import React from 'react';

import { Files } from '../model/';
import { notify, upload } from '../helpers/';
import Path from 'path';
import { Observable } from "rxjs/Observable";
import { t } from '../locales/';

export const sort = function(files, type){
    if(type === 'name'){
        return sortByName(files);
    }else if(type === 'date'){
        return sortByDate(files);
    }else{
        return sortByType(files);
    }
    function sortByType(files){
        return files.sort((fileA, fileB) => {
            if(fileA.icon === 'loading' && fileB.icon !== 'loading'){return +1;}
            else if(fileA.icon !== 'loading' && fileB.icon === 'loading'){return -1;}
            else{
                if(['directory', 'link'].indexOf(fileA.type) === -1 && ['directory', 'link'].indexOf(fileB.type) !== -1){
                    return +1;
                }else if(['directory', 'link'].indexOf(fileA.type) !== -1 && ['directory', 'link'].indexOf(fileB.type) === -1){
                    return -1;
                }else{
                    if(fileA.name[0] === "." && fileB.name[0] !== ".") return +1;
                    else if(fileA.name[0] !== "." && fileB.name[0] === ".") return -1;
                    else{
                        const aExt = Path.extname(fileA.name.toLowerCase()),
                              bExt = Path.extname(fileB.name.toLowerCase());
                        if(fileA.name.toLowerCase() === fileB.name.toLowerCase()){
                            return fileA.name > fileB.name ? +1 : -1;
                        }else{
                            if(aExt !== bExt) return aExt > bExt ? +1 : -1;
                            else return fileA.name.toLowerCase() > fileB.name.toLowerCase() ? +1 : -1;
                        }
                    }
                }
            }
        });
    }
    function sortByName(files){
        return files.sort((fileA, fileB) => {
            if(fileA.icon === 'loading' && fileB.icon !== 'loading'){return +1;}
            else if(fileA.icon !== 'loading' && fileB.icon === 'loading'){return -1;}
            else{
                if(fileA.name[0] === "." && fileB.name[0] !== ".") return +1;
                else if(fileA.name[0] !== "." && fileB.name[0] === ".") return -1;
                else{
                    if(fileA.name.toLowerCase() === fileB.name.toLowerCase()){
                        return fileA.name > fileB.name ? +1 : -1;
                    }
                    return fileA.name.toLowerCase() > fileB.name.toLowerCase() ? +1 : -1;
                }
            }
        });
    }
    function sortByDate(files){
        return files.sort((fileA, fileB) => {
            if(fileA.icon === 'loading' && fileB.icon !== 'loading'){return +1;}
            else if(fileA.icon !== 'loading' && fileB.icon === 'loading'){return -1;}
            else{
                if(fileB.time === fileA.time){
                    return fileA.name > fileB.name ? +1 : -1;
                }
                return fileB.time - fileA.time;
            }
        });
    }
};

export const onCreate = function(path, type, file){
    if(type === 'file'){
        return Files.touch(path, file)
            .then(() => {
                notify.send(t('A file named "{{VALUE}}" was created', Path.basename(path)), 'success');
                return Promise.resolve();
            })
            .catch((err) => {
                notify.send(err, 'error');
                return Promise.reject(err);
            });
    }else if(type === 'directory'){
        return Files.mkdir(path)
            .then(() => notify.send(t('A folder named "{{VALUE}}" was created"', Path.basename(path)), 'success'))
            .catch((err) => notify.send(err, 'error'));
    }else{
        return Promise.reject({message: t('internal error: can\'t create a {{VALUE}}', type.toString()), code: 'UNKNOWN_TYPE'});
    }
};

export const onRename = function(from, to, type){
    return Files.mv(from, to, type)
        .then(() => notify.send(t('The file "{{VALUE}}" was renamed', Path.basename(from)), 'success'))
        .catch((err) => notify.send(err, 'error'));
};

export const onDelete = function(path, type){
    return Files.rm(path, type)
        .then(() => notify.send(t('The file {{VALUE}} was deleted"', Path.basename(path)), 'success'))
        .catch((err) => notify.send(err, 'error'));
};

export const onMultiDelete = function(arrOfPath){
    return Promise.all(arrOfPath.map((p) => Files.rm(p)))
        .then(() => notify.send(t('All done!'), 'success'))
        .catch((err) => notify.send(err, 'error'));
}

export const onMultiRename = function(arrOfPath){
    return Promise.all(arrOfPath.map((p) => Files.mv(p[0], p[1])))
        .then(() => notify.send(t('All done!'), 'success'))
        .catch((err) => notify.send(err, 'error'));
}

/*
 * The upload method has a few strategies:
 * 1. user is coming from drag and drop + browser provides support to read entire folders
 * 2. user is coming from drag and drop + browser DOES NOT provides support to read entire folders
 * 3. user is coming from a upload form button as he doesn't have drag and drop with files
 */
export const onUpload = function(path, e){
    let extractFiles = null;
    if(e.dataTransfer === undefined){ // case 3
        extractFiles = extract_upload_crappy_hack_but_official_way(e.target);
    } else {
        if(e.dataTransfer.types && e.dataTransfer.types.length >= 0){
            if(e.dataTransfer.types[0] === "text/uri-list"){
                return
            }
        }
        extractFiles = extract_upload_directory_the_way_that_works_but_non_official(e.dataTransfer.items || [], []) // case 1
            .then((files) => {
                if(files.length === 0){ // case 2
                    return extract_upload_crappy_hack_but_official_way(e.dataTransfer);
                }
                return Promise.resolve(files);
            })
    }

    extractFiles.then((files) => upload.add(path, files));

    // adapted from: https://stackoverflow.com/questions/105034/create-guid-uuid-in-javascript
    function _rand_id(){
        function s4() {
            return Math.floor((1 + Math.random()) * 0x10000)
                .toString(16)
                .substring(1);
        }
        return s4() + s4() + s4() + s4();
    }

    function extract_upload_directory_the_way_that_works_but_non_official(items, files = []){
        const traverseDirectory = (item, _files, parent_id) => {
            let file = {
                path: item.fullPath
            };
            if(item.isFile){
                return new Promise((done, err) => {
                    file.type = "file";
                    item.file((_file, _err) => {
                        if(!_err){
                            file.file = _file;
                            if(parent_id) file._prior = parent_id;
                            _files.push(file);
                        }
                        done(_files);
                    });
                });
            }else if(item.isDirectory){
                file.type = "directory";
                file.path += "/";
                file._id = _rand_id();
                if(parent_id) file._prior = parent_id;
                _files.push(file);

                let reader = item.createReader();
                const filereader = function(r){
                    return new Promise((done) => {
                        r.readEntries(function(entries){
                            Promise.all(entries.map((entry) => {
                                return traverseDirectory(entry, _files, file._id);
                            })).then((e) => {
                                if(entries.length > 0){
                                    return filereader(r).then(done);
                                }
                                return done(e);
                            })
                        });
                    });
                }
                return filereader(reader).then(() => {
                    return Promise.resolve(_files)
                });
            }else{
                return Promise.resolve();
            }
        };
        return Promise.all(
            Array.prototype.slice.call(items).map((item) => {
                if(typeof item.webkitGetAsEntry === 'function'){
                    return traverseDirectory(item.webkitGetAsEntry(), files.slice(0));
                }
            }).filter((e) => e)
        ).then((res) => Promise.resolve([].concat.apply([], res)));
    }

    function extract_upload_crappy_hack_but_official_way(data){
        const _files = data.files;
        return Promise.all(
            Array.prototype.slice.call(_files).map((_file) => {
                return detectType(_file)
                    .then(transform);
                function detectType(_f){
                    // the 4096 is an heuristic I've observed and taken from: https://stackoverflow.com/questions/25016442/how-to-distinguish-if-a-file-or-folder-is-being-dragged-prior-to-it-being-droppe
                    // however the proposed answer is just wrong as it doesn't consider folder with name such as: test.png
                    // and as Stackoverflow favor consanguinity with their point system, I couldn't rectify the proposed answer.
                    // The following code is actually working as expected
                    if(_file.size % 4096 !== 0){
                        return Promise.resolve('file');
                    }
                    return new Promise((done, err) => {
                        let reader = new window.FileReader();
                        reader.onload = function() {
                            done('file');
                        };
                        reader.onerror = function() {
                            done('directory');
                        };
                        reader.readAsText(_f);
                    });
                }

                function transform(_type){
                    let file = {
                        type: _type,
                        path: _file.name
                    };
                    if(file.type === 'file'){
                        file.file = _file;
                    }else{
                        file.path += "/";
                    }
                    return Promise.resolve(file);
                }
            })
        );
    }
};


export const onSearch = (keyword, path = "/") => {
    return new Observable((obs) => {
        Files.search(keyword, path)
            .then((f) => obs.next(f))
            .catch((err) => obs.error(err));
    });
};