import * as Config from 'config'
import h from 'h'
import * as Router from 'router'
import * as Duration from 'duration'

export function view(config: Config.Config, showPage: (route: Router.Route) => void) {
  const duration = document.createTextNode(Duration.prettyPrint(Config.getDuration(config)))
  const wd = () => duration.textContent = Duration.prettyPrint(Config.getDuration(config))
  return h('div',
    { className: 'g-Layout__Page' },
      h('header', { className: 'g-Layout__Header' }, 'Tabata timer'),
      h('form',
        { className: 'g-Form'
        , onsubmit: (e: Event) => {
            e.preventDefault()
            const timerRoute: Router.Route = { name: 'timer', config }
            history.pushState({}, '', Router.toString(timerRoute))
            showPage(timerRoute)
        }},
        h('section',
          { className: 'g-Form__Section' },
          numberInput('Warm Up', 0, config.warmup, n => { config.warmup = n; wd()})
        ),
        h('section',
          { className: 'g-Form__Section' },
          h('h1', { className: 'g-Form__Title' }, 'Tabatas'),
          h('div',
            { className: 'g-Form__Line' },
            numberInput('Prep', 0, config.prepare, n => { config.prepare = n; wd()}),
            operator('+'),
            numberInput('Cycles', 1, config.cycles, n => { config.cycles = n; wd()}),
            operator('× ('),
            numberInput('Work', 5, config.work, n => { config.work = n; wd()}),
            operator('+'),
            numberInput('Rest', 5, config.rest, n => { config.rest = n; wd()}),
            operator(')')
          ),
          tabatasSection(
            config.tabatas,
            (str: string) => { config.tabatas.push(str); wd() },
            (index: number, str: string) => { config.tabatas[index] = str; wd() },
            (index: number) => { config.tabatas.splice(index, 1); wd() }
          )
        ),
        h('section',
          { className: 'g-Form__Section' },
          h('h1', { className: 'g-Title' }, 'Duration'),
          h('div', { className: 'g-Form__Duration' }, duration)
        ),
        h('button', { className: 'g-Button' }, 'Start')
      )
  )
}

function operator(str: string): Element {
  return h('span', { className: 'g-Form__Operator' }, str)
}

function tabatasSection(
  init: string[],
  onAdd: (str: string) => void,
  onUpdate: (index: number, str: string) => void,
  onRemove: (inedx: number) => void
) {
  const tabatas = h('ol', { className: 'g-List' })
  let counter = init.length
  let removedIndexes: number[] = []
  let adjustIndex = (index: number) => index - removedIndexes.filter(i => i < index).length

  init.forEach((initStr, index) => {
    const { tabata } = tabataInput(
      initStr,
      (str: string) => onUpdate(adjustIndex(index), str),
      () => {
        onRemove(adjustIndex(index))
        tabatas.removeChild(tabata)
        removedIndexes.push(index)
      }
    )
    tabatas.appendChild(tabata)
  })

  return h('div',
    { className: 'g-Form__Tabatas' },
    tabatas,
    h('input',
      { type: 'button',
        value: 'Add tabata',
        className: 'g-Button',
        onclick: (e: Event) => {
          let index = counter++
          const txt = `Exercise ${adjustIndex(index) + 1}`
          onAdd(txt)
          let { tabata, textInput } = tabataInput(
            txt,
            (str: string) => onUpdate(adjustIndex(index), str),
            () => {
              onRemove(adjustIndex(index))
              tabatas.removeChild(tabata)
              removedIndexes.push(index)
            }
          )
          tabatas.appendChild(tabata)
          textInput.select()
        }
      }
    )
  )
}

interface TabataInput {
  tabata: Element,
  textInput: HTMLInputElement,
}

function tabataInput(
  init: string,
  onUpdate: (str: string) => void,
  onRemove: () => void
): TabataInput {
  const textInput = h('input',
    { value: init,
      className: 'g-Input g-Form__TabataInput',
      required: 'required',
      oninput: (e: Event) => {
        if (e.target !== null) {
          const target = e.target as HTMLInputElement
          onUpdate(target.value.trim())
        }
      }
    }
  ) as HTMLInputElement

  const tabata = h('li',
    { className: 'g-Form__Tabata'},
    textInput,
    h('input',
      { type: 'button',
        value: 'Remove',
        className: 'g-Button',
        onclick: (e: Event) => onRemove()
      }
    )
  )

  return { tabata, textInput }
}

function numberInput(
  labelValue: string,
  min: number,
  value: number,
  update: (n: number) => void
): Element {
  return h('label',
    { className: 'g-Form__Label',
      oninput: (e: Event) => {
        if (e.target !== null) {
          const target = e.target as HTMLInputElement
          update(parseInt(target.value) || 0)
        }
      }
    },
    labelValue,
    h('input',
      { className: 'g-Input g-Form__NumberInput',
        type: 'number',
        required: 'required',
        min,
        value
      }))
}