import Database from "better-sqlite3";
import { mkdirSync } from "node:fs";
import { dirname } from "node:path";
import type { Env } from "../env.js";

export function openDb(env: Env): Database.Database {
  mkdirSync(dirname(env.DB_PATH), { recursive: true });
  const db = new Database(env.DB_PATH);
  db.pragma("journal_mode = WAL");
  migrate(db, env);
  return db;
}

function migrate(db: Database.Database, env: Env): void {
  db.exec(`
    CREATE TABLE IF NOT EXISTS devices (
      id INTEGER PRIMARY KEY AUTOINCREMENT,
      entity_id TEXT NOT NULL UNIQUE,
      name TEXT NOT NULL,
      kind TEXT NOT NULL CHECK (kind IN ('switch', 'number')),
      priority INTEGER NOT NULL,
      min_value REAL NOT NULL DEFAULT 0,
      max_value REAL NOT NULL DEFAULT 1,
      dwell_seconds INTEGER NOT NULL DEFAULT 300,
      manual_override INTEGER NOT NULL DEFAULT 0,
      shed INTEGER NOT NULL DEFAULT 0,
      last_changed_at TEXT
    );

    CREATE TABLE IF NOT EXISTS settings (
      key TEXT PRIMARY KEY,
      value TEXT NOT NULL
    );

    CREATE TABLE IF NOT EXISTS control_actions (
      id INTEGER PRIMARY KEY AUTOINCREMENT,
      timestamp_ms INTEGER NOT NULL,
      entity_id TEXT NOT NULL,
      action TEXT NOT NULL CHECK (action IN ('shed', 'restore')),
      reason TEXT NOT NULL
    );

    CREATE TABLE IF NOT EXISTS block_history (
      block_start_ms INTEGER PRIMARY KEY,
      average_w REAL NOT NULL
    );
  `);

  const existingTarget = db.prepare("SELECT value FROM settings WHERE key = 'target_kw'").get();
  if (!existingTarget) {
    db.prepare("INSERT INTO settings (key, value) VALUES ('target_kw', ?)").run(String(env.TARGET_KW));
  }

  const deviceColumns = new Set(
    (db.prepare("PRAGMA table_info(devices)").all() as { name: string }[]).map((c) => c.name),
  );
  if (!deviceColumns.has("only_when_sun")) {
    db.exec("ALTER TABLE devices ADD COLUMN only_when_sun INTEGER NOT NULL DEFAULT 0");
  }
  if (!deviceColumns.has("from_time")) {
    db.exec("ALTER TABLE devices ADD COLUMN from_time TEXT");
  }
  if (!deviceColumns.has("to_time")) {
    db.exec("ALTER TABLE devices ADD COLUMN to_time TEXT");
  }
  if (!deviceColumns.has("enable_url")) {
    db.exec("ALTER TABLE devices ADD COLUMN enable_url TEXT");
  }
  if (!deviceColumns.has("disable_url")) {
    db.exec("ALTER TABLE devices ADD COLUMN disable_url TEXT");
  }
}