package db

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

    _ "modernc.org/sqlite"
)

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

type Store struct {
    *Queries
    db *sql.DB
}

func Open() (*Store, error) {
    home, err := os.UserHomeDir()
    if err != nil {
        return nil, fmt.Errorf("home dir: %w", err)
    }
    dir := filepath.Join(home, ".config", "ai-agent")
    if err := os.MkdirAll(dir, 0o755); err != nil {
        return nil, fmt.Errorf("create config dir: %w", err)
    }
    return OpenPath(filepath.Join(dir, "ai-agent.db"))
}

func OpenPath(path string) (*Store, error) {
    conn, err := sql.Open("sqlite", path+"?_journal_mode=WAL&_busy_timeout=5000&_foreign_keys=ON")
    if err != nil {
        return nil, fmt.Errorf("open db: %w", err)
    }
    if err := runMigrations(conn); err != nil {
        conn.Close()
        return nil, fmt.Errorf("migrations: %w", err)
    }
    return &Store{Queries: New(conn), db: conn}, nil
}

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

func (s *Store) DB() *sql.DB {
    return s.db
}

func runMigrations(conn *sql.DB) error {
    entries, err := migrations.ReadDir("migrations")
    if err != nil {
        return fmt.Errorf("read migrations dir: %w", err)
    }
    for _, entry := range entries {
        if entry.IsDir() {
            continue
        }
        data, err := migrations.ReadFile("migrations/" + entry.Name())
        if err != nil {
            return fmt.Errorf("read migration %s: %w", entry.Name(), err)
        }
        if _, err := conn.Exec(string(data)); err != nil {
            return fmt.Errorf("exec migration %s: %w", entry.Name(), err)
        }
    }
    return nil
}