import {wrapIn, setBlockType, chainCommands, toggleMark, exitCode,
        joinUp, joinDown, lift, selectParentNode} from "prosemirror-commands"
import {wrapInList, splitListItem, liftListItem, sinkListItem} from "prosemirror-schema-list"
import {undo, redo} from "prosemirror-history"
import {undoInputRule} from "prosemirror-inputrules"
import {Command} from "prosemirror-state"
import {Schema} from "prosemirror-model"

const mac = typeof navigator != "undefined" ? /Mac|iP(hone|[oa]d)/.test(navigator.platform) : false

/// Inspect the given schema looking for marks and nodes from the
/// basic schema, and if found, add key bindings related to them.
/// This will add:
///
/// * **Mod-b** for toggling [strong](#schema-basic.StrongMark)
/// * **Mod-i** for toggling [emphasis](#schema-basic.EmMark)
/// * **Mod-`** for toggling [code font](#schema-basic.CodeMark)
/// * **Ctrl-Shift-0** for making the current textblock a paragraph
/// * **Ctrl-Shift-1** to **Ctrl-Shift-Digit6** for making the current
///   textblock a heading of the corresponding level
/// * **Ctrl-Shift-Backslash** to make the current textblock a code block
/// * **Ctrl-Shift-8** to wrap the selection in an ordered list
/// * **Ctrl-Shift-9** to wrap the selection in a bullet list
/// * **Ctrl->** to wrap the selection in a block quote
/// * **Enter** to split a non-empty textblock in a list item while at
///   the same time splitting the list item
/// * **Mod-Enter** to insert a hard break
/// * **Mod-_** to insert a horizontal rule
/// * **Backspace** to undo an input rule
/// * **Alt-ArrowUp** to `joinUp`
/// * **Alt-ArrowDown** to `joinDown`
/// * **Mod-BracketLeft** to `lift`
/// * **Escape** to `selectParentNode`
///
/// You can suppress or map these bindings by passing a `mapKeys`
/// argument, which maps key names (say `"Mod-B"` to either `false`, to
/// remove the binding, or a new key name string.
export function buildKeymap(schema: Schema, mapKeys?: {[key: string]: false | string}) {
  let keys: {[key: string]: Command} = {}, type
  function bind(key: string, cmd: Command) {
    if (mapKeys) {
      let mapped = mapKeys[key]
      if (mapped === false) return
      if (mapped) key = mapped
    }
    keys[key] = cmd
  }

  bind("Mod-z", undo)
  bind("Shift-Mod-z", redo)
  bind("Backspace", undoInputRule)
  if (!mac) bind("Mod-y", redo)

  bind("Alt-ArrowUp", joinUp)
  bind("Alt-ArrowDown", joinDown)
  bind("Mod-BracketLeft", lift)
  bind("Escape", selectParentNode)

  if (type = schema.marks.strong) {
    bind("Mod-b", toggleMark(type))
    bind("Mod-B", toggleMark(type))
  }
  if (type = schema.marks.em) {
    bind("Mod-i", toggleMark(type))
    bind("Mod-I", toggleMark(type))
  }
  if (type = schema.marks.code)
    bind("Mod-`", toggleMark(type))

  if (type = schema.nodes.bullet_list)
    bind("Shift-Ctrl-8", wrapInList(type))
  if (type = schema.nodes.ordered_list)
    bind("Shift-Ctrl-9", wrapInList(type))
  if (type = schema.nodes.blockquote)
    bind("Ctrl->", wrapIn(type))
  if (type = schema.nodes.hard_break) {
    let br = type, cmd = chainCommands(exitCode, (state, dispatch) => {
      if (dispatch) dispatch(state.tr.replaceSelectionWith(br.create()).scrollIntoView())
      return true
    })
    bind("Mod-Enter", cmd)
    bind("Shift-Enter", cmd)
    if (mac) bind("Ctrl-Enter", cmd)
  }
  if (type = schema.nodes.list_item) {
    bind("Enter", splitListItem(type))
    bind("Mod-[", liftListItem(type))
    bind("Mod-]", sinkListItem(type))
  }
  if (type = schema.nodes.paragraph)
    bind("Shift-Ctrl-0", setBlockType(type))
  if (type = schema.nodes.code_block)
    bind("Shift-Ctrl-\\", setBlockType(type))
  if (type = schema.nodes.heading)
    for (let i = 1; i <= 6; i++) bind("Shift-Ctrl-" + i, setBlockType(type, {level: i}))
  if (type = schema.nodes.horizontal_rule) {
    let hr = type
    bind("Mod-_", (state, dispatch) => {
      if (dispatch) dispatch(state.tr.replaceSelectionWith(hr.create()).scrollIntoView())
      return true
    })
  }

  return keys
}