/*
 * Copyright (c) 2016-2020 Martin Donath <martin.donath@squidfunk.com>
 *
 * Permission is hereby granted, free of charge, to any person obtaining a copy
 * of this software and associated documentation files (the "Software"), to
 * deal in the Software without restriction, including without limitation the
 * rights to use, copy, modify, merge, publish, distribute, sublicense, and/or
 * sell copies of the Software, and to permit persons to whom the Software is
 * furnished to do so, subject to the following conditions:
 *
 * The above copyright notice and this permission notice shall be included in
 * all copies or substantial portions of the Software.
 *
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
 * FITNESS FOR A PARTICULAR PURPOSE AND NON-INFRINGEMENT. IN NO EVENT SHALL THE
 * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
 * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS
 * IN THE SOFTWARE.
 */

// TODO: remove this after we finished refactoring
// tslint:disable

import "../stylesheets/app.scss"
import "../stylesheets/app-palette.scss"

import * as Clipboard from "clipboard"
import { identity, values } from "ramda"
import {
  EMPTY,
  Observable,
  merge,
  of,
  fromEvent,
  OperatorFunction,
  pipe
} from "rxjs"
import {
  delay,
  filter,
  map,
  pluck,
  switchMap,
  switchMapTo,
  tap,
  distinctUntilKeyChanged,
  shareReplay
} from "rxjs/operators"

import {
  Component,
  paintHeaderShadow,
  mountHero,
  mountTableOfContents,
  mountTabs,
  switchComponent,
  watchComponentMap,
} from "./components"
import {
  watchHeader,
  watchSearchQuery,
  watchSearchReset,
  getElement,
  watchToggle,
  setToggle,
  getElements,
  watchMedia,
  watchDocument,
  watchLocationHash,
  watchMain,
  watchViewport,
  watchKeyboard
} from "./observables"
import {
  isSearchResultMessage,
  setupSearchWorker
} from "./workers"
import { renderSource } from "templates"
import { not, takeIf } from "utilities"
import { renderClipboard } from "templates/clipboard"
import { fetchGitHubStats } from "modules/source/github"
import { mountNavigation } from "components2/navigation"
import { mountSearchResult } from "components2/search"
import { renderTable } from "templates/table"

/* ----------------------------------------------------------------------------
 * Types
 * ------------------------------------------------------------------------- */

/**
 * Configuration
 */
export interface Config {
  base: string                         /* Base URL */
  worker: {
    search: string                     /* Search worker URL */
    packer: string                     /* Packer worker URL */
  }
}

/* ----------------------------------------------------------------------------
 * TODO: where do we put this stuff?
 * ------------------------------------------------------------------------- */

document.documentElement.classList.remove("no-js")
document.documentElement.classList.add("js")

/* Test for iOS */
if (navigator.userAgent.match(/(iPad|iPhone|iPod)/g))
  document.documentElement.classList.add("ios")

const names: Component[] = [
  "container",                       /* Container */
  "header",                          /* Header */
  "header-title",                    /* Header title */
  "hero",                            /* Hero */
  "main",                            /* Main area */
  "navigation",                      /* Navigation */
  "search",                          /* Search */
  "search-query",                    /* Search input */
  "search-reset",                    /* Search reset */
  "search-result",                   /* Search results */
  "tabs",                            /* Tabs */
  "toc"                              /* Table of contents */
]

/* ----------------------------------------------------------------------------
 * Helper functions
 * ------------------------------------------------------------------------- */

/**
 * Ensure that the given value is a valid configuration
 *
 * We could use `jsonschema` or any other schema validation framework, but that
 * would just add more bloat to the bundle, so we'll keep it plain and simple.
 *
 * @param config - Configuration
 *
 * @return Test result
 */
function isConfig(config: any): config is Config {
  return typeof config === "object"
      && typeof config.base === "string"
      && typeof config.worker === "object"
      && typeof config.worker.search === "string"
      && typeof config.worker.packer === "string"
}

/**
 * Yes, this is a super hacky implementation. Needs clean up.
 */
function repository() {
  const el = getElement<HTMLAnchorElement>(".md-source[href]") // TODO: dont use classes
  console.log(el)
  if (!el)
    return EMPTY

  const data = sessionStorage.getItem("repository")
  if (data) {
    const x = JSON.parse(data)
    return of(x)
  }

  // TODO: do correct rounding, see GitHub
  function format(value: number) {
    return value > 999
      ? `${(value / 1000).toFixed(1)}k`
      : `${(value)}`
  }

  // github repository...
  const [, user, repo] = el.href.match(/^.+github\.com\/([^\/]+)\/?([^\/]+)?.*$/i)

  // storage memoization!?
  // get, if not available, exec and persist

  // getOrRetrieve... storage$.

  // Show repo stats
  if (user && repo) {
    return fetchGitHubStats(user, repo)
      .pipe(
        map(({ stargazers_count, forks_count }) => ([
          `${format(stargazers_count || 0)} Stars`,
          `${format(forks_count || 0)} Forks`
        ])),
        tap(data => sessionStorage.setItem("repository", JSON.stringify(data)))
      )

  // Show user or organization stats
  } else if (user) {
    return fetchGitHubStats(user)
      .pipe(
        map(({ public_repos }) => ([
          `${format(public_repos || 0)} Repositories`
        ])),
        tap(data => sessionStorage.setItem("repository", JSON.stringify(data)))
      )
  }
  return of([])
}

/* ----------------------------------------------------------------------------
 * Functions
 * ------------------------------------------------------------------------- */

/**
 * Initialize Material for MkDocs
 *
 * @param config - Configuration
 */
export function initialize(config: unknown) {
  if (!isConfig(config))
    throw new SyntaxError(`Invalid configuration: ${JSON.stringify(config)}`)

  // TODO: WIP repo rendering
  repository().subscribe(facts => {
    if (facts.length) {
      const sources = getElements(".md-source__repository")
      sources.forEach(repo => {
        repo.dataset.mdState = "done"
        repo.appendChild(
          renderSource(facts)
        )
      })
    }
  })

  // pass config here!?
  const document$ = watchDocument()
  const hash$ = watchLocationHash()
  const viewport$ = watchViewport()
  const screen$ = watchMedia("(min-width: 960px)")
  const tablet$ = watchMedia("(min-width: 1220px)")

  /* ----------------------------------------------------------------------- */

  /* Create component map observable */
  const components$ = watchComponentMap(names, { document$ })
  const component = <T extends HTMLElement>(name: Component): Observable<T> => {
    return components$
      .pipe(
        switchComponent<T>(name)
      )
  }

  /* Create header observable */
  const header$ = component("header")  // TODO:!
    .pipe(
      switchMap(watchHeader)
    )

  /* Create header shadow toggle */
  component("header")
    .pipe(
      switchMap(el => main$
        .pipe(
          paintHeaderShadow(el) // technically, this could be done in paintMain
        )
      )
    )
      .subscribe()

  // DONE
  const main$ = component("main")
    .pipe(
      switchMap(el => watchMain(el, { header$, viewport$ })),
      shareReplay(1) // TODO: mount!?
    )

  // ---------------------------------------------------------------------------

  /* ----------------------------------------------------------------------- */

  const drawer = getElement<HTMLInputElement>("[data-md-toggle=drawer]")!

  /* ----------------------------------------------------------------------- */

  // build a single search observable???

  const query$ = component<HTMLInputElement>("search-query")
    .pipe(
      switchMap(el => watchSearchQuery(el))
    )

  const sw = setupSearchWorker(config.worker.search, {
    base: config.base,
    query$
  })

  const result$ = sw.rx$ // move worker initialization into mountSearch ?
    .pipe(
      filter(isSearchResultMessage),
      pluck("data")
    )

  const search = getElement<HTMLInputElement>("[data-md-toggle=search]")!
  const searchActive$ = watchToggle(search)
    .pipe(
      delay(400)
    )

  query$
    .pipe(
      distinctUntilKeyChanged("focus"),
      tap(query => {
        if (query.focus)
          setToggle(search, query.focus) // paintSearchQuery?
        // console.log(query)
      })
    )
      .subscribe()

  // implement toggle function that returns the toggles as observable...
  const reset$ = component("search-reset")
    .pipe(
      switchMap(watchSearchReset)
    )

  /* ----------------------------------------------------------------------- */

  // DONE (partly)
  const navigation$ = component("navigation")
    .pipe(
      mountNavigation({ main$, viewport$, screen$ })
    )

  const toc$ = component("toc")
    .pipe(
      mountTableOfContents({ header$, main$, viewport$, tablet$ })
    )

  // TODO: naming?
  const resultComponent$ = component("search-result")
    .pipe(
      mountSearchResult({ viewport$, result$, query$: query$.pipe(
        distinctUntilKeyChanged("value"),
      ) })
    ) // temporary fix

  // mount hideable...

  const tabs$ = component("tabs")
    .pipe(
      mountTabs({ header$, viewport$, screen$ })
    )

  const hero$ = component("hero")
    .pipe(
      mountHero({ header$, viewport$, screen$ })
    )

  // function watchKeyboard
  const key$ = watchKeyboard()

  // shortcodes
  key$
    .pipe(
      takeIf(not(searchActive$))
    )
      .subscribe(key => {
        if (
          document.activeElement && (
            ["TEXTAREA", "SELECT", "INPUT"].includes(
              document.activeElement.tagName
            ) ||
            document.activeElement instanceof HTMLElement &&
            document.activeElement.isContentEditable
          )
        ) {
          // do nothing...
        } else {
          if (key.type === "KeyS" || key.type === "KeyF") {
            setToggle(search, true)
          }
        }
      })
  // check which element is focused...
  // note that all links have tabindex=-1
  key$
    .pipe(
      takeIf(searchActive$),

      /* Abort if meta key (macOS) or ctrl key (Windows) is pressed */
      tap(key => {
        console.log("jo", key)
        if (key.type === "Enter") {
          if (document.activeElement === getElement("[data-md-component=search-query]")) {
            key.claim()
            // intercept hash change after search closed
          } else {
            setToggle(search, false)
          }
        }

        if (key.type === "ArrowUp" || key.type === "ArrowDown") {
          const active = getElements("[data-md-component=search-query], [data-md-component=search-result] [href]")
          const i = Math.max(0, active.findIndex(el => el === document.activeElement))
          const x = Math.max(0, (i + active.length + (key.type === "ArrowUp" ? -1 : +1)) % active.length)
          active[x].focus()

          /* Prevent scrolling of page */
          key.claim()

        } else if (key.type === "Escape" || key.type === "Tab") {
          setToggle(search, false)
          getElement("[data-md-component=search-query]")!.blur()

        } else {
          if (search.checked && document.activeElement !== getElement("[data-md-component=search-query]")) {
            getElement("[data-md-component=search-query]")!.focus()
          }
        }
      })
    )
      .subscribe()

  // TODO: close search on hashchange
  // anchor jump -> always close drawer + search

  // focus search on reset, on toggle and on keypress if open
  merge(searchActive$.pipe(filter(identity)), reset$)
    .pipe(
      switchMapTo(component<HTMLInputElement>("search-query")),
      tap(el => el.focus()) // TODO: only if element isnt focused! setFocus? setToggle?
    )
      .subscribe()

      // focusable -> setFocus(true, false)

  /* ----------------------------------------------------------------------- */

  /* Open details before printing */
  merge(
    watchMedia("print").pipe(filter(identity)), // Webkit
    fromEvent(window, "beforeprint") // IE, FF
  )
    .subscribe(() => {
      const details = getElements("details")
      Array.prototype.forEach.call(details, detail => {
        detail.setAttribute("open", "")
      })
    })

  // Close drawer and search on hash change
  hash$.subscribe(() => {
    setToggle(drawer, false)
    setToggle(search, false) // we probably need to delay the anchor jump for search
  })

  /* ----------------------------------------------------------------------- */

  /* Clipboard.js integration */
  if (Clipboard.isSupported()) {
    const blocks = getElements("pre > code")
    for (const [index, block] of blocks.entries()) {
      const parent = block.parentElement!
      parent.id = `__code_${index}`
      parent.insertBefore(renderClipboard(parent.id), block)
    }

    /* Initialize Clipboard listener */
    const copy = new Clipboard(".md-clipboard") // create observable...

    /* Success handler */
    // copy.on("success", action => {
    //   alert("Copied to clipboard") // TODO: integrate snackbar
    //   // TODO: add a snackbar/notification

    // })
  }

  /* Wrap all data tables for better overflow scrolling */
  const tables = getElements<HTMLTableElement>("table:not([class])")
  const placeholder = document.createElement("table")
  tables.forEach(table => {
    table.replaceWith(placeholder)
    placeholder.replaceWith(renderTable(table))
  })

  // search lock
  let lastOffset = 0
  tablet$.pipe(
    switchMap(active => {
      return !active ? watchToggle(search) : EMPTY
    }),
    switchMap(toggle => {
      if (toggle) {
        console.log("ACTIVE")
        return of(document.body)
          .pipe(
            tap(() => lastOffset = window.pageYOffset),
            delay(400),
            tap(() => {
              window.scrollTo(0, 0),
              console.log("scrolled... to top, locked body")
              document.body.dataset.mdState = "lock"
            })
          )
      } else {
        console.log("INACTIVE")
        return of(document.body)
          .pipe(
            tap(() => document.body.dataset.mdState = ""),
            delay(100),
            tap(() => {
              window.scrollTo(0, lastOffset)
            })
          )
      }
      return EMPTY
    })
  )
    .subscribe(x => console.log("SEARCHLOCK", x))

  /* ----------------------------------------------------------------------- */

  // get headerHEIGHT! only if header is sticky!

  // // lockHeader at...
  // const direction$ = agent.viewport.offset$.pipe(
  //   bufferCount(2, 1), // determine scroll direction
  //   map(([{ y: y0 }, { y: y1 }]) => y1 > y0),
  //   distinctUntilChanged(),
  // )

  // document.body.style.minHeight = "100vh"

  // // if true => then + HEADER. otherwise not
  // let last = 0
  // combineLatest([direction$, header$]).pipe(
  //   tap(([direction, { height }]) => { // TODO: only if sticky!
  //     const offset = 48
  //     console.log(window.pageYOffset, height, last)
  //     if (Math.abs(window.pageYOffset - last) < height + offset) { // TODO: add sensitivity offset!
  //       return
  //     }
  //     if (direction) {
  //       document.body.style.height = `${window.pageYOffset + offset + height}px`
  //     } else {
  //       document.body.style.height = `${window.pageYOffset - offset}px` // offset
  //     }
  //     last = window.pageYOffset
  //   })
  // )
  //   .subscribe()

  // // toiggle

  /* ----------------------------------------------------------------------- */

  const state = {
    search: {
      query$,
      result$: resultComponent$,
      reset$,
    },
    main$,
    navigation$,
    toc$,
    tabs$,
    hero$
  }

  const { search: temp, ...rest } = state
  merge(...values(rest), ...values(temp))
    .subscribe() // potential memleak <-- use takeUntil

  return {
    // agent,
    state
  }
}

// function mountSearchQuery(

// ): OperatorFunction<HTMLInputElement, SearchQuery> {
//   return pipe(
//     switchMap(el => watchSearchQuery(el))
//   )
// }