local ToolbarBuilder = require('Module:Toolbar')



local p = {} -- Page object

local trackingCategories = {} -- Table for storing the tracking categories.

local demo



-- Define a custom error message for this module.

local function err(msg, section)

	local help

	if section then

		help = ' ([[Template:Page-multi#' .. section .. '|help]])'

	else

		help = ''

	end

	local cat

	if demo == 'yes' then

		cat = ''

	else

		cat = '[[Category:PageLinks transclusions with errors]]'

	end

	return '<span class="error">[[Template:Page-multi|Page-multi]] error: ' .. msg 

        .. help .. '.</span>' .. cat

end



----------------------------------------------------------------------------------------------

--      To add more link types, write a function that produces an individual link, and put  --

--      it at the bottom of the list below. Then, add a link code for your function to the  --

--      "linktypes" table. Try and make the code three letters or less. 

--

--      If you want more helper strings, you can define them in the generatePageDataStrings --

--      function below.                                                                     --

----------------------------------------------------------------------------------------------



----------------------------------------------------------------------------------------------

--                                LINK FUNCTIONS START                                      --

----------------------------------------------------------------------------------------------



local function makePageLink()

	return p.fullText and '[[:' .. p.fullText .. '|' .. p.fullText .. ']]' or ''

end



local function makeTalkLink()

	return '[[' .. tostring(p.talkPageTitle) .. '|talk]]'

end



local function makeTalkOrSubjectLink()

	if p.isTalkPage then

		return '[[:' .. tostring(p.subjectPageTitle) .. '|subject]]'

	else

		return '[[' .. tostring(p.talkPageTitle) .. '|talk]]'

	end

end



local function makeWhatLinksHereLink()

	return '[[Special:WhatLinksHere/' .. p.fullText .. '|links]]'

end



local function makeRelatedChangesLink()

	return '[[Special:RelatedChanges/' .. p.fullText .. '|related]]'

end



local function makeEditLink()

	return '[[Special:EditPage/' .. p.fullText .. '|edit]]'

end



local function makeHistoryLink()

	return '[[Special:PageHistory/' .. p.fullText .. '|history]]'

end



local function makeWatchLink()

	return '[' .. p:fullUrl( 'action=watch' ) .. ' watch]'

end



local function makeTargetLogsLink()

	local url = mw.uri.fullUrl( 'Special:Log', 'page=' .. mw.uri.encode(p.fullText) )

	return '[' .. tostring(url) .. ' logs]'

end



local function makeEditFilterLogLink()

	local url = mw.uri.fullUrl( 'Special:AbuseLog', 'wpSearchTitle=' .. mw.uri.encode(p.fullText) )

	return '[' .. tostring(url) .. ' abuse&nbsp;filter&nbsp;log]'

end



local function makePageViewsLink(args)

	local endDate, startDate = "", ""

	

	if args.date then

		local date = string.gsub(args.date,"-","")

		date = os.time{year=string.sub(date,1,4), month=string.sub(date,5,6), day=string.sub(date,7,8)}

		endDate = os.date("%Y-%m-%d", date - (1*86400))

		startDate = os.date("%Y-%m-%d", date - (30*86400))

	else

		endDate = os.date("%Y-%m-%d")

		startDate = os.date("%Y-%m-%d", os.time() - (60*86400))

	end

	

	local project = string.sub(mw.site.server,3)

	local url = mw.uri.encode(p.fullText, "WIKI")

	local urlargs = '?start=' .. startDate .. '&end=' .. endDate .. '&project=' .. project .. '&pages=' .. tostring(url)

	

	if #urlargs > 255 then -- Extra chars can tip it over the max length for an IW link.

		return '[https://pageviews.toolforge.org/?' .. urlargs .. ' stats]'

	end

	return '[[:toolforge:pageviews/' .. urlargs .. '|stats]]'

end



local function makeHistory500Link()

	local url = p:fullUrl( 'action=history&limit=500' );

	return '[' .. url .. ' long history]'

end



----------------------------------------------------------------------------------------------

--                                   LINK FUNCTIONS END                                     --

--      To enable new link functions, add the code to the "linktypes" table directly below. --

----------------------------------------------------------------------------------------------



local linktypes = {

    't'       = makeTalkLink,

    'ts'      = makeTalkOrSubjectLink,

    'wlh'     = makeWhatLinksHereLink,

    'rc'      = makeRelatedChangesLink,

    'edit'    = makeEditLink,

    'h'       = makeHistoryLink,

    'w'       = makeWatchLink,

    'tl'      = makeTargetLogsLink,

    'efl'     = makeEditFilterLogLink,

    'vlm-sgs' = makePageViewsLink,

    'pv'      = makePageViewsLink,

    'h500'    = makeHistory500Link,

}



local function getLink(linktype, args)

	local func = linktypeslinktype

	if func then

		return func(args)

	else

        return err('"' .. linktype .. '" is not a valid link code', 'Not a valid link code')

	end

end



local function makeToolbar(args)

    local targs = {}

    local numArgsExist = false

    for k, v in pairs(args) do

        if type(k) == 'number' and p then

            numArgsExist = true

            targsk = getLink(v, args)

        end

    end

    targs.style = args.small and 'font-size: 90%;'

    targs.separator = args.separator or 'dot'

    targs.class = 'lx'

    

    if numArgsExist == false then

        return nil -- Don't return a toolbar if no numeric arguments exist. -- this bit looks odd

    else

        return ToolbarBuilder.main(targs)

    end

end



local function generatePageDataStrings(args)

    -- If the page name is absent or blank, return an error and a tracking category.

    if args.page == '' or not args.page then

        return err('no page detected')

    end

    local noError

    noError, p = pcall(mw.title.new, args.page)

    if not noError then

    	return err('pcall mw.title failed')

	end

	if args.exists and (not p or p'id' == 0) then

    	return err('page not found')

    end

end



local function generateTrackingCategories()

    if demo == 'yes' then

        return ''

    else

        return table.concat(trackingCategories)

    end

end



-- This function generates a table of all available link types, with their previews.

-- It is used in the module documentation.

local function getLinkTable(args)

    demo = args.demo -- Set the demo variable.

    -- Generate the page data strings and return any errors.

    local dataStringError = generatePageDataStrings(args)

    if dataStringError then

        return dataStringError

    end

    

    -- Build a table of all of the links.

    local result = '<table class="wikitable plainlinks sortable">'

        .. '\n<tr><th>Code</th><th>Preview</th></tr>'

    for i, value in ipairs(linktypes) do

        local code = value1

        result = result .. "\n<tr><td>'''" .. code .. "'''</td><td>" .. getLink(code, args) .. '</td></tr>'

    end

    result = result .. '\n</table>'

    

    return result

end



local function getSingleLink(args)

    demo = args.demo -- Set the demo variable.

    -- Generate the page data strings and return any errors.

    local dataStringError = generatePageDataStrings(args)

    if dataStringError then

        return dataStringError

    end

    

    local linktype = args1

    if not linktype then 

        return err('no link type specified')

    end

    local result = getLink(linktype, args)

    result = result .. generateTrackingCategories()

    return result

end



local function getLinksToolbar(args)

    demo = args.demo -- Set the demo variable.

    -- Generate the page data strings and return any errors.

    local dataStringError = generatePageDataStrings(args)

    if dataStringError then

        return dataStringError

    end    

    

    -- Build the template output.

    local result = makeToolbar(args) -- Get the toolbar contents.

    result = (result or '') .. generateTrackingCategories()

    return result

end



local function getLinks(args)

	local result = getLinksToolbar(args)



	if result then

		if args.sup then

			result = '<sup>' .. result .. '</sup>'

		end

		result = '&nbsp;' .. result

	else

		result = '' -- If there are no links specified, don't return the toolbar at all.

	end

	if args.nopage then

		result = '<span>' .. result .. '</span>'

	else

		if p then

			result = '<span>' .. makePageLink() .. result .. '</span>'

		else

			result = '<span>[[' .. args.page .. ']]' .. result .. '</span>'

		end

	end



	return result

end



local function getExampleLinks(args)

    -- This function enables example output without having to specify any

    -- parameters to #invoke.

    args.demo = 'yes'

    args.page = 'Example'

    return getLinks(args)

end



local function makeWrapper(func)

    return function (frame)

        -- If called via #invoke, use the args passed into the invoking template.

        -- Otherwise, for testing purposes, assume args are being passed directly in.

        local origArgs

        if frame == mw.getCurrentFrame() then

            origArgs = frame:getParent().args

            for k, v in pairs(frame.args) do

                origArgs = frame.args

                break

            end

        else

            origArgs = frame

        end

 

        -- Strip whitespace, and treat blank arguments as nil.

        -- 'page', and 'separator' have different behaviour depending on

        -- whether they are blank or nil, so keep them as they are.

        local args = {}

        for k, v in pairs(origArgs) do

            v = mw.text.trim(v)

            if v ~= '' or k == 'page' or k == 'separator' then

                argsk = v

            end

        end

    

        return func(args)

    end

end



return {

    main = makeWrapper(getLinks),

    single = makeWrapper(getSingleLink),

    toolbar = makeWrapper(getLinksToolbar),

    linktable = makeWrapper(getLinkTable),

    example = makeWrapper(getExampleLinks)

}