import './view.js?reader-v1'
import { createTOCView } from './ui/tree.js'
import { createMenu } from './ui/menu.js'
import { Overlayer } from './overlayer.js'

const getCSS = ({ spacing, justify, hyphenate }) => `
    @namespace epub "http://www.idpf.org/2007/ops";
    html {
        color-scheme: light dark;
    }
    /* https://github.com/whatwg/html/issues/5426 */
    @media (prefers-color-scheme: dark) {
        a:link {
            color: lightblue;
        }
    }
    p, li, blockquote, dd {
        line-height: ${spacing};
        text-align: ${justify ? 'justify' : 'start'};
        -webkit-hyphens: ${hyphenate ? 'auto' : 'manual'};
        hyphens: ${hyphenate ? 'auto' : 'manual'};
        -webkit-hyphenate-limit-before: 3;
        -webkit-hyphenate-limit-after: 2;
        -webkit-hyphenate-limit-lines: 2;
        hanging-punctuation: allow-end last;
        widows: 2;
    }
    /* prevent the above from overriding the align attribute */
    [align="left"] { text-align: left; }
    [align="right"] { text-align: right; }
    [align="center"] { text-align: center; }
    [align="justify"] { text-align: justify; }

    pre {
        white-space: pre-wrap !important;
    }
    aside[epub|type~="endnote"],
    aside[epub|type~="footnote"],
    aside[epub|type~="note"],
    aside[epub|type~="rearnote"] {
        display: none;
    }
`

const $ = document.querySelector.bind(document)

const locales = 'en'
const percentFormat = new Intl.NumberFormat(locales, { style: 'percent' })
const listFormat = new Intl.ListFormat(locales, { style: 'short', type: 'conjunction' })

const formatLanguageMap = x => {
    if (!x) return ''
    if (typeof x === 'string') return x
    const keys = Object.keys(x)
    return x[keys[0]]
}

const formatOneContributor = contributor => typeof contributor === 'string'
    ? contributor : formatLanguageMap(contributor?.name)

const formatContributor = contributor => Array.isArray(contributor)
    ? listFormat.format(contributor.map(formatOneContributor))
    : formatOneContributor(contributor)

class Reader {
    #tocView
    style = {
        spacing: 1.4,
        justify: true,
        hyphenate: true,
    }
    annotations = new Map()
    annotationsByValue = new Map()
    closeSideBar() {
        $('#dimming-overlay').classList.remove('show')
        $('#side-bar').classList.remove('show')
    }
    constructor() {
        $('#side-bar-button').addEventListener('click', () => {
            $('#dimming-overlay').classList.add('show')
            $('#side-bar').classList.add('show')
        })
        $('#dimming-overlay').addEventListener('click', () => this.closeSideBar())

        const menu = createMenu([
            {
                name: 'layout',
                label: 'Layout',
                type: 'radio',
                items: [
                    ['Paginated', 'paginated'],
                    ['Scrolled', 'scrolled'],
                ],
                onclick: value => {
                    this.view?.renderer.setAttribute('flow', value)
                },
            },
        ])
        menu.element.classList.add('menu')

        $('#menu-button').append(menu.element)
        $('#menu-button > button').addEventListener('click', () =>
            menu.element.classList.toggle('show'))
        menu.groups.layout.select('scrolled')
    }
    async open(file) {
        this.view = document.createElement('foliate-view')
        document.body.append(this.view)
        await this.view.open(file)
        this.view.renderer.setAttribute('flow', 'scrolled')
        let moving = false
        let previousStart = null
        const moveSection = async direction => {
            const renderer = this.view.renderer
            if (moving || !renderer.scrolled || !direction) return
            const start = renderer.start
            const end = renderer.end
            const viewSize = renderer.viewSize
            if (direction > 0 && end < viewSize - 2) return
            if (direction < 0 && start > 2) return
            moving = true
            try {
                if (direction > 0) await this.view.next()
                else await this.view.prev()
            } finally {
                moving = false
                previousStart = null
            }
        }
        const moveAcrossSections = () => {
            const renderer = this.view.renderer
            const start = renderer.start
            const direction = previousStart == null ? 0 : start - previousStart
            previousStart = start
            moveSection(direction)
        }
        let boundContainer = null
        const bindScrollContainer = () => {
            const container = this.view.renderer.shadowRoot?.querySelector('#container') || this.view.renderer
            if (container === boundContainer) return
            boundContainer = container
            container.addEventListener('scroll', moveAcrossSections)
            container.addEventListener('wheel', event => {
            if (event.deltaY) moveSection(event.deltaY > 0 ? 1 : -1)
            }, { passive: true })
        }
        bindScrollContainer()
        this.view.renderer.addEventListener('load', bindScrollContainer)
        setInterval(bindScrollContainer, 200)
        let touchStartY = null
        this.view.renderer.addEventListener('touchstart', event => {
            touchStartY = event.touches[0]?.clientY ?? null
        }, { passive: true })
        this.view.renderer.addEventListener('touchend', event => {
            if (touchStartY == null) return
            const delta = touchStartY - (event.changedTouches[0]?.clientY ?? touchStartY)
            touchStartY = null
            if (Math.abs(delta) > 24) moveSection(delta > 0 ? 1 : -1)
        }, { passive: true })
        this.view.addEventListener('load', this.#onLoad.bind(this))
        this.view.addEventListener('relocate', this.#onRelocate.bind(this))

        const { book } = this.view
        book.transformTarget?.addEventListener('data', ({ detail }) => {
            detail.data = Promise.resolve(detail.data).catch(e => {
                console.error(new Error(`Failed to load ${detail.name}`, { cause: e }))
                return ''
            })
        })
        this.view.renderer.setStyles?.(getCSS(this.style))
        await Promise.race([
            this.view.goTo(0),
            new Promise(resolve => setTimeout(resolve, 3000)),
        ])

        $('#header-bar').style.visibility = 'visible'
        $('#nav-bar').style.visibility = 'visible'
        $('#left-button').addEventListener('click', () => this.view.goLeft())
        $('#right-button').addEventListener('click', () => this.view.goRight())

        const slider = $('#progress-slider')
        slider.dir = book.dir
        slider.addEventListener('input', e =>
            this.view.goToFraction(parseFloat(e.target.value)))
        for (const fraction of this.view.getSectionFractions()) {
            const option = document.createElement('option')
            option.value = fraction
            $('#tick-marks').append(option)
        }

        document.addEventListener('keydown', this.#handleKeydown.bind(this))

        const title = formatLanguageMap(book.metadata?.title) || 'Untitled Book'
        document.title = title
        $('#side-bar-title').innerText = title
        $('#side-bar-author').innerText = formatContributor(book.metadata?.author)
        Promise.resolve(book.getCover?.())?.then(blob =>
            blob ? $('#side-bar-cover').src = URL.createObjectURL(blob) : null)

        const toc = book.toc
        if (toc) {
            this.#tocView = createTOCView(toc, href => {
                this.view.goTo(href).catch(e => console.error(e))
                this.closeSideBar()
            })
            $('#toc-view').append(this.#tocView.element)
            const entries = []
            const append = (items, depth = 0) => {
                for (const item of items || []) {
                    entries.push({ label: item.label || '未命名章节', href: item.href, depth })
                    append(item.subitems, depth + 1)
                }
            }
            append(toc)
            if (window.parent !== window) window.parent.postMessage({ type: 'voice-foliate-toc', entries }, location.origin)
        }

        // load and show highlights embedded in the file by Calibre
        const bookmarks = await book.getCalibreBookmarks?.()
        if (bookmarks) {
            const { fromCalibreHighlight } = await import('./epubcfi.js')
            for (const obj of bookmarks) {
                if (obj.type === 'highlight') {
                    const value = fromCalibreHighlight(obj)
                    const color = obj.style.which
                    const note = obj.notes
                    const annotation = { value, color, note }
                    const list = this.annotations.get(obj.spine_index)
                    if (list) list.push(annotation)
                    else this.annotations.set(obj.spine_index, [annotation])
                    this.annotationsByValue.set(value, annotation)
                }
            }
            this.view.addEventListener('create-overlay', e => {
                const { index } = e.detail
                const list = this.annotations.get(index)
                if (list) for (const annotation of list)
                    this.view.addAnnotation(annotation)
            })
            this.view.addEventListener('draw-annotation', e => {
                const { draw, annotation } = e.detail
                const { color } = annotation
                draw(Overlayer.highlight, { color })
            })
            this.view.addEventListener('show-annotation', e => {
                const annotation = this.annotationsByValue.get(e.detail.value)
                if (annotation.note) alert(annotation.note)
            })
        }
    }
    #handleKeydown(event) {
        const k = event.key
        if (k === 'ArrowLeft' || k === 'h') this.view.goLeft()
        else if(k === 'ArrowRight' || k === 'l') this.view.goRight()
    }
    #onLoad({ detail: { doc } }) {
        doc.addEventListener('keydown', this.#handleKeydown.bind(this))
    }
    #onRelocate({ detail }) {
        const { fraction, location, tocItem, pageItem, cfi } = detail
        const percent = percentFormat.format(fraction)
        const loc = pageItem
            ? `Page ${pageItem.label}`
            : `Loc ${location.current}`
        const slider = $('#progress-slider')
        slider.style.visibility = 'visible'
        slider.value = fraction
        slider.title = `${percent} · ${loc}`
        if (tocItem?.href) this.#tocView?.setCurrentHref?.(tocItem.href)
        if (window.parent !== window) window.parent.postMessage({
            type: 'voice-foliate-relocate', fraction,
            cfi: cfi || '', href: tocItem?.href || ''
        }, globalThis.location.origin)
    }
}

const open = async file => {
    document.body.removeChild($('#drop-target'))
    const reader = new Reader()
    globalThis.reader = reader
    await reader.open(file)
}

const dragOverHandler = e => e.preventDefault()
const dropHandler = e => {
    e.preventDefault()
    const item = Array.from(e.dataTransfer.items)
        .find(item => item.kind === 'file')
    if (item) {
        const entry = item.webkitGetAsEntry()
        open(entry.isFile ? item.getAsFile() : entry).catch(e => console.error(e))
    }
}
const dropTarget = $('#drop-target')
dropTarget.addEventListener('drop', dropHandler)
dropTarget.addEventListener('dragover', dragOverHandler)

$('#file-input').addEventListener('change', e =>
    open(e.target.files[0]).catch(e => console.error(e)))
$('#file-button').addEventListener('click', () => $('#file-input').click())

const params = new URLSearchParams(location.search)
const url = params.get('url')
const proxy = params.get('proxy')
if (params.get('embed') === '1') document.documentElement.classList.add('embedded')
const fileNameHint = params.get('file_name') || ''
globalThis.foliateFileNameHint = fileNameHint
window.addEventListener('message', event => {
    if (event.source !== window.parent || event.data?.type !== 'voice-foliate-goto') return
    if (event.data.href) globalThis.reader?.view?.goTo(event.data.href).catch(e => console.error(e))
})
window.addEventListener('message', event => {
    if (event.source !== window.parent) return
    const type = event.data?.type
    if (type === 'voice-foliate-seek') globalThis.reader?.view?.goToFraction(Number(event.data.percent) / 100)
    else if (type === 'voice-foliate-prev') globalThis.reader?.view?.prev()
    else if (type === 'voice-foliate-next') globalThis.reader?.view?.next()
})
window.addEventListener('message', event => {
    if (event.source !== window.parent || event.data?.type !== 'voice-foliate-goto-cfi') return
    if (event.data.cfi) globalThis.reader?.view?.goTo(event.data.cfi).catch(e => console.error(e))
})
window.addEventListener('message', async event => {
    if (event.source !== window.parent || event.data?.type !== 'voice-foliate-search') return
    const results = []
    for await (const group of globalThis.reader?.view?.search?.({ query: event.data.query }) || []) {
        for (const item of group.subitems || []) results.push({ label: group.label || '电子书位置', cfi: item.cfi, excerpt: item.excerpt || { pre: '', match: event.data.query, post: '' } })
        if (results.length >= 100) break
    }
    window.parent.postMessage({ type: 'voice-foliate-search-results', results: results.slice(0, 100) }, location.origin)
})
if (url) open(proxy || url).then(() => window.parent !== window && window.parent.postMessage({ type: 'voice-foliate-ready' }, location.origin)).catch(e => { console.error(e); if (window.parent !== window) window.parent.postMessage({ type: 'voice-foliate-error', message: e?.message || 'FOLIATE_LOAD_FAILED' }, location.origin) })
else dropTarget.style.visibility = 'visible'