package database

import (
	"database/sql"
	"fmt"
	"os"
	"time"

	_ "github.com/lib/pq"
)

func Connect() (*sql.DB, error) {
	dbHost := getEnv("DB_HOST", "localhost")
	dbPort := getEnv("DB_PORT", "5432")
	dbUser := getEnv("DB_USER", "postgres")
	dbPassword := getEnv("DB_PASSWORD", "")
	dbName := getEnv("DB_NAME", "backend_template")
	sslMode := getEnv("DB_SSL_MODE", "disable")

	connStr := fmt.Sprintf("host=%s port=%s user=%s password=%s dbname=%s sslmode=%s",
		dbHost, dbPort, dbUser, dbPassword, dbName, sslMode)

	db, err := sql.Open("postgres", connStr)
	if err != nil {
		return nil, err
	}

	// Verify connection
	if err = db.Ping(); err != nil {
		return nil, err
	}

	return db, nil
}

func FindUserByID(db *sql.DB, id string) (*User, error) {
	var user User
	var createdAtUnix, updatedAtUnix int64

	err := db.QueryRow(`
		SELECT id, username, email, password_hash, 
		       EXTRACT(EPOCH FROM created_at)::bigint, 
		       EXTRACT(EPOCH FROM updated_at)::bigint 
		FROM user_auth 
		WHERE id = $1
	`, id).Scan(
		&user.ID, &user.Username, &user.Email, &user.PasswordHash,
		&createdAtUnix, &updatedAtUnix,
	)

	if err == sql.ErrNoRows {
		return nil, nil
	}
	if err != nil {
		return nil, err
	}

	user.CreatedAt = timeFromUnix(createdAtUnix)
	user.UpdatedAt = timeFromUnix(updatedAtUnix)

	return &user, nil
}

func FindUserByUsername(db *sql.DB, username string) (*User, error) {
	var user User
	var createdAtUnix, updatedAtUnix int64

	err := db.QueryRow(`
		SELECT id, username, email, password_hash, 
		       EXTRACT(EPOCH FROM created_at)::bigint, 
		       EXTRACT(EPOCH FROM updated_at)::bigint 
		FROM user_auth 
		WHERE username = $1
	`, username).Scan(
		&user.ID, &user.Username, &user.Email, &user.PasswordHash,
		&createdAtUnix, &updatedAtUnix,
	)

	if err == sql.ErrNoRows {
		return nil, nil
	}
	if err != nil {
		return nil, err
	}

	user.CreatedAt = timeFromUnix(createdAtUnix)
	user.UpdatedAt = timeFromUnix(updatedAtUnix)

	return &user, nil
}

func getEnv(key, defaultValue string) string {
	if value := os.Getenv(key); value != "" {
		return value
	}
	return defaultValue
}

func timeFromUnix(timestamp int64) time.Time {
	return time.Unix(timestamp, 0)
}