(function () {
  "use strict";

  var ENTER_KEY = 13;
  var newTodoDom = document.getElementById("new-todo");
  var syncDom = document.getElementById("sync-wrapper");

  var db = new PouchDB("todos");
  var remoteCouch = "http://admin:123456@127.0.0.1:5984/todos";
  var cookie;

  db.info().then(function (info) {
    db.changes({ since: info.update_seq, live: true }).on("change", function (change) {
      showTodos();
    });
  });

  // We have to create a new todo document and enter it in the database
  function addTodo(text) {
    var todo = {
      title: text,
      completed: false,
    };
    db.post(todo).then(function (response) {
      console.log("Successfully posted a todo!");
    });
  }

  // Show the current list of todos by reading them from the database
  function showTodos() {
    db.allDocs({ include_docs: true, conflicts: true })
      .then(function (doc) {
        console.log(doc);
        redrawTodosUI(doc.rows);
      })
      .catch(function (err) {
        console.log(err);
      });
  }

  // Remove all conflicting revisions from the database
  function resolveConflict(todo, rev) {
    console.log(todo, rev)
    todo._conflicts.forEach((r) => {
      if (r !== rev) {
        db.remove(todo._id, r);
      }
    });
    if (todo._rev !== rev) {
      db.remove(todo._id, todo._rev);
    }
  }

  function checkboxChanged(todo, event) {
    todo.completed = event.target.checked;
    db.put(todo);
  }

  // User pressed the delete button for a todo, delete it
  function deleteButtonPressed(todo) {
    db.remove(todo);
  }

  // The input box when editing a todo has blurred, we should save
  // the new title or delete the todo if the title is empty
  function todoBlurred(todo, event) {
    var trimmedText = event.target.value.trim();
    if (!trimmedText) {
      db.remove(todo);
    } else {
      todo.title = trimmedText;
      db.put(todo);
    }
  }

  // Initialise a sync with the remote server
  function sync() {
    // syncDom.setAttribute("data-sync-state", "syncing");
    var remote = new PouchDB(remoteCouch, { headers: { Cookie: cookie } });
    var pushRep = db.replicate
      .to(remote, {
        continuous: true,
      })
      .on("active", syncStarted)
      .on("error", syncError)
      .on("paused", syncComplete)
      .on("complete", syncComplete);
    var pullRep = db.replicate
      .from(remote, {
        continuous: true,
      })
      .on("active", syncStarted)
      .on("error", syncError)
      .on("paused", syncComplete)
      .on("complete", syncComplete);
  }

  // EDITING STARTS HERE (you dont need to edit anything below this line)

  // There was some form or error syncing
  function syncStarted() {
    syncDom.setAttribute("data-sync-state", "syncing");
  }
  function syncComplete() {
    syncDom.setAttribute("data-sync-state", "complete");
  }
  function syncError() {
    syncDom.setAttribute("data-sync-state", "error");
  }

  // User has double clicked a todo, display an input so they can edit the title
  function todoDblClicked(todo) {
    var div = document.getElementById("li_" + todo._id);
    var inputEditTodo = document.getElementById("input_" + todo._id);
    div.className = "editing";
    inputEditTodo.focus();
  }

  // If they press enter while editing an entry, blur it to trigger save
  // (or delete)
  function todoKeyPressed(todo, event) {
    if (event.keyCode === ENTER_KEY) {
      var inputEditTodo = document.getElementById("input_" + todo._id);
      inputEditTodo.blur();
    }
  }

  // Given an object representing a todo, this will create a list item
  // to display it.
  function createTodoListItem(todo) {
    var checkbox = document.createElement("input");
    checkbox.className = "toggle";
    checkbox.type = "checkbox";
    checkbox.addEventListener("change", checkboxChanged.bind(this, todo));

    var label = document.createElement("label");
    label.appendChild(document.createTextNode(todo.title));
    label.addEventListener("dblclick", todoDblClicked.bind(this, todo));

    var deleteLink = document.createElement("button");
    deleteLink.className = "destroy";
    deleteLink.addEventListener("click", deleteButtonPressed.bind(this, todo));

    var divDisplay = document.createElement("div");
    divDisplay.className = "view";
    divDisplay.appendChild(checkbox);
    divDisplay.appendChild(label);
    divDisplay.appendChild(deleteLink);

    var inputEditTodo = document.createElement("input");
    inputEditTodo.id = "input_" + todo._id;
    inputEditTodo.className = "edit";
    inputEditTodo.value = todo.title;
    inputEditTodo.addEventListener("keypress", todoKeyPressed.bind(this, todo));
    inputEditTodo.addEventListener("blur", todoBlurred.bind(this, todo));

    var li = document.createElement("li");
    li.id = "li_" + todo._id;
    li.appendChild(divDisplay);
    li.appendChild(inputEditTodo);

    if (todo._conflicts) {
      var conflictsP = document.createElement("p");
      conflictsP.textContent = "conflicts with: ";

      var ca = document.createElement("a");
      ca.textContent = "(Keep this revision)";
      ca.onclick = () => resolveConflict(todo, todo._rev);
      conflictsP.appendChild(ca);

      todo._conflicts.forEach((rev) => {
        db.get(todo._id, { rev }).then(function (t) {
          var ca = document.createElement("a");
          ca.textContent = t.title;
          ca.onclick = () => resolveConflict(todo, rev);

          conflictsP.appendChild(ca);
        });
      });

      li.appendChild(conflictsP);
    }

    if (todo.completed) {
      li.className += "complete";
      checkbox.checked = true;
    }

    return li;
  }

  function redrawTodosUI(todos) {
    var ul = document.getElementById("todo-list");
    ul.innerHTML = "";
    todos.forEach(function (todo) {
      ul.appendChild(createTodoListItem(todo.doc));
    });
  }

  function newTodoKeyPressHandler(event) {
    if (event.keyCode === ENTER_KEY) {
      addTodo(newTodoDom.value);
      newTodoDom.value = "";
    }
  }

  function addEventListeners() {
    newTodoDom.addEventListener("keypress", newTodoKeyPressHandler, false);
  }

  addEventListeners();
  showTodos();

  if (remoteCouch) {
    sync();
  }
})();