import { DatabaseSync } from 'node:sqlite';
import { mkdirSync } from 'node:fs';

// Schema for the private incident notebook and the Git fix-candidate inbox.
// Deployment-receipt tables live in receipts.mjs, next to the code that
// actually owns that data — this file only owns the notebook's own shape.
const SCHEMA = `
PRAGMA journal_mode=WAL;
PRAGMA foreign_keys=ON;
CREATE TABLE IF NOT EXISTS incidents(
  id TEXT PRIMARY KEY,
  title TEXT NOT NULL,
  project TEXT,
  status TEXT NOT NULL DEFAULT 'investigating',
  severity TEXT NOT NULL DEFAULT 'annoyance',
  detected_at TEXT NOT NULL,
  symptom TEXT NOT NULL,
  impact TEXT DEFAULT '',
  root_cause TEXT DEFAULT '',
  confidence TEXT DEFAULT 'unknown',
  fix TEXT DEFAULT '',
  verification TEXT DEFAULT '',
  prevention TEXT DEFAULT '',
  remaining_risk TEXT DEFAULT '',
  lesson TEXT DEFAULT '',
  public_summary TEXT DEFAULT '',
  created_at TEXT NOT NULL,
  updated_at TEXT NOT NULL
);
CREATE TABLE IF NOT EXISTS timeline(
  id INTEGER PRIMARY KEY AUTOINCREMENT,
  incident_id TEXT NOT NULL REFERENCES incidents(id) ON DELETE CASCADE,
  at TEXT NOT NULL,
  kind TEXT NOT NULL,
  body TEXT NOT NULL
);
CREATE TABLE IF NOT EXISTS hypotheses(
  id INTEGER PRIMARY KEY AUTOINCREMENT,
  incident_id TEXT NOT NULL REFERENCES incidents(id) ON DELETE CASCADE,
  statement TEXT NOT NULL,
  status TEXT NOT NULL DEFAULT 'untested',
  evidence TEXT DEFAULT ''
);
CREATE TABLE IF NOT EXISTS candidates(
  id INTEGER PRIMARY KEY AUTOINCREMENT,
  repo TEXT NOT NULL,
  sha TEXT NOT NULL,
  committed_at TEXT NOT NULL,
  subject TEXT NOT NULL,
  paths TEXT DEFAULT '',
  reason TEXT NOT NULL,
  state TEXT NOT NULL DEFAULT 'new',
  incident_id TEXT,
  UNIQUE(repo, sha)
);`;

// Additive, best-effort migrations for columns that shipped after the
// initial schema. SQLite has no "ADD COLUMN IF NOT EXISTS", so each one is
// tried and a "duplicate column" failure is the expected steady state once
// it's already applied everywhere.
const MIGRATIONS = [
  "ALTER TABLE incidents ADD COLUMN published_at TEXT DEFAULT ''",
  "ALTER TABLE incidents ADD COLUMN public_slug TEXT DEFAULT ''",
];

export function openDb(path = 'data/trace.db') {
  mkdirSync('data', { recursive: true });
  mkdirSync('data/exports', { recursive: true });
  const db = new DatabaseSync(path);
  db.exec(SCHEMA);
  for (const sql of MIGRATIONS) {
    try {
      db.exec(sql);
    } catch (error) {
      if (!String(error.message).includes('duplicate column')) throw error;
    }
  }
  return db;
}