/** @module config */
/** @hidden */
let _ = require('lodash');

import { StringValueMap } from '../data/StringValueMap';
import { RecursiveObjectReader } from '../reflect/RecursiveObjectReader';

/**
 * Contains a key-value map with configuration parameters. 
 * All values stored as strings and can be serialized as JSON or string forms.
 * When retrieved the values can be automatically converted on read using GetAsXXX methods.
 *
 * The keys are case-sensitive, so it is recommended to use consistent C-style as: <code>"my_param"</code>
 *  
 * Configuration parameters can be broken into sections and subsections using dot notation as:
 * <code>"section1.subsection1.param1"</code>. Using GetSection method all parameters from specified section
 * can be extracted from a ConfigMap.
 * 
 * The ConfigParams supports serialization from/to plain strings as:
 * <code>"key1=123;key2=ABC;key3=2016-09-16T00:00:00.00Z"</code>
 * 
 * ConfigParams are used to pass configurations to [[IConfigurable]] objects.
 * They also serve as a basis for more concrete configurations such as [[https://pip-services3-node.github.io/pip-services3-components-node/classes/connect.connectionparams.html ConnectionParams]]
 * or [[https://pip-services3-node.github.io/pip-services3-components-node/classes/auth.credentialparams.html CredentialParams]] (in the Pip.Services components package).
 * 
 * @see [[IConfigurable]]
 * @see [[StringValueMap]]
 * 
 * ### Example ###
 * 
 *     let config = ConfigParams.fromTuples(
 *         "section1.key1", "AAA",
 *         "section1.key2", 123,
 *         "section2.key1", true
 *     );
 *             
 *     config.getAsString("section1.key1"); // Result: AAA
 *     config.getAsInteger("section1.key1"); // Result: 0
 *     
 *     section1 = config.getSection("section1");
 *     section1.toString(); // Result: key1=AAA;key2=123
 *  
 */
export class ConfigParams extends StringValueMap {

	/**
	 * Creates a new ConfigParams and fills it with values.
	 * 
	 * @param values 	(optional) an object to be converted into key-value pairs to initialize this config map.
	 * 
	 * @see [[StringValueMap.constructor]]
	 */
	public constructor(values: any = null) {
		super(values);
	}

	/**
	 * Gets a list with all 1st level section names.
	 * 
	 * @returns a list of section names stored in this ConfigMap.
	 */
	public getSectionNames(): string[] {
		let sections: string[] = [];

		for (let key in this) {
			if (this.hasOwnProperty(key)) {
				let pos = key.indexOf('.');
				let section: string = key;
				if (pos > 0)
					section = key.substring(0, pos);

				// Perform case sensitive search
				let found = false;
				for (let index = 0; index < sections.length; index++) {
					if (section == sections[index]) {
						found = true;
						break;
					}
				}

				if (!found)
					sections.push(section);
			}
		}

		return sections;
	}

	/**
	 * Gets parameters from specific section stored in this ConfigMap.
	 * The section name is removed from parameter keys.
	 * 
	 * @param section	name of the section to retrieve configuration parameters from.
	 * @returns 		all configuration parameters that belong to the section named 'section'. 
	 */
	public getSection(section: string): ConfigParams {
		let result = new ConfigParams();
		let prefix = section + ".";

		for (let key in this) {
			if (this.hasOwnProperty(key)) {
				// Prevents exception on the next line
				if (key.length < prefix.length)
					continue;

				// Perform case sensitive match
				let keyPrefix = key.substring(0, prefix.length);
				if (keyPrefix == prefix) {
					let name = key.substring(prefix.length);
					result.put(name, this[key]);
				}
			}
		}

		return result;
	}

	/**
	 * Adds parameters into this ConfigParams under specified section.
	 * Keys for the new parameters are appended with section dot prefix.
	 * 
	 * @param section 			name of the section where add new parameters
	 * @param sectionParams 	new parameters to be added.
	 */
	public addSection(section: string, sectionParams: ConfigParams): void {
		if (section == null)
			throw new Error("Section name cannot be null");

		if (sectionParams != null) {
			for (let key in sectionParams) {
				if (sectionParams.hasOwnProperty(key)) {
					let name = key;

					if (name.length > 0 && section.length > 0)
						name = section + "." + name;
					else if (name.length == 0)
						name = section;

					let value = sectionParams[key];

					this.put(name, value);
				}
			}
		}
	}

	/**
	 * Overrides parameters with new values from specified ConfigParams
	 * and returns a new ConfigParams object.
	 * 
	 * @param configParams		ConfigMap with parameters to override the current values.
	 * @returns					a new ConfigParams object.
	 * 
	 * @see [[setDefaults]]
	 */
	public override(configParams: ConfigParams): ConfigParams {
		let map = StringValueMap.fromMaps(this, configParams);
		return new ConfigParams(map);
	}

	/**
	 * Set default values from specified ConfigParams and returns a new ConfigParams object.
	 * 
	 * @param defaultConfigParams	ConfigMap with default parameter values.
	 * @returns						a new ConfigParams object.
	 * 
	 * @see [[override]]
	 */
	public setDefaults(defaultConfigParams: ConfigParams): ConfigParams {
		let map = StringValueMap.fromMaps(defaultConfigParams, this);
		return new ConfigParams(map);
	}

	/**
	 * Creates a new ConfigParams object filled with key-value pairs from specified object.
	 * 
	 * @param value		an object with key-value pairs used to initialize a new ConfigParams.
	 * @returns			a new ConfigParams object.
	 */
	public static fromValue(value: any): ConfigParams {
		let map = RecursiveObjectReader.getProperties(value);
		return new ConfigParams(map);
	}

	/**
	 * Creates a new ConfigParams object filled with provided key-value pairs called tuples.
	 * Tuples parameters contain a sequence of key1, value1, key2, value2, ... pairs.
	 * 
	 * @param tuples	the tuples to fill a new ConfigParams object.
	 * @returns			a new ConfigParams object.
	 * 
	 * @see [[StringValueMap.fromTuplesArray]]
	 */
	public static fromTuples(...tuples: any[]): ConfigParams {
		let map = StringValueMap.fromTuplesArray(tuples);
		return new ConfigParams(map);
	}

	/**
	 * Creates a new ConfigParams object filled with key-value pairs serialized as a string.
	 * 
	 * @param line 		a string with serialized key-value pairs as "key1=value1;key2=value2;..."
	 * 					Example: "Key1=123;Key2=ABC;Key3=2016-09-16T00:00:00.00Z"
	 * @returns			a new ConfigParams object.
	 * 
	 * @see [[StringValueMap.fromString]]
	 */
	public static fromString(line: string): ConfigParams {
		let map = StringValueMap.fromString(line);
		return new ConfigParams(map);
	}

	/**
	 * Merges two or more ConfigParams into one. The following ConfigParams override
	 * previously defined parameters.
	 * 
	 * @param configs 	a list of ConfigParams objects to be merged.
	 * @returns			a new ConfigParams object.
	 * 
	 * @see [[StringValueMap.fromMaps]]
	 */
	public static mergeConfigs(...configs: ConfigParams[]): ConfigParams {
		let map = StringValueMap.fromMaps(...configs);
		return new ConfigParams(map);
	}
}