users (
+  id uuid primary key default gen_random_uuid(),
+  email text not null unique,
+  password_hash text not null,
+  display_name text not null,
+  role user_role not null default 'student',
+  created_at timestamptz not null default now(),
+  updated_at timestamptz not null default now()
+);
+
+create table courses (
+  id uuid primary key default gen_random_uuid(),
+  slug text not null unique,
+  title text not null,
+  description text not null default '',
+  category text not null,
+  cover_image_url text,
+  status course_status not null default 'draft',
+  instructor_id uuid not null references users(id),
+  published_at timestamptz,
+  created_at timestamptz not null default now(),
+  updated_at timestamptz not null default now(),
+  constraint courses_published_at_check check (
+    (status = 'published' and published_at is not null) or status <> 'published'
+  )
+);
+
+create table lessons (
+  id uuid primary key default gen_random_uuid(),
+  course_id uuid not null references courses(id) on delete cascade,
+  title text not null,
+  description text not null default '',
+  position integer not null check (position > 0),
+  duration_seconds integer check (duration_seconds is null or duration_seconds >= 0),
+  access_level lesson_access_level not null default 'enrolled',
+  created_at timestamptz not null default now(),
+  updated_at timestamptz not null default now(),
+  unique (course_id, position)
+);
+
+-- Video delivery is intentionally provider-neutral. A lesson can be moved from
+-- one provider to another without changing the lesson itself.
+create table lesson_media (
+  id uuid primary key default gen_random_uuid(),
+  lesson_id uuid not null references lessons(id) on delete cascade,
+  provider text not null,
+  external_id text not null,
+  playback_url text,
+  embed_url text,
+  status media_status not null default 'processing',
+  duration_seconds integer check (duration_seconds is null or duration_seconds >= 0),
+  metadata jsonb not null default '{}'::jsonb,
+  created_at timestamptz not null default now(),
+  updated_at timestamptz not null default now(),
+  unique (provider, external_id)
+);
+
+create table course_enrollments (
+  id uuid primary key default gen_random_uuid(),
+  course_id uuid not null references courses(id) on delete cascade,
+  user_id uuid not null references users(id) on delete cascade,
+  enrolled_at timestamptz not null default now(),
+  revoked_at timestamptz,
+  unique (course_id, user_id)
+);
+
+create table lesson_progress (
+  lesson_id uuid not null references lessons(id) on delete cascade,
+  user_id uuid not null references users(id) on delete cascade,
+  watched_seconds integer not null default 0 check (watched_seconds >= 0),
+  completed_at timestamptz,
+  updated_at timestamptz not null default now(),
+  primary key (lesson_id, user_id)
+);
+
+create table assets (
+  id uuid primary key default gen_random_uuid(),
+  course_id uuid references courses(id) on delete cascade,
+  lesson_id uuid references lessons(id) on delete cascade,
+  name text not null,
+  kind asset_kind not null,
+  url text not null,
+  size_bytes bigint check (size_bytes is null or size_bytes >= 0),
+  description text not null default '',
+  access_level lesson_access_level not null default 'enrolled',
+  created_at timestamptz not null default now(),
+  updated_at timestamptz not null default now(),
+  constraint assets_parent_check check (
+    (course_id is not null and lesson_id is null) or (course_id is null and lesson_id is not null)
+  )
+);
+
+create table comments (
+  id uuid primary key default gen_random_uuid(),
+  course_id uuid not null references courses(id) on delete cascade,
+  lesson_id uuid references lessons(id) on delete set null,
+  author_id uuid not null references users(id),
+  body text not null check (char_length(body) between 1 and 4000),
+  created_at timestamptz not null default now(),
+  updated_at timestamptz not null default now()
+);
+
+create table comment_replies (
+  id uuid primary key default gen_random_uuid(),
+  comment_id uuid not null unique references comments(id) on delete cascade,
+  author_id uuid not null references users(id),
+  body text not null check (char_length(body) between 1 and 4000),
+  created_at timestamptz not null default now(),
+  updated_at timestamptz not null default now()
+);
+
+create index courses_published_index on courses (published_at desc) where status = 'published';
+create index lessons_course_position_index on lessons (course_id, position);
+create index lesson_media_lesson_index on lesson_media (lesson_id);
+create index enrollments_active_index on course_enrollments (user_id, course_id) where revoked_at is null;
+create index comments_course_created_index on comments (course_id, created_at desc);
+
+create function set_updated_at() returns trigger language plpgsql as $$
+begin
+  new.updated_at = now();
+  return new;
+end;
+$$;
+
+create trigger users_set_updated_at before update on users for each row execute function set_updated_at();
+create trigger courses_set_updated_at before update on courses for each row execute function set_updated_at();
+create trigger lessons_set_updated_at before update on lessons for each row execute function set_updated_at();
+create trigger lesson_media_set_updated_at before update on lesson_media for each row execute function set_updated_at();
+create trigger lesson_progress_set_updated_at before update on lesson_progress for each row execute function set_updated_at();
+create trigger assets_set_updated_at before update on assets for each row execute function set_updated_at();
+create trigger comments_set_updated_at before update on comments for each row execute function set_updated_at();
+create trigger comment_replies_set_updated_at before update on comment_replies for each row execute function set_updated_at();