Mikubot-2/otouto/plugins/wikipedia.lua

local wikipedia = {}

local HTTPS = require('ssl.https')
local URL = require('socket.url')
local JSON = require('dkjson')
local utilities = require('otouto.utilities')

wikipedia.command = 'wikipedia <query>'

function wikipedia:init(config)
	wikipedia.triggers = utilities.triggers(self.info.username, config.cmd_pat):t('wikipedia', true):t('wiki', true):t('w', true).table
	wikipedia.doc = config.cmd_pat .. [[wikipedia <query>
Returns an article from Wikipedia.
Aliases: ]] .. config.cmd_pat .. 'w, ' .. config.cmd_pat .. 'wiki'
	wikipedia.search_url = 'https://' .. config.lang .. '.wikipedia.org/w/api.php?action=query&list=search&format=json&srsearch='
	wikipedia.res_url = 'https://' .. config.lang .. '.wikipedia.org/w/api.php?action=query&prop=extracts&format=json&exchars=4000&exsectionformat=plain&titles='
	wikipedia.art_url = 'https://' .. config.lang .. '.wikipedia.org/wiki/'
end

function wikipedia:action(msg, config)
	local input = utilities.input_from_msg(msg)
	if not input then
		utilities.send_reply(self, msg, wikipedia.doc, true)
		return
	end

	local jstr, code = HTTPS.request(wikipedia.search_url .. URL.escape(input))
	if code ~= 200 then
		utilities.send_reply(self, msg, config.errors.connection)
		return
	end

	local data = JSON.decode(jstr)
	if data.query.searchinfo.totalhits == 0 then
		utilities.send_reply(self, msg, config.errors.results)
		return
	end

	local title
	for _, v in ipairs(data.query.search) do
		if not v.snippet:match('may refer to:') then
			title = v.title
			break
		end
	end
	if not title then
		utilities.send_reply(self, msg, config.errors.results)
		return
	end

	local res_jstr, res_code = HTTPS.request(wikipedia.res_url .. URL.escape(title))
	if res_code ~= 200 then
		utilities.send_reply(self, msg, config.errors.connection)
		return
	end

	local _, text = next(JSON.decode(res_jstr).query.pages)
	if not text then
		utilities.send_reply(self, msg, config.errors.results)
		return
	end

	text = text.extract
	-- Remove crap and take only the first paragraph.
	text = text:gsub('</?.->', ''):gsub('%[.+%]', '')
	local l = text:find('\n')
	if l then
		text = text:sub(1, l-1)
	end
	local url = wikipedia.art_url .. URL.escape(title)
	title = utilities.html_escape(title)
	-- If the beginning of the article is the title, embolden that.
	-- Otherwise, we'll add a title in bold.
	local short_title = title:gsub('%(.+%)', '')
	local combined_text, count = text:gsub('^'..short_title, '<b>'..short_title..'</b>')
	local body
	if count == 1 then
		body = combined_text
	else
		body = '<b>' .. title .. '</b>\n' .. text
	end
	local output = string.format(
		'%s\n<a href="%s">Read more.</a>',
		body,
		utilities.html_escape(url)
	)
	utilities.send_message(self, msg.chat.id, output, true, nil, 'html')
end

return wikipedia