package database

import (
	"context"
	"database/sql"
	"fmt"
	"os"
	"path/filepath"
	"time"

	_ "modernc.org/sqlite"
)

func Open(path string) (*sql.DB, error) {
	directory := filepath.Dir(path)
	if directory != "." {
		if err := os.MkdirAll(directory, 0o750); err != nil {
			return nil, fmt.Errorf("create database directory: %w", err)
		}
	}
	db, err := sql.Open("sqlite", path+"?_pragma=foreign_keys(1)&_pragma=journal_mode(WAL)&_pragma=busy_timeout(5000)")
	if err != nil {
		return nil, err
	}
	db.SetMaxOpenConns(1)
	ctx, cancel := context.WithTimeout(context.Background(), 10*time.Second)
	defer cancel()
	if err := db.PingContext(ctx); err != nil {
		_ = db.Close()
		return nil, err
	}
	if err := migrate(ctx, db); err != nil {
		_ = db.Close()
		return nil, err
	}
	return db, nil
}

func migrate(ctx context.Context, db *sql.DB) error {
	const schema = `
CREATE TABLE IF NOT EXISTS users (
  id TEXT PRIMARY KEY,
  email TEXT NOT NULL UNIQUE COLLATE NOCASE,
  password_hash TEXT NOT NULL,
  created_at TEXT NOT NULL
);
CREATE TABLE IF NOT EXISTS refresh_tokens (
  id INTEGER PRIMARY KEY AUTOINCREMENT,
  token_hash TEXT NOT NULL UNIQUE,
  user_id TEXT NOT NULL REFERENCES users(id) ON DELETE CASCADE,
  expires_at TEXT NOT NULL,
  created_at TEXT NOT NULL,
  revoked_at TEXT
);
CREATE INDEX IF NOT EXISTS refresh_tokens_user_idx ON refresh_tokens(user_id);
CREATE TABLE IF NOT EXISTS records (
  user_id TEXT NOT NULL REFERENCES users(id) ON DELETE CASCADE,
  entity TEXT NOT NULL,
  record_id TEXT NOT NULL,
  payload TEXT,
  updated_at TEXT NOT NULL,
  deleted INTEGER NOT NULL DEFAULT 0,
  version INTEGER NOT NULL,
  PRIMARY KEY (user_id, entity, record_id)
);
CREATE TABLE IF NOT EXISTS changes (
  sequence INTEGER PRIMARY KEY AUTOINCREMENT,
  user_id TEXT NOT NULL REFERENCES users(id) ON DELETE CASCADE,
  entity TEXT NOT NULL,
  record_id TEXT NOT NULL,
  payload TEXT,
  updated_at TEXT NOT NULL,
  deleted INTEGER NOT NULL,
  version INTEGER NOT NULL
);
CREATE INDEX IF NOT EXISTS changes_user_sequence_idx ON changes(user_id, sequence);
`
	_, err := db.ExecContext(ctx, schema)
	return err
}