export const close = (appName, setApps) => {
  setApps(apps => apps.filter(a => a && a.name !== appName))
}

const findSmallestMissing = (arr = []) => {
   let count = 1;
   if(!arr?.length){
      return count;
   };
   while(arr.indexOf(count) !== -1){
      count++;
   };
   return count;
};

export const open = ({ appName, buttons, height, width }, setApps, props = {}) => {
  setApps(apps => {
    const untouched = apps.filter(a => a.pos.length === 1).map(a => a.pos[0])
    const newPos = findSmallestMissing(untouched);

    return (
      apps && apps.length > 0
        ? !apps.some(a => a.name === appName)
            ? [...apps, { name: appName, min: false, max: false, height, width, pos: [newPos], buttons, props }]
            : apps
        : [{ name: appName, min: false, max: false, height, width, pos: [newPos], buttons, props }]
    )
  })
}

export const focus = (appName, setApps) => {
  setApps(apps => {
    const i = apps.length > 0 && apps.findIndex(a => a.name === appName)
    return i !== apps.length - 1
      ? [...apps.filter((_, n) => n !== i), apps[i]]
      : apps
  })
}

export const unfocus = (appName, setApps) => {
  setApps(apps => {
    const i = apps.findIndex(a => a.name === appName)
    return i !== 0
      ? [apps[i], ...apps.filter((_, n) => n !== i)]
      : apps
  })
}

export const toggleMin = (appName, apps, setApps) => {
  setApps(apps => ([
    ...apps.map(a => a.name === appName ? { ...a, min: !a.min } : a)
  ]))
  apps.find(a => a.name === appName).min
    ? focus(appName, setApps)
    : unfocus(appName, setApps)
}

export const toggleMax = (appName, setApps) => setApps(apps => ([
  ...apps.map(a => a.name === appName ? { ...a, max: !a.max } : a)
]))

export const move = (app, winRef, setApps) => {
  winRef.current.onmousedown = (event) => {
    if (!app.max && event.target.classList && event.target.classList.contains('window__title')) {
      const shiftX = event.clientX - winRef.current.getBoundingClientRect().left
      const shiftY = event.clientY - winRef.current.getBoundingClientRect().top
      winRef.current.classList.add('moving')
      focus(app.name, setApps)

      function moveAt (pageX, pageY) {
        const x = pageX - shiftX
        const y = pageY - shiftY

        setApps(apps => ([...apps.map(a => a && a.name === app.name
          ? { ...a, pos: [x + 'px', y < '32' ? '32px' : y + 'px'] }
          : a
        )]))
      }

      const onMouseMove = (event) => {
        moveAt(event.pageX, event.pageY)
      }

      document.addEventListener('mousemove', onMouseMove)

      document.onmouseup = () => {
        document.removeEventListener('mousemove', onMouseMove)
        winRef.current.classList.remove('moving')
        document.onmouseup = null
      }
    }
  }

  winRef.current.ondragstart = () => null
}