package com.github.jreddit.oauth.param;

import java.util.HashSet;
import java.util.Set;

/**
 * Builder for the scopes of a request.
 * 
 * @author Simon Kassing
 *
 */
public class RedditScopeBuilder {

    /** Set of reddit scopes. */
    private Set<RedditScope> scopes;
    
    public RedditScopeBuilder() {
        scopes = new HashSet<RedditScope>();
    }
    
    /**
     * Build a string for the request. Called upon by
     * <i>RedditToken</i> when requesting a token that
     * allows scope definition.
     * 
     * @return String list of the scopes
     */
    public String build() {
        
        // Add each scope to the scope list
        String s = "";
        for (RedditScope scope : scopes) {
            s += scope.value() + RedditScope.SEPARATOR;
        }
        
        // Remove final separator
        if (s.length() > 0) {
            s = s.substring(0, s.length() - RedditScope.SEPARATOR.length());
        }
        
        // Return scope list
        return s;
        
    }
    
    /**
     * Add a scope to the builder. If the scope has already 
     * been added, it will not be added double.
     * 
     * @param scope Reddit scope
     * 
     * @return This builder
     */
    public RedditScopeBuilder addScope(RedditScope scope) {
        scopes.add(scope);
        return this;
    }
    
    /**
     * Add multiple scopes to the builder. If a scope has already 
     * been added, it will not be added double.
     * 
     * @param scopes Multiple scopes
     * 
     * @return This builder
     */
    public RedditScopeBuilder addScopes(RedditScope... scopes) {
        for (RedditScope scope : scopes) {
            addScope(scope);
        }
        return this;
    }
    
    /**
     * Remove a scope from the builder.
     * 
     * @param scope Reddit scope
     * 
     * @return This builder
     */
    public RedditScopeBuilder removeScope(RedditScope scope) {
        scopes.remove(scope);
        return this;
    }
    
    /**
     * Remove multiple scopes from the builder.
     * 
     * @param scopes Multiple scopes
     * 
     * @return This builder
     */
    public RedditScopeBuilder removeScopes(RedditScope... scopes) {
        for (RedditScope scope : scopes) {
            removeScope(scope);
        }
        return this;
    }
    
}