-- 001_init.sql
PRAGMA foreign_keys = ON;

CREATE TABLE IF NOT EXISTS users (
  id INTEGER PRIMARY KEY AUTOINCREMENT,
  username TEXT NOT NULL UNIQUE,
  password_salt TEXT NOT NULL,
  password_hash TEXT NOT NULL,
  rating INTEGER NOT NULL DEFAULT 0,
  created_at INTEGER NOT NULL
);

CREATE TABLE IF NOT EXISTS sessions (
  token TEXT PRIMARY KEY,
  user_id INTEGER NOT NULL,
  expires_at INTEGER NOT NULL,
  created_at INTEGER NOT NULL,
  FOREIGN KEY(user_id) REFERENCES users(id) ON DELETE CASCADE
);

CREATE TABLE IF NOT EXISTS problems (
  id INTEGER PRIMARY KEY AUTOINCREMENT,
  slug TEXT NOT NULL UNIQUE,
  title TEXT NOT NULL,
  statement_md TEXT NOT NULL,
  difficulty INTEGER NOT NULL DEFAULT 1,
  source TEXT NOT NULL DEFAULT '',
  statement_url TEXT NOT NULL DEFAULT '',
  llm_profile_json TEXT NOT NULL DEFAULT '{}',
  sample_input TEXT NOT NULL DEFAULT '',
  sample_output TEXT NOT NULL DEFAULT '',
  created_at INTEGER NOT NULL
);

CREATE TABLE IF NOT EXISTS problem_tags (
  problem_id INTEGER NOT NULL,
  tag TEXT NOT NULL,
  PRIMARY KEY(problem_id, tag),
  FOREIGN KEY(problem_id) REFERENCES problems(id) ON DELETE CASCADE
);

CREATE TABLE IF NOT EXISTS submissions (
  id INTEGER PRIMARY KEY AUTOINCREMENT,
  user_id INTEGER NOT NULL,
  problem_id INTEGER NOT NULL,
  contest_id INTEGER,
  language TEXT NOT NULL,
  code TEXT NOT NULL,
  status TEXT NOT NULL,
  score INTEGER NOT NULL DEFAULT 0,
  time_ms INTEGER NOT NULL DEFAULT 0,
  memory_kb INTEGER NOT NULL DEFAULT 0,
  compile_log TEXT NOT NULL DEFAULT '',
  runtime_log TEXT NOT NULL DEFAULT '',
  created_at INTEGER NOT NULL,
  FOREIGN KEY(user_id) REFERENCES users(id) ON DELETE CASCADE,
  FOREIGN KEY(problem_id) REFERENCES problems(id) ON DELETE CASCADE,
  FOREIGN KEY(contest_id) REFERENCES contests(id) ON DELETE SET NULL
);

CREATE TABLE IF NOT EXISTS wrong_book (
  user_id INTEGER NOT NULL,
  problem_id INTEGER NOT NULL,
  last_submission_id INTEGER,
  note TEXT NOT NULL DEFAULT '',
  updated_at INTEGER NOT NULL,
  PRIMARY KEY(user_id, problem_id),
  FOREIGN KEY(user_id) REFERENCES users(id) ON DELETE CASCADE,
  FOREIGN KEY(problem_id) REFERENCES problems(id) ON DELETE CASCADE,
  FOREIGN KEY(last_submission_id) REFERENCES submissions(id) ON DELETE SET NULL
);

CREATE TABLE IF NOT EXISTS contests (
  id INTEGER PRIMARY KEY AUTOINCREMENT,
  title TEXT NOT NULL,
  starts_at INTEGER NOT NULL,
  ends_at INTEGER NOT NULL,
  rule_json TEXT NOT NULL DEFAULT '{}'
);

CREATE TABLE IF NOT EXISTS contest_problems (
  contest_id INTEGER NOT NULL,
  problem_id INTEGER NOT NULL,
  idx INTEGER NOT NULL,
  PRIMARY KEY(contest_id, problem_id),
  FOREIGN KEY(contest_id) REFERENCES contests(id) ON DELETE CASCADE,
  FOREIGN KEY(problem_id) REFERENCES problems(id) ON DELETE CASCADE
);

CREATE TABLE IF NOT EXISTS contest_registrations (
  contest_id INTEGER NOT NULL,
  user_id INTEGER NOT NULL,
  registered_at INTEGER NOT NULL,
  PRIMARY KEY(contest_id, user_id),
  FOREIGN KEY(contest_id) REFERENCES contests(id) ON DELETE CASCADE,
  FOREIGN KEY(user_id) REFERENCES users(id) ON DELETE CASCADE
);

CREATE TABLE IF NOT EXISTS kb_articles (
  id INTEGER PRIMARY KEY AUTOINCREMENT,
  slug TEXT NOT NULL UNIQUE,
  title TEXT NOT NULL,
  content_md TEXT NOT NULL,
  created_at INTEGER NOT NULL
);

CREATE TABLE IF NOT EXISTS kb_article_links (
  article_id INTEGER NOT NULL,
  problem_id INTEGER NOT NULL,
  PRIMARY KEY(article_id, problem_id),
  FOREIGN KEY(article_id) REFERENCES kb_articles(id) ON DELETE CASCADE,
  FOREIGN KEY(problem_id) REFERENCES problems(id) ON DELETE CASCADE
);

CREATE TABLE IF NOT EXISTS import_jobs (
  id INTEGER PRIMARY KEY AUTOINCREMENT,
  status TEXT NOT NULL,
  trigger TEXT NOT NULL DEFAULT 'manual',
  total_count INTEGER NOT NULL DEFAULT 0,
  processed_count INTEGER NOT NULL DEFAULT 0,
  success_count INTEGER NOT NULL DEFAULT 0,
  failed_count INTEGER NOT NULL DEFAULT 0,
  options_json TEXT NOT NULL DEFAULT '{}',
  last_error TEXT NOT NULL DEFAULT '',
  started_at INTEGER NOT NULL,
  finished_at INTEGER,
  updated_at INTEGER NOT NULL,
  created_at INTEGER NOT NULL
);

CREATE TABLE IF NOT EXISTS import_job_items (
  id INTEGER PRIMARY KEY AUTOINCREMENT,
  job_id INTEGER NOT NULL,
  source_path TEXT NOT NULL,
  status TEXT NOT NULL DEFAULT 'queued',
  title TEXT NOT NULL DEFAULT '',
  difficulty INTEGER NOT NULL DEFAULT 0,
  problem_id INTEGER,
  error_text TEXT NOT NULL DEFAULT '',
  started_at INTEGER,
  finished_at INTEGER,
  updated_at INTEGER NOT NULL,
  created_at INTEGER NOT NULL,
  FOREIGN KEY(job_id) REFERENCES import_jobs(id) ON DELETE CASCADE,
  UNIQUE(job_id, source_path)
);

CREATE TABLE IF NOT EXISTS problem_drafts (
  user_id INTEGER NOT NULL,
  problem_id INTEGER NOT NULL,
  language TEXT NOT NULL DEFAULT 'cpp',
  code TEXT NOT NULL DEFAULT '',
  stdin TEXT NOT NULL DEFAULT '',
  updated_at INTEGER NOT NULL,
  created_at INTEGER NOT NULL,
  PRIMARY KEY(user_id, problem_id),
  FOREIGN KEY(user_id) REFERENCES users(id) ON DELETE CASCADE,
  FOREIGN KEY(problem_id) REFERENCES problems(id) ON DELETE CASCADE
);

CREATE TABLE IF NOT EXISTS problem_solution_jobs (
  id INTEGER PRIMARY KEY AUTOINCREMENT,
  problem_id INTEGER NOT NULL,
  status TEXT NOT NULL DEFAULT 'queued',
  progress INTEGER NOT NULL DEFAULT 0,
  message TEXT NOT NULL DEFAULT '',
  created_by INTEGER NOT NULL DEFAULT 0,
  max_solutions INTEGER NOT NULL DEFAULT 3,
  created_at INTEGER NOT NULL,
  started_at INTEGER,
  finished_at INTEGER,
  updated_at INTEGER NOT NULL,
  FOREIGN KEY(problem_id) REFERENCES problems(id) ON DELETE CASCADE
);

CREATE TABLE IF NOT EXISTS problem_solutions (
  id INTEGER PRIMARY KEY AUTOINCREMENT,
  problem_id INTEGER NOT NULL,
  variant INTEGER NOT NULL DEFAULT 1,
  title TEXT NOT NULL DEFAULT '',
  idea_md TEXT NOT NULL DEFAULT '',
  explanation_md TEXT NOT NULL DEFAULT '',
  code_cpp TEXT NOT NULL DEFAULT '',
  complexity TEXT NOT NULL DEFAULT '',
  tags_json TEXT NOT NULL DEFAULT '[]',
  source TEXT NOT NULL DEFAULT 'llm',
  created_at INTEGER NOT NULL,
  updated_at INTEGER NOT NULL,
  FOREIGN KEY(problem_id) REFERENCES problems(id) ON DELETE CASCADE
);

CREATE INDEX IF NOT EXISTS idx_submissions_user_created_at ON submissions(user_id, created_at DESC);
CREATE INDEX IF NOT EXISTS idx_submissions_problem_created_at ON submissions(problem_id, created_at DESC);
CREATE INDEX IF NOT EXISTS idx_submissions_contest_user_created_at ON submissions(contest_id, user_id, created_at DESC);
CREATE INDEX IF NOT EXISTS idx_problem_tags_tag ON problem_tags(tag);
CREATE INDEX IF NOT EXISTS idx_kb_article_links_problem_id ON kb_article_links(problem_id);
CREATE INDEX IF NOT EXISTS idx_import_jobs_created_at ON import_jobs(created_at DESC);
CREATE INDEX IF NOT EXISTS idx_import_jobs_status ON import_jobs(status, updated_at DESC);
CREATE INDEX IF NOT EXISTS idx_import_job_items_job_status ON import_job_items(job_id, status, updated_at DESC);
CREATE INDEX IF NOT EXISTS idx_problem_drafts_updated ON problem_drafts(updated_at DESC);
CREATE INDEX IF NOT EXISTS idx_problem_solution_jobs_problem ON problem_solution_jobs(problem_id, created_at DESC);
CREATE INDEX IF NOT EXISTS idx_problem_solutions_problem ON problem_solutions(problem_id, variant, id);