// Setup
subscriptions = []

currencies = new Map()
currencies.set("$", 6.78)
currencies.set("€", 7.47)
currencies.set("DKK", 1)

// The name of the data in localStorage
localDataName = "subscriptionInformation"
localSortPreferenceName = "sortPreference"
localHasChangedOrder = "hasChangedOrder"

// Initial scroll distance to bottom of the page.
let scrollDistance = getDocHeight()

// Function that top/bottom button calls. Scrolls to top if user has scrolled 50% down, bottom otherwise.
let scrollToTopOrBottom = () => {
  window.scrollTo({
    top: scrollDistance,
    left: 0,
    behavior: 'smooth'
  })
}

// Gets the height of the page.
function getDocHeight() {
  let D = document;
  return Math.max(
    D.body.scrollHeight, D.documentElement.scrollHeight,
    D.body.offsetHeight, D.documentElement.offsetHeight,
    D.body.clientHeight, D.documentElement.clientHeight
  )
}

// Keep track of the window height.
let winheight = window.innerHeight || (document.documentElement || document.body).clientHeight;
window.onresize = () => {
  winheight = window.innerHeight || (document.documentElement || document.body).clientHeight;
}

// Calculate whether the button should say top or bottom
window.onscroll = () => {
  let docHeight = getDocHeight()
  let trackLength = docHeight - winheight

  let scrollTop = window.pageYOffset || (document.documentElement || document.body.parentNode || document.body).scrollTop
  let pctScrolled = Math.floor(scrollTop/trackLength * 100) // gets percentage scrolled (ie: 80 or NaN if tracklength == 0)

  if (pctScrolled > 50){
    document.querySelector('#myBtn').innerHTML = "Top";
    scrollDistance = 0
  }
  else{
    document.querySelector('#myBtn').innerHTML = "Bottom"
    scrollDistance = trackLength
  }
}

// Returns true if valid subscription, false if not.
let isValidSubscription = (subscription) => {
  if (isNaN(subscription.amount)) {
    alert("Amount is not a number")
    return false
  }
  if (!([...currencies.keys()].includes(subscription.currency))) {
    alert("Currency is not a valid currency")
    return false
  }
  if (isNaN(subscription.months)) {
    alert("Months are not a number")
    return false
  }

  // Title of subscription must be unique.
  if (subscriptions.map((sub) => sub.title).includes(subscription.title)) {
    alert("Subscription name not unique")
    return false
  }

  return true
}

// Create a new subscription
let newSubscription = () => {
  // Open the popup
  Swal.fire({
    title: 'Insert subscription information',
    html:
      '<hr class="is-black">' +
      '<label class="label has-text-left">Title</label> ' +
      '<input id="swal-input1" class="swal2-input" placeholder="Subscription title" value="">' +
      '<label class="label has-text-left">Amount</label> ' +
      '<input id="swal-input2" class="swal2-input" placeholder="Original Amount" value="">' +
      '<label class="label has-text-left">Currency</label> ' +
      '<input id="swal-input3" class="swal2-input" placeholder="Original Currency" value="">' +
      '<label class="label has-text-left">Over how many months</label> ' +
      '<input id="swal-input4" class="swal2-input" placeholder="Over how many months" value="">' +
      '<label class="label has-text-left">Other notes</label> ' +
      '<textarea id="swal-input5" class="textarea" placeholder="Notes" rows="4" cols="4">' + '</textarea>',
    focusConfirm: false,
    preConfirm: () => {
      // Create a new temporary subscription
      let newSub = {
        title: document.getElementById('swal-input1').value,
        amount: document.getElementById('swal-input2').value,
        currency: document.getElementById('swal-input3').value,
        months: document.getElementById('swal-input4').value,
        notes: document.getElementById('swal-input5').value,
        changed: false
      }

      // Do some form validation
      let valid = isValidSubscription(newSub)

      // Update the table if form was validated successfully
      if (valid){
        subscriptions.push(newSub)
        updateTable()
      }
    }
  })
}

// Edit a subscription
let editSubscription = (btn) => {
  // Find out which subscription we're editing
  let currentSubscription = getSubscriptionFromButton(btn)

  // Open the popup, and fill in the current subscription information in the form
  Swal.fire({
    title: 'Insert subscription information',
    html:
      '<hr class="is-black">' +
      '<label class="label has-text-left">Title</label> ' +
      '<input id="swal-input1" class="swal2-input" placeholder="Subscription title" value="' + currentSubscription.title + '">' +
      '<label class="label has-text-left">Amount</label> ' +
      '<input id="swal-input2" class="swal2-input" placeholder="Original Amount" value="' + currentSubscription.amount + '">' +
      '<label class="label has-text-left">Currency</label> ' +
      '<input id="swal-input3" class="swal2-input" placeholder="Original Currency" value="' + currentSubscription.currency + '">' +
      '<label class="label has-text-left">Over how many months</label> ' +
      '<input id="swal-input4" class="swal2-input" placeholder="Over how many months" value="' + currentSubscription.months + '">' +
      '<label class="label has-text-left">Other notes</label> ' +
      '<textarea id="swal-input5" class="textarea" placeholder="Notes" rows="4" cols="4">' + currentSubscription.notes + '</textarea>',
    focusConfirm: false,
    cancelButtonColor: '#d33',
    showCancelButton: true,
    preConfirm: () => {
      // Create a new temporary subscription
      let newSub = {
        title: document.getElementById('swal-input1').value,
        amount: document.getElementById('swal-input2').value,
        currency: document.getElementById('swal-input3').value,
        months: document.getElementById('swal-input4').value,
        notes: document.getElementById('swal-input5').value,
        changed: false
      }

      let valid = isValidSubscription(newSub)
      if (valid){
        // Update the table if form was validated successfully
        deleteSubscription(currentSubscription)
        subscriptions.push(newSub)
        updateTable()
      }
    }
  })
}

// Add a new currency. Called by the add currency button
let addCurrency = () => {
  // Fire popup
  Swal.fire({
    title: 'Insert currency information',
    html:
      '<input id="swal-input1" class="swal2-input" placeholder="Currency Symbol">' +
      '<input id="swal-input2" class="swal2-input" placeholder="DKK Rate">',
    focusConfirm: false,
    preConfirm: () => {
      // Register the new possible currency
      let newCurrency = {
        symbol: document.getElementById('swal-input1').value,
        rate: document.getElementById('swal-input2').value,
      }

      // Check that the rate is a number
      if (isNaN(newCurrency.rate)) {
        alert("DKK exchange rate is now a number")
        return
      }

      // Update with the new currency, and refresh the table
      currencies.set(newCurrency.symbol, newCurrency.rate)
      updateTable()
    }
  })
}

// Delete all subscriptions.
let Reset = () => {
  Swal.fire({
    title: 'Are you sure?',
    text: "You won't be able to revert this!",
    icon: 'warning',
    showCancelButton: true,
    confirmButtonColor: '#3085d6',
    cancelButtonColor: '#d33',
    confirmButtonText: 'Yes, delete it!'
  }).then((result) => {
    if (result.value) {
      subscriptions = []
      updateTable()
      Swal.fire(
        'Reset!',
        'Your subscriptions have been reset.',
        'success'
      )
    }
  })
}


// Method for updating the table with new information.
let updateTable = () => {
  // Create a new replacement tbody
  let newTbody = document.createElement('tbody');
  newTbody.classList.add("tbody")

  // Sort by users preference


  // Add rows from data in memory.
  populateTable(newTbody)

  // Replace the old tbody with the new cleared one
  let oldTbody = document.querySelector('.tbody')
  oldTbody.parentNode.replaceChild(newTbody, oldTbody)

  // Save the new information locally.
  setStored(localDataName, JSON.stringify(getSaveInfo()))
}

// Populate a tbody with subscriptions from the subscriptions array.
let populateTable = (tbody) => {
  // Store the total cost of all subscriptions
  total = 0

  // calculate the monthly cost in dkk of each item, and add it to the running total
  for (elem of subscriptions) {
    elem.monthly = elem.amount / elem.months
    elem.indkk = elem.monthly * currencies.get(elem.currency)
    total += elem.indkk
  }

  // Update tablefoot with total monthly cost and amount of subscriptions.
  document.querySelector('#total').innerHTML = total.toFixed(2)
  document.querySelector('#amountOfSubscriptions').innerHTML = subscriptions.length

  // Begin to create table rows
  for (let i = 0; i < subscriptions.length; i++) {
    // Select a subscription on index i, and create a new empty row
    let elem = subscriptions[i]
    var tr = document.createElement('tr');

    // Calculate the subscriptions percentage-wise cost of the monthly total.
    elem.percentOfWhole = elem.indkk / total * 100;

    // If this element has been changed (ie. created, moved), mark it for the user.
    if (elem.changed) {
      tr.classList = "is-selected"
      elem.changed = false
    }

    // Create the row.
    tr.innerHTML = '<td>' + elem.title + '</td>' +
      '<td>' + elem.monthly.toFixed(2) + '</td>' +
      '<td>' + elem.currency + '</td>' +
      '<td>' + elem.indkk.toFixed(2) + '</td>' +
      '<td>' + elem.percentOfWhole.toFixed(2) + '%</td>' +
      '<td>' + '<button class="button" onclick="getInfoOfSubscription(this)">Info</button>' + '</td>' +
      '<td>' + '<button class="button" onclick="askToDeleteRow(this)">Delete</button>' + '</td>' +
      '<td>' + `<button class="button" onclick="moveRow(this, -1)">Up</button>` + `<button class="button" onclick="moveRow(this, +1)">Down</button>` + `<button class="button" onclick="editSubscription(this)">Edit</button>` + '</td>';

    // Append the new row
    tbody.appendChild(tr);
  }
}

// Create a pie-chart with the cost of each subscription
let PieChart = () => {

  // Get data ready for CanvasJS.
  let data = []
  for (subscription of subscriptions) {
    console.log(subscription)
    data.push({y: subscription.percentOfWhole, label: subscription.title})
  }

  // Create the chart with CanvasJS.
  let chart = new CanvasJS.Chart("chartContainer", {
    animationEnabled: true,
    title: {
      text: "Monthly Expenses"
    },
    data: [{
      type: "pie",
      startAngle: 240,
      yValueFormatString: "##0.00\"%\"",
      indexLabel: "{label} {y}",
      dataPoints: data
    }]
  });

  // Lastly, render it.
  chart.render()
}

// Ask the user what to sort by, and then sorts the array.
let Sort = async () => {

  // The input options for SWAL2
  const inputOptions = new Promise((resolve) => {
    resolve({
      'Lex': 'Lexi.',
      'Price': 'Price'
    })
  })

  // Fire the popup
  const {value: sortBy} = await Swal.fire({
    title: 'Sort by what',
    input: 'radio',
    inputOptions: inputOptions,
    inputValidator: (value) => {
      if (!value) {
        return 'You need to choose something!'
      }
    }
  })

  // Sort the array, and save the sorting preference
  if (sortBy) {
    if (sortBy == "Lex") {
      setStored(localSortPreferenceName, "Lex")
      sortSubscriptionsByName()
      updateTable()
    } else if (sortBy == "Price") {
      setStored(localSortPreferenceName, "Price")
      sortSubscriptionsByPrice()
      updateTable()
    }
  }
}

// different sorters for subscriptions array
let sortSubscriptionsByPrice = () => {
  subscriptions.sort((a, b) => {
    if (a.indkk > b.indkk) {
      return -1;
    }
    if (b.indkk > a.indkk) {
      return 1;
    }
    return 0;
  })
}
let sortSubscriptionsByName = () => {
  subscriptions.sort((a, b) => {
    if (a.title > b.title) {
      return 1;
    }
    if (b.title > a.title) {
      return -1;
    }
    return 0;
  })
}


// Gets more information on a subscription, and displays it in a popup
let getInfoOfSubscription = (btn) => {
  let currentSub = getSubscriptionFromButton(btn)
  Swal.fire(
    currentSub.title,
    `${currentSub.amount}${currentSub.currency} over ${currentSub.months} months, which equates to <br>
     ${currentSub.monthly}${currentSub.currency} monthly, or about ${currentSub.indkk} DKK <br> ` +
    // Display notes only if there are some.
    (currentSub.notes === undefined ? "" : (
      `
     Notes: <br>
    <div class="control">
        <textarea class="textarea" disabled>${currentSub.notes}</textarea>
    </div>
    `)),
    'question'
  )
}

// Since title is unique, this finds the title of the row from which a button was pressed, and returns that subscription from the subscription array
let getSubscriptionFromButton = (button) => {
  let tr = button.parentNode.parentNode
  let title = tr.firstChild.textContent
  return subscriptions.filter(s => s.title == title)[0]
}

// Moves a row by some direction (+x, -x)
let moveRow = (btn, direction) => {

  // Find the subscriptions current index
  let currentSub = getSubscriptionFromButton(btn)
  let indexOfCurrentRow = subscriptions.indexOf(currentSub)

  // If trying to move a subscription out of bounds
  if (indexOfCurrentRow + direction < 0 || indexOfCurrentRow + direction >= subscriptions.length) {
    Swal.fire({
      icon: 'error',
      title: 'Oops...',
      text: 'Cant move this object ' + (direction == -1 ? "up" : "down"),
    })
  } else {
    // Move the subscription
    subscriptions[indexOfCurrentRow] = subscriptions[indexOfCurrentRow + direction]
    subscriptions[indexOfCurrentRow + direction] = currentSub
    currentSub.changed = true
    updateTable()

    // Store that the user has a custom order
    setStored(localHasChangedOrder, true)
  }
}


let askToDeleteRow = (btn) => {
  Swal.fire({
    title: 'Are you sure?',
    text: "You won't be able to revert this!",
    icon: 'warning',
    showCancelButton: true,
    confirmButtonColor: '#3085d6',
    cancelButtonColor: '#d33',
    confirmButtonText: 'Yes, delete it!'
  }).then((result) => {
    if (result.value) {
      deleteSubscription(getSubscriptionFromButton(btn))
      Swal.fire(
        'Deleted!',
        'Your file has been deleted.',
        'success'
      )
    }
  })
}

let deleteSubscription = (subscription) => {
  subscriptions = subscriptions.filter(s => s.title != subscription.title)
  updateTable()
}

// Make subscriptions and currency ready to be stored as JSON
let getSaveInfo = () => {
  return {subscriptions: subscriptions, keys: [...currencies.keys()], values: [...currencies.values()]}
}

// Parse a save object, and use it as the current info.
let loadSaveInfo = (loadedSave) => {
  subscriptions = loadedSave.subscriptions

  currencies.clear()
  for (let i = 0; i < loadedSave.keys.length; i++) {
    currencies.set(loadedSave.keys[i], loadedSave.values[i])
  }
}

// Save a local JSON version of the current state.
let saveToFile = () => {
  var dataStr = "data:text/json;charset=utf-8," + encodeURIComponent(JSON.stringify(getSaveInfo()));
  var downloadAnchorNode = document.createElement('a');
  downloadAnchorNode.setAttribute("href", dataStr);
  downloadAnchorNode.setAttribute("download", "save" + ".json");
  document.body.appendChild(downloadAnchorNode); // required for firefox
  downloadAnchorNode.click();
  downloadAnchorNode.remove();
}

// Load a local JSON version of some state.
let load = () => {
  var input, file, fr;

  if (typeof window.FileReader !== 'function') {
    alert("The file API isn't supported on this browser yet.");
    return;
  }

  input = document.getElementById('fileinput');
  if (!input) {
    alert("Um, couldn't find the fileinput element.");
  } else if (!input.files) {
    alert("This browser doesn't seem to support the `files` property of file inputs.");
  } else if (!input.files[0]) {
    alert("Please select a file before clicking 'Load'");
  } else {
    file = input.files[0];
    fr = new FileReader();
    fr.onload = receivedText;
    fr.readAsText(file);
  }

  function receivedText(e) {
    let lines = e.target.result;
    loadedSave = JSON.parse(lines);
    loadSaveInfo(loadedSave)

    updateTable()
  }
}

// Retrieve the key value pair vname, vvalue
function getStored(vname) {
  if (typeof (Storage) !== "undefined") {
    return localStorage.getItem(vname)
  } else {
    return getCookie(vname)
  }
}

// Store the key value pair vname, vvalue
function setStored(vname, vvalue) {
  if (typeof (Storage) !== "undefined") {
    return localStorage.setItem(vname, vvalue)
  } else {
    return setCookie(vname, vvalue)
  }
}


// Fallback if browser doesn't support HTML5 localstorage
function setCookie(cname, cvalue, exdays) {
  var d = new Date();
  d.setTime(d.getTime() + (exdays * 24 * 60 * 60 * 1000));
  var expires = "expires=" + d.toUTCString();
  document.cookie = cname + "=" + cvalue + ";" + expires + ";path=/";
}

function getCookie(cname) {
  var name = cname + "=";
  var decodedCookie = decodeURIComponent(document.cookie);
  var ca = decodedCookie.split(';');
  for (var i = 0; i < ca.length; i++) {
    var c = ca[i];
    while (c.charAt(0) == ' ') {
      c = c.substring(1);
    }
    if (c.indexOf(name) == 0) {
      return c.substring(name.length, c.length);
    }
  }
  return "";
}


// Try to load data from local storage. If this fails, there's probably not any data to retrieve.
try {
  loadSaveInfo(JSON.parse(getStored(localDataName)))

  // Find out if we want to sort the array of the users data.
  if (!getStored(localHasChangedOrder)){
    let userSortPref = getStored(localSortPreferenceName)
    if (userSortPref === undefined){
      sortSubscriptionsByName()
    }
    else{
      if (userSortPref == "Price"){
        sortSubscriptionsByPrice()
      }
      else{
        sortSubscriptionsByName()
      }
    }
  }
  updateTable()
} catch (e) {
  console.log("Didn't find any locally stored data")
  console.log(e)
}