/**
 * @module botbuilder-prompts
 */
/**
 * Copyright (c) Microsoft Corporation. All rights reserved.  
 * Licensed under the MIT License.
 */
import { Promiseable, Activity, TurnContext } from 'botbuilder';
import { ChoiceFactory, ChoiceFactoryOptions, Choice } from 'botbuilder-choices';
import { PromptValidator } from './textPrompt';
import { sendPrompt } from './internal';
import { ListStyle } from './choicePrompt';
import * as Recognizers from '@microsoft/recognizers-text-choice';

/** 
 * :package: **botbuilder-prompts**
 * 
 * Map of `ConfirmPrompt` choices for each locale the bot supports. 
 */
export interface ConfirmChoices {
    [locale:string]: (string|Choice)[];
}

/** 
 * :package: **botbuilder-prompts**
 * 
 * Prompts the user to answer a yes/no question. 
 * 
 * The [prompt()](#prompt) method will attempt to send a set of buttons yes/no buttons for the 
 * user to click. By default, the text of the titles for these buttons will always be in English 
 * but you can easily add support for other languages using the prompts [choices](#choices) 
 * property.   
 *
 * **Usage Example:**
 *
 * ```JavaScript
 * const { createConfirmPrompt } = require('botbuilder-prompts');
 * 
 * const confirmPrompt = createConfirmPrompt();
 * ```
 * @param O (Optional) type of result returned by the [recognize()](#recognize) method. This defaults to a boolean `true` or `false` but can be changed by the prompts custom validator.
 */
export interface ConfirmPrompt<O = boolean> {
    /** 
     * Allows for the localization of the confirm prompts yes/no choices to other locales besides 
     * english. The key of each entry is the languages locale code and should be lower cased. A
     * default fallback set of choices can be specified using a key of '*'. 
     * 
     * The default choices are configured to be `{ '*': ['yes', 'no'] }`. 
     * 
     * **Example usage:**
     * 
     * ```JavaScript
     * const confirmPrompt = createConfirmPrompt();
     * 
     * // Configure yes/no choices for english and spanish (default)
     * confirmPrompt.choices['*'] = ['sí', 'no'];
     * confirmPrompt.choices['es'] = ['sí', 'no'];
     * confirmPrompt.choices['en-us'] = ['yes', 'no'];
     * ```
     */
    choices: ConfirmChoices;

    /** 
     * Style of choices sent to user when [prompt()](#prompt) is called. Defaults to 
     * `ListStyle.auto`.
     */
    style: ListStyle;

    /** 
     * Additional options used to configure the output of the `ChoiceFactory`. Defaults to
     * `{ includeNumbers: false }`. 
     */
    choiceOptions: ChoiceFactoryOptions;

    /**
     * Sends a formated prompt to the user.
     * 
     * By default, this will attempt to send the user yes & no choices as buttons using 
     * `ChoiceFactory.forChannel()`. If the channel doesn't support buttons it will fallback to
     * appending ` (yes or no)` to the prompt. You can override this behavior using the prompts
     * [style](#style) property.
     * 
     * Further tweaks can be made to the rendering of the yes/no choices using the 
     * [choiceOptions](#choiceoptions) property. 
     *
     * **Usage Example:**
     *
     * ```JavaScript
     * await confirmPrompt.prompt(context, `This will cancel your order. Are you sure?`);
     * ```
     * @param context Context for the current turn of conversation.
     * @param prompt Text or activity to send as the prompt.
     * @param speak (Optional) SSML that should be spoken for prompt. The prompts `inputHint` will be automatically set to `expectingInput`.
     */
    prompt(context: TurnContext, prompt: string|Partial<Activity>, speak?: string): Promise<void>;

    /**
     * Recognizes and validates the users reply. The result of the call will either be the 
     * recognized value or `undefined`. 
     * 
     * The recognize() method will not automatically re-prompt the user so either the caller or the
     * prompts custom validator will need to implement re-prompting logic.
     *
     * **Usage Example:**
     *
     * ```JavaScript
     * const confirmed = await confirmPrompt.recognize(context);
     * if (typeof confirmed == 'boolean') {
     *    if (confirmed) {
     *       // User said yes
     *    } else {
     *       // User said no
     *    }
     * }
     * ```
     * @param context Context for the current turn of conversation.
     */
    recognize(context: TurnContext): Promise<O|undefined>;
}

/**
 * :package: **botbuilder-prompts**
 * 
 * Creates a new prompt that asks the user to answer a yes/no question.
 *
 * **Usage Example:**
 *
 * ```JavaScript
 * const { createConfirmPrompt } = require('botbuilder-prompts');
 * 
 * const confirmPrompt = createConfirmPrompt(async (context, confirmed) => {
 *    if (typeof confirmed != 'boolean') {
 *       await confirmPrompt.prompt(context, `Please answer "yes" or "no".`);
 *    }
 *    return confirmed; 
 * });
 * ```
 * @param O (Optional) type of result returned by the `recognize()` method. This defaults to a boolean `true` or `false` but can be changed by the prompts custom validator.
 * @param validator (Optional) validator for providing additional validation logic or customizing the prompt sent to the user when invalid.
 * @param defaultLocale (Optional) locale to use if `context.activity.locale` is not specified. Defaults to a value of `en-us`.
 */
export function createConfirmPrompt<O = boolean>(validator?: PromptValidator<O>, defaultLocale?: string): ConfirmPrompt<O> {
    return {
        choices: { '*': ['yes', 'no'] },        
        style: ListStyle.auto,
        choiceOptions: { includeNumbers: false },
        prompt: function prompt(context, prompt, speak) {
            // Get locale specific choices
            let locale = context.activity && context.activity.locale ? context.activity.locale.toLowerCase() : '*';
            if (!this.choices.hasOwnProperty(locale)) { locale = '*' }
            const choices = this.choices[locale];

            let msg: Partial<Activity>;
            if (typeof prompt !== 'object') {
                switch (this.style) {
                    case ListStyle.auto:
                    default:
                        msg = ChoiceFactory.forChannel(context, choices, prompt, speak, this.choiceOptions);
                        break;
                    case ListStyle.inline:
                        msg = ChoiceFactory.inline(choices, prompt, speak, this.choiceOptions);
                        break;
                    case ListStyle.list:
                        msg = ChoiceFactory.list(choices, prompt, speak, this.choiceOptions);
                        break;
                    case ListStyle.suggestedAction:
                        msg = ChoiceFactory.suggestedAction(choices, prompt, speak);
                        break;
                    case ListStyle.none:
                        msg = { type: 'message', text: prompt };
                        if (speak) { msg.speak = speak }
                        break;
                }
            } else {
                msg = Object.assign({}, prompt);
                if (speak) { msg.speak = speak }
            }
            return sendPrompt(context, msg)
        },
        recognize: function recognize(context) {
            const request = context.activity || {};
            const utterance = request.text || '';
            const locale =  request.locale || defaultLocale || 'en-us';
            const results = Recognizers.recognizeBoolean(utterance, locale);
            const value = results.length > 0 && results[0].resolution ? results[0].resolution.value : undefined;
            return Promise.resolve(validator ? validator(context, value) : value as any);
        }
    };
}