package store

import (
	"database/sql"
	"embed"
	"fmt"
	"os"
	"path/filepath"

	_ "modernc.org/sqlite"
)

//go:embed migrations/*.sql
var migrationsFS embed.FS

type Store struct {
	DB      *sql.DB
	DataDir string
}

func Open(dataDir string) (*Store, error) {
	if err := os.MkdirAll(filepath.Join(dataDir, "artifacts"), 0o755); err != nil {
		return nil, fmt.Errorf("create data dir: %w", err)
	}
	dbPath := filepath.Join(dataDir, "artifacto.db")
	dsn := "file:" + dbPath + "?_pragma=journal_mode(WAL)&_pragma=foreign_keys(ON)&_pragma=busy_timeout(5000)"
	db, err := sql.Open("sqlite", dsn)
	if err != nil {
		return nil, fmt.Errorf("open db: %w", err)
	}
	db.SetMaxOpenConns(1)
	if err := db.Ping(); err != nil {
		return nil, fmt.Errorf("ping db: %w", err)
	}
	s := &Store{DB: db, DataDir: dataDir}
	if err := s.migrate(); err != nil {
		return nil, fmt.Errorf("migrate: %w", err)
	}
	return s, nil
}

func (s *Store) Close() error { return s.DB.Close() }

func (s *Store) migrate() error {
	entries, err := migrationsFS.ReadDir("migrations")
	if err != nil {
		return err
	}
	for _, e := range entries {
		if e.IsDir() {
			continue
		}
		b, err := migrationsFS.ReadFile("migrations/" + e.Name())
		if err != nil {
			return err
		}
		if _, err := s.DB.Exec(string(b)); err != nil {
			return fmt.Errorf("apply %s: %w", e.Name(), err)
		}
	}
	return nil
}

func (s *Store) ArtifactPath(slug string) string {
	return filepath.Join(s.DataDir, "artifacts", slug+".html")
}

func (s *Store) MetaGet(key string) (string, error) {
	var v string
	err := s.DB.QueryRow(`SELECT value FROM meta WHERE key = ?`, key).Scan(&v)
	if err == sql.ErrNoRows {
		return "", nil
	}
	return v, err
}

func (s *Store) MetaSet(key, value string) error {
	_, err := s.DB.Exec(`INSERT INTO meta(key,value) VALUES(?,?) ON CONFLICT(key) DO UPDATE SET value=excluded.value`, key, value)
	return err
}