'use strict';

/**
 * Module dependencies.
 */

var buddy = require('co-body');
var forms = require('formidable');

var qs = require('qs');

/**
 * Expose `requestbody()`.
 */

module.exports = requestbody;

/**
 *
 * @param {Object} options
 * @see https://github.com/dlau/koa-body
 * @api public
 */
function requestbody(opts) {
    opts = opts || {};
    opts.patchNode = 'patchNode' in opts ? opts.patchNode : false;
    opts.patchKoa = 'patchKoa' in opts ? opts.patchKoa : true;
    opts.multipart = 'multipart' in opts ? opts.multipart : false;
    opts.encoding = 'encoding' in opts ? opts.encoding : 'utf-8';
    opts.jsonLimit = 'jsonLimit' in opts ? opts.jsonLimit : '1mb';
    opts.formLimit = 'formLimit' in opts ? opts.formLimit : '56kb';
    opts.formidable = 'formidable' in opts ? opts.formidable : {};
    opts.textLimit = 'textLimit' in opts ? opts.textLimit : '56kb';
    opts.strict = 'strict' in opts ? opts.strict : true;

    return function*(next) {
        var body = {};
        // so don't parse the body in strict mode
        if (!opts.strict || ["GET", "HEAD", "DELETE"].indexOf(this.method.toUpperCase()) === -1) {
            if (this.is('json')) {
                body = yield buddy.json(this, {
                    encoding: opts.encoding,
                    limit: opts.jsonLimit
                });
            } else if (this.is('urlencoded')) {
                body = yield buddy.form(this, {
                    encoding: opts.encoding,
                    limit: opts.formLimit
                });
            } else if (this.is('text')) {
                body = yield buddy.text(this, {
                    encoding: opts.encoding,
                    limit: opts.textLimit
                });
            } else if (opts.multipart && this.is('multipart')) {
                body = yield formy(this, opts.formidable);
            }
        }

        if (opts.patchNode) {
            this.req.body = body;
        }
        if (opts.patchKoa) {
            this.request.body = body;
        }
        yield next;
    };
}

/**
 * Donable formidable
 *
 * @param  {Stream} ctx
 * @param  {Object} opts
 * @return {Object}
 * @api private
 */
function formy(ctx, opts) {
    return function(done) {
        var fields = {};
        var files = {};
        var fieldsArray = [];
        var form = new forms.IncomingForm(opts)
        form
            .on('end', function() {
                fields = qs.parse(fieldsArray.join('&'), {decoder: decodeURIComponent});
                if (Object.keys(files).length !== 0) {
                    fields._files = files;
                }
                done(null, fields);
            })
            .on('error', function(err) {
                done(err);
            })
            .on('field', function(field, value) {
                // if (fields[field]) {
                //     if (Array.isArray(fields[field])) {
                //         fields[field].push(value);
                //     } else {
                //         fields[field] = [fields[field], value];
                //     }
                // } else {
                //
                //     fields[field] = value;
                // }
                fieldsArray.push(field + '=' + encodeURIComponent(value));
            })
            .on('file', function(field, file) {
                if (files[field]) {
                    if (Array.isArray(files[field])) {
                        files[field].push(file);
                    } else {
                        files[field] = [files[field], file];
                    }
                } else {
                    files[field] = file;
                }
            });
        if (opts.onFileBegin) {
            form.on('fileBegin', opts.onFileBegin);
        }
        form.parse(ctx.req);
    };
}