// Package db opens the SQLite database and holds the query layer.
package db

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

	_ "modernc.org/sqlite"
)

//go:embed schema.sql
var Schema string

// DB wraps *sql.DB. Other packages may run raw SQL through it.
type DB struct {
	*sql.DB
}

// Open opens (or creates) the database, applies schema.sql and migrations.
func Open(path string) (*DB, error) {
	sqlDB, err := sql.Open("sqlite", path+"?_pragma=journal_mode(WAL)&_pragma=busy_timeout(5000)&_pragma=foreign_keys(1)")
	if err != nil {
		return nil, err
	}
	// SQLite allows one writer. A single connection avoids SQLITE_BUSY
	// between goroutines; busy_timeout covers external writers.
	sqlDB.SetMaxOpenConns(1)
	d := &DB{sqlDB}
	if _, err := d.ExecContext(context.Background(), Schema); err != nil {
		return nil, fmt.Errorf("apply schema: %w", err)
	}
	if err := d.migrate(context.Background()); err != nil {
		return nil, fmt.Errorf("migrate: %w", err)
	}
	return d, nil
}