# vim:fileencoding=utf-8
# License: GPL v3 Copyright: 2016, Kovid Goyal <kovid at kovidgoyal.net>
from __python__ import hash_literals

from complete import create_search_bar
from dom import set_css, svgicon, ensure_id
from elementmaker import E
from gettext import gettext as _
from modals import error_dialog
from widgets import create_tree, find_text_in_tree, scroll_tree_item_into_view
from read_book.globals import toc_anchor_map, set_toc_anchor_map, current_spine_item, current_layout_mode


def update_visible_toc_nodes(visible_anchors):
    update_visible_toc_nodes.data = visible_anchors
update_visible_toc_nodes.data = {}


def iter_toc_nodes(node, callback):
    if callback(node):
        return
    for child in node.children:
        if callback(child):
            return

def get_highlighted_toc_nodes(toc, spine, parent_map, id_map):
    data = update_visible_toc_nodes.data
    ans = {}
    if data.has_visible:
        ans = data.visible_anchors
    else:
        if data.before:
            ans[data.before] = True
        else:
            nodes_before = v'[]'
            iter_toc_nodes(toc, def(node):
                if node.dest is current_spine_item():
                    return True
                nodes_before.push(node)
            )
            if nodes_before.length:
                ans[nodes_before[-1].id] = True
    for node_id in Object.keys(ans):
        pid = parent_map[node_id]
        while pid:
            ans[pid] = True
            pid = parent_map[pid]
    return ans


def create_toc_tree(toc, onclick):

    parent_map, id_map = {}, {}

    def process_node(node, parent):
        id_map[node.id] = node
        parent_map[node.id] = parent
        for c in node.children:
            process_node(c, node)

    process_node(toc)
    highlighted_toc_nodes = get_highlighted_toc_nodes(toc, parent_map, id_map)

    def populate_data(node, li, a):
        li.dataset.tocDest = node.dest or ''
        li.dataset.tocFrag = node.frag or ''
        title = node.title or ''
        if highlighted_toc_nodes[node.id]:
            a.appendChild(E.b(E.i(title)))
        else:
            a.textContent = title

    return create_tree(toc, populate_data, onclick)

def do_search(text):
    container = document.getElementById(this)
    a = find_text_in_tree(container, text)
    if not text:
        return
    if not a:
        return error_dialog(_('No matches found'), _(
            'The text "{}" was not found in the Table of Contents').format(text))
    scroll_tree_item_into_view(a)

def create_toc_panel(book, container, onclick, onclose):
    container.appendChild(E.div(
        style='display: flex; justify-content: space-between; padding: 1ex 1em; border-bottom: solid 1px currentColor',
        E.h2(_('Table of Contents')),
        E.div(svgicon('close'), style='cursor:pointer', onclick=def(event):event.preventDefault(), event.stopPropagation(), onclose(event);, class_='simple-link'),
    ))
    def handle_click(event, li):
        if event.button is 0:
            onclick(li.dataset.tocDest, li.dataset.tocFrag)
    toc_panel = create_toc_tree(book.manifest.toc, handle_click)
    toc_panel_id = ensure_id(toc_panel)
    set_css(container, display='flex', flex_direction='column')
    set_css(toc_panel, flex_grow='10')
    container.appendChild(toc_panel)
    search_button = E.div(class_='simple-link', svgicon('search'))
    t = _('Search Table of Contents')
    search_bar = create_search_bar(do_search.bind(toc_panel_id), 'search-book-toc', button=search_button, placeholder=t)
    set_css(search_bar, flex_grow='10', margin_right='1em')
    container.appendChild(E.div(style='margin: 1ex 1em; display: flex;', search_bar, search_button))


def current_toc_anchor_map(tam, anchor_funcs):
    current_map = toc_anchor_map()
    if not (current_map and current_map.layout_mode is current_layout_mode() and current_map.width is window.innerWidth and current_map.height is window.innerHeight):
        name = current_spine_item().name
        am = {}
        anchors = v'[]'
        for anchor in (tam[name] or v'[]'):
            val = anchor_funcs.pos_for_elem()
            if anchor.frag:
                elem = document.getElementById(anchor.frag)
                if elem:
                    val = anchor_funcs.pos_for_elem(elem)
            am[anchor.id] = val
            anchors.push(anchor.id)
        anchors.sort(def (a, b): anchor_funcs.cmp(am[a], am[b]);)
        sort_map = {aid: i for i, aid in enumerate(anchors)}

        current_map = {'layout_mode': current_layout_mode, 'width': window.innerWidth, 'height': window.innerHeight, 'pos_map': am, 'sort_map':sort_map}
        set_toc_anchor_map(current_map)
    return current_map


def update_visible_toc_anchors(toc_anchor_map, anchor_funcs):
    tam = current_toc_anchor_map(toc_anchor_map, anchor_funcs)
    before = after = None
    visible_anchors = {}
    has_visible = False
    for anchor_id in tam.pos_map:
        pos = tam.pos_map[anchor_id]
        visibility = anchor_funcs.visibility(pos)
        if visibility < 0:
            before = anchor_id
        elif visibility is 0:
            has_visible = True
            visible_anchors[anchor_id] = True
        elif visibility > 0:
            after = anchor_id
            break

    return {'visible_anchors':visible_anchors, 'has_visible':has_visible, 'before':before, 'after':after}