require('strict')

local libraryUtil = require('libraryUtil')

local checkType = libraryUtil.checkType

local checkTypeMulti = libraryUtil.checkTypeMulti

local mRepr = require('Module:Repr')



local p = {}

local mockTitleRegistry = {}

local mockCurrentTitle = nil



-- Keep a reference to the original mw.title.new function so that we can use it

-- when mw.title.new is patched with our custom function.

local titleNew = mw.title.new



--[[

-- Capitalize a string.

--]]

local function capitalize(s)

	return s:sub(1, 1):upper() .. s:sub(2, -1)

end



--[[

-- Check that a named argument is one of multiple types.

--]]

local function checkTypeForNamedArgMulti(name, argName, arg, expectTypes)

	local argType = type(arg)

	for _, expectedType in ipairs(expectTypes) do

		if argType == expectedType then

			return

		end

	end

	error(

		string.format(

			"bad named argument %s to '%s' (%s expected, got %s)",

			argName,

			name,

			mw.text.listToText(expectTypes, ', ', ' or '),

			argType

		),

		3

	)

end



--[[

-- Set a property on an object to the given value, if that value is not nil.

--]]

local function maybeSetProperty(object, property, value)

	if value ~= nil then

		rawset(object, property, value)

	end

end



--[[

-- Construct a mock title from a string, an ID or an options table. If we were

-- passed a mock title object to start with, return it as-is.

--]]

local function constructMockTitle(titleOrOptions)

	if titleOrOptions == nil then

		return nil

	end

	local titleOrOptionsType = type(titleOrOptions)

	if titleOrOptionsType == 'string' or titleOrOptionsType == 'number' then

		return p.MockTitle{title = titleOrOptions}

	elseif titleOrOptionsType == 'table' then

		if type(titleOrOptions.getContent) == 'function' then

			return titleOrOptions

		else

			return p.MockTitle(titleOrOptions)

		end

	else

		error(

			string.format(

				'Invalid type specified to constructMockTitle (expected string, number, table or nil; received %s)',

				titleOrOptionsType

			),

			2

		)

	end

end



--[[

-- Get a table of protection levels with the levels set by the user. The

-- makeOptionsKey is a function that takes a protection action as an input and

-- gives the option table key for that action. The function returns two values:

-- the table of protection levels (as used by the protectionLevels and

-- cascadingProtection title object properties), and a boolean flag indicating

-- whether any protection levels were set.

--]]

local function getProtectionLevels(options, makeOptionsKey)

	local levels = {

		 = {},

		move = {},

		create = {},

		upload = {},

	}

	local isSet = false

	for action in pairs(levels) do

		local level = optionsmakeOptionsKey(action)]

		if level then

			levelsaction][1 = level

			isSet = true

		end

	end

	return levels, isSet

end



--[[

-- Set protection levels

--]]

local function setProtectionLevels(title, options)

	local protectionLevels, isProtectionSet = getProtectionLevels(

		options,

		function (action)

			return action .. 'Protection'

		end

	)

	if isProtectionSet then

		rawset(title, 'protectionLevels', protectionLevels)

	end

end



--[[

-- Set cascading protection

--]]

local function setCascadingProtection(title, options)

	local cascadingProtectionLevels, isCascadingProtectionSet = getProtectionLevels(

		options,

		function (action)

			return string.format('cascading%sProtection', capitalize(action))

		end

	)

	local cascadingSourcesExist = options.cascadingProtectionSources and #options.cascadingProtectionSources >= 1

	if isCascadingProtectionSet and cascadingSourcesExist then

		rawset(

			title,

			'cascadingProtection',

			{

				restrictions = cascadingProtectionLevels,

				sources = options.cascadingProtectionSources,

			}

		)

	elseif isCascadingProtectionSet then

		error('a cascading protection argument was given but the cascadingProtectionSources argument was missing or empty', 2)

	elseif cascadingSourcesExist then

		error('the cascadingProtectionSources argument was given, but no cascading protection argument was given', 2)

	end

end



--[[

-- Set page content, if specified

--]]

local function maybeSetContent(titleObject, content)

	if content then

		rawset(titleObject, 'getContent', function () return content end)

	end

end



--[[

-- Set properties in the file table, as well as the fileExists property

--]]

local function setFileProperties(title, options)

	if title.file then

		for _, property in ipairs{'exists', 'width', 'height', 'pages', 'size', 'mimeType', 'length'} do

			local optionName = 'file' .. capitalize(property)

			maybeSetProperty(title.file, property, optionsoptionName])

		end

	end

end



--[[

-- Changes the associated titles to be patched if applicable

--]]

local function patchAssociatedTitleObjects(title)

	for _, property in ipairs{'basePageTitle', 'rootPageTitle', 'talkPageTitle', 'subjectPageTitle'} do

		local mockTitle = mockTitleRegistrytitleproperty and titleproperty].prefixedText

		if mockTitle then

			rawset(title, property, mockTitle)

		end

	end

	rawset(title, 'subPageTitle', function(text)

		return mw.title.makeTitle( title.namespace, title.text .. '/' .. text )

	end)

end



--[[

-- Patch an existing title object with the given options.

--]]

function p.patchTitleObject(title, options)

	checkType('patchTitleObject', 1, title, 'table')

	checkType('patchTitleObject', 2, options, 'table')

	

	-- Set simple properties

	for _, property in ipairs{'id', 'isRedirect', 'exists', 'contentModel'} do

		maybeSetProperty(title, property, optionsproperty])

	end

	

	-- Set redirect title

	maybeSetProperty(title, 'redirectTarget', constructMockTitle(options.redirectTarget))

	

	-- Set complex properties

	setProtectionLevels(title, options)

	setCascadingProtection(title, options)

	maybeSetContent(title, options.content)

	setFileProperties(title, options)

	

	return title

end



--[[

-- Construct a new mock title.

--]]

function p.MockTitle(options)

	checkType('MockTitle', 1, options, 'table')

	checkTypeForNamedArgMulti('MockTitle', 'title', options.title, {'string', 'number'})

	-- Create the title object with the original mw.title.new so that we don't

	-- look in the mock title registry here when mw.title.new is patched.

	local title = titleNew(options.title)

	return p.patchTitleObject(title, options)

end



--[[

-- Register a mock title.

-- This can be a mock title object or a table of options for MockTitle.

--]]

function p.registerMockTitle(titleOrOptions)

	checkType('registerMockTitle', 1, titleOrOptions, 'table')

	local title = constructMockTitle(titleOrOptions)

	mockTitleRegistrytitle.prefixedText = title

end



--[[

-- Remove a title from the mock title registry.

-- Returns the title that was removed.

--]]

function p.deregisterMockTitle(titleOrOptions)

	checkTypeMulti('deregisterMockTitle', 1, titleOrOptions, {'number', 'string', 'table'})

	local title = constructMockTitle(titleOrOptions)

	if not title then

		return nil

	end

	local registeredTitle = mockTitleRegistrytitle.prefixedText

	mockTitleRegistrytitle.prefixedText = nil

	return registeredTitle

end



--[[

-- Register multiple mock titles.

--]]

function p.registerMockTitles(...)

	for i, titleOrOptions in ipairs{...} do

		checkType('registerMockTitles', i, titleOrOptions, 'table')

		p.registerMockTitle(titleOrOptions)

	end

end



--[[

-- Deregister multiple mock titles.

-- Returns a sequence of titles that were removed.

--]]

function p.deregisterMockTitles(...)

	local removedTitles = {}

	for i, titleOrOptions in ipairs{...} do

		checkTypeMulti('deregisterMockTitles', i, titleOrOptions, {'number', 'string', 'table'})

		table.insert(removedTitles, p.deregisterMockTitle(titleOrOptions))

	end

	return removedTitles

end



--[[

-- Clear the mock title registry.

--]]

function p.clearMockTitleRegistry()

	mockTitleRegistry = {}

end



--[[

-- Register a mock title as the current title.

-- This can be a string, a mock title object or a table of options for

-- MockTitle.

--]]

function p.registerMockCurrentTitle(titleOrOptions)

	checkType('registerMockCurrentTitle', 1, titleOrOptions, 'table')

	local title = constructMockTitle(titleOrOptions)

	mockCurrentTitle = title

end



--[[

-- Deregister the registered current mock title.

--]]

function p.deregisterMockCurrentTitle()

	mockCurrentTitle = nil

end



--[[

-- Clear all registered mock titles.

-- This clears the mock title registry and deregisters the current mock title.

--]]

function p.clearAllMockTitles()

	p.clearMockTitleRegistry()

	p.deregisterMockCurrentTitle()

end



--[[

-- Look up a title in the mock title registry.

--]]

local function lookUpTitleInRegistry(title)

	return mockTitleRegistrytitle.prefixedText

end



--[[

-- Look up the registered mock current title.

--]]

local function lookUpMockCurrentTitle()

	return mockCurrentTitle

end



--[[

-- Patch the given title function.

-- This replaces the title function with a function that looks up the title

-- from some source. Exactly how the title is looked up is determined by the

-- lookUpMockTitle argument. This should be a function that takes a title object

-- as input and returns a mock title object as output.

--]]

local function patchTitleFunc(funcName, lookUpMockTitle)

	local oldFunc = mw.titlefuncName

	mw.titlefuncName = function(...)

		local title = oldFunc(...)

		if not title then

			error(

				string.format(

					'Could not make title object from invocation %s',

					mRepr.invocationRepr{

						funcName = 'mw.title.' .. funcName,

						args = {...}

					}

				),

				2

			)

		end

		local mockTitle = lookUpMockTitle(title)

		-- This type of patching has to be applied to all titles and after all

		-- mocks are defined to ensure it works

		if mockTitle then

			patchAssociatedTitleObjects(mockTitle)

			return mockTitle

		else

			patchAssociatedTitleObjects(title)

			return title

		end

	end

	return oldFunc

end



--[[

-- Handle the patch process.

-- This takes care of setting up before the patch, running the specified

-- function after the patch, tearing down the patch, and returning the results.

-- The setup process is handled using the setup function, which takes no

-- parameters. Teardown is handled by the teardown function, which takes the

-- values returned by the setup function as input. The user-supplied function

-- is passed in as the func argument, which takes the remaining parameters as

-- arguments.

--]]

local function patch(setup, teardown, func, ...)

	local setupResults = {setup()}

	local results = {pcall(func, ...)}

	local success = table.remove(results, 1)

	teardown(unpack(setupResults))

	if success then

		return unpack(results)

	else

		error(results1], 3)

	end

end



--[[

-- Patch mw.title.new.

-- The original mw.title.new is restored after running the given function.

--]]

function p.patchTitleNew(func, ...)

	checkType('patchTitleNew', 1, func, 'function')



	local function setup()

		return patchTitleFunc('new', lookUpTitleInRegistry)

	end

	

	local function teardown(oldTitleNew)

		mw.title.new = oldTitleNew

	end

	

	return patch(

		setup,

		teardown,

		func,

		...

	)

end



--[[

-- Patch mw.title.makeTitle.

-- The original mw.title.makeTitle is restored after running the given function.

--]]

function p.patchMakeTitle(func, ...)

	checkType('patchMakeTitle', 1, func, 'function')



	local function setup()

		return patchTitleFunc('makeTitle', lookUpTitleInRegistry)

	end

	

	local function teardown(oldMakeTitle)

		mw.title.makeTitle = oldMakeTitle

	end

	

	return patch(

		setup,

		teardown,

		func,

		...

	)

end



--[[

-- Patch mw.title.getCurrentTitle.

-- The original mw.title.getCurrentTitle is restored after running the given

-- function.

--]]

function p.patchGetCurrentTitle(func, ...)

	checkType('patchGetCurrentTitle', 1, func, 'function')



	local function setup()

		return patchTitleFunc('getCurrentTitle', lookUpMockCurrentTitle)

	end

	

	local function teardown(oldGetCurrentTitle)

		mw.title.getCurrentTitle = oldGetCurrentTitle

	end

	

	return patch(

		setup,

		teardown,

		func,

		...

	)

end



--[[

-- Patch mw.title.new, mw.title.makeTitle and mw.title.getCurrentTitle.

-- The original title functions are restored after running the given function.

--]]

function p.patchTitleConstructors(func, ...)

	checkType('patchTitleConstructors', 1, func, 'function')



	local function setup()

		local oldTitleNew = patchTitleFunc('new', lookUpTitleInRegistry)

		local oldMakeTitle = patchTitleFunc('makeTitle', lookUpTitleInRegistry)

		local oldGetCurrentTitle = patchTitleFunc('getCurrentTitle', lookUpMockCurrentTitle)

		return oldTitleNew, oldMakeTitle, oldGetCurrentTitle

	end

	

	local function teardown(oldTitleNew, oldMakeTitle, oldGetCurrentTitle)

		mw.title.new = oldTitleNew

		mw.title.makeTitle = oldMakeTitle

		mw.title.getCurrentTitle = oldGetCurrentTitle

	end

	

	return patch(

		setup,

		teardown,

		func,

		...

	)

end



return p