var sortState = {
  sortBy: "sortAuthor",
  sortOrder: "asc",
};

function init() {
  fetch("/api/books")
    .then((response) => response.json())
    .then((books) => {
      // prepare response
      books.forEach(apiResponseParsing);
      document.getElementById("search").addEventListener("input", (e) => {
        renderTable(search(books, e.target.value));
      });
      renderTable(books);
    });
}

function renderTable(books, sortField) {
  if (sortField) {
    if (sortState.sortBy === sortField && sortState.sortOrder === "asc") {
      sortState.sortOrder = "desc";
    } else {
      sortState.sortOrder = "asc";
    }
    sortState.sortBy = sortField;
  }
  books.sort((one, two) =>
    (one[sortState.sortBy] + one["sortTitle"]).localeCompare(
      two[sortState.sortBy] + two["sortTitle"]
    )
  );
  if (sortState.sortOrder === "desc") {
    books.reverse();
  }
  books.forEach((e, i) => (e.rowNumber = i)); // re-key

  // rendering
  var bookElement = document.getElementById("books");
  bookElement.innerHTML = TableTemplate(books);

  // add listeners for selecting book to view
  Array.from(bookElement.querySelectorAll("tbody tr"))
    .slice(1) // remove header from Array
    .forEach((row) => {
      row.addEventListener("click", (e) => {
        // add listener to swap current book
        document.getElementById("current").innerHTML = BookTemplate(
          books[e.currentTarget.id]
        );
      });
    });
  // add sorting callbacks
  Array.from(bookElement.querySelectorAll("tbody tr th[data-sort-by]")).forEach(
    (row) => {
      row.addEventListener("click", function (e) {
        renderTable(books, e.target.dataset.sortBy); // only add callback when there's a sortBy attribute
      });
    }
  );
  // mark currently active column
  bookElement
    .querySelector("tbody tr th[data-sort-by=" + sortState.sortBy + "]")
    .classList.add(sortState.sortOrder);
}

function apiResponseParsing(book) {
  book.sortTitle = titleCleaner(book.title);
  if (!book["isbn-10"] && book["isbn-13"]) {
    book["isbn-10"] = ISBNfromEAN(book["isbn-13"]);
  }
  if (!book.coverURL && book["isbn-10"]) {
    book.coverURL =
      `https://images-na.ssl-images-amazon.com/images/P/` +
      book["isbn-10"] +
      `.01.LZZ.jpg`;
  }
  return book;
}

function search(books, searchBy) {
  searchBy = searchCleaner(searchBy);
  if (searchBy !== "") {
    books = books.filter(
      ({ title, authors, genre, publisher, series, year }) => {
        return Object.values({
          title,
          authors: authors.join(" "),
          genre,
          publisher,
          series,
          year,
        }).find((field) => searchCleaner(field).indexOf(searchBy) !== -1);
      }
    );
  }
  return books;
}

function titleCleaner(title) {
  return title
    .replace('"', "")
    .replace(":", "")
    .replace(/^(An?|The)\s/i, "");
}

function searchCleaner(str) {
  return str
    .toLowerCase()
    .replaceAll('"', "")
    .replaceAll(":", "")
    .replaceAll("'", "")
    .replaceAll(" ", "");
}

function ISBNfromEAN(EAN) {
  ISBN = EAN.slice(3, 12);
  var checkdigit =
    (11 - (ISBN.split("").reduce((s, n, k) => s + n * (10 - k), 0) % 11)) % 11;
  return ISBN + (checkdigit === 10 ? "X" : checkdigit);
}

function BookTemplate({
  "isbn-13": isbn13,
  authors,
  coverURL,
  description,
  format,
  notes,
  onLoan,
  publisher,
  series,
  signed,
  title,
  volume,
  year,
}) {
  return `${coverURL ? `<img src="${coverURL}"/>` : ""}
  <h1 ${onLoan ? "class='onLoan' " : ""}>${title}</h1>
  <h2>${authors}</h2>
  <span>${isbn13}</span><br/>
  <span>${publisher}, ${year}</span><br/>
  ${
    series
      ? `<span>${series}${volume ? `, Volume ${volume}` : ""}</span><br/>`
      : ""
  }
  ${signed ? "<span>Signed by the author ✒</span><br/>" : ""}
  <span>${format}</span>
  ${onLoan ? `<h2 class="onLoan">On loan to ${onLoan}</h2>` : ""}
  <div class="description">
    <p>${description}</p>
    ${notes ? `<span>Notes:</span><p>${notes}</p>` : ""}
  </div>`;
}

function TableRowTemplate({
  "isbn-13": isbn13,
  authors,
  onLoan,
  publisher,
  rowNumber,
  signed,
  title,
  year,
}) {
  return `<tr class="tRow ${onLoan ? "onLoan" : ""}" id="${rowNumber}">
    <td class="title">
      ${title} ${
    signed ? '<span class="signed" title="Signed by the author" >✒</span>︎' : ""
  }
    </td>
    <td class="author">${authors}</td>
    <td class="publisher">${publisher}</td>
    <td class="year">${year}</td>
    <td class="isbn">${isbn13}</td>
  </tr>`;
}

function TableTemplate(books) {
  return `<table class="bookTable">
    <tr>
      <th data-sort-by="sortTitle" class="tHeader title">Title</th>
      <th data-sort-by="sortAuthor" class="tHeader author">Author</th>
      <th data-sort-by="publisher" class="tHeader publisher">Publisher</th>
      <th data-sort-by="year" class="tHeader year">Year</th>
      <th class="tHeader isbn">ISBN</th>
    </tr>${books.reduce((acc, book) => {
      return acc.concat(TableRowTemplate(book));
    }, "")} </table>`;
}