import Database from 'better-sqlite3';
import fs from 'node:fs';
import path from 'node:path';
import { DB_PATH } from '../config.js';

const SCHEMA = `
CREATE TABLE IF NOT EXISTS meta (
  key   TEXT PRIMARY KEY,
  value TEXT NOT NULL
);

CREATE TABLE IF NOT EXISTS items (
  unique_name       TEXT PRIMARY KEY,   -- e.g. T4_BAG@1
  base_name         TEXT NOT NULL,      -- e.g. T4_BAG
  enchantment       INTEGER NOT NULL DEFAULT 0,
  tier              INTEGER,
  weight            REAL,
  item_value        INTEGER,
  shop_category     TEXT,
  shop_subcategory  TEXT,
  crafting_category TEXT,
  name_en           TEXT
);
CREATE INDEX IF NOT EXISTS idx_items_base ON items(base_name);
CREATE INDEX IF NOT EXISTS idx_items_name_en ON items(name_en);

CREATE TABLE IF NOT EXISTS recipes (
  id             INTEGER PRIMARY KEY AUTOINCREMENT,
  output_item    TEXT NOT NULL,
  variant        INTEGER NOT NULL DEFAULT 0,  -- alternative recipe index for the same output
  amount_crafted REAL NOT NULL DEFAULT 1,
  silver_cost    REAL NOT NULL DEFAULT 0,
  focus_cost     REAL NOT NULL DEFAULT 0,
  source         TEXT NOT NULL DEFAULT 'crafting'  -- 'crafting' | 'upgrade' (enchanting)
);
CREATE INDEX IF NOT EXISTS idx_recipes_output ON recipes(output_item);

CREATE TABLE IF NOT EXISTS recipe_inputs (
  recipe_id         INTEGER NOT NULL REFERENCES recipes(id) ON DELETE CASCADE,
  input_item        TEXT NOT NULL,
  count             REAL NOT NULL,
  max_return_amount REAL,  -- 0 means the resource is never returned (e.g. artifacts)
  PRIMARY KEY (recipe_id, input_item)
);
CREATE INDEX IF NOT EXISTS idx_recipe_inputs_item ON recipe_inputs(input_item);
`;

let db: Database.Database | null = null;

export function getDb(): Database.Database {
  if (!db) {
    fs.mkdirSync(path.dirname(DB_PATH), { recursive: true });
    db = new Database(DB_PATH);
    db.pragma('journal_mode = WAL');
    db.pragma('foreign_keys = ON');
    db.exec(SCHEMA);
  }
  return db;
}

export function getMeta(key: string): string | null {
  const row = getDb().prepare('SELECT value FROM meta WHERE key = ?').get(key) as
    | { value: string }
    | undefined;
  return row?.value ?? null;
}

export function setMeta(key: string, value: string): void {
  getDb()
    .prepare('INSERT INTO meta (key, value) VALUES (?, ?) ON CONFLICT(key) DO UPDATE SET value = excluded.value')
    .run(key, value);
}