package sqlite

import (
	"context"
	"database/sql"
	"fmt"
	"messenger/internal/models"
	//"time"
)

type UserRepository struct {
	db *DB
}

func NewUserRepository(db *DB) *UserRepository {
	return &UserRepository{db: db}
}

func (r *UserRepository) Create(ctx context.Context, user *models.User) error {
	query := `
		INSERT INTO users (login, password_hash, role, created_at)
		VALUES (?, ?, ?, ?)
		RETURNING id
	`
	
	err := r.db.QueryRowContext(ctx, query, user.Login, user.PasswordHash, user.Role, user.CreatedAt).Scan(&user.ID)
	if err != nil {
		return fmt.Errorf("failed to create user: %w", err)
	}
	
	return nil
}

func (r *UserRepository) FindByID(ctx context.Context, id int64) (*models.User, error) {
	query := `
		SELECT id, login, password_hash, role, last_seen, created_at
		FROM users
		WHERE id = ?
	`
	
	var user models.User
	var lastSeen sql.NullTime
	
	err := r.db.QueryRowContext(ctx, query, id).Scan(
		&user.ID, &user.Login, &user.PasswordHash, &user.Role,
		&lastSeen, &user.CreatedAt,
	)
	
	if err == sql.ErrNoRows {
		return nil, nil
	}
	if err != nil {
		return nil, fmt.Errorf("failed to find user by id: %w", err)
	}
	
	if lastSeen.Valid {
		user.LastSeen = &lastSeen.Time
	}
	
	return &user, nil
}

func (r *UserRepository) FindByLogin(ctx context.Context, login string) (*models.User, error) {
	query := `
		SELECT id, login, password_hash, role, last_seen, created_at
		FROM users
		WHERE login = ?
	`
	
	var user models.User
	var lastSeen sql.NullTime
	
	err := r.db.QueryRowContext(ctx, query, login).Scan(
		&user.ID, &user.Login, &user.PasswordHash, &user.Role,
		&lastSeen, &user.CreatedAt,
	)
	
	if err == sql.ErrNoRows {
		return nil, nil
	}
	if err != nil {
		return nil, fmt.Errorf("failed to find user by login: %w", err)
	}
	
	if lastSeen.Valid {
		user.LastSeen = &lastSeen.Time
	}
	
	return &user, nil
}

func (r *UserRepository) SearchByLogin(ctx context.Context, query string, limit int) ([]*models.User, error) {
	sqlQuery := `
		SELECT id, login, role, last_seen, created_at
		FROM users
		WHERE login LIKE ? || '%'
		ORDER BY login
		LIMIT ?
	`
	
	rows, err := r.db.QueryContext(ctx, sqlQuery, query, limit)
	if err != nil {
		return nil, fmt.Errorf("failed to search users: %w", err)
	}
	defer rows.Close()
	
	var users []*models.User
	for rows.Next() {
		var user models.User
		var lastSeen sql.NullTime
		
		err := rows.Scan(&user.ID, &user.Login, &user.Role, &lastSeen, &user.CreatedAt)
		if err != nil {
			return nil, fmt.Errorf("failed to scan user: %w", err)
		}
		
		if lastSeen.Valid {
			user.LastSeen = &lastSeen.Time
		}
		
		users = append(users, &user)
	}
	
	return users, nil
}

func (r *UserRepository) UpdateLastSeen(ctx context.Context, userID int64) error {
	query := `UPDATE users SET last_seen = CURRENT_TIMESTAMP WHERE id = ?`
	
	result, err := r.db.ExecContext(ctx, query, userID)
	if err != nil {
		return fmt.Errorf("failed to update last_seen: %w", err)
	}
	
	rows, err := result.RowsAffected()
	if err != nil {
		return err
	}
	
	if rows == 0 {
		return fmt.Errorf("user not found: %d", userID)
	}
	
	return nil
}

func (r *UserRepository) UpdateRole(ctx context.Context, userID int64, role models.UserRole) error {
	query := `UPDATE users SET role = ? WHERE id = ?`
	
	result, err := r.db.ExecContext(ctx, query, role, userID)
	if err != nil {
		return fmt.Errorf("failed to update role: %w", err)
	}
	
	rows, err := result.RowsAffected()
	if err != nil {
		return err
	}
	
	if rows == 0 {
		return fmt.Errorf("user not found: %d", userID)
	}
	
	return nil
}

func (r *UserRepository) Delete(ctx context.Context, userID int64) error {
	query := `DELETE FROM users WHERE id = ?`
	
	result, err := r.db.ExecContext(ctx, query, userID)
	if err != nil {
		return fmt.Errorf("failed to delete user: %w", err)
	}
	
	rows, err := result.RowsAffected()
	if err != nil {
		return err
	}
	
	if rows == 0 {
		return fmt.Errorf("user not found: %d", userID)
	}
	
	return nil
}

func (r *UserRepository) Exists(ctx context.Context, login string) (bool, error) {
	query := `SELECT EXISTS(SELECT 1 FROM users WHERE login = ?)`
	
	var exists bool
	err := r.db.QueryRowContext(ctx, query, login).Scan(&exists)
	if err != nil {
		return false, fmt.Errorf("failed to check user existence: %w", err)
	}
	
	return exists, nil
}