package lib

import (
	"crypto/rand"
	"database/sql"
	"encoding/hex"
	"fmt"

	_ "github.com/tursodatabase/libsql-client-go/libsql"
)

var db *sql.DB

// GenerateNewID generates a DB with the format "prefix_randomstring".
func GenerateNewID(prefix string) string {
    randomBytes := make([]byte, 16)
    if _, err := rand.Read(randomBytes); err != nil {
        panic(err)
    }
    return fmt.Sprintf("%s_%s", prefix, hex.EncodeToString(randomBytes))
}

// Initialize the database connection
func InitializeDB(url, authToken string) error {
    var err error
    connectionString := fmt.Sprintf("%s?authToken=%s", url, authToken)
    db, err = sql.Open("libsql", connectionString)
    if err != nil {
        return fmt.Errorf("error opening database: %v", err)
    }

    // Test the connection
    err = db.Ping()
    if err != nil {
        return fmt.Errorf("error connecting to the database: %v", err)
    }

    return nil
}

func InitializeSchema() error {
    if db == nil {
        return fmt.Errorf("database not initialized")
    }

    migrations := []string{
        `CREATE TABLE IF NOT EXISTS users (
            id TEXT PRIMARY KEY,
            name TEXT NOT NULL,
            email TEXT UNIQUE NOT NULL,
            password TEXT NOT NULL
        )`,
        `CREATE TABLE IF NOT EXISTS rooms (
            id TEXT PRIMARY KEY,
            created_at TIMESTAMP DEFAULT CURRENT_TIMESTAMP,
            userId TEXT NOT NULL,
            roomName TEXT,
            topicName TEXT,
            visible BOOLEAN DEFAULT false,
            scale TEXT DEFAULT '0.5,1,2,3,5',
            FOREIGN KEY (userId) REFERENCES users(id)
        )`,
        `CREATE TABLE IF NOT EXISTS sessions (
            id TEXT PRIMARY KEY,
            user_id TEXT NOT NULL,
            created_at TIMESTAMP DEFAULT CURRENT_TIMESTAMP,
            expires_at TIMESTAMP NOT NULL,
            FOREIGN KEY (user_id) REFERENCES users(id)
        )`,
    }

    for _, migration := range migrations {
        _, err := db.Exec(migration)
        if err != nil {
            return fmt.Errorf("error executing migration: %v", err)
        }
    }

    return nil
}

// GetDB returns the database connection
func GetDB() *sql.DB {
    return db
}