/** @module config */
import { StringValueMap } from 'pip-services4-commons-node';
import { RecursiveObjectReader } from 'pip-services4-commons-node';

/**
 * 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-services4-node.github.io/pip-services4-components-node/classes/connect.connectionparams.html ConnectionParams]]
 * or [[https://pip-services4-node.github.io/pip-services4-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[] {
        const sections: string[] = [];

        for (const key in this) {
            if (Object.prototype.hasOwnProperty.call(this, key)) {
                const 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 {
        const result = new ConfigParams();
        const prefix = section + ".";

        for (const key in this) {
            if (Object.prototype.hasOwnProperty.call(this, key)) {
                // Prevents exception on the next line
                if (key.length < prefix.length) {
                    continue;
                }

                // Perform case sensitive match
                const keyPrefix = key.substring(0, prefix.length);
                if (keyPrefix == prefix) {
                    const 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 (const key in sectionParams) {
                if (Object.prototype.hasOwnProperty.call(sectionParams, key)) {
                    let name = key;

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

                    const 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 {
        const 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 {
        const 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 {
        const 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 {
        const 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 {
        const 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 {
        const map = StringValueMap.fromMaps(...configs);
        return new ConfigParams(map);
    }
}