let items = {};
const id = new URLSearchParams(window.location.search).get('id');

document.onreadystatechange = function() {
  if (document.readyState === 'interactive') {
    fetchItems(fillForm);
  }
}

function fetchItems(cb) {
  fetch('/api/items').then(r => r.json()).then((data) => {
    items = data;
    cb();
  });
}

function fillForm() {
  const item = items[id];
  knownTypes();

  const is_in = document.getElementById('is_in');

  for (const [_, item] of Object.entries(items)) {
    const option = document.createElement('option');
    option.value = item.id;
    option.textContent = `${item.id} ${item.name && `(${item.name})` || ''}`
    is_in.appendChild(option);
  };

  document.getElementById('id').placeholder = '';

  if (id && item) {
    document.getElementById('id').value = item.id;
    document.getElementById('is_in').value = item.is_in;
    document.getElementById('coords_bl').value = item.coords_bl;
    document.getElementById('coords_tr').value = item.coords_tr;
    document.getElementById('type').value = item.type;
    document.getElementById('name').value = item.name;
    document.getElementById('content').value = item.content;
    document.getElementById('note').value = item.note;
    document.getElementById('hidden').checked = item.hidden;
    document.getElementById('last_updated').value = formatTimestamp(item.last_updated);

    formCoordsToMap();
  }

  const saveBtn = document.getElementById('save');
  const delBtn = document.getElementById('delete');

  saveBtn.onclick = function(e) {
    e.preventDefault();
    save();
  };

  delBtn.onclick = function(e) {
    e.preventDefault();
    del();
  }
}

function knownTypes() {
  let map = {};
  for (const i of Object.values(items)) {
    if (i.type) {
      map[i.type] = true;
    }
  }
  let types = Object.keys(map).sort().join(', ')
  document.getElementById('knowntypes').textContent = `Known types: ${types}.`;
}

function save() {
  const item = {
    id: document.getElementById('id').value || '',
    is_in: document.getElementById('is_in').value || null,
    coords_bl: document.getElementById('coords_bl').value || null,
    coords_tr: document.getElementById('coords_tr').value || null,
    type: document.getElementById('type').value || null,
    name: document.getElementById('name').value || null,
    content: document.getElementById('content').value || null,
    note: document.getElementById('note').value || null,
    hidden: document.getElementById('hidden').checked,
  }

  fetchItems(() => {
    if (item.id.includes('?')) {
      let n = 1;
      while (true) {
        const candidate = item.id.replace('?', n++);
        if (!Object.keys(items).includes(candidate)) {
          item.id = candidate;
          break;
        }
      }
    }

    if (items[item.id]) {
      if (!id || (id && id != item.id)) {
        alert(`ID ${item.id} exists. Please chose a different ID or edit the existing ${item.id} item!`);
        return;
      }
    }

    const original_id = id || item.id;

    fetch(`/api/items/${original_id}`, {
      method: 'PUT',
      headers: {'Content-Type': 'application/json'},
      body: JSON.stringify(item),
    })
    .then(r => {
      if (r.ok) {
        window.location.href = '../';
      } else {
        r.text().then(t => alert(`Error:\n${t}`));
      }
    }).catch(error => {
      alert(`Error:\n${error}`);
    });
  });
}

function del() {
  if (id && confirm('Are you sure?')) {
    fetch(`/api/items/${id}`, {method: 'DELETE'}).then(r => {
      if (r.ok) {
        window.location.href = '../';
      } else {
        r.text().then(t => alert(`Error:\n${t}`));
      }
    }).catch(error => {
      alert(`Error:\n${error}`);
    });
  }
}

let clicks = {x: [], y: []};
function mapClick(e) {
  let x = Math.floor(31 / e.target.width * e.layerX);
  let y = Math.floor(10 / e.target.height * e.layerY);

  let humanPos = (x, y) => {
    return `${String.fromCharCode(65 + 8 - y)}${x}`;
  };

  if (x > 0 && x < 31 && y > 0 && y < 9) {
    if (clicks.x.length > 1) {
      clicks.x = [x];
      clicks.y = [y];
    } else {
      clicks.x.push(x);
      clicks.y.push(y);
    }

    if (clicks.x.length > 1) {
      clicks.x.sort((a,b) => a-b);
      clicks.y.sort((a,b) => a-b);
      renderMap(clicks.x, clicks.y);

      let coords_bl = humanPos(clicks.x[0], clicks.y[1]);
      let coords_tr = humanPos(clicks.x[1], clicks.y[0]);
      
      document.getElementById('coords_bl').value = coords_bl;
      document.getElementById('coords_tr').value = coords_tr;
    }
  }
}

function formCoordsToMap() {
  const coords_bl = document.getElementById('coords_bl').value || '';
  const coords_tr = document.getElementById('coords_tr').value || '';
  if (coords_bl.length > 1 && coords_tr.length > 1) {
    coordsToMap(coords_bl, coords_tr);
  }
}

function formatTimestamp(ts) {
    const date = new Date(ts * 1000);
    // using Swedish format as a hack to get an iso formatted date
    return date.toLocaleDateString("sv", {timeZone: "UTC"}).replace(/\-\d+$/,'') 
}