import { onBlur } from "../display/focus"
import { setGuttersForLineNumbers, updateGutters } from "../display/gutters"
import { alignHorizontally } from "../display/line_numbers"
import { loadMode, resetModeState } from "../display/mode_state"
import { initScrollbars, updateScrollbars } from "../display/scrollbars"
import { updateSelection } from "../display/selection"
import { regChange } from "../display/view_tracking"
import { getKeyMap } from "../input/keymap"
import { defaultSpecialCharPlaceholder } from "../line/line_data"
import { Pos } from "../line/pos"
import { findMaxLine } from "../line/spans"
import { clearCaches, compensateForHScroll, estimateLineHeights } from "../measurement/position_measurement"
import { replaceRange } from "../model/changes"
import { mobile, windows } from "../util/browser"
import { addClass, rmClass } from "../util/dom"
import { off, on } from "../util/event"

import { themeChanged } from "./utils"

export let Init = {toString: function(){return "CodeMirror.Init"}}

export let defaults = {}
export let optionHandlers = {}

export function defineOptions(CodeMirror) {
  let optionHandlers = CodeMirror.optionHandlers

  function option(name, deflt, handle, notOnInit) {
    CodeMirror.defaults[name] = deflt
    if (handle) optionHandlers[name] =
      notOnInit ? (cm, val, old) => {if (old != Init) handle(cm, val, old)} : handle
  }

  CodeMirror.defineOption = option

  // Passed to option handlers when there is no old value.
  CodeMirror.Init = Init

  // These two are, on init, called from the constructor because they
  // have to be initialized before the editor can start at all.
  option("value", "", (cm, val) => cm.setValue(val), true)
  option("mode", null, (cm, val) => {
    cm.doc.modeOption = val
    loadMode(cm)
  }, true)

  option("indentUnit", 2, loadMode, true)
  option("indentWithTabs", false)
  option("smartIndent", true)
  option("tabSize", 4, cm => {
    resetModeState(cm)
    clearCaches(cm)
    regChange(cm)
  }, true)
  option("lineSeparator", null, (cm, val) => {
    cm.doc.lineSep = val
    if (!val) return
    let newBreaks = [], lineNo = cm.doc.first
    cm.doc.iter(line => {
      for (let pos = 0;;) {
        let found = line.text.indexOf(val, pos)
        if (found == -1) break
        pos = found + val.length
        newBreaks.push(Pos(lineNo, found))
      }
      lineNo++
    })
    for (let i = newBreaks.length - 1; i >= 0; i--)
      replaceRange(cm.doc, val, newBreaks[i], Pos(newBreaks[i].line, newBreaks[i].ch + val.length))
  })
  option("specialChars", /[\u0000-\u001f\u007f\u00ad\u061c\u200b-\u200f\u2028\u2029\ufeff]/g, (cm, val, old) => {
    cm.state.specialChars = new RegExp(val.source + (val.test("\t") ? "" : "|\t"), "g")
    if (old != Init) cm.refresh()
  })
  option("specialCharPlaceholder", defaultSpecialCharPlaceholder, cm => cm.refresh(), true)
  option("electricChars", true)
  option("inputStyle", mobile ? "contenteditable" : "textarea", () => {
    throw new Error("inputStyle can not (yet) be changed in a running editor") // FIXME
  }, true)
  option("spellcheck", false, (cm, val) => cm.getInputField().spellcheck = val, true)
  option("rtlMoveVisually", !windows)
  option("wholeLineUpdateBefore", true)

  option("theme", "default", cm => {
    themeChanged(cm)
    guttersChanged(cm)
  }, true)
  option("keyMap", "default", (cm, val, old) => {
    let next = getKeyMap(val)
    let prev = old != Init && getKeyMap(old)
    if (prev && prev.detach) prev.detach(cm, next)
    if (next.attach) next.attach(cm, prev || null)
  })
  option("extraKeys", null)

  option("lineWrapping", false, wrappingChanged, true)
  option("gutters", [], cm => {
    setGuttersForLineNumbers(cm.options)
    guttersChanged(cm)
  }, true)
  option("fixedGutter", true, (cm, val) => {
    cm.display.gutters.style.left = val ? compensateForHScroll(cm.display) + "px" : "0"
    cm.refresh()
  }, true)
  option("coverGutterNextToScrollbar", false, cm => updateScrollbars(cm), true)
  option("scrollbarStyle", "native", cm => {
    initScrollbars(cm)
    updateScrollbars(cm)
    cm.display.scrollbars.setScrollTop(cm.doc.scrollTop)
    cm.display.scrollbars.setScrollLeft(cm.doc.scrollLeft)
  }, true)
  option("lineNumbers", false, cm => {
    setGuttersForLineNumbers(cm.options)
    guttersChanged(cm)
  }, true)
  option("firstLineNumber", 1, guttersChanged, true)
  option("lineNumberFormatter", integer => integer, guttersChanged, true)
  option("showCursorWhenSelecting", false, updateSelection, true)

  option("resetSelectionOnContextMenu", true)
  option("lineWiseCopyCut", true)

  option("readOnly", false, (cm, val) => {
    if (val == "nocursor") {
      onBlur(cm)
      cm.display.input.blur()
      cm.display.disabled = true
    } else {
      cm.display.disabled = false
    }
    cm.display.input.readOnlyChanged(val)
  })
  option("disableInput", false, (cm, val) => {if (!val) cm.display.input.reset()}, true)
  option("dragDrop", true, dragDropChanged)
  option("allowDropFileTypes", null)

  option("cursorBlinkRate", 530)
  option("cursorScrollMargin", 0)
  option("cursorHeight", 1, updateSelection, true)
  option("singleCursorHeightPerLine", true, updateSelection, true)
  option("workTime", 100)
  option("workDelay", 100)
  option("flattenSpans", true, resetModeState, true)
  option("addModeClass", false, resetModeState, true)
  option("pollInterval", 100)
  option("undoDepth", 200, (cm, val) => cm.doc.history.undoDepth = val)
  option("historyEventDelay", 1250)
  option("viewportMargin", 10, cm => cm.refresh(), true)
  option("maxHighlightLength", 10000, resetModeState, true)
  option("moveInputWithCursor", true, (cm, val) => {
    if (!val) cm.display.input.resetPosition()
  })

  option("tabindex", null, (cm, val) => cm.display.input.getField().tabIndex = val || "")
  option("autofocus", null)
}

function guttersChanged(cm) {
  updateGutters(cm)
  regChange(cm)
  alignHorizontally(cm)
}

function dragDropChanged(cm, value, old) {
  let wasOn = old && old != Init
  if (!value != !wasOn) {
    let funcs = cm.display.dragFunctions
    let toggle = value ? on : off
    toggle(cm.display.scroller, "dragstart", funcs.start)
    toggle(cm.display.scroller, "dragenter", funcs.enter)
    toggle(cm.display.scroller, "dragover", funcs.over)
    toggle(cm.display.scroller, "dragleave", funcs.leave)
    toggle(cm.display.scroller, "drop", funcs.drop)
  }
}

function wrappingChanged(cm) {
  if (cm.options.lineWrapping) {
    addClass(cm.display.wrapper, "CodeMirror-wrap")
    cm.display.sizer.style.minWidth = ""
    cm.display.sizerWidth = null
  } else {
    rmClass(cm.display.wrapper, "CodeMirror-wrap")
    findMaxLine(cm)
  }
  estimateLineHeights(cm)
  regChange(cm)
  clearCaches(cm)
  setTimeout(() => updateScrollbars(cm), 100)
}
