local mSIPA_API = require('Module:Sensitive IP addresses/API')
local yesno = require('Module:Yesno')

local p = {}

-- Strips a suffix from a CIDR string if the suffix is of a given bitLength.
-- bitLength must be either 32 or 128.
-- This is intended to allow CIDR strings to be represented as a single IP
-- address if this can be done unambiguously.
local function stripCIDRSuffix(cidr, bitLength)
	assert(bitLength == 32 or bitLength == 128, 'bitLength was not 32 or 128')
	local pattern = '/' .. bitLength .. '$'
	cidr = cidr:gsub(pattern, '')
	return cidr
end

-- Takes an array of CIDR ranges and returns a new array with ranges
-- appropriate for printing.
local function prettifyRanges(ranges, bitLength)
	local ret = {}
	for i, cidr in ipairs(ranges) do
		ret[i] = stripCIDRSuffix(cidr, bitLength)
	end
	return ret
end

-- Turns an array of CIDR ranges into its string representation.
local function stringifyRanges(ranges, bitLength, separator)
	if not ranges then
		return ''
	end
	ranges = prettifyRanges(ranges, bitLength)
	return table.concat(ranges, separator)
end

function p._table(options)
	-- Return a wikitext table summarizing all the sensitive IP ranges
	-- and the entities they belong to.

	-- Load dependencies
	local lang = mw.language.getContentLanguage()

	-- Set up options
	options = options or {}
	local rangeSeparator = options.rangeseparator or ', '
	local showNotes = yesno(options.notes)

	-- Get the entity data
	local data = mSIPA_API.query{entities={'all'}}
	if data['error'] then
		error(string.format('%s: %s', data['error'].code, data['error'].info))
	end

	-- Make the table root
	local root = mw.html.create('table')
	root:addClass('sensitive-ip-addresses')
	if options.class then
		root:addClass(options.class)
	end
	if options.style then
		root:cssText(options.style)
	end

	-- Add main header
	if options.mainheader then
		root:tag('caption'):wikitext(options.mainheader)
	end

	-- Add column headers
	local headerRow = root:tag('tr')
	headerRow
		:tag('th')
			:cssText(options.cellstyle)
			:wikitext('[[IPv4]]')
			:done()
		:tag('th')
			:cssText(options.cellstyle)
			:wikitext('[[IPv6]]')
			:done()
		:tag('th')
			:cssText(options.cellstyle)
			:wikitext('Description')
	if showNotes then
		headerRow:tag('th')
			:cssText(options.cellstyle)
			:wikitext('Notes')
	end

	-- Add data cells
	for i, id in ipairs(data.sensitiveips['entity-ids']) do
		local entityData = data.sensitiveips.entities[id]
		if not options.reason or options.reason == entityData.reason then
			local dataRow = root:tag('tr')
			dataRow
				:tag('td')
					:cssText(options.cellstyle)
					:wikitext(stringifyRanges(
						entityData.ipv4Ranges,
						32,
						rangeSeparator
					))
					:done()
				:tag('td')
					:cssText(options.cellstyle)
					:wikitext(stringifyRanges(
						entityData.ipv6Ranges,
						128,
						rangeSeparator
					))
					:done()
				:tag('td')
					:cssText(options.cellstyle)
					:wikitext(lang:ucfirst(entityData.description))
			if showNotes then
				dataRow:tag('td')
					:cssText(options.cellstyle)
					:wikitext(entityData.notes)
			end
		end
	end

	return tostring(root)
end

function p.table(frame)
	local args = require('Module:Arguments').getArgs(frame, {
		frameOnly = true
	})
	return p._table(args)
end

return p