document.body.style.border = "5px solid red";

function onError(error) {
    console.error(`Error: ${error}`);
    $('#error-message').text(`Error: ${error}`);
    $('#error-message').show();
    $('#loading').hide();
    $('#book-info').hide();
}

function getCurrentTab() {
    console.debug("Querying active tab.");
    var queryInfo = {
      active: true,
      currentWindow: true
    };

    return browser.tabs.query(queryInfo)
    .then(function(tabs) {
        if (tabs.length == 1){
            let url = tabs[0].url;
            console.info(`Active URL: ${url}`);
            return url;
        } else {
            console.error(`Expected 1 active tab, received: ${tabs}`);
            throw 'Failed to get active tab.';
        }
    }, onError);
}

function extractBookId(url){
    console.debug(`Extracting book id from ${url}`);
    // match a url like:
    // https://www.safaribooksonline.com/library/view/startup-opportunities-2nd/9781119378181/
    // https://www.safaribooksonline.com/library/view/startup-growth-engines/77961SEM00001/
    let match = url.match(/\/library\/view\/[^\/]+\/(\w+)\//);
    let bookId = match && match[1];

    if (bookId)  {
        console.debug(`Extracted book id: ${bookId}`);
        return bookId;
    }else{
        console.error('Could not extract book id from url, only '
                    +'domain "www.safaribooksonline.com“ is supported.');
        throw 'Failed to extract book id.';
    }
}

// class MiniWebServer{

//     constructor() {
//         this.url = "http://127.0.0.1:8080/test.zip"
//     }

//     downloadTestZip(){
//         console.info(`Downloading ${this.url}`)
//         return fetch(this.url, {
//             credentials: 'include'
//         }).then((res) => {
//             console.log(`Getting blob.`)
//             return res.blob()
//         }).then(JSZip.loadAsync)
//         .then((zip) => {
//             this.zip = zip
//         })

//     }

//     fetchUrl(url){
//         let name = "meta/"+url.replace(/[^a-z0-9]/gi, '_').toLowerCase()
//         this.zip.file(name)
//         .
//     }
// }

class Book{

    constructor(book_id, epub) {
        this.book_id = book_id;
        this.raw_book = {};
        this.chapter_list = [];
        this.book_files = {}
        this.book_info = null
        this.book_toc = null
        this.book_flattoc = null
    }

    downloadResource(url){
        console.info(`Downloading ${url}`)
        return fetch(url, {
            credentials: 'include'
        }).then((res) => {
            console.log(`Downloaded.`)
            return res;
        }, onError)
    }

    downloadJson(url){
        return this.downloadResource(url)
            .then((res) => {
                return res.json();
            }, onError);
    }

    downloadBookInfo(){
        console.info(`Downloading book info for ${this.book_id}`);
        let url = `https://www.safaribooksonline.com/api/v1/book/${this.book_id}/`;
        return this.downloadJson(url)
            .then((book_info)=>{
                this.book_info = book_info;
            }, onError);
    }

    downloadChapterList(){
        function helper(book, url){
            console.info(`Downloading chapter list ${url}`);
            return book.downloadJson(url)
                .then((chapter_list)=>{
                    book.chapter_list
                        = book.chapter_list.concat(chapter_list.results);

                    if (chapter_list.next != null){
                        return helper(book, chapter_list.next);
                    }
                }, onError);
        }

        return helper(this, this.book_info.chapter_list)
            .then(() => {
                console.info(`Chapter List Downloaded.`);
            }, onError);
    }

    downloadMetaContent(){
        let downloads = []

        this.insertBookFile({
            url: this.book_info.cover,
            file: "cover.img",
            context: null,
            mime: null
        })

        downloads.push(
            this.downloadJson(this.book_info.toc)
            .then((json)=>{
                this.book_toc=json
            }))
        downloads.push(
            this.downloadJson(this.book_info.flat_toc)
            .then((json)=>{
                this.book_flattoc=json
            }))
        downloads.push(
            Promise.map(this.book_info.chapters, (chapter) => {
                return this.downloadJson(chapter)
                        .then((json) => {
                             return this.extractChapterAssets(json)
                        })
            },{concurrency: 1}))

        return Promise.all(downloads)
    }

    downloadMetaContent(){
        let downloads = []
        // downloads.push(this.downloadResource(this.book_info.cover))
        downloads.push(
            this.downloadJson(this.book_info.toc)
            .then((json)=>{
                this.book_toc=json
            }))
        downloads.push(
            this.downloadJson(this.book_info.flat_toc)
            .then((json)=>{
                this.book_flattoc=json
            }))
        downloads.push(
            Promise.map(this.book_info.chapters, (chapter) => {
                return this.downloadJson(chapter)
                        .then((json) => {
                             return this.extractChapterAssets(json)
                        })
            },{concurrency: 1}))

        return Promise.all(downloads)
    }


    extractChapterAssets(json){
        if (!json.asset_base_url
            || !json.content){
            throw "Missing data."
        }

        // Html
        this.insertBookFile({
            url: json.content,
            file: json.full_path,
            context: null,
            mime: null
        })
        // List of images.
        for (let idx in json.images){
            this.insertBookFile({
                url: json.asset_base_url + json.images[idx],
                file: json.images[idx],
                context: null,
                mime: null
            })
        }
        // List of stylesheets.
        for (let idx in json.stylesheets){
            this.insertBookFile({
                url: json.stylesheets[idx].original_url,
                file: json.stylesheets[idx].full_path,
                context: null,
                mime: null
            })
        }
    }

    insertBookFile(obj){
        this.book_files[obj.url] = obj
    }
}

function renderInfo(book){
    $("#book-name").text(book.book_info.title);
    $("#book-cover").attr("src", book.book_info.cover);
    $('#book-info').show();
}

function renderChapterList(book){
    // Add chapters to UI
    for (let chapter_idx in book.chapter_list) {
        console.log(book.chapter_list[chapter_idx])
        let chapter = book.chapter_list[chapter_idx];
        var chapter_dom = $("<li></li>")
                    .addClass("list-group-item")
                    .html(chapter.title)
                    .attr("chapterIndex", chapter_idx);
        $("#book-chapter-list").append(chapter_dom);
    }
    $('#loading').hide();
}

function createEpub(book, epub){
    for (let url in book.raw_book){
        let name = "meta/"+book.raw_book[url].url.replace(/[^a-z0-9]/gi, '_').toLowerCase()
        epub.addFile(name, book.raw_book[url].clone().blob())
    }
    // epub.addFile("book_info.json", JSON.stringify(book.book_info))
    // epub.addFile("book_files.json", JSON.stringify(book.book_files))
    // epub.addFile("book_toc.json", JSON.stringify(book.book_toc))
    // epub.addFile("book_flattoc.json", JSON.stringify(book.book_flattoc))
    epub.addFile("book.json", JSON.stringify(book, null, '\t'))
}

function onDownloadBookClicked(){
    console.info("Begin book download.");
    $('#loading').show();
    $('#error-message').hide();
    $('#book-info').hide();

    getCurrentTab()
    .then(extractBookId, onError)
    .then((book_id) => {
        epub = new EpubWriter();
        book = new Book(book_id);
        book.downloadBookInfo()
        .then(() => { renderInfo(book); })
        .then(() => { return book.downloadChapterList(); })
        .then(() => { return renderChapterList(book); })
        .then(() => { return book.downloadContent(); })
        .then(() => { return createEpub(book, epub); })
        .then(() => { return epub.generateAsync(); })
        .then((file) => {
            let filename = "books/" + "test" + ".zip"
            // book.filename.replace(/[^a-z0-9]/gi, '_').toLowerCase()
            let url = window.URL.createObjectURL(file)
            browser.downloads.download({ "filename" : filename, url : url})
        })

    }, onError);
}

document.addEventListener('DOMContentLoaded', function() {
    console.log("Start safari book hunter.");
    $('#loading').hide();
    $('#error-message').hide();
    $('#book-info').hide();

    $('#download-book-button').click(() => {
        onDownloadBookClicked();
    });



    $('#deselect-all-button').show()
    $('#download-button').show()
$('#download-section').hide();
    // let bookInfo = new BookInfo();
})