package database

import (
	"context"
	"database/sql"
	"fmt"

	_ "modernc.org/sqlite"
)

// DB wraps sql.DB so the rest of the codebase has a single type to depend on.
type DB struct {
	*sql.DB
}

// Connect opens (or creates) the SQLite file at path and runs pragmas for
// safe, performant operation. Pass ":memory:" for tests.
func Connect(_ context.Context, path string) (*DB, error) {
	db, err := sql.Open("sqlite", path)
	if err != nil {
		return nil, fmt.Errorf("open sqlite: %w", err)
	}

	// WAL mode gives much better read concurrency without blocking reads
	// during writes. foreign_keys must be enabled per-connection in SQLite.
	pragmas := []string{
		"PRAGMA journal_mode=WAL;",
		"PRAGMA foreign_keys=ON;",
		"PRAGMA busy_timeout=5000;",
	}
	for _, p := range pragmas {
		if _, err := db.Exec(p); err != nil {
			return nil, fmt.Errorf("pragma %q: %w", p, err)
		}
	}

	if err := db.Ping(); err != nil {
		return nil, fmt.Errorf("ping sqlite: %w", err)
	}

	return &DB{db}, nil
}